From my ealier post .. (for convenience if we could stay with photons for a while that would be nice..)
QUOTE (me+)
1/ The source emits a wavepacket.
2/ The wavepacket passes through the first pinhole
3/ We get a diffraction pattern on a screen .. the screen has two holes in it which are (say) 1mm apart.
4/ Let the area of the diffraction pattern where most of the energy is be (say) 10mm^2
5/ Each hole in the screen has an area of (say) 0.05mm^2
6/ An equal amount of energy passes through both pinholes
7/ At this stage the wavepacket is looking infinitely divisible
8/ Of the original energy 99.9% is absorbed or reflected off the first screen
9/ Of the 0.1% (total) that passes through the first screen...
QUOTE (JR+)
..at point 8 it is not about energy but about prbability. The energy is not spread out but the probability is spread out. This simply means that it is a matter of chance not a real dispersion of energy since the energy is quantized. When it is detected at the detection plate, all the energy is still there!
I suspect 8/ is the bit Einstein didn't like.
We're dividing the 0.1% probability of passing through the pinholes into two parts, saying the phase of the probability is the same at both slits and subsequently doing a vector addition of the probability after travelling via any path to the point of detection (at the screen) to get (statistically) the right answer.
If our emission event looks like an impulse and our detection event looks like an impulse and our probability operation has pretty much null properties in the time domain then I'm not clear about our reason for trying to wrap our photon up into a wavepacket at any stage of the analysis.
As a test I'd be interested to see a suitable experiment* where a wave packet gives the right answer so we can see whether a wavepacket encapsulates any properties that a wavefunction does not.
Best wishes,
-C2.
* Any suggestions?
I suspect 8/ is the bit Einstein didn't like.
We're dividing the 0.1% probability of passing through the pinholes into two parts, saying the phase of the probability is the same at both slits and subsequently doing a vector addition of the probability after travelling via any path to the point of detection (at the screen) to get (statistically) the right answer.
If our emission event looks like an impulse and our detection event looks like an impulse and our probability operation has pretty much null properties in the time domain then I'm not clear about our reason for trying to wrap our photon up into a wavepacket at any stage of the analysis.
As a test I'd be interested to see a suitable experiment* where a wave packet gives the right answer so we can see whether a wavepacket encapsulates any properties that a wavefunction does not.
Best wishes,
-C2.
* Any suggestions?
Hi Confuesd2, Janrinze, yquantum, Laserlight, Mate, Neil Farbstein,
I like the idea that Confused2 has stated that we try and deal with photons if possible. I understand that electrons have a lot in common with the photons but there are further complications due to the relatively high mass (fermions) and the very short de Broglie Wavelength and "low" speed relative to Light also 1/2 vs full integer spin. Also they are permanently charged. Regarding photons... "ideally" they exhibit a total lack of locality until they are "detected". When detected they lose that non-locality and are fully localized. This is usually referred to as the collapse of the wavefunction in the Copenhagen Interpretation. Alternatively a protective measurement can partially localize the wavefunction and we can know a little more about the path but we cannot know any specific which way information without completely destroying the interference. It is a contradiction to say the "wave" passed through only one slit and then produced an interference pattern.
You can prove this by simply covering one slit and you will see that there will be no interference... indeed there can be no interference. Experimentally this is also verified. Any measurement which localizes the "particle" sufficiently to be capable of passing through only one slit immediately decoheres the wave. Now any wavelike properties that this "particle" exhibits subsequent to this "decoherence" will not be linked to the original source. Photons that then pass through the two slits will act independently and do not interfere since they are not the same source any longer. Naturally I hope we already understand that interference is not a two (or more) photon event but an event that occurs one photon at a time, that is unless the two separate sources are not artificially correlated to an incredible level of precision. To me this seems very obvious but there seems to be a reluctance to believe the results of experiment that one single photon that passes both slits is the source of the interference ... this is simply repeated for as many coherent photons repeat this event. Are there any that doubt this experimentally determined fact?
You could measure some photons on the source side of the slit and then measure the "absorption event" at the screen. Each of these conditions will exhibit spatial wave phenomena and after that single detection the photons will no longer take part in any further coherent interference effects but will exhibit either "ballistic" characteristics from there on as you may expect from the localized "particle", or it "initializes" the "particle" in a Quantum Zeno reset of the state... or both (I suspect both). This interpretation is not the straight Copenhagen Interpretation which takes no account of protective measurements nor Quantum Zeno effect. I suspect that an event that causes the photon to lose the original qubit of information without being absorbed through "scattering" means that the photon starts to spread again from that "detection focus", spreading with the inverse square law, once again "seeking all paths". In one way this occurs when the wave of some photons pass through a double slit. Remember the majority of photons are absorbed on the source side of the slits but the fate of these "collapsed" and scattered/absorbed photons is removed from partaking in the final interference pattern. Only photons that actually pass through the slits and are not "blocked" will take part in the pattern and by definition these photons are totally unobserved.
On hitting the screen any previously detected photons will not be part of the original coherent pattern but will "probably" fall on a pattern that correlates very strongly with the delocalization event in the new time and space coordinates and not with the original source. The kind of scattering (Thompson or Rayleigh Scattering) will depend on "ambient" phenomena in space. This correlates strongly with the environment in which the event is occurring... "free" electron scattering or "confined" electron scattering. It has got to be one or the other as I have previously indicated. It will be usually an electron scattering event and not a sub-nuclear particle scattering event since scattering is strongly wavelength/frequency dependent... The electrons will be associated with atomic shells in atoms 'somewhere".
1) Interference is a single photon phenomenon.
2) Interference patterns do not differ regardless of the fact that one photon an hour passes the slits or a trillion a second... this produces the same pattern.
These facts must be answered. If you want to ignore them then this goes against actual experiment and we will learn nothing from the experiments done in the past. Within the bounds of known experiment ... and we know this pretty well is we at least understand what is happening if not why it is happening.
What we need to do is not address our prejudices in this matter and address the nature of the phenomena. At the same time we have the exact nature of this wave phenomena at the same time as it exhibits "statistical" behavior. There is a third further fact that also must be addressed, and I have said this before and it seems that I am talking to myself on this one...
3) The wave phenomena itself is "perfect" down to the sources being correlated to within a small fraction of a wavelength.
This also "obeys" statistical probability but holograms are a particularly important phenomena... just how do people think these things occur? It is not "magic".. What I have said previously is that these represent two differently geared imperatives which are mutually incompatible in the limit (measurables and statistics). What we actually "know" is that a "dark room" with a single source of divergent coherent radiation produces "perfect" wavefront replicas of the entire room that can reconstruct the source and also the entire room to boot. You can't ignore that all source photons carry very significant phase information about "seeking all possible paths" in the "dark room" and this is recorded in the emulsion. This "information" is actually standing wave information that interact inside the emulsion differentially exposing interfering wavefronts "in depth" inside the hologram's emulsion... bright then dark! These standing waves imply solutions to Schrodinger or Dirac's Wave Equation... or at least some kind of wave equation... get out your hand lens and you can see the "waves" in the holograms gelatin, and "they are not going anywhere". These are not progressive waves which would pass through the photographic emulsion exposing the entire body of the gelatin with "statistical" processes. This very same hologram could equally be exposed one photon at a time with an "hour" between individual photons provided the room remains "fixed" in place and "dark" other than the one source of coherent light (perhaps using a single excited quantum dot). The fringing is responding to standing waves in space... Yes or no?? The fringes are equivalent to where light is absorbed or not absorbed in the silver halide crystals... in depth. This will continue to go round in circles until someone comes up with some other consistent theory that tallies with the experiment. In this same "dark room" go place your double slits experiment in there as well and see what the hologram records. Input is welcome.
Cheers
I like the idea that Confused2 has stated that we try and deal with photons if possible. I understand that electrons have a lot in common with the photons but there are further complications due to the relatively high mass (fermions) and the very short de Broglie Wavelength and "low" speed relative to Light also 1/2 vs full integer spin. Also they are permanently charged. Regarding photons... "ideally" they exhibit a total lack of locality until they are "detected". When detected they lose that non-locality and are fully localized. This is usually referred to as the collapse of the wavefunction in the Copenhagen Interpretation. Alternatively a protective measurement can partially localize the wavefunction and we can know a little more about the path but we cannot know any specific which way information without completely destroying the interference. It is a contradiction to say the "wave" passed through only one slit and then produced an interference pattern.
You can prove this by simply covering one slit and you will see that there will be no interference... indeed there can be no interference. Experimentally this is also verified. Any measurement which localizes the "particle" sufficiently to be capable of passing through only one slit immediately decoheres the wave. Now any wavelike properties that this "particle" exhibits subsequent to this "decoherence" will not be linked to the original source. Photons that then pass through the two slits will act independently and do not interfere since they are not the same source any longer. Naturally I hope we already understand that interference is not a two (or more) photon event but an event that occurs one photon at a time, that is unless the two separate sources are not artificially correlated to an incredible level of precision. To me this seems very obvious but there seems to be a reluctance to believe the results of experiment that one single photon that passes both slits is the source of the interference ... this is simply repeated for as many coherent photons repeat this event. Are there any that doubt this experimentally determined fact?
You could measure some photons on the source side of the slit and then measure the "absorption event" at the screen. Each of these conditions will exhibit spatial wave phenomena and after that single detection the photons will no longer take part in any further coherent interference effects but will exhibit either "ballistic" characteristics from there on as you may expect from the localized "particle", or it "initializes" the "particle" in a Quantum Zeno reset of the state... or both (I suspect both). This interpretation is not the straight Copenhagen Interpretation which takes no account of protective measurements nor Quantum Zeno effect. I suspect that an event that causes the photon to lose the original qubit of information without being absorbed through "scattering" means that the photon starts to spread again from that "detection focus", spreading with the inverse square law, once again "seeking all paths". In one way this occurs when the wave of some photons pass through a double slit. Remember the majority of photons are absorbed on the source side of the slits but the fate of these "collapsed" and scattered/absorbed photons is removed from partaking in the final interference pattern. Only photons that actually pass through the slits and are not "blocked" will take part in the pattern and by definition these photons are totally unobserved.
On hitting the screen any previously detected photons will not be part of the original coherent pattern but will "probably" fall on a pattern that correlates very strongly with the delocalization event in the new time and space coordinates and not with the original source. The kind of scattering (Thompson or Rayleigh Scattering) will depend on "ambient" phenomena in space. This correlates strongly with the environment in which the event is occurring... "free" electron scattering or "confined" electron scattering. It has got to be one or the other as I have previously indicated. It will be usually an electron scattering event and not a sub-nuclear particle scattering event since scattering is strongly wavelength/frequency dependent... The electrons will be associated with atomic shells in atoms 'somewhere".
1) Interference is a single photon phenomenon.
2) Interference patterns do not differ regardless of the fact that one photon an hour passes the slits or a trillion a second... this produces the same pattern.
These facts must be answered. If you want to ignore them then this goes against actual experiment and we will learn nothing from the experiments done in the past. Within the bounds of known experiment ... and we know this pretty well is we at least understand what is happening if not why it is happening.
What we need to do is not address our prejudices in this matter and address the nature of the phenomena. At the same time we have the exact nature of this wave phenomena at the same time as it exhibits "statistical" behavior. There is a third further fact that also must be addressed, and I have said this before and it seems that I am talking to myself on this one...
3) The wave phenomena itself is "perfect" down to the sources being correlated to within a small fraction of a wavelength.
This also "obeys" statistical probability but holograms are a particularly important phenomena... just how do people think these things occur? It is not "magic".. What I have said previously is that these represent two differently geared imperatives which are mutually incompatible in the limit (measurables and statistics). What we actually "know" is that a "dark room" with a single source of divergent coherent radiation produces "perfect" wavefront replicas of the entire room that can reconstruct the source and also the entire room to boot. You can't ignore that all source photons carry very significant phase information about "seeking all possible paths" in the "dark room" and this is recorded in the emulsion. This "information" is actually standing wave information that interact inside the emulsion differentially exposing interfering wavefronts "in depth" inside the hologram's emulsion... bright then dark! These standing waves imply solutions to Schrodinger or Dirac's Wave Equation... or at least some kind of wave equation... get out your hand lens and you can see the "waves" in the holograms gelatin, and "they are not going anywhere". These are not progressive waves which would pass through the photographic emulsion exposing the entire body of the gelatin with "statistical" processes. This very same hologram could equally be exposed one photon at a time with an "hour" between individual photons provided the room remains "fixed" in place and "dark" other than the one source of coherent light (perhaps using a single excited quantum dot). The fringing is responding to standing waves in space... Yes or no?? The fringes are equivalent to where light is absorbed or not absorbed in the silver halide crystals... in depth. This will continue to go round in circles until someone comes up with some other consistent theory that tallies with the experiment. In this same "dark room" go place your double slits experiment in there as well and see what the hologram records. Input is welcome.
Cheers
GE,
I agree with your premise regarding standing waves... but with a caveat. The
coherent photons are propagating/traveling thru the volume of the cavity
of "space" but the standing waves that you refer to are the energy density
signatures of "interfering" waves at fixed superposition points in geometric space.
At any point of crossing, the waves represent superpositions of energy density
within the confines of the cavity but you cannot observe the interference or
overlap of wave energy until it is detected. The energy contained within
propagating coherent photon waves is crossing, but not interfering until
matter absorbs the resultant standing wave EM energy at the point of detection.
My assertion is that standing waves are the summation of EM energy at fixed
superposition points in space. Interference/summation occurs at the point of
detection.
A simple water wave example:
A wave propagating across a long wave tank will move away from the source
toward the end of the tank. If you stick a pencil vertically into the water at any
point in front of the wave you will detect part of the wave energy at that point
even as the rest of the wave energy continues past that point.
If you have 2 synchronous but separated wave sources, each wave will propagate
from its point of origin with its individual wave energy moving away from the
source. At the locations where the 2 separate waves overlap and superpose their
summed energy, a standing wave will form as both wave energies that are
in phase superose at those fixed spatial locations. The individual wave energy
passing thru those wave superposition interference points will continue advancing
and the total standing wave energy at those overlap points will not be observed
unless they are detected due to wave collapse/summation.
Comments, discussion?
LL
I agree with your premise regarding standing waves... but with a caveat. The
coherent photons are propagating/traveling thru the volume of the cavity
of "space" but the standing waves that you refer to are the energy density
signatures of "interfering" waves at fixed superposition points in geometric space.
At any point of crossing, the waves represent superpositions of energy density
within the confines of the cavity but you cannot observe the interference or
overlap of wave energy until it is detected. The energy contained within
propagating coherent photon waves is crossing, but not interfering until
matter absorbs the resultant standing wave EM energy at the point of detection.
My assertion is that standing waves are the summation of EM energy at fixed
superposition points in space. Interference/summation occurs at the point of
detection.
A simple water wave example:
A wave propagating across a long wave tank will move away from the source
toward the end of the tank. If you stick a pencil vertically into the water at any
point in front of the wave you will detect part of the wave energy at that point
even as the rest of the wave energy continues past that point.
If you have 2 synchronous but separated wave sources, each wave will propagate
from its point of origin with its individual wave energy moving away from the
source. At the locations where the 2 separate waves overlap and superpose their
summed energy, a standing wave will form as both wave energies that are
in phase superose at those fixed spatial locations. The individual wave energy
passing thru those wave superposition interference points will continue advancing
and the total standing wave energy at those overlap points will not be observed
unless they are detected due to wave collapse/summation.
Comments, discussion?
LL
GE,
To elaborate on your example of a holographic emulsion that captures the
inteference pattern of a "scene", we must understand that the scene is
a mosaic of individual wave energy superpositions caused by reflections from the
scene, each with different spatial and time references.
Each physical item that is part of the scene is reflecting its own relative time,
position, and phase information, as it relates to a single coherent photon source.
The hologram pattern that is recorded in the emulsion follows the ISL, as it
relates to the distance from the objects that form the image, as well as throughout
the thickness and physical dimensions of the emulsion.
The interference recorded throughout the emulsion is due to superpositions of
the wave phases at points of interference between the scene wave pattern and
the reference beam. The scene objects that are recorded are the interference
standing waves where the energy of the waves superpose across the
detection/recording emulsion medium.
Comments?
LL
To elaborate on your example of a holographic emulsion that captures the
inteference pattern of a "scene", we must understand that the scene is
a mosaic of individual wave energy superpositions caused by reflections from the
scene, each with different spatial and time references.
Each physical item that is part of the scene is reflecting its own relative time,
position, and phase information, as it relates to a single coherent photon source.
The hologram pattern that is recorded in the emulsion follows the ISL, as it
relates to the distance from the objects that form the image, as well as throughout
the thickness and physical dimensions of the emulsion.
The interference recorded throughout the emulsion is due to superpositions of
the wave phases at points of interference between the scene wave pattern and
the reference beam. The scene objects that are recorded are the interference
standing waves where the energy of the waves superpose across the
detection/recording emulsion medium.
Comments?
LL
Hi LL,
Re:- your simple water wave example.
We seem to agree that to know all about a wave DSE all you need to do is work out the wave amplitude and phase at a particular point (we've seen the maths for that several times) and Bob's your uncle. I don't understand why you (elsewhere) need to introduce standing waves and cavities just so you can add two waves from two sources .. can you explain?
Best wishes,
-C2.
Re:- your simple water wave example.
We seem to agree that to know all about a wave DSE all you need to do is work out the wave amplitude and phase at a particular point (we've seen the maths for that several times) and Bob's your uncle. I don't understand why you (elsewhere) need to introduce standing waves and cavities just so you can add two waves from two sources .. can you explain?
Best wishes,
-C2.
Hi GE,
QUOTE (GE+)
What we actually "know" is that a "dark room" with a single source of divergent coherent radiation produces "perfect" wavefront replicas of the entire room that can reconstruct the source and also the entire room to boot.
Looking at http://en.wikipedia.org/wiki/Holography we see that a hologram is an interference effect between a reference beam and an 'object' beam. The absolute phase of the source is irrelevent because the effect relies on the phase difference between the reference and object beams as they meet in the recording medium.
In your explanation you use the word 'wavefront' - this is a problem for anyone familiar with the speed of light and the way wavefronts generally expand at it. If we go back to Laserlight's simple wave analysis (sans cavities sans standing waves ) then we start to get the right answers. If we abandon simple wave analysis then we start to get the wrong answers. Could this be trying to tell us something about the nature of a (single) photon?
Best wishes,
-C2.
Looking at http://en.wikipedia.org/wiki/Holography we see that a hologram is an interference effect between a reference beam and an 'object' beam. The absolute phase of the source is irrelevent because the effect relies on the phase difference between the reference and object beams as they meet in the recording medium.
In your explanation you use the word 'wavefront' - this is a problem for anyone familiar with the speed of light and the way wavefronts generally expand at it. If we go back to Laserlight's simple wave analysis (sans cavities sans standing waves ) then we start to get the right answers. If we abandon simple wave analysis then we start to get the wrong answers. Could this be trying to tell us something about the nature of a (single) photon?
Best wishes,
-C2.
QUOTE (Confused2+May 5 2007, 12:12 AM)
If our emission event looks like an impulse and our detection event looks like an impulse and our probability operation has pretty much null properties in the time domain then I'm not clear about our reason for trying to wrap our photon up into a wavepacket at any stage of the analysis.
As a test I'd be interested to see a suitable experiment* where a wave packet gives the right answer so we can see whether a wavepacket encapsulates any properties that a wavefunction does not.
Best wishes,
-C2.
* Any suggestions?
C2,
Do you by any chance have in mind specific property which could distinguish one from
another?
Anton
As a test I'd be interested to see a suitable experiment* where a wave packet gives the right answer so we can see whether a wavepacket encapsulates any properties that a wavefunction does not.
Best wishes,
-C2.
* Any suggestions?
C2,
Do you by any chance have in mind specific property which could distinguish one from
another?
Anton
QUOTE (Anton+)
Do you by any chance have in mind specific property which could distinguish one from another?
The specific property I had in mind was along the lines that one works and the other doesn't. Earlier I proposed dividing a wavepacket between two pinholes .. hmm.. not so good.
Best wishes,
-C2.
The specific property I had in mind was along the lines that one works and the other doesn't. Earlier I proposed dividing a wavepacket between two pinholes .. hmm.. not so good.
Best wishes,
-C2.
Good Elf wrote:
Why would that be a contradiction? It is not that the real world ( "real" conditionally speaking ) has to be logical or comprehensible to our minds. Nor we can say that we know about so called real world enough so nothing can exist if we cannot detect it or observe it with our current level of the technological development.
Why would that be a contradiction? It is not that the real world ( "real" conditionally speaking ) has to be logical or comprehensible to our minds. Nor we can say that we know about so called real world enough so nothing can exist if we cannot detect it or observe it with our current level of the technological development.
You can prove this by simply covering one slit and you will see that there will be no interference... indeed there can be no interference. Experimentally this is also verified. Any measurement which localizes the "particle" sufficiently to be capable of passing through only one slit immediately decoheres the wave. Now any wavelike properties that this "particle" exhibits subsequent to this "decoherence" will not be linked to the original source. Photons that then pass through the two slits will act independently and do not interfere since they are not the same source any longer. Naturally I hope we already understand that interference is not a two (or more) photon event but an event that occurs one photon at a time, that is unless the two separate sources are not artificially correlated to an incredible level of precision. To me this seems very obvious but there seems to be a reluctance to believe the results of experiment that one single photon that passes both slits is the source of the interference ... this is simply repeated for as many coherent photons repeat this event. Are there any that doubt this experimentally determined fact?
Yes. Which does not necessary imply that what you said is not the fact indeed.
What would be interesting is to design an experiment with one slit which would "give" an interference. I have a rough idea how that could possibly be done.
Anton
QUOTE
I like the idea that Confused2 has stated that we try and deal with photons if possible. I understand that electrons have a lot in common with the photons but there are further complications due to the relatively high mass (fermions) and the very short de Broglie Wavelength and "low" speed relative to Light also 1/2 vs full integer spin. Also they are permanently charged. Regarding photons... "ideally" they exhibit a total lack of locality until they are "detected". When detected they lose that non-locality and are fully localized. This is usually referred to as the collapse of the wavefunction in the Copenhagen Interpretation. Alternatively a protective measurement can partially localize the wavefunction and we can know a little more about the path but we cannot know any specific which way information without completely destroying the interference. It is a contradiction to say the "wave" passed through only one slit and then produced an interference pattern.
Why would that be a contradiction? It is not that the real world ( "real" conditionally speaking ) has to be logical or comprehensible to our minds. Nor we can say that we know about so called real world enough so nothing can exist if we cannot detect it or observe it with our current level of the technological development.
QUOTE (->
| QUOTE |
| I like the idea that Confused2 has stated that we try and deal with photons if possible. I understand that electrons have a lot in common with the photons but there are further complications due to the relatively high mass (fermions) and the very short de Broglie Wavelength and "low" speed relative to Light also 1/2 vs full integer spin. Also they are permanently charged. Regarding photons... "ideally" they exhibit a total lack of locality until they are "detected". When detected they lose that non-locality and are fully localized. This is usually referred to as the collapse of the wavefunction in the Copenhagen Interpretation. Alternatively a protective measurement can partially localize the wavefunction and we can know a little more about the path but we cannot know any specific which way information without completely destroying the interference. It is a contradiction to say the "wave" passed through only one slit and then produced an interference pattern. |
Why would that be a contradiction? It is not that the real world ( "real" conditionally speaking ) has to be logical or comprehensible to our minds. Nor we can say that we know about so called real world enough so nothing can exist if we cannot detect it or observe it with our current level of the technological development.
You can prove this by simply covering one slit and you will see that there will be no interference... indeed there can be no interference. Experimentally this is also verified. Any measurement which localizes the "particle" sufficiently to be capable of passing through only one slit immediately decoheres the wave. Now any wavelike properties that this "particle" exhibits subsequent to this "decoherence" will not be linked to the original source. Photons that then pass through the two slits will act independently and do not interfere since they are not the same source any longer. Naturally I hope we already understand that interference is not a two (or more) photon event but an event that occurs one photon at a time, that is unless the two separate sources are not artificially correlated to an incredible level of precision. To me this seems very obvious but there seems to be a reluctance to believe the results of experiment that one single photon that passes both slits is the source of the interference ... this is simply repeated for as many coherent photons repeat this event. Are there any that doubt this experimentally determined fact?
Yes. Which does not necessary imply that what you said is not the fact indeed.
What would be interesting is to design an experiment with one slit which would "give" an interference. I have a rough idea how that could possibly be done.
Anton
QUOTE (Anton+)
What would be interesting is to design an experiment with one slit which would "give" an interference. I have a rough idea how that could possibly be done.
http://en.wikipedia.org/wiki/Diffraction#T..._of_diffraction
"The very heart of the explanation of all diffraction phenomena is interference."
-C2
http://en.wikipedia.org/wiki/Diffraction#T..._of_diffraction
"The very heart of the explanation of all diffraction phenomena is interference."
-C2
QUOTE (Confused2+May 5 2007, 01:42 PM)
QUOTE (Anton+)
What would be interesting is to design an experiment with one slit which would "give" an interference. I have a rough idea how that could possibly be done.
http://en.wikipedia.org/wiki/Diffraction#T..._of_diffraction
"The very heart of the explanation of all diffraction phenomena is interference."
-C2
I was thinking along a speculation of arranging a set up for the single slit experiment which would have as the result an interference pattern of hits on the screen.
Anton
http://en.wikipedia.org/wiki/Diffraction#T..._of_diffraction
"The very heart of the explanation of all diffraction phenomena is interference."
-C2
I was thinking along a speculation of arranging a set up for the single slit experiment which would have as the result an interference pattern of hits on the screen.
Anton
Hi Anton,
See http://www.teachspin.com/instruments/two_s...periments.shtml .. they give the result for each slit too.
-C2.
See http://www.teachspin.com/instruments/two_s...periments.shtml .. they give the result for each slit too.
-C2.
QUOTE (Confused2+May 5 2007, 02:19 PM)
Hi Anton,
See http://www.teachspin.com/instruments/two_s...periments.shtml .. they give the result for each slit too.
-C2.
C2,
I read this article too but that is still not what I have in mind.
What I have in mind is still a rough idea. If I will be able to develop it in the satisfactory manner I will post it. Right now I am not sure where would lead me, if anywhere.
Sorry for mentioning it at all while I am still not sure about it . That was a mistake of thinking aloud, so to speak.
Anton
See http://www.teachspin.com/instruments/two_s...periments.shtml .. they give the result for each slit too.
-C2.
C2,
I read this article too but that is still not what I have in mind.
What I have in mind is still a rough idea. If I will be able to develop it in the satisfactory manner I will post it. Right now I am not sure where would lead me, if anywhere.
Sorry for mentioning it at all while I am still not sure about it . That was a mistake of thinking aloud, so to speak.
Anton
Hi All,
I am a bit confused about the whole hologram discussion.
creating parts of a hologram with only one photon is completely impossible.
Actually when creating a hologram one needs to keep in mind that the spatial coherence of a laser restricts the size of the space that can be illuminated while still resulting in a distinguishable interference pattern (the hologram).
Spatial coherence implies that each photon emitted is in phase with the previous and following photon. And when intensity is high the result is (almost) identical to one large wavepacket with the physical lenght of the spatial coherence of the laser. The spatial coherence lenght usually stems from the way the laser is built. With gas lasers it is in the order of N times the tube length. No idea what it is with solid-state lasers though but it must be in the order of N times its cavity lenght. With gas lasers N is relatively small.
I agree with C2 that the classical hologram is created by means of direct and indirect illumination of a photographic emulsion. This creates a superposition of all possible paths from the source to the plate. Where possible means from any reflective surface. The result will be a time integrated intensity for the duration of the exposure of the photographic emulsion. The longer the spactial coherence the higher the quality of the hologram. Increasing intensity has the same effect since more photons are available to generate the hologram though insufficient spatial coherence will result in loss of the 'proper' interference patern..
With regard to the DS experiment it looks like LL is implying that the 'spatial coherence' of a single photon is infinite, which is wrong i.m.h.o. This reasoning leads to a misconception that the photon interferes with itself over very long distances and therefore could generate a hologram all by it self (albeit not being able to express that since it can manifest only once on the photographic plate by interacting with the photgraphic emulsion) His reasoning does not explain why there will be any interference at all. Since the photon hits just about anything in the room and should therefore have equal opportunity to be absorbed just about anywhere. The resulting interference pattern should therefore be with an intensity that equals the area of the photographic plate divided by the total area of the rest of the 'room'..
Now back to the DS experiment. There is no difference whether we use photons or electrons in regard to the outcome of the experiment. If we try to measure the momentum this will result in loss of the interference pattern. In terms of spatial coherence there could (should?) be some situation where wave packets from different sources (slits) do not temporally overlap when arriving at a specific point of detection. (we could do such an experiment with computer simulations of wave packets and verify the results in real life.) The thing is that when we talk about wave packets and diffraction the wave packet is non-uniformly spread out over a large area and forms a wavefront. This could imply that this wavefront should be seen as one single event. On detection the wave should not collapse but the wavefront will contract to the place where it actually interacts with something. Thereby creating the localized detection of an amount of energy. Since the spread of the wavepacket over the wave front (by proof of the DS experiment) appears not nescessarily to be contiguous (can be cut up but is still one event) we need some other method of allowing it to be in multiple places at once. A multiverse solution seems adequate but does not really fit in Occam's Razor i.m.h.o. since that would hardly explain the probability distribution (all universes should be infinitsimally small but have equal probability..) So what would fit here without having to resort to extreme or radical ideas? Brings to mind that apparently the information of wavecollapse should propagate instantaneously all over the entire wavefront.
Food for thought..
Jan Rinze.
I am a bit confused about the whole hologram discussion.
creating parts of a hologram with only one photon is completely impossible.
Actually when creating a hologram one needs to keep in mind that the spatial coherence of a laser restricts the size of the space that can be illuminated while still resulting in a distinguishable interference pattern (the hologram).
Spatial coherence implies that each photon emitted is in phase with the previous and following photon. And when intensity is high the result is (almost) identical to one large wavepacket with the physical lenght of the spatial coherence of the laser. The spatial coherence lenght usually stems from the way the laser is built. With gas lasers it is in the order of N times the tube length. No idea what it is with solid-state lasers though but it must be in the order of N times its cavity lenght. With gas lasers N is relatively small.
I agree with C2 that the classical hologram is created by means of direct and indirect illumination of a photographic emulsion. This creates a superposition of all possible paths from the source to the plate. Where possible means from any reflective surface. The result will be a time integrated intensity for the duration of the exposure of the photographic emulsion. The longer the spactial coherence the higher the quality of the hologram. Increasing intensity has the same effect since more photons are available to generate the hologram though insufficient spatial coherence will result in loss of the 'proper' interference patern..
With regard to the DS experiment it looks like LL is implying that the 'spatial coherence' of a single photon is infinite, which is wrong i.m.h.o. This reasoning leads to a misconception that the photon interferes with itself over very long distances and therefore could generate a hologram all by it self (albeit not being able to express that since it can manifest only once on the photographic plate by interacting with the photgraphic emulsion) His reasoning does not explain why there will be any interference at all. Since the photon hits just about anything in the room and should therefore have equal opportunity to be absorbed just about anywhere. The resulting interference pattern should therefore be with an intensity that equals the area of the photographic plate divided by the total area of the rest of the 'room'..
Now back to the DS experiment. There is no difference whether we use photons or electrons in regard to the outcome of the experiment. If we try to measure the momentum this will result in loss of the interference pattern. In terms of spatial coherence there could (should?) be some situation where wave packets from different sources (slits) do not temporally overlap when arriving at a specific point of detection. (we could do such an experiment with computer simulations of wave packets and verify the results in real life.) The thing is that when we talk about wave packets and diffraction the wave packet is non-uniformly spread out over a large area and forms a wavefront. This could imply that this wavefront should be seen as one single event. On detection the wave should not collapse but the wavefront will contract to the place where it actually interacts with something. Thereby creating the localized detection of an amount of energy. Since the spread of the wavepacket over the wave front (by proof of the DS experiment) appears not nescessarily to be contiguous (can be cut up but is still one event) we need some other method of allowing it to be in multiple places at once. A multiverse solution seems adequate but does not really fit in Occam's Razor i.m.h.o. since that would hardly explain the probability distribution (all universes should be infinitsimally small but have equal probability..) So what would fit here without having to resort to extreme or radical ideas? Brings to mind that apparently the information of wavecollapse should propagate instantaneously all over the entire wavefront.
Food for thought..
Jan Rinze.
QUOTE (janrinze+May 5 2007, 04:14 PM)
Hi All,
I am a bit confused about the whole hologram discussion.
creating parts of a hologram with only one photon is completely impossible.
Actually when creating a hologram one needs to keep in mind that the spatial coherence of a laser restricts the size of the space that can be illuminated while still resulting in a distinguishable interference pattern (the hologram).
Spatial coherence implies that each photon emitted is in phase with the previous and following photon. And when intensity is high the result is (almost) identical to one large wavepacket with the physical lenght of the spatial coherence of the laser. The spatial coherence lenght usually stems from the way the laser is built. With gas lasers it is in the order of N times the tube length. No idea what it is with solid-state lasers though but it must be in the order of N times its cavity lenght. With gas lasers N is relatively small.
I agree with C2 that the classical hologram is created by means of direct and indirect illumination of a photographic emulsion. This creates a superposition of all possible paths from the source to the plate. Where possible means from any reflective surface. The result will be a time integrated intensity for the duration of the exposure of the photographic emulsion. The longer the spactial coherence the higher the quality of the hologram. Increasing intensity has the same effect since more photons are available to generate the hologram though insufficient spatial coherence will result in loss of the 'proper' interference patern..
With regard to the DS experiment it looks like LL is implying that the 'spatial coherence' of a single photon is infinite, which is wrong i.m.h.o. This reasoning leads to a misconception that the photon interferes with itself over very long distances and therefore could generate a hologram all by it self (albeit not being able to express that since it can manifest only once on the photographic plate by interacting with the photgraphic emulsion) His reasoning does not explain why there will be any interference at all. Since the photon hits just about anything in the room and should therefore have equal opportunity to be absorbed just about anywhere. The resulting interference pattern should therefore be with an intensity that equals the area of the photographic plate divided by the total area of the rest of the 'room'..
Now back to the DS experiment. There is no difference whether we use photons or electrons in regard to the outcome of the experiment. If we try to measure the momentum this will result in loss of the interference pattern. In terms of spatial coherence there could (should?) be some situation where wave packets from different sources (slits) do not temporally overlap when arriving at a specific point of detection. (we could do such an experiment with computer simulations of wave packets and verify the results in real life.) The thing is that when we talk about wave packets and diffraction the wave packet is non-uniformly spread out over a large area and forms a wavefront. This could imply that this wavefront should be seen as one single event. On detection the wave should not collapse but the wavefront will contract to the place where it actually interacts with something. Thereby creating the localized detection of an amount of energy. Since the spread of the wavepacket over the wave front (by proof of the DS experiment) appears not nescessarily to be contiguous (can be cut up but is still one event) we need some other method of allowing it to be in multiple places at once. A multiverse solution seems adequate but does not really fit in Occam's Razor i.m.h.o. since that would hardly explain the probability distribution (all universes should be infinitsimally small but have equal probability..) So what would fit here without having to resort to extreme or radical ideas? Brings to mind that apparently the information of wavecollapse should propagate instantaneously all over the entire wavefront.
Food for thought..
Jan Rinze.
The hologram records the interactions of a huge number of photons all destructively and constructivly interfring with each other.
I am a bit confused about the whole hologram discussion.
creating parts of a hologram with only one photon is completely impossible.
Actually when creating a hologram one needs to keep in mind that the spatial coherence of a laser restricts the size of the space that can be illuminated while still resulting in a distinguishable interference pattern (the hologram).
Spatial coherence implies that each photon emitted is in phase with the previous and following photon. And when intensity is high the result is (almost) identical to one large wavepacket with the physical lenght of the spatial coherence of the laser. The spatial coherence lenght usually stems from the way the laser is built. With gas lasers it is in the order of N times the tube length. No idea what it is with solid-state lasers though but it must be in the order of N times its cavity lenght. With gas lasers N is relatively small.
I agree with C2 that the classical hologram is created by means of direct and indirect illumination of a photographic emulsion. This creates a superposition of all possible paths from the source to the plate. Where possible means from any reflective surface. The result will be a time integrated intensity for the duration of the exposure of the photographic emulsion. The longer the spactial coherence the higher the quality of the hologram. Increasing intensity has the same effect since more photons are available to generate the hologram though insufficient spatial coherence will result in loss of the 'proper' interference patern..
With regard to the DS experiment it looks like LL is implying that the 'spatial coherence' of a single photon is infinite, which is wrong i.m.h.o. This reasoning leads to a misconception that the photon interferes with itself over very long distances and therefore could generate a hologram all by it self (albeit not being able to express that since it can manifest only once on the photographic plate by interacting with the photgraphic emulsion) His reasoning does not explain why there will be any interference at all. Since the photon hits just about anything in the room and should therefore have equal opportunity to be absorbed just about anywhere. The resulting interference pattern should therefore be with an intensity that equals the area of the photographic plate divided by the total area of the rest of the 'room'..
Now back to the DS experiment. There is no difference whether we use photons or electrons in regard to the outcome of the experiment. If we try to measure the momentum this will result in loss of the interference pattern. In terms of spatial coherence there could (should?) be some situation where wave packets from different sources (slits) do not temporally overlap when arriving at a specific point of detection. (we could do such an experiment with computer simulations of wave packets and verify the results in real life.) The thing is that when we talk about wave packets and diffraction the wave packet is non-uniformly spread out over a large area and forms a wavefront. This could imply that this wavefront should be seen as one single event. On detection the wave should not collapse but the wavefront will contract to the place where it actually interacts with something. Thereby creating the localized detection of an amount of energy. Since the spread of the wavepacket over the wave front (by proof of the DS experiment) appears not nescessarily to be contiguous (can be cut up but is still one event) we need some other method of allowing it to be in multiple places at once. A multiverse solution seems adequate but does not really fit in Occam's Razor i.m.h.o. since that would hardly explain the probability distribution (all universes should be infinitsimally small but have equal probability..) So what would fit here without having to resort to extreme or radical ideas? Brings to mind that apparently the information of wavecollapse should propagate instantaneously all over the entire wavefront.
Food for thought..
Jan Rinze.
The hologram records the interactions of a huge number of photons all destructively and constructivly interfring with each other.
QUOTE (Neil Farbstein+May 5 2007, 05:20 PM)
The hologram records the interactions of a huge number of photons all destructively and constructivly interfring with each other.
Hi Neil,
That is exactly what I was implying..
Makes me wonder if I need to be more clear in my expression of thoughts here.
Jan Rinze.
Hi Neil,
That is exactly what I was implying..
Makes me wonder if I need to be more clear in my expression of thoughts here.
Jan Rinze.
QUOTE (janrinze+May 5 2007, 06:40 PM)
Hi Neil,
That is exactly what I was implying..
Makes me wonder if I need to be more clear in my expression of thoughts here.
Jan Rinze.
Can you tell me about yourslef Jan?
That is exactly what I was implying..
Makes me wonder if I need to be more clear in my expression of thoughts here.
Jan Rinze.
Can you tell me about yourslef Jan?
Hi janrinze et al,
IMHO maximum clarity and brevity is good.
On topic - a 'view' about whether or not a single photon only interferes with itself would be interesting ..
See http://www.lns.cornell.edu/spr/2006-08/msg0074988.html for a bit of background to this.
IMHO .. with a single source we are looking at single photon interference in the DSE and holograms.
Thoughts welcome.
Best wishes,
-C2.
IMHO maximum clarity and brevity is good.
On topic - a 'view' about whether or not a single photon only interferes with itself would be interesting ..
See http://www.lns.cornell.edu/spr/2006-08/msg0074988.html for a bit of background to this.
IMHO .. with a single source we are looking at single photon interference in the DSE and holograms.
Thoughts welcome.
Best wishes,
-C2.
QUOTE (Confused2+May 5 2007, 09:57 PM)
Hi janrinze et al,
IMHO maximum clarity and brevity is good.
On topic - a 'view' about whether or not a single photon only interferes with itself would be interesting ..
See http://www.lns.cornell.edu/spr/2006-08/msg0074988.html for a bit of background to this.
IMHO .. with a single source we are looking at single photon interference in the DSE and holograms.
Thoughts welcome.
Best wishes,
-C2.
Hi C2,
As supported by the link you provided, I see no reason why there should be a difference between a photon interfering with itself or multiple photons interfering. Interference is a 'summation' of all arriving waves.
The problem with creating an experimental setup to prove this is that we need some form of coherence between two sources and there is hardly a method to do so with two separate sources. Splitting a 'beam' is much easier.
Jan Rinze.
IMHO maximum clarity and brevity is good.
On topic - a 'view' about whether or not a single photon only interferes with itself would be interesting ..
See http://www.lns.cornell.edu/spr/2006-08/msg0074988.html for a bit of background to this.
IMHO .. with a single source we are looking at single photon interference in the DSE and holograms.
Thoughts welcome.
Best wishes,
-C2.
Hi C2,
As supported by the link you provided, I see no reason why there should be a difference between a photon interfering with itself or multiple photons interfering. Interference is a 'summation' of all arriving waves.
The problem with creating an experimental setup to prove this is that we need some form of coherence between two sources and there is hardly a method to do so with two separate sources. Splitting a 'beam' is much easier.
Jan Rinze.
Hi janrinze et al,
More stuff to think about
If we took two 50 cent coins ( a dollar) in our hand and threw them up in the air then I think it would be remarkable if they always landed on top of each other ( to make up a dollar). Some kind of spooky force or what?
If we look at the result of a single photon DSE (click to enlarge)
we see what is effectively a level shifted cos^2 function - there are twice as many photons counted at the peaks as can be accounted for by the addition of the diffraction totals - these 'extra' counts (of course) make up for the absence of photons in the cancellation regions. Some kind of spooky force or what?
To predict the outcome (some of us) used Feynman's sum over paths method. If we were observing a situation where photons could later choose a partner I am not convinced that the vector sum for each path would be compatible with the way the shape of the wavefunction (the interference pattern) seems to be the same regardless of intensity.
For evidence of two photon interference .. this might be interesting.
http://forum.physorg.com/index.php?showtop...ndpost&p=159134
Your thoughts would be most welcome.
Best wishes,
-C2.
More stuff to think about
If we took two 50 cent coins ( a dollar) in our hand and threw them up in the air then I think it would be remarkable if they always landed on top of each other ( to make up a dollar). Some kind of spooky force or what?
If we look at the result of a single photon DSE (click to enlarge)
we see what is effectively a level shifted cos^2 function - there are twice as many photons counted at the peaks as can be accounted for by the addition of the diffraction totals - these 'extra' counts (of course) make up for the absence of photons in the cancellation regions. Some kind of spooky force or what?
To predict the outcome (some of us) used Feynman's sum over paths method. If we were observing a situation where photons could later choose a partner I am not convinced that the vector sum for each path would be compatible with the way the shape of the wavefunction (the interference pattern) seems to be the same regardless of intensity.
For evidence of two photon interference .. this might be interesting.
http://forum.physorg.com/index.php?showtop...ndpost&p=159134
Your thoughts would be most welcome.
Best wishes,
-C2.
Hi C2 and the rest.
it looks like we go round in circles.
the cosine is the real part in e^(ikx) so i don't understand you problem with that. adding two waves makes things a little more complicated since it is all about phase difference then.
If we are going to reiterate the cause of an interference pattern I don't intend to take part in that. finding an explanation for a local result (a particle or photon) when the wavefront of appears to have been spread over a large area is much harder to comprehend. When using the probabilities, the integral over the area should equal 1 and therefore a particle or photon will be detected somewhere over the area.
If the result of the interference will be that only one photon is detected that inherently means that only one photon participated in the interference itself. This does not exclude however that when two photons interfere we will find two photons on the detection area.
In simplified and infinitsimally time intervals the chances of finding two photons at the same exact moment would be infinitesimal as well. Only can we deduce that the detection of a photon takes an infinitsimal amount of time?
Jan Rinze.
it looks like we go round in circles.
the cosine is the real part in e^(ikx) so i don't understand you problem with that. adding two waves makes things a little more complicated since it is all about phase difference then.
If we are going to reiterate the cause of an interference pattern I don't intend to take part in that. finding an explanation for a local result (a particle or photon) when the wavefront of appears to have been spread over a large area is much harder to comprehend. When using the probabilities, the integral over the area should equal 1 and therefore a particle or photon will be detected somewhere over the area.
If the result of the interference will be that only one photon is detected that inherently means that only one photon participated in the interference itself. This does not exclude however that when two photons interfere we will find two photons on the detection area.
In simplified and infinitsimally time intervals the chances of finding two photons at the same exact moment would be infinitesimal as well. Only can we deduce that the detection of a photon takes an infinitsimal amount of time?
Jan Rinze.
Hi Laserlight, Confused2, janrinze, Neil Farbstein, Mate
I do not expect "everyone" to follow this point nor do I wish to convince everyone this is the only answer or interpretation to this problem. You are not going to read this in any text book either. What I am saying is this thread is a "process" and unless you see the "process" you will instinctively not want to go there. There will be a few who have read enough to understand why this is needed and why I choose to proceed along this path. I have chosen this experiment and this process to answer much more important questions about the Holographic Universe and the Anti-de Sitter Spaces in a variant of the AdS/CFT correspondence of one kind of possible string theory not presently being investigated by science. It is a 10 dimensional theory in which these additional D6 branes are embedded through reciprocal spaces into normal spacetime. It is my belief this is the way in which the Universe really is and why all attempts to find higher dimensions have failed to this point in time. This theory is 100% testable using current physics so I make no apologies for it. That is why I am pursuing a "common" experiment that cannot be entirely explained using current Quantum Theory or even straight Optics. It leads to a "transparent" definition of time itself through the Delayed Choice Quantum Eraser Experiment as stated in this threads name... "Problem with the two slit experiment, Observing later"... The observing later refers to the DCQE Experiment.
I do not expect "everyone" to follow this point nor do I wish to convince everyone this is the only answer or interpretation to this problem. You are not going to read this in any text book either. What I am saying is this thread is a "process" and unless you see the "process" you will instinctively not want to go there. There will be a few who have read enough to understand why this is needed and why I choose to proceed along this path. I have chosen this experiment and this process to answer much more important questions about the Holographic Universe and the Anti-de Sitter Spaces in a variant of the AdS/CFT correspondence of one kind of possible string theory not presently being investigated by science. It is a 10 dimensional theory in which these additional D6 branes are embedded through reciprocal spaces into normal spacetime. It is my belief this is the way in which the Universe really is and why all attempts to find higher dimensions have failed to this point in time. This theory is 100% testable using current physics so I make no apologies for it. That is why I am pursuing a "common" experiment that cannot be entirely explained using current Quantum Theory or even straight Optics. It leads to a "transparent" definition of time itself through the Delayed Choice Quantum Eraser Experiment as stated in this threads name... "Problem with the two slit experiment, Observing later"... The observing later refers to the DCQE Experiment.
QUOTE (Laserlight+)
I agree with your premise regarding standing waves... but with a caveat. The coherent photons are propagating/traveling thru the volume of the cavity of "space" but the standing waves that you refer to are the energy density signatures of "interfering" waves at fixed superposition points in geometric space.
http://forum.physorg.com/index.php?showtop...ndpost&p=207996
http://forum.physorg.com/index.php?showtop...ndpost&p=207996
That is absolutely correct. The cavity structure found by the photons are not the result of these propagating waves but an existing matter wave geometry. Clearly standing waves depend on "cavities". The nature of the Wheeler Feynman Absorber Theory is such that we can only detect the retarded waves as we view them. These waves appear to increase in intensity near to boundaries to our space (a boson fermion interface) and to our time by virtue of the theory of special relativity... that rotation on the light cone wall that "wraps" with deBroglie Matter Waves...
+ 
= 
What is illustrated here is the two different waves... the advanced (converging) and retarded waves (diverging) combining to form standing waves (stationary). It does not show attenuation of the amplitude of these waves further from these sources. These "waves" cancel over the regions of space since they combine like this...
... click to enlarge...
While we cannot see the advanced waves from the future we can see the retarded waves from the past. When they combine they lead to regions where we have those standing waves and outside the regions we see them attenuated eventually to what appears to be "nothing". This could indicate sources inside atoms such as the "shells" for instance. At great distances from sources the "seeking all paths" nature of the wavelets of individual photons encounter "mirrors" in our Universe. This is the "dark room" that I am alluding to, where there are no emissions from sources other than the primary source. Naturally I use this idea to show the phenomena in an "gedanken experiment" ... the making of a common Hologram, in the real world this global structure is dynamically altering in space with the evolution of time from such influences as gross particle movements and even the thermal Brownian movement of larger particles in the optic range, as well as other very explainable influences usually not accounted for in most theories involving quantum optics. If I use a "mirror" when I am taking a real hologram, all that is happening is the "dark geometry" in the room is being illuminated from a secondary source as seen from the external geometry. To see this phenomenon experimentally the "dark room" must be kept as still as is possible to indicate these fringes inside a photoemulsion. In the practical situation of course these are "dynamic situations" with particles moving under the the dynamics of least action unless acted on by a force.
These secondary reflections are "virtual photons" but in actual fact they are primary photons seeking all paths and their wavefronts reflecting off all these "surfaces" forming real or virtual images... whether upright, inverted, diminished or enlarged. As I have said much earlier in this thread these are photons for "free" forming endless processions of unseen wavefronts echoing between mirrors in worlds which are "Looking Glass Universes", every sub-atomic particle is a "lens" or mirror be it plane, curved or even negatively refracting. This is the "reality" we are experiencing... it is ultimately not the fiction of "particles". They take no energy to form and they take no part in the ultimate absorption process since all this information will ultimately reduce down to the absorption of a single photon somewhere.
All this "information" is really there but because this is a wave description, the Universe acts as a superposition of all these interferences as reflected from all these sources which are currently "mirrors". These atoms and other geometric spatial objects that fill space are "mirrors"... this is an experimental fact... and what the light is seeing executing its "seeking all paths" wave state is the light cone walls of these individual "structures" hanging in space. We should understand this is "something" that is always there even when there is no light in that space. These provide the standing wave element that defines all spatial geometry and it includes the extent and size of all contained spaces at all frequencies.
If light when it is "seeking all paths" cannot go there and the information from any space is not able to be retrieved from that place, then these features define limits of our three dimensional space. All physics takes place within this self defined space obeying the Lagrangian which is the expression of the Principle of Least Action.
+ = What is illustrated here is the two different waves... the advanced (converging) and retarded waves (diverging) combining to form standing waves (stationary). It does not show attenuation of the amplitude of these waves further from these sources. These "waves" cancel over the regions of space since they combine like this...
... click to enlarge...
While we cannot see the advanced waves from the future we can see the retarded waves from the past. When they combine they lead to regions where we have those standing waves and outside the regions we see them attenuated eventually to what appears to be "nothing". This could indicate sources inside atoms such as the "shells" for instance. At great distances from sources the "seeking all paths" nature of the wavelets of individual photons encounter "mirrors" in our Universe. This is the "dark room" that I am alluding to, where there are no emissions from sources other than the primary source. Naturally I use this idea to show the phenomena in an "gedanken experiment" ... the making of a common Hologram, in the real world this global structure is dynamically altering in space with the evolution of time from such influences as gross particle movements and even the thermal Brownian movement of larger particles in the optic range, as well as other very explainable influences usually not accounted for in most theories involving quantum optics. If I use a "mirror" when I am taking a real hologram, all that is happening is the "dark geometry" in the room is being illuminated from a secondary source as seen from the external geometry. To see this phenomenon experimentally the "dark room" must be kept as still as is possible to indicate these fringes inside a photoemulsion. In the practical situation of course these are "dynamic situations" with particles moving under the the dynamics of least action unless acted on by a force.
These secondary reflections are "virtual photons" but in actual fact they are primary photons seeking all paths and their wavefronts reflecting off all these "surfaces" forming real or virtual images... whether upright, inverted, diminished or enlarged. As I have said much earlier in this thread these are photons for "free" forming endless processions of unseen wavefronts echoing between mirrors in worlds which are "Looking Glass Universes", every sub-atomic particle is a "lens" or mirror be it plane, curved or even negatively refracting. This is the "reality" we are experiencing... it is ultimately not the fiction of "particles". They take no energy to form and they take no part in the ultimate absorption process since all this information will ultimately reduce down to the absorption of a single photon somewhere.
All this "information" is really there but because this is a wave description, the Universe acts as a superposition of all these interferences as reflected from all these sources which are currently "mirrors". These atoms and other geometric spatial objects that fill space are "mirrors"... this is an experimental fact... and what the light is seeing executing its "seeking all paths" wave state is the light cone walls of these individual "structures" hanging in space. We should understand this is "something" that is always there even when there is no light in that space. These provide the standing wave element that defines all spatial geometry and it includes the extent and size of all contained spaces at all frequencies.
If light when it is "seeking all paths" cannot go there and the information from any space is not able to be retrieved from that place, then these features define limits of our three dimensional space. All physics takes place within this self defined space obeying the Lagrangian which is the expression of the Principle of Least Action.
QUOTE (Wikipedia: Lagrangian+)
... The same principle, and the Lagrange formalism, are tied closely to Noether's Theorem, which relates physical conserved quantities to continuous symmetries of a physical system. Lagrangian mechanics and Noether's Theorem together yield a natural formalism for first quantization by including commutators between certain terms of the Lagrangian equations of motion for a physical system.
Wikipedia: Lagrangian
Wikipedia: Lagrangian
These "symmetries" define boundaries of the Universe... as we have noted in the course on electron optics, the symmetry of boundaries does not require actual particles on the boundary in all space to define them.
Bragg Law: TEM Theory
Only the overall symmetry defines then so that we can have boundaries defined inside (or even outside or between "particles") cavities where there are no particles "locally" but the semi-global symmetry of particles can "fix" a dimensional reflection plane in space owing only to the presence of these distributed "mirrors".
The geometry of "quantum space" is fixed by these boundaries... this even includes the boundary of our Universe. The exception to this completely locked energy system are phenomena that can swap "domains" from "Space-Time" to "Reciprocal Space" by actually entering the structure of the reciprocal space and frequency linked spacetimes through a process of a quantum leap or "Instanton".
http://en.wikipedia.org/wiki/Instanton
Cheers
Bragg Law: TEM Theory
Only the overall symmetry defines then so that we can have boundaries defined inside (or even outside or between "particles") cavities where there are no particles "locally" but the semi-global symmetry of particles can "fix" a dimensional reflection plane in space owing only to the presence of these distributed "mirrors".
The geometry of "quantum space" is fixed by these boundaries... this even includes the boundary of our Universe. The exception to this completely locked energy system are phenomena that can swap "domains" from "Space-Time" to "Reciprocal Space" by actually entering the structure of the reciprocal space and frequency linked spacetimes through a process of a quantum leap or "Instanton".
http://en.wikipedia.org/wiki/Instanton
Cheers
QUOTE (Confused2+May 5 2007, 12:17 PM)
Hi LL,
Re:- your simple water wave example.
We seem to agree that to know all about a wave DSE all you need to do is work out the wave amplitude and phase at a particular point (we've seen the maths for that several times) and Bob's your uncle. I don't understand why you (elsewhere) need to introduce standing waves and cavities just so you can add two waves from two sources .. can you explain?
Best wishes,
-C2.
Hi C2,
We are talking about energy as it propagates thru "volumetric" space. Volume
implies physical dimensions. If you have volume and physical dimensions then by
definition you have a "cavity". The physical dimensions (distance) between
any 2 parallel planes in space can be considered a cavity, and this is exactly what
we have when you consider a wavefront expanding in 3 dimensions (plus time)
from a start point to a point of interference or detection.
A traveling wave radiates thru an x, y, z, coordinate system that is relative to the
volume in which it propagates over a time base, and the wave will attempt to
disperse its energy throughout the volume thru which it is propagating. A single
wave that does not encounter some physical obstruction in volumetric space will
not develop any detectable interference because there are no points of
superposition or energy mixing. When two or more time synchronous (coherent)waves that
are radiating from different source locations cross thru each other in the x, y, and
z cavity volume thru which they are propagating, their individual wave energies
superpose at fixed locations along the expanding wave fronts. These are standing waves,
and as long as the distance and synchronous timing from the sources
remains the same the energy of subsequent waves will always superpose in the
same locations along the travelling wave fronts.
If you look at your wave applets you will see that the overlap points of wave
energy superposition throughout the volume of the cavity are forming standing
waves that radiate in straight lines from the slit wall to the screen. If you change
the spatial gap between the slits, by default you also change the wave
superposition overlap points and affect the timing and position of the standing
waves and the pattern that appears on the screen. Basically, you are changing
the wave timng relationship to the fixed volumetric dimensions of the cavity.
If you change the coherent frequency of the wave you are doing the same thing.
Waves that cross, but that are not coherent, have random points of superposition
along their wavefronts and do not form fixed standing waves. They cannot form
a fixed energy pattern because their points of energy superposition and timing
thru a fixed spatial volume is incoherent.
Comments, questions?
LL
Re:- your simple water wave example.
We seem to agree that to know all about a wave DSE all you need to do is work out the wave amplitude and phase at a particular point (we've seen the maths for that several times) and Bob's your uncle. I don't understand why you (elsewhere) need to introduce standing waves and cavities just so you can add two waves from two sources .. can you explain?
Best wishes,
-C2.
Hi C2,
We are talking about energy as it propagates thru "volumetric" space. Volume
implies physical dimensions. If you have volume and physical dimensions then by
definition you have a "cavity". The physical dimensions (distance) between
any 2 parallel planes in space can be considered a cavity, and this is exactly what
we have when you consider a wavefront expanding in 3 dimensions (plus time)
from a start point to a point of interference or detection.
A traveling wave radiates thru an x, y, z, coordinate system that is relative to the
volume in which it propagates over a time base, and the wave will attempt to
disperse its energy throughout the volume thru which it is propagating. A single
wave that does not encounter some physical obstruction in volumetric space will
not develop any detectable interference because there are no points of
superposition or energy mixing. When two or more time synchronous (coherent)waves that
are radiating from different source locations cross thru each other in the x, y, and
z cavity volume thru which they are propagating, their individual wave energies
superpose at fixed locations along the expanding wave fronts. These are standing waves,
and as long as the distance and synchronous timing from the sources
remains the same the energy of subsequent waves will always superpose in the
same locations along the travelling wave fronts.
If you look at your wave applets you will see that the overlap points of wave
energy superposition throughout the volume of the cavity are forming standing
waves that radiate in straight lines from the slit wall to the screen. If you change
the spatial gap between the slits, by default you also change the wave
superposition overlap points and affect the timing and position of the standing
waves and the pattern that appears on the screen. Basically, you are changing
the wave timng relationship to the fixed volumetric dimensions of the cavity.
If you change the coherent frequency of the wave you are doing the same thing.
Waves that cross, but that are not coherent, have random points of superposition
along their wavefronts and do not form fixed standing waves. They cannot form
a fixed energy pattern because their points of energy superposition and timing
thru a fixed spatial volume is incoherent.
Comments, questions?
LL
Hi Janrinze,
If you accept that a photon is energy in the form of a wave, then I propose that
a wave can be "deformed" and that the energy that it contains can interfere with
itself due to relative phase changes within the wave.
If you accept that a photon is energy in the form of a wave, then I propose that
a wave can be "deformed" and that the energy that it contains can interfere with
itself due to relative phase changes within the wave.
With regard to the DS experiment it looks like LL is implying that the 'spatial coherence' of a single photon is infinite, which is wrong i.m.h.o. This reasoning leads to a misconception that the photon interferes with itself over very long distances and therefore could generate a hologram all by it self (albeit not being able to express that since it can manifest only once on the photographic plate by interacting with the photgraphic emulsion) His reasoning does not explain why there will be any interference at all. Since the photon hits just about anything in the room and should therefore have equal opportunity to be absorbed just about anywhere. The resulting interference pattern should therefore be with an intensity that equals the area of the photographic plate divided by the total area of the rest of the 'room'..
How big is a photon? It is wave energy radiating from a dipole source and it
expands exponentially to fill geometric space between fixed points following the
Inverse Square Law. A photon only interferes with itself if the energy
it contains undergoes a phase, timing, and direction change that is induced by
interacting with physical matter. This requires the energy of a photon to cross
or fold back onto itself, which it cannot do without a physical "catalyst".
It is my contention that the expanding EM wave energy of a photon hits everything
in the room as it disperses and follows the ISL. The wave energy that is reflected
from the different fixed spatial locations of the contents of the room cavity causes
wave timing distortions and self interference within the phase components of the
reflecting wavefront.
When you have trillions of wavefronts (intensity) all following the same spatial
wave paths you get fixed standing waves throughout the volume of the room cavity
and thru the emulsion, and you observe "perspective" of the elements of the
scene. When you shine a coherent dispersed beam across the fixed physical
recording medium (emulsion) the crossing wave energies of the reflected waves
and the energy of the reference beam waves superpose and standing
wave patterns are the result. The resulting recorded standing waves have phase
and timing relevance to all fixed reference points of the scene across 3 spatial
dimensions.
As we have discussed previously, if you break a hologram, each piece of the
hologram will contain the full detail of the entire recorded scene and it will be
geometrically scaled to the dimensions of the pieces.
Comments, discussion?
LL
QUOTE
I am a bit confused about the whole hologram discussion.
creating parts of a hologram with only one photon is completely impossible.
creating parts of a hologram with only one photon is completely impossible.
If you accept that a photon is energy in the form of a wave, then I propose that
a wave can be "deformed" and that the energy that it contains can interfere with
itself due to relative phase changes within the wave.
QUOTE (->
| QUOTE |
| I am a bit confused about the whole hologram discussion. creating parts of a hologram with only one photon is completely impossible. |
If you accept that a photon is energy in the form of a wave, then I propose that
a wave can be "deformed" and that the energy that it contains can interfere with
itself due to relative phase changes within the wave.
With regard to the DS experiment it looks like LL is implying that the 'spatial coherence' of a single photon is infinite, which is wrong i.m.h.o. This reasoning leads to a misconception that the photon interferes with itself over very long distances and therefore could generate a hologram all by it self (albeit not being able to express that since it can manifest only once on the photographic plate by interacting with the photgraphic emulsion) His reasoning does not explain why there will be any interference at all. Since the photon hits just about anything in the room and should therefore have equal opportunity to be absorbed just about anywhere. The resulting interference pattern should therefore be with an intensity that equals the area of the photographic plate divided by the total area of the rest of the 'room'..
How big is a photon? It is wave energy radiating from a dipole source and it
expands exponentially to fill geometric space between fixed points following the
Inverse Square Law. A photon only interferes with itself if the energy
it contains undergoes a phase, timing, and direction change that is induced by
interacting with physical matter. This requires the energy of a photon to cross
or fold back onto itself, which it cannot do without a physical "catalyst".
It is my contention that the expanding EM wave energy of a photon hits everything
in the room as it disperses and follows the ISL. The wave energy that is reflected
from the different fixed spatial locations of the contents of the room cavity causes
wave timing distortions and self interference within the phase components of the
reflecting wavefront.
When you have trillions of wavefronts (intensity) all following the same spatial
wave paths you get fixed standing waves throughout the volume of the room cavity
and thru the emulsion, and you observe "perspective" of the elements of the
scene. When you shine a coherent dispersed beam across the fixed physical
recording medium (emulsion) the crossing wave energies of the reflected waves
and the energy of the reference beam waves superpose and standing
wave patterns are the result. The resulting recorded standing waves have phase
and timing relevance to all fixed reference points of the scene across 3 spatial
dimensions.
As we have discussed previously, if you break a hologram, each piece of the
hologram will contain the full detail of the entire recorded scene and it will be
geometrically scaled to the dimensions of the pieces.
Comments, discussion?
LL
Hi LL,
OK so it is standing waves in a cavity ..
Can I try to summarise this?
1/ The inverse square law applies to waves in the DSE
2/ The principle of superposition applies to waves in the DSE
3/ At the point of detection waves add following the rules of addition for waves from two sources.
If we assume continuous sinewave excitation then any of the standard DSE equations apply (with varying degrees of rigour) with the exception that ( by convention ) the inverse square law is usually ignored - it would be trivial (but messy) to add the inverse square law into any or all of these equations. This analysis gives a good match to the observed results.
If we have a good result without knowing (say) X then it is reasonable to assume that the result is either independent of or (at least) insensitive to X.
If you have chosen an experiment that is insensitive or independent of X then it will be difficult or impossible to use the experiment to prove anything about X - except (of course) that the result is insensitive or independent of X.
'X factors' would seem to include:-
The material the slits are made of
The size of the cavity
The properties of the walls of the cavity
The age of the Universe
The size of the Universe
The number of dimensions
And much more..
Young's genius was the ability to see that the DSE (aka Young's slits) did measure the one thing that he wanted to measure - the wavelength of light - clearly and unambiguously.
Comments and suggestions most welcome..
Best wishes,
-C2.
OK so it is standing waves in a cavity ..
Can I try to summarise this?
1/ The inverse square law applies to waves in the DSE
2/ The principle of superposition applies to waves in the DSE
3/ At the point of detection waves add following the rules of addition for waves from two sources.
If we assume continuous sinewave excitation then any of the standard DSE equations apply (with varying degrees of rigour) with the exception that ( by convention ) the inverse square law is usually ignored - it would be trivial (but messy) to add the inverse square law into any or all of these equations. This analysis gives a good match to the observed results.
If we have a good result without knowing (say) X then it is reasonable to assume that the result is either independent of or (at least) insensitive to X.
If you have chosen an experiment that is insensitive or independent of X then it will be difficult or impossible to use the experiment to prove anything about X - except (of course) that the result is insensitive or independent of X.
'X factors' would seem to include:-
The material the slits are made of
The size of the cavity
The properties of the walls of the cavity
The age of the Universe
The size of the Universe
The number of dimensions
And much more..
Young's genius was the ability to see that the DSE (aka Young's slits) did measure the one thing that he wanted to measure - the wavelength of light - clearly and unambiguously.
Comments and suggestions most welcome..
Best wishes,
-C2.
QUOTE (Confused2+May 5 2007, 11:27 PM)
If we took two 50 cent coins ( a dollar) in our hand and threw them up in the air then I think it would be remarkable if they always landed on top of each other ( to make up a dollar). Some kind of spooky force or what?
If we look at the result of a single photon DSE (click to enlarge)
we see what is effectively a level shifted cos^2 function - there are twice as many photons counted at the peaks as can be accounted for by the addition of the diffraction totals - these 'extra' counts (of course) make up for the absence of photons in the cancellation regions. Some kind of spooky force or what?
C2,
actually there is no any constructive or destructive interference going on, but some other currently unknown " mechanism " is the cause of that discrepancy in the distribution of hits in particular, and the cause of that configuration of distribution of hits in general?
Anton
If we look at the result of a single photon DSE (click to enlarge)
we see what is effectively a level shifted cos^2 function - there are twice as many photons counted at the peaks as can be accounted for by the addition of the diffraction totals - these 'extra' counts (of course) make up for the absence of photons in the cancellation regions. Some kind of spooky force or what?
C2,
actually there is no any constructive or destructive interference going on, but some other currently unknown " mechanism " is the cause of that discrepancy in the distribution of hits in particular, and the cause of that configuration of distribution of hits in general?
Anton
We're doomed? Not so fast..
Mathematicians feel free to help (or abandon ship)
Laserlight's original analysis included an excitation function like e^i (wt + kr) /r^2
Since we weren't interested in time we got an intensity (sum) given by something like e^(i k r_1) / (r_1)^2 + e^(i k r_2)/(r_2) ^2
Pinching some stuff from QM analysis we'd probably be better off working with amplitude rather than intensity
so this probably works better as ( (e^( i k r_1)) /r_1 + (e^( i k r_2)) /r_2) )^2
- hopefully this is independent of time and not too far wide of the mark (might come back to this later to check for complete nonsense)
Since a single photon gives the same result as a continuous sinewave we could propose a single photon excitation (amplitude) looks something like e^(i k r)/ r <- which is independant of time(!)
As Good Elf has been saying since 2000BC .. once we're independant of time we can spend as long as we like working out our sum over paths.. diffraction etc..
Being independant of time we can cover a lot of distance - like back to the big bang and on to the big whimper(?) but we still have the inverse square law to keep us local (ish) .
The DSE doesn't seem to work with time .. I think we need another experiment to sort out what 'time' means.
Nurse.. where's my medication?
-C2.
Mathematicians feel free to help (or abandon ship)
Laserlight's original analysis included an excitation function like e^i (wt + kr) /r^2
Since we weren't interested in time we got an intensity (sum) given by something like e^(i k r_1) / (r_1)^2 + e^(i k r_2)/(r_2) ^2
Pinching some stuff from QM analysis we'd probably be better off working with amplitude rather than intensity
so this probably works better as ( (e^( i k r_1)) /r_1 + (e^( i k r_2)) /r_2) )^2
- hopefully this is independent of time and not too far wide of the mark (might come back to this later to check for complete nonsense)
Since a single photon gives the same result as a continuous sinewave we could propose a single photon excitation (amplitude) looks something like e^(i k r)/ r <- which is independant of time(!)
As Good Elf has been saying since 2000BC .. once we're independant of time we can spend as long as we like working out our sum over paths.. diffraction etc..
Being independant of time we can cover a lot of distance - like back to the big bang and on to the big whimper(?) but we still have the inverse square law to keep us local (ish) .
The DSE doesn't seem to work with time .. I think we need another experiment to sort out what 'time' means.
Nurse.. where's my medication?
-C2.
Hi Laserlight, C2 and the rest,
we seem to have different approaches to the way a single photon can travel through space. The proposition of two way waves by Laserlight will not be valid with the notion of finite lenght wavepackets imho. Whereas the reasoning of C2 in regard to Young's experiment (the DSE) is more rigorous in explaining the results withouth the need to resort to more complex solutions.
I agree with Laserlight's intentions to get a more overall and indepth explanation for a wider range of effects but his proposed solutions seem contrived in respect to the simplicity of simple wavetheory. Even with simple wave theory the mathematics for explaining the results of a hologram are pretty straight forward and match the experimental results nicely. The reverse has already been proven by computer generated holograms. These holograms are the result of calculating the phase difference of all paths taken and compute the interference pattern over the hologram. They also include the inverse square law to account for the intensities that should be used for each path.
A completely different issue would be that the world on a quantum scale is filled with waves which are present at the zero point enegy. Those waves are omni present and could apply to the ideas of Laserlight where the waves create a hologram which accounts for all the observables in the known universe.
As a side note, the waves emanating from a slit are not subject to the inverse square law as per-se. The wavefront has an intensity that varies over the angle of dispersion. After normalizing the wavefront in respect to a function which describes that intensity the inverse square law can be applied..
Still the proposition of Laserlight does not explain why everything in the entire universe should be acting as a mirror but the holographic plate appears not to act like a mirror. It would even imply that all photons will end up at the holographic plate.. (unless I completely have missed the point in his proposal.)
Jan Rinze.
we seem to have different approaches to the way a single photon can travel through space. The proposition of two way waves by Laserlight will not be valid with the notion of finite lenght wavepackets imho. Whereas the reasoning of C2 in regard to Young's experiment (the DSE) is more rigorous in explaining the results withouth the need to resort to more complex solutions.
I agree with Laserlight's intentions to get a more overall and indepth explanation for a wider range of effects but his proposed solutions seem contrived in respect to the simplicity of simple wavetheory. Even with simple wave theory the mathematics for explaining the results of a hologram are pretty straight forward and match the experimental results nicely. The reverse has already been proven by computer generated holograms. These holograms are the result of calculating the phase difference of all paths taken and compute the interference pattern over the hologram. They also include the inverse square law to account for the intensities that should be used for each path.
A completely different issue would be that the world on a quantum scale is filled with waves which are present at the zero point enegy. Those waves are omni present and could apply to the ideas of Laserlight where the waves create a hologram which accounts for all the observables in the known universe.
As a side note, the waves emanating from a slit are not subject to the inverse square law as per-se. The wavefront has an intensity that varies over the angle of dispersion. After normalizing the wavefront in respect to a function which describes that intensity the inverse square law can be applied..
Still the proposition of Laserlight does not explain why everything in the entire universe should be acting as a mirror but the holographic plate appears not to act like a mirror. It would even imply that all photons will end up at the holographic plate.. (unless I completely have missed the point in his proposal.)
Jan Rinze.
For laserlight:
http://www.rp-photonics.com/coherence.html
this might shed some light on the need for spatial coherence in respect to creating holograms.
Jan Rinze.
http://www.rp-photonics.com/coherence.html
this might shed some light on the need for spatial coherence in respect to creating holograms.
Jan Rinze.
Hi Laserlight,
it just struck me, when it is only interference of single photons then any monochromatic lightsource would do if we would like to create holograms...
strangely that only applies for the reverse, viewing a hologram..
Jan Rinze.
it just struck me, when it is only interference of single photons then any monochromatic lightsource would do if we would like to create holograms...
strangely that only applies for the reverse, viewing a hologram..
Jan Rinze.
QUOTE (JR+)
it just struck me, when it is only interference of single photons then any monochromatic lightsource would do if we would like to create holograms...
I think it may be that the source needs to be traceable back to a point source (as well as monochromatic). Playing with a laser gives me the distinct impression that it has much in common with a point source.
Strangely early hoilograms were always viewed in laser light - I don't know whether this was because nobody noticed they worked anyway (??) or whether there is now some trick - like hologram films are very very thin - or something else.
Best wishes,
-C2.
I think it may be that the source needs to be traceable back to a point source (as well as monochromatic). Playing with a laser gives me the distinct impression that it has much in common with a point source.
Strangely early hoilograms were always viewed in laser light - I don't know whether this was because nobody noticed they worked anyway (??) or whether there is now some trick - like hologram films are very very thin - or something else.
Best wishes,
-C2.
Hi C2,
there is no need for traceability, it is just the wavefront that gets reflected from the hologram at certain points. This simply results into the percieved hologram. The parts of the wavefront interfere at the retina (the eye) to form the image.
When using white light the hologram is still visible as long as the light emanates from a point source. Ambient light would simply generate an almost infinite amount of holograms which become indistinguishable from one another.. Using a laser would yield the best result since the power concentrated in the coherent monochromatic lightsource will amplify one single image at the retina.
So no tricks here just improved efficiency when using lasers.. The use of new powerful lightsources generally available like halogen lamps or even LEDs allow for much simpler setups when viewing a hologram. The wavelenghts close to the wavelenght of the original lightsource will create (almost) overlapping images on the retina. The rest of the wavelenghts will create a more or less ambient flood on top of the image.. This even allows for 'full-colour' holograms like:
http://www.xyzrgb.com/holos/terminator.html
The caveat here is that this is a three colour hologram (RGB) as opposed to a real full colour hologram.
Jan Rinze.
there is no need for traceability, it is just the wavefront that gets reflected from the hologram at certain points. This simply results into the percieved hologram. The parts of the wavefront interfere at the retina (the eye) to form the image.
When using white light the hologram is still visible as long as the light emanates from a point source. Ambient light would simply generate an almost infinite amount of holograms which become indistinguishable from one another.. Using a laser would yield the best result since the power concentrated in the coherent monochromatic lightsource will amplify one single image at the retina.
So no tricks here just improved efficiency when using lasers.. The use of new powerful lightsources generally available like halogen lamps or even LEDs allow for much simpler setups when viewing a hologram. The wavelenghts close to the wavelenght of the original lightsource will create (almost) overlapping images on the retina. The rest of the wavelenghts will create a more or less ambient flood on top of the image.. This even allows for 'full-colour' holograms like:
http://www.xyzrgb.com/holos/terminator.html
The caveat here is that this is a three colour hologram (RGB) as opposed to a real full colour hologram.
Jan Rinze.
To all,
I have wondered today ( wandered is also an applicable expression ) about this hypothetical situation.
We conducted the DSE with the A slit detecting an electron/photon passing through, and there was no an interference recorded on the screen.
But our detection screen can fly like a space ship, and we are gradually moving the screen ( which can be as big/wide as we want it to be) away from the slits.
The question/speculation is this.
It seems to me that even we have a which way information, and even we did not record an interference pattern because of that , that at the certain distance between the slits and the flying detection screen an interference would appear again , if the momentum from the slit A to the detection screen would be indistinguishable from the momentum from the slit B to the detection screen.
?
A Running Away Quantum Distance Erasing Complicator?
Anton
I have wondered today ( wandered is also an applicable expression ) about this hypothetical situation.
We conducted the DSE with the A slit detecting an electron/photon passing through, and there was no an interference recorded on the screen.
But our detection screen can fly like a space ship, and we are gradually moving the screen ( which can be as big/wide as we want it to be) away from the slits.
The question/speculation is this.
It seems to me that even we have a which way information, and even we did not record an interference pattern because of that , that at the certain distance between the slits and the flying detection screen an interference would appear again , if the momentum from the slit A to the detection screen would be indistinguishable from the momentum from the slit B to the detection screen.
?
A Running Away Quantum Distance Erasing Complicator?
Anton
Hi C2,
The ISL is what provides the length geometry necessary for the interference and superposition results at any fixed screen spacing from the slits. When the
screen length is moved further away from the slits the interference image
expands to perfectly match the requirements of the ISL. Recall what happens
when you have a fixed projector and then move the movie screen away from
it. The projected image expands....it follows the ISL because the cavity volume
between the projector and the screen is increasing exponentially with the
movement. Any reference point of the projected image on the screen will
transcribe a curve with increasing volume as the screen moves away, but the
standing wave that exists between the source and the moving image is still a straight line as the screen recedes.
Determining the wavelength of light is relatively easy if you know the distances
between the fixed planes and apply simple geometry/mathematics because we
are dealing with fixed (finite) dimensions of the cavity, and a fixed wavelength.
Regardless of the dimensions (within reason) the geometrical relationship that
exists between the wavelength and the dimensions of the cavity will always be the
same, so you will always get the same answer for the wavelength, if it is fixed.
Comments?
LL
QUOTE
If we assume continuous sinewave excitation then any of the standard DSE equations apply (with varying degrees of rigour) with the exception that ( by convention ) the inverse square law is usually ignored - it would be trivial (but messy) to add the inverse square law into any or all of these equations. This analysis gives a good match to the observed results.
If we have a good result without knowing (say) X then it is reasonable to assume that the result is either independent of or (at least) insensitive to X.
If you have chosen an experiment that is insensitive or independent of X then it will be difficult or impossible to use the experiment to prove anything about X - except (of course) that the result is insensitive or independent of X.
'X factors' would seem to include:-
The material the slits are made of
The size of the cavity
The properties of the walls of the cavity
The age of the Universe
The size of the Universe
The number of dimensions
And much more..
Young's genius was the ability to see that the DSE (aka Young's slits) did measure the one thing that he wanted to measure - the wavelength of light - clearly and unambiguously.
If we have a good result without knowing (say) X then it is reasonable to assume that the result is either independent of or (at least) insensitive to X.
If you have chosen an experiment that is insensitive or independent of X then it will be difficult or impossible to use the experiment to prove anything about X - except (of course) that the result is insensitive or independent of X.
'X factors' would seem to include:-
The material the slits are made of
The size of the cavity
The properties of the walls of the cavity
The age of the Universe
The size of the Universe
The number of dimensions
And much more..
Young's genius was the ability to see that the DSE (aka Young's slits) did measure the one thing that he wanted to measure - the wavelength of light - clearly and unambiguously.
The ISL is what provides the length geometry necessary for the interference and superposition results at any fixed screen spacing from the slits. When the
screen length is moved further away from the slits the interference image
expands to perfectly match the requirements of the ISL. Recall what happens
when you have a fixed projector and then move the movie screen away from
it. The projected image expands....it follows the ISL because the cavity volume
between the projector and the screen is increasing exponentially with the
movement. Any reference point of the projected image on the screen will
transcribe a curve with increasing volume as the screen moves away, but the
standing wave that exists between the source and the moving image is still a straight line as the screen recedes.
Determining the wavelength of light is relatively easy if you know the distances
between the fixed planes and apply simple geometry/mathematics because we
are dealing with fixed (finite) dimensions of the cavity, and a fixed wavelength.
Regardless of the dimensions (within reason) the geometrical relationship that
exists between the wavelength and the dimensions of the cavity will always be the
same, so you will always get the same answer for the wavelength, if it is fixed.
Comments?
LL
I'm wondering if there is a pattern in the detection events. Perhaps looking at how the events build up over time to produce the interference pattern could provide us with some insights.
Hi C2,
Time is relative. You are disregarding the fact that the geometry changes with
time (distance), if the reference points are moving. In the case of the DSE,
we have 2 fixed planes, but you must consider that the energy contained in
the propagating wavefront, which is curved, is detected along the flat surface of
the screen plane. This yields a gausian distribution of the energy across the
flat plane.
If the detection screen was curved to matched the curvature of the wavefront we
would have a linear energy distribution at the screen, and the influence of the ISL
on energy distribution would be "unity" (linear) for a fixed distance from the souce.
Space is curved, time is linear.
Comments?
LL
QUOTE
Since a single photon gives the same result as a continuous sinewave we could propose a single photon excitation (amplitude) looks something like e^(i k r)/ r <- which is independant of time(!)
As Good Elf has been saying since 2000BC .. once we're independant of time we can spend as long as we like working out our sum over paths.. diffraction etc..
Being independant of time we can cover a lot of distance - like back to the big bang and on to the big whimper(?) but we still have the inverse square law to keep us local (ish) .
The DSE doesn't seem to work with time .. I think we need another experiment to sort out what 'time' means.
As Good Elf has been saying since 2000BC .. once we're independant of time we can spend as long as we like working out our sum over paths.. diffraction etc..
Being independant of time we can cover a lot of distance - like back to the big bang and on to the big whimper(?) but we still have the inverse square law to keep us local (ish) .
The DSE doesn't seem to work with time .. I think we need another experiment to sort out what 'time' means.
Time is relative. You are disregarding the fact that the geometry changes with
time (distance), if the reference points are moving. In the case of the DSE,
we have 2 fixed planes, but you must consider that the energy contained in
the propagating wavefront, which is curved, is detected along the flat surface of
the screen plane. This yields a gausian distribution of the energy across the
flat plane.
If the detection screen was curved to matched the curvature of the wavefront we
would have a linear energy distribution at the screen, and the influence of the ISL
on energy distribution would be "unity" (linear) for a fixed distance from the souce.
Space is curved, time is linear.
Comments?
LL
Hi Jan,
I'm not clear about what you are saying it is a bit ambiguous, can you detail what
you mean? I thought my explanation was the essence of wave simplicity. Maybe
not.
I'm not clear about what you are saying it is a bit ambiguous, can you detail what
you mean? I thought my explanation was the essence of wave simplicity. Maybe
not.
As a side note, the waves emanating from a slit are not subject to the inverse square law as per-se. The wavefront has an intensity that varies over the angle of dispersion. After normalizing the wavefront in respect to a function which describes that intensity the inverse square law can be applied..
Regarding your comment about the waves emanating from a slit are not subject
to the ISL.....see my recent post to C2 regarding a curved wavefront and a
planar detection screen. I can assure you that the ISL is required to yield the
gaussian distribution results of the DSE. We must consider how radiating
and expanding wave energy distributes itself along a fixed plane.
The emulsion is transparent to the optical range of EM energies used to expose
the wave pattern. The EM waves can travel thru it but at a reduced velocity
relative to the index of refraction of the emulsion vs. the n of air. Of course there
will be some small mirror "reflection" from the emulsion similar as to what you
would see from reflection off of the surface of water. It depends on the index of refraction
of the material and the frequency/wavelenth of the coherent light source.
Other frequencies outside of the desired "tuned" optimal EM spectrum are being
reflected from the surface of the emulsion, so the mirror effect is still in effect for
those frequencies.
Comments?
LL
QUOTE
we seem to have different approaches to the way a single photon can travel through space. The proposition of two way waves by Laserlight will not be valid with the notion of finite lenght wavepackets imho. Whereas the reasoning of C2 in regard to Young's experiment (the DSE) is more rigorous in explaining the results withouth the need to resort to more complex solutions.
I agree with Laserlight's intentions to get a more overall and indepth explanation for a wider range of effects but his proposed solutions seem contrived in respect to the simplicity of simple wavetheory. Even with simple wave theory the mathematics for explaining the results of a hologram are pretty straight forward and match the experimental results nicely. The reverse has already been proven by computer generated holograms. These holograms are the result of calculating the phase difference of all paths taken and compute the interference pattern over the hologram. They also include the inverse square law to account for the intensities that should be used for each path.
I agree with Laserlight's intentions to get a more overall and indepth explanation for a wider range of effects but his proposed solutions seem contrived in respect to the simplicity of simple wavetheory. Even with simple wave theory the mathematics for explaining the results of a hologram are pretty straight forward and match the experimental results nicely. The reverse has already been proven by computer generated holograms. These holograms are the result of calculating the phase difference of all paths taken and compute the interference pattern over the hologram. They also include the inverse square law to account for the intensities that should be used for each path.
I'm not clear about what you are saying it is a bit ambiguous, can you detail what
you mean? I thought my explanation was the essence of wave simplicity. Maybe
not.
QUOTE (->
| QUOTE |
| we seem to have different approaches to the way a single photon can travel through space. The proposition of two way waves by Laserlight will not be valid with the notion of finite lenght wavepackets imho. Whereas the reasoning of C2 in regard to Young's experiment (the DSE) is more rigorous in explaining the results withouth the need to resort to more complex solutions. I agree with Laserlight's intentions to get a more overall and indepth explanation for a wider range of effects but his proposed solutions seem contrived in respect to the simplicity of simple wavetheory. Even with simple wave theory the mathematics for explaining the results of a hologram are pretty straight forward and match the experimental results nicely. The reverse has already been proven by computer generated holograms. These holograms are the result of calculating the phase difference of all paths taken and compute the interference pattern over the hologram. They also include the inverse square law to account for the intensities that should be used for each path. |
I'm not clear about what you are saying it is a bit ambiguous, can you detail what
you mean? I thought my explanation was the essence of wave simplicity. Maybe
not.
As a side note, the waves emanating from a slit are not subject to the inverse square law as per-se. The wavefront has an intensity that varies over the angle of dispersion. After normalizing the wavefront in respect to a function which describes that intensity the inverse square law can be applied..
Regarding your comment about the waves emanating from a slit are not subject
to the ISL.....see my recent post to C2 regarding a curved wavefront and a
planar detection screen. I can assure you that the ISL is required to yield the
gaussian distribution results of the DSE. We must consider how radiating
and expanding wave energy distributes itself along a fixed plane.
QUOTE
Still the proposition of Laserlight does not explain why everything in the entire universe should be acting as a mirror but the holographic plate appears not to act like a mirror. It would even imply that all photons will end up at the holographic plate.. (unless I completely have missed the point in his proposal.)
The emulsion is transparent to the optical range of EM energies used to expose
the wave pattern. The EM waves can travel thru it but at a reduced velocity
relative to the index of refraction of the emulsion vs. the n of air. Of course there
will be some small mirror "reflection" from the emulsion similar as to what you
would see from reflection off of the surface of water. It depends on the index of refraction
of the material and the frequency/wavelenth of the coherent light source.
Other frequencies outside of the desired "tuned" optimal EM spectrum are being
reflected from the surface of the emulsion, so the mirror effect is still in effect for
those frequencies.
Comments?
LL
QUOTE (janrinze+May 6 2007, 12:33 PM)
For laserlight:
http://www.rp-photonics.com/coherence.html
this might shed some light on the need for spatial coherence in respect to creating holograms.
Jan Rinze.
Hi Jan,
I have no problem with this approach since spatial coherence is directly
proportional to temporal coherence. Distance between fixed points is linear
and time between fixed points is linear, it is just a matter of perspective.
They are complementary and can be used interchangeably.
Comments?
LL
http://www.rp-photonics.com/coherence.html
this might shed some light on the need for spatial coherence in respect to creating holograms.
Jan Rinze.
Hi Jan,
I have no problem with this approach since spatial coherence is directly
proportional to temporal coherence. Distance between fixed points is linear
and time between fixed points is linear, it is just a matter of perspective.
They are complementary and can be used interchangeably.
Comments?
LL
QUOTE (Mate+May 6 2007, 03:55 PM)
To all,
I have wondered today ( wandered is also an applicable expression ) about this hypothetical situation.
We conducted the DSE with the A slit detecting an electron/photon passing through, and there was no an interference recorded on the screen.
But our detection screen can fly like a space ship, and we are gradually moving the screen ( which can be as big/wide as we want it to be) away from the slits.
The question/speculation is this.
It seems to me that even we have a which way information, and even we did not record an interference pattern because of that , that at the certain distance between the slits and the flying detection screen an interference would appear again , if the momentum from the slit A to the detection screen would be indistinguishable from the momentum from the slit B to the detection screen.
?
A Running Away Quantum Distance Erasing Complicator?
Anton
Hi Mate,
In the case that you specified, with a moving screen, we would observe a
red dopler shift of the photon frequency as the screen moves away from the
source. We would not observe interference per se. The frequency of the
photon stays the same but our moving frame of reference changes the observed
frequency/phase relationship over increasing distance and time because the
relative wave length is increasing from our "moving" point of perspective.
Regards,
LL
I have wondered today ( wandered is also an applicable expression ) about this hypothetical situation.
We conducted the DSE with the A slit detecting an electron/photon passing through, and there was no an interference recorded on the screen.
But our detection screen can fly like a space ship, and we are gradually moving the screen ( which can be as big/wide as we want it to be) away from the slits.
The question/speculation is this.
It seems to me that even we have a which way information, and even we did not record an interference pattern because of that , that at the certain distance between the slits and the flying detection screen an interference would appear again , if the momentum from the slit A to the detection screen would be indistinguishable from the momentum from the slit B to the detection screen.
?
A Running Away Quantum Distance Erasing Complicator?
Anton
Hi Mate,
In the case that you specified, with a moving screen, we would observe a
red dopler shift of the photon frequency as the screen moves away from the
source. We would not observe interference per se. The frequency of the
photon stays the same but our moving frame of reference changes the observed
frequency/phase relationship over increasing distance and time because the
relative wave length is increasing from our "moving" point of perspective.
Regards,
LL
Hi LL,
QUOTE (LL+)
The ISL is what provides the length geometry necessary for the interference and superposition results at any fixed screen spacing from the slits.
Probably the simplest place to start is here - the basic DSE equation http://schools.matter.org.uk/Content/Inter...ce/formula.html .. as a point of interest you can see that the distance between the points of destructive interference varies as the distance from slits to screen.
Fairly good analysis is available here :- http://hyperphysics.phy-astr.gsu.edu/hbase...ffracon.html#c1 including a calculation of absolute intensity. In general small angle approximations are used to simplify analysis - I can find (again) the link that doesn't use these approximations if you are unhappy with the rigour of the hyperphysics analysis.
Probably the simplest place to start is here - the basic DSE equation http://schools.matter.org.uk/Content/Inter...ce/formula.html .. as a point of interest you can see that the distance between the points of destructive interference varies as the distance from slits to screen.
Fairly good analysis is available here :- http://hyperphysics.phy-astr.gsu.edu/hbase...ffracon.html#c1 including a calculation of absolute intensity. In general small angle approximations are used to simplify analysis - I can find (again) the link that doesn't use these approximations if you are unhappy with the rigour of the hyperphysics analysis.
QUOTE (LL+)
Time is relative...This yields a Gaussian distribution of the energy across the flat plane.
I'd rather rely on the analysis given in the links above.
HOWEVER
There is a very serious point about the way ALL of the analyses refer to continuous sinewave excitation - it means everything is set up - steady state - this should not apply for a single photon and yet it seems it does. One has the choice of ignoring the evidence or drawing a logical conclusion based on the evidence - if the evidence is correct and the logic is correct then the conclusion ought to be correct - at least until superceded by better logic or better evidence - or it can be shown that the person drawing the conclusion is .. let's not go there unless we have to.
Best wishes,
-C2.
I'd rather rely on the analysis given in the links above.
HOWEVER
There is a very serious point about the way ALL of the analyses refer to continuous sinewave excitation - it means everything is set up - steady state - this should not apply for a single photon and yet it seems it does. One has the choice of ignoring the evidence or drawing a logical conclusion based on the evidence - if the evidence is correct and the logic is correct then the conclusion ought to be correct - at least until superceded by better logic or better evidence - or it can be shown that the person drawing the conclusion is .. let's not go there unless we have to.
Best wishes,
-C2.
Hi C2,
I don't understand what point you are trying to make. I have repeatedly said
that I agree with the mathematics of the results of the DSE...it is accurate and
predictable...no argument there. My goal is to formalize the reason that the
mathematics works from a physical, real world, perspective. IMO, mathematics
is just a numerical description of the results. Unless we understand the wave
physics involved, and the relationship to time and space that creates the DSE effect,
we are no further along in our quest to comprehend the physical model.
Again, I defer to my argument that I can mathematically predict that the sun will
rise again tomorrow but that does not explain the physics involved with the
occurance. Knowing the intricacies, and explaining WHY and HOW a physical
phenomenon occurs, is of utmost importance for full comprehension of the
physical mechanism. It will occur regardless of the mathematics.
Regards,
LL
I don't understand what point you are trying to make. I have repeatedly said
that I agree with the mathematics of the results of the DSE...it is accurate and
predictable...no argument there. My goal is to formalize the reason that the
mathematics works from a physical, real world, perspective. IMO, mathematics
is just a numerical description of the results. Unless we understand the wave
physics involved, and the relationship to time and space that creates the DSE effect,
we are no further along in our quest to comprehend the physical model.
Again, I defer to my argument that I can mathematically predict that the sun will
rise again tomorrow but that does not explain the physics involved with the
occurance. Knowing the intricacies, and explaining WHY and HOW a physical
phenomenon occurs, is of utmost importance for full comprehension of the
physical mechanism. It will occur regardless of the mathematics.
Regards,
LL
Hi LL,
QUOTE (LL+)
I don't understand what point you are trying to make.
The point I am trying to make is that the analyses that we agree give the right answer ought not to work for a single photon and yet they do.
Do you draw any conclusion from that?
Best wishes,
C2.
The point I am trying to make is that the analyses that we agree give the right answer ought not to work for a single photon and yet they do.
Do you draw any conclusion from that?
Best wishes,
C2.
Hi Laserlight, C2 and the rest,
apparently my remark about spatial coherence did not ring a bel amongst you.
Spatial coherence implies that there is a (very) long wave packet (in the range of centimeters or even meters) that spreads out over the setup and during its travel through the setup it creates the interference pattern. When the packet has ended its journey (because the energy gets absorbed at 'random' points during its travel) there is no wave left.
This sums it up as being an event with a finite time span.
The same can be done for a single photon, the spatial coherence then is very short but sufficient to view a hologram. It is however too short to create the hologram. It is long enough to create the interference pattern seen with a DS experiment.
I cannot access the following reference but it does zoom in on the single photon experiments:
http://ieeexplore.ieee.org/Xplore/login.js...rnumber=1314185
Jan Rinze.
apparently my remark about spatial coherence did not ring a bel amongst you.
Spatial coherence implies that there is a (very) long wave packet (in the range of centimeters or even meters) that spreads out over the setup and during its travel through the setup it creates the interference pattern. When the packet has ended its journey (because the energy gets absorbed at 'random' points during its travel) there is no wave left.
This sums it up as being an event with a finite time span.
The same can be done for a single photon, the spatial coherence then is very short but sufficient to view a hologram. It is however too short to create the hologram. It is long enough to create the interference pattern seen with a DS experiment.
I cannot access the following reference but it does zoom in on the single photon experiments:
http://ieeexplore.ieee.org/Xplore/login.js...rnumber=1314185
Jan Rinze.
C2,
Yes, I think I see a direct correlation. A single photon is a wave phenomenon
and all single photons en masse will obey the same common rules. There is
nothing unique about one photon vs. billions of photons...they are all single
wave events and will all act the same under the same experimental conditions.
The only difference between photons is the phase angle that they are in as they
enter/exit the "cavities" of the slits, everything else in the DSE is fixed in time and
space. The only variable is the phase of the photon at a specific point in space.
Whether it is one photon or an unlimited number of photons, the only difference
is the intensity and location of results that will be observed at the detection
screen. The only physical mechanism that can change the location where the
energy of the photon is released at the screen is the phase angle relationship of
the photon. Everything else is "fixed".
Regards,
LL
QUOTE
The point I am trying to make is that the analyses that we agree give the right answer ought not to work for a single photon and yet they do.
Do you draw any conclusion from that?
Do you draw any conclusion from that?
Yes, I think I see a direct correlation. A single photon is a wave phenomenon
and all single photons en masse will obey the same common rules. There is
nothing unique about one photon vs. billions of photons...they are all single
wave events and will all act the same under the same experimental conditions.
The only difference between photons is the phase angle that they are in as they
enter/exit the "cavities" of the slits, everything else in the DSE is fixed in time and
space. The only variable is the phase of the photon at a specific point in space.
Whether it is one photon or an unlimited number of photons, the only difference
is the intensity and location of results that will be observed at the detection
screen. The only physical mechanism that can change the location where the
energy of the photon is released at the screen is the phase angle relationship of
the photon. Everything else is "fixed".
Regards,
LL
Hi Jan,
On the contrary, we have discussed spatial/temporal coherence at length quite
some time ago. If you re-read my description regarding single photon
energy distribution and internal wave interference, I think you will find that it mostly
agrees with your proposal. However, I am not convinced that the energy of the
distributed photon necessarily is fully absorbed at random points. The energy/
intensity of the wavefront is reflected or re-emitted from physical surfaces, but
not necessarily in phase with the original wave.
Even in the DSE we are observing the reflection of the photon energy intensity
from the bright bands. Was it absorbed or reflected from the surface of the screen?
It was reflected from the screen at the same frequency as the incident photons.
The individual photon waves were re-emitted from the screen surface,
so the wave energy is still intact but diminished in intensity because there is some
energy loss and the total distance from the slit sources to the point of
observation has increased. The ISL is at work again.
Comments?
LL
QUOTE
apparently my remark about spatial coherence did not ring a bel amongst you.
Spatial coherence implies that there is a (very) long wave packet (in the range of centimeters or even meters) that spreads out over the setup and during its travel through the setup it creates the interference pattern. When the packet has ended its journey (because the energy gets absorbed at 'random' points during its travel) there is no wave left.
This sums it up as being an event with a finite time span.
Spatial coherence implies that there is a (very) long wave packet (in the range of centimeters or even meters) that spreads out over the setup and during its travel through the setup it creates the interference pattern. When the packet has ended its journey (because the energy gets absorbed at 'random' points during its travel) there is no wave left.
This sums it up as being an event with a finite time span.
On the contrary, we have discussed spatial/temporal coherence at length quite
some time ago. If you re-read my description regarding single photon
energy distribution and internal wave interference, I think you will find that it mostly
agrees with your proposal. However, I am not convinced that the energy of the
distributed photon necessarily is fully absorbed at random points. The energy/
intensity of the wavefront is reflected or re-emitted from physical surfaces, but
not necessarily in phase with the original wave.
Even in the DSE we are observing the reflection of the photon energy intensity
from the bright bands. Was it absorbed or reflected from the surface of the screen?
It was reflected from the screen at the same frequency as the incident photons.
The individual photon waves were re-emitted from the screen surface,
so the wave energy is still intact but diminished in intensity because there is some
energy loss and the total distance from the slit sources to the point of
observation has increased. The ISL is at work again.
Comments?
LL
Hi LL,janrinze et al,
A continuous sinewave is one that begins at t= - inf and ends at t= + inf . When I turn my laser on so's I can look at the interference pattern - clearly I did not turn my laser on at t = -inf . The DSE is an instrument for analysing what you call 'single wave events' and as such it looks to me like the single wave event started at - inf and finishes at (say) the instant of detection. Please say that by now you have realised that a w(1) 'wavefront' is interfering with a w(N+0.5) wavefornt to give cancellation - if not we just have to go round again.
jan may be proposing a photon wavepacket that is always long enough (in the time domain) so it gives a sufficiently good result that we can't tell the difference - clarification please.
Best wishes,
-C2.
A continuous sinewave is one that begins at t= - inf and ends at t= + inf . When I turn my laser on so's I can look at the interference pattern - clearly I did not turn my laser on at t = -inf . The DSE is an instrument for analysing what you call 'single wave events' and as such it looks to me like the single wave event started at - inf and finishes at (say) the instant of detection. Please say that by now you have realised that a w(1) 'wavefront' is interfering with a w(N+0.5) wavefornt to give cancellation - if not we just have to go round again.
jan may be proposing a photon wavepacket that is always long enough (in the time domain) so it gives a sufficiently good result that we can't tell the difference - clarification please.
Best wishes,
-C2.
C2,
The time (t=0) begins when the sinewave is initially observed, or is "boxed"
between the start and end time intervals.
What is it that you don't understand about me agreeing with the math? The
math merely a way to quantify the result of the DSE...the wave physics occurs
despite the math interpretation. It is a physical phenomenon.
Comments?
LL
QUOTE
A continuous sinewave is one that begins at t= - inf and ends at t= + inf . When I turn my laser on so's I can look at the interference pattern - clearly I did not turn my laser on at t = -inf . The DSE is an instrument for analysing what you call 'single wave events' and as such it looks to me like the single wave event started at - inf and finishes at (say) the instant of detection.
The time (t=0) begins when the sinewave is initially observed, or is "boxed"
between the start and end time intervals.
What is it that you don't understand about me agreeing with the math? The
math merely a way to quantify the result of the DSE...the wave physics occurs
despite the math interpretation. It is a physical phenomenon.
Comments?
LL
Hi LL et al,
If we look at the result of a single photon DSE (click to enlarge)
Let's start by agreeing these peaks happen where the path length (back to the source) differs by (edit .. no wavelengths), one wavelength, two wavelengths, three wavelengths and so on .. yes?
Best wishes,
-C2.
If we look at the result of a single photon DSE (click to enlarge)
Let's start by agreeing these peaks happen where the path length (back to the source) differs by (edit .. no wavelengths), one wavelength, two wavelengths, three wavelengths and so on .. yes?
Best wishes,
-C2.
Hi LL and C2,
I think that C2 is getting close.
Lets keep our minds and tempers cool.
With the DS experiment the domain is exactly the period between switching on and off.
With a single photon we need to consider that the time between 'on' and 'off' is very short. This is no problem when doing the DS experiment. The reason is that the measured time difference (or phase difference) is in the order of a few cycles. and the photon consists of a wavepacket of many cycles. So the interference will be easily created.
The only thing needed is to get experimental results to verify this and to determine the spatial coherence of a single photon. In QM this should be related to the energy of the photon.
I am losing perspective in this thread about what the issue really is.
We all agree that the current theories comply with the experimental data.
My viewpoint was to see if conservation of momentum could yield a clue to the path taken without disturbing the interference pattern.
I have two statements to clarify my ideas:
1.The single photon experiments only work if the total pathlenght difference is small compared to the lenght of the wavepacket.
2.For large pathlenght differences long wavepackets need to be used and since the invention of the laser this can be experimentally verified.
The effect that a photon can be streched out over a large area does only imply a wave front, it will not spread out before the wave front nor after it (this is a bit simplified but does make things more 'sensible') In computational simulations called 'ray-casting' the results are very convincing and most (DS experiments still fall out of scope here) effects of optics and light scattering are consistent with experiments.
I feel that my contribution to this thread is diminishing and therefore I will take a short break to see how it evolves.
No problems with any of its contributors, just me failing to come up with new or better ideas.
Jan Rinze.
I think that C2 is getting close.
Lets keep our minds and tempers cool.
With the DS experiment the domain is exactly the period between switching on and off.
With a single photon we need to consider that the time between 'on' and 'off' is very short. This is no problem when doing the DS experiment. The reason is that the measured time difference (or phase difference) is in the order of a few cycles. and the photon consists of a wavepacket of many cycles. So the interference will be easily created.
The only thing needed is to get experimental results to verify this and to determine the spatial coherence of a single photon. In QM this should be related to the energy of the photon.
I am losing perspective in this thread about what the issue really is.
We all agree that the current theories comply with the experimental data.
My viewpoint was to see if conservation of momentum could yield a clue to the path taken without disturbing the interference pattern.
I have two statements to clarify my ideas:
1.The single photon experiments only work if the total pathlenght difference is small compared to the lenght of the wavepacket.
2.For large pathlenght differences long wavepackets need to be used and since the invention of the laser this can be experimentally verified.
The effect that a photon can be streched out over a large area does only imply a wave front, it will not spread out before the wave front nor after it (this is a bit simplified but does make things more 'sensible') In computational simulations called 'ray-casting' the results are very convincing and most (DS experiments still fall out of scope here) effects of optics and light scattering are consistent with experiments.
I feel that my contribution to this thread is diminishing and therefore I will take a short break to see how it evolves.
No problems with any of its contributors, just me failing to come up with new or better ideas.
Jan Rinze.
Hi janrinze et al,
Sorry the discussion has reverted to the basic 'how does it work'... probably my fault
. If we are to detect the momentum of a 'something' then it would be nice to know what the 'something' is.
If we imagine an EM burst of (say) 100 cycles then the w0_0 concidence will occur 100 times, the w1_0 will occur 99 times .. and so on. To escape detection I suggest the number of cycles in a wavepacket must always be substantially greater than the number we observe at any time - or a wavepacket is a poor model of what is actually going on.
Is anyone else willing and able to defend wavepackets?
Best wishes,
-C2.
Sorry the discussion has reverted to the basic 'how does it work'... probably my fault
. If we are to detect the momentum of a 'something' then it would be nice to know what the 'something' is. If we imagine an EM burst of (say) 100 cycles then the w0_0 concidence will occur 100 times, the w1_0 will occur 99 times .. and so on. To escape detection I suggest the number of cycles in a wavepacket must always be substantially greater than the number we observe at any time - or a wavepacket is a poor model of what is actually going on.
Is anyone else willing and able to defend wavepackets?
Best wishes,
-C2.
LL wrote:
In the case that you specified, with a moving screen, we would observe a
red dopler shift of the photon frequency as the screen moves away from the
source. We would not observe interference per se. The frequency of the
photon stays the same but our moving frame of reference changes the observed
frequency/phase relationship over increasing distance and time because the
relative wave length is increasing from our "moving" point of perspective.
LL,
yes, of course, I was an ambiguous in describing the preconditions of the hypothetical. I did not imagine that detection screen is in constant moving, I just added a space ship in the sense that detection screen can be put at any distance between the slits and itself in a straight line, so to speak. And that it can be as big and as wide as we want. In short, the detection screen moves for some distance from the slit, stops, then we conduct the experiment. And we repeat that proceeding until we find the distance when an interference ( possibly )appears again.
Moreover, perhaps the distance would not have to be a great one. Can you ( or anyone else here who knows mathematics better than moi, that is, everybody ) calculate at which distance between the slits and the detection screen the line from slit A would be indistinguishable from the line from the slit B, if the distance between slits themselves would be as smaller as it is allowed for DSE to work?
Anton
QUOTE
In the case that you specified, with a moving screen, we would observe a
red dopler shift of the photon frequency as the screen moves away from the
source. We would not observe interference per se. The frequency of the
photon stays the same but our moving frame of reference changes the observed
frequency/phase relationship over increasing distance and time because the
relative wave length is increasing from our "moving" point of perspective.
LL,
yes, of course, I was an ambiguous in describing the preconditions of the hypothetical. I did not imagine that detection screen is in constant moving, I just added a space ship in the sense that detection screen can be put at any distance between the slits and itself in a straight line, so to speak. And that it can be as big and as wide as we want. In short, the detection screen moves for some distance from the slit, stops, then we conduct the experiment. And we repeat that proceeding until we find the distance when an interference ( possibly )appears again.
Moreover, perhaps the distance would not have to be a great one. Can you ( or anyone else here who knows mathematics better than moi, that is, everybody ) calculate at which distance between the slits and the detection screen the line from slit A would be indistinguishable from the line from the slit B, if the distance between slits themselves would be as smaller as it is allowed for DSE to work?
Anton
Hi janrinze, Laserlight, Confused2, Yquantum, Neil Farbstein, Mate et al,
QUOTE (janrinze+)
With the DS experiment the domain is exactly the period between switching on and off.
With a single photon we need to consider that the time between 'on' and 'off' is very short. This is no problem when doing the DS experiment. The reason is that the measured time difference (or phase difference) is in the order of a few cycles. and the photon consists of a wavepacket of many cycles. So the interference will be easily created.
The only thing needed is to get experimental results to verify this and to determine the spatial coherence of a single photon. In QM this should be related to the energy of the photon.
With a single photon we need to consider that the time between 'on' and 'off' is very short. This is no problem when doing the DS experiment. The reason is that the measured time difference (or phase difference) is in the order of a few cycles. and the photon consists of a wavepacket of many cycles. So the interference will be easily created.
The only thing needed is to get experimental results to verify this and to determine the spatial coherence of a single photon. In QM this should be related to the energy of the photon.
I appreciate your contribution janrinze and it is difficult to see just how to proceed at this stage. What I would say is it still seems to be an intermittently productive thread. What I have omitted to do was to have a historical perspective on this "process" so I will lightly indicate what is the background of this "gem". All this did not come about easily or instantly. Spatial coherence can occur over light years as noted by Hanbury Brown and Twiss. Spatial coherence works with incoherent monochromatic sources and even solar illumination. Monochromatic sources of "strong" radiation appear to self-organize. They appear to organize themselves on common wavefronts when the solid angle of a source is very small or spatially filtered. Naturally it helps to select a single wavelength to do anything useful but Young used natural sunlight when he demonstrated to the Royal Institution (Society?) in 1807 (I think!).
http://en.wikipedia.org/wiki/Thomas_Young_%28scientist%29
http://en.wikipedia.org/wiki/Double-slit_experiment
This reference does not directly attribute the Double Slit Experiment to Young. I find this a bit strange perhaps it is because originally it was performed using not a double slit but a card, or in some references a wire, and a pinhole.
http://www.cavendishscience.org/phys/tyoung/tyoung.htm
For a more lucid account look here...
http://www.manhattanrarebooks-science.com/young.htm
YOUNG, Thomas. The Bakerian Lecture: "On the theory of light and colours," in Philosophical Transactions of the Royal Society, pts 1 & 2, pp 12-48; WITH: "An account of some cases of the production of colours, not hitherto described", in Philosophical Transactions, pp. 387-97. London: G. and G. Nicol, 1802.
Quoting directly from the article (this may also explain Mate's most recent question)...
http://en.wikipedia.org/wiki/Thomas_Young_%28scientist%29
http://en.wikipedia.org/wiki/Double-slit_experiment
This reference does not directly attribute the Double Slit Experiment to Young. I find this a bit strange perhaps it is because originally it was performed using not a double slit but a card, or in some references a wire, and a pinhole.
http://www.cavendishscience.org/phys/tyoung/tyoung.htm
For a more lucid account look here...
http://www.manhattanrarebooks-science.com/young.htm
YOUNG, Thomas. The Bakerian Lecture: "On the theory of light and colours," in Philosophical Transactions of the Royal Society, pts 1 & 2, pp 12-48; WITH: "An account of some cases of the production of colours, not hitherto described", in Philosophical Transactions, pp. 387-97. London: G. and G. Nicol, 1802.
Quoting directly from the article (this may also explain Mate's most recent question)...
QUOTE (Philosophical Transactions+)
"I therefore made a rectangular hole in a card, and bent its ends so as to support a hair parallel to the sides of the hole; then, upon applying the eye near the hole, the hair, of course, appeared dilated by indistinct vision into a surface, of which the breadth was determined by the distance of the hair and the magnitude of the hole, independently of the temporary aperture of the pupil. When the hair approached so near to the direction of the margin of a candle that the inflected light was sufficiently copious to produce a sensible effect, the fringes began to appear; and it was easy to estimate the proportion of their breadth to the apparent breadth of the hair across the image of which they extended. I found that six of the brightest red fringes, nearly at equal distance, occupied the whole of that image. The breadth of the aperture was 66/1000 [of an inch], and its distance from the hair 8/10 of an inch; the diameter of the hair was ... 1/600 [of an inch]. Hence, we have 11/1000 for the deviation of the first red fringe at the distance of 8/10; and as 8/10 / 11/1000 = 1/600 / 11/480000, or 1/43636 [of an inch] for the difference of the routes of the red light where it was most intense."
http://www.manhattanrarebooks-science.com/young.htm
http://www.manhattanrarebooks-science.com/young.htm
As you all can see the original way in which this experiment was performed was very basic and used a human hair and the light of a single candle. This established the wave nature of light and became the cornerstone of modern quantum mechanics. I have read of an actual demonstration of this experiment later to either the Royal Society or to the Royal Institution in 1908 showing a similar version of this experiment..
QUOTE (The Physics Teacher 24 217-219+ 1986)
Here is how it was done: A narrow beam of sunlight was split with what Young described as "a slip of card, about one thirtieth of an inch in breadth (thickness)." The slip of card was held edgewise into the sunbeam, which was made to enter the room horizontally by means of a "looking glass" (mirror) and a tiny hole in a "window shutter". The sunbeam had a diameter slightly greater than the thickness of the card. When the card was placed properly it split the beam into two slivers, one passing on each side of the slip of card
This was then allowed to fall on a suitably positioned screen to show the interference to the assembled audience. Or at least this seems close to the story I heard. Later the experiment was based on two pinholes and later refined to slits being much brighter than the pinholes. The original experiment using a card or wire (as I heard it).
The double-slit experiment : PhysicsWeb
This is an excellent article and indicates the problem of actually trying to do this experiment using electrons... giving an idea of how small the slits would need to be...
The double-slit experiment : PhysicsWebThis is an excellent article and indicates the problem of actually trying to do this experiment using electrons... giving an idea of how small the slits would need to be...
QUOTE (PhysicsWeb Article+)
"We choose to examine a phenomenon which is impossible, absolutely impossible, to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery." Feynman went on to add: "We should say right away that you should not try to set up this experiment. This experiment has never been done in just this way. The trouble is that the apparatus would have to be made on an impossibly small scale to show the effects we are interested in. We are doing a "thought experiment", which we have chosen because it is easy to think about. We know the results that would be obtained because there are many experiments that have been done, in which the scale and the proportions have been chosen to show the effects we shall describe".
Richard Feynman: Lectures in Physics
Richard Feynman: Lectures in Physics
We see that it is "very hard" even with todays technology to actually do this experiment using electrons... but experiment shows it can be done. The interference of the electron waves has been demonstrated very clearly... but we shall stick with photons since they are easier to deal with.
It is my contention that a single photon can be launched by the act of only switching on. This behaves like a single simple impulse because the act of launching the photon completes the event since it is only "rate of change" in the electric and magnetic fields that truncate the pulse in space and time. The switch on provides a DC step pulse but the launched wavelet is composed of the rate of change of this field which rapidly drops to zero for finite events in the real world. This is regardless of he fact that the field can then be maintained at the final switch on potential indefinitely. This provides photons with an apparent sync function packet form. "Some" of the wave will propagate backwards into the near-field region to complete the action at the source as residual inductive influences.
These fields are superluminal and could be interpreted as observations of Wheeler and Feynman's Advanced waves in the near field... A very brief glimpse of something otherwise globally canceled in the outer far field Universe. Long after the wave propagates forward in time the more this function is established with leading and trailing edges. Though the amplitude of the wave (especially the leading and trailing extremities) rapidly shrinks in absolute amplitude the further away from the maximum, it never actually reaches a true zero due to the influence of this evanescent field complementary part of the wave still having an influence on on the far field. This is usually considered part of the radiation impedance of the "antenna". This is because the packet is actually a harmonic oscillator and will not have an infinite number of internal frequencies but is confined to a finite Fourier composition (less than infinite). It must seem to most that this almost infinitesimally small influence must be of no consequence to most observers of this phenomenon especially with the apparently overwhelming "noise" in these systems. In Wheeler Feynman Theory this influence never theoretically ends and is not a causal influence but an acausal one acting from the distant future canceling the retarded wave everywhere it is not detected, even propagating way back ultimately into the "Big Bang". At the same time other influences propagate into the far future never fully dissipating and ready to rise again when conditions are suitable. Photons never age and their influence is ultimately wavelike rather than particulate in this theory. This theory supports the idea that we can see photons that originated almost from the beginning of the Universe as if they were emitted "today". Therefore allowing for the red shift we can see pictures of distant parts of the Universe that are showing light that has taken over 12 Billion years to arrive without any distortion or corruption through the power of the Hubble Deep Field Pictures (see below).
http://en.wikipedia.org/wiki/Hubble_Deep_Field
It is not difficult to believe that over that time and that distance, if so much can be retained from the deep past, then it is possible that "everything" is retained. I realize that this idea is not the one usually taught but it is one that has not been convincingly shown to be false and is after all resulted in a Nobel Prize in Physics for Wheeler and Feynman. Quantum noise surely would interfere with these images and they would not be limited only by the failure of the perfection in the optical systems. Therefore the conclusion I draw from this is the same as the one drawn from the argument that relates "statistical interpretations" vs "realism" involving measurables I have placed previously in this thread. These two approaches are incompatible but one (statistical interpretations) is not able to explain these otherwise little miracles of light.
Cheers
It is my contention that a single photon can be launched by the act of only switching on. This behaves like a single simple impulse because the act of launching the photon completes the event since it is only "rate of change" in the electric and magnetic fields that truncate the pulse in space and time. The switch on provides a DC step pulse but the launched wavelet is composed of the rate of change of this field which rapidly drops to zero for finite events in the real world. This is regardless of he fact that the field can then be maintained at the final switch on potential indefinitely. This provides photons with an apparent sync function packet form. "Some" of the wave will propagate backwards into the near-field region to complete the action at the source as residual inductive influences.
These fields are superluminal and could be interpreted as observations of Wheeler and Feynman's Advanced waves in the near field... A very brief glimpse of something otherwise globally canceled in the outer far field Universe. Long after the wave propagates forward in time the more this function is established with leading and trailing edges. Though the amplitude of the wave (especially the leading and trailing extremities) rapidly shrinks in absolute amplitude the further away from the maximum, it never actually reaches a true zero due to the influence of this evanescent field complementary part of the wave still having an influence on on the far field. This is usually considered part of the radiation impedance of the "antenna". This is because the packet is actually a harmonic oscillator and will not have an infinite number of internal frequencies but is confined to a finite Fourier composition (less than infinite). It must seem to most that this almost infinitesimally small influence must be of no consequence to most observers of this phenomenon especially with the apparently overwhelming "noise" in these systems. In Wheeler Feynman Theory this influence never theoretically ends and is not a causal influence but an acausal one acting from the distant future canceling the retarded wave everywhere it is not detected, even propagating way back ultimately into the "Big Bang". At the same time other influences propagate into the far future never fully dissipating and ready to rise again when conditions are suitable. Photons never age and their influence is ultimately wavelike rather than particulate in this theory. This theory supports the idea that we can see photons that originated almost from the beginning of the Universe as if they were emitted "today". Therefore allowing for the red shift we can see pictures of distant parts of the Universe that are showing light that has taken over 12 Billion years to arrive without any distortion or corruption through the power of the Hubble Deep Field Pictures (see below).
http://en.wikipedia.org/wiki/Hubble_Deep_Field
It is not difficult to believe that over that time and that distance, if so much can be retained from the deep past, then it is possible that "everything" is retained. I realize that this idea is not the one usually taught but it is one that has not been convincingly shown to be false and is after all resulted in a Nobel Prize in Physics for Wheeler and Feynman. Quantum noise surely would interfere with these images and they would not be limited only by the failure of the perfection in the optical systems. Therefore the conclusion I draw from this is the same as the one drawn from the argument that relates "statistical interpretations" vs "realism" involving measurables I have placed previously in this thread. These two approaches are incompatible but one (statistical interpretations) is not able to explain these otherwise little miracles of light.
Cheers
Hi janrinze, Laserlight, Confused2, Yquantum, Neil Farbstein, Mate et al,
I think you guys might appreciate this development in Physics...
Electromagnetic "wormhole" results from turning invisible sphere inside out: Scientific American
Seems I have already used this phrase before... he he he! This is a device that can "shortcut light through space"
Jan Rinze.
I think you guys might appreciate this development in Physics...
Electromagnetic "wormhole" results from turning invisible sphere inside out: Scientific American
Seems I have already used this phrase before... he he he! This is a device that can "shortcut light through space"
QUOTE (Scientific American Article+)
light-warping trick works for an open tube with flared ends. Viewed straight on, light zipping down the cylinder would be plainly visible. But from the side, the light would appear to come out of nowhere, as though sent on a detour to another dimension and back.
The idea is the same as that of a wormhole linking two distant points in spacetime, hence the nickname. "We're tricking the electromagnetic waves … into thinking that, actually, space has been changed," Greenleaf says.
"It's a very nice twist" on the spherical cloak, says physicist John Pendry of Imperial College London, one of the physicists who first worked out the idea. "We can invent a secret connection between two parts of space, and that is interesting."
May 04, 2007
Envision This: Mathematicians Design Invisible Tunnel
Electromagnetic "wormhole" results from turning invisible sphere inside out
By JR Minkel
Cheers
The idea is the same as that of a wormhole linking two distant points in spacetime, hence the nickname. "We're tricking the electromagnetic waves … into thinking that, actually, space has been changed," Greenleaf says.
"It's a very nice twist" on the spherical cloak, says physicist John Pendry of Imperial College London, one of the physicists who first worked out the idea. "We can invent a secret connection between two parts of space, and that is interesting."
May 04, 2007
Envision This: Mathematicians Design Invisible Tunnel
Electromagnetic "wormhole" results from turning invisible sphere inside out
By JR Minkel
Cheers
GE,
Basically, a "light pipe". Isn't the same thing routinely done with fiberoptic
cable?
LL
Basically, a "light pipe". Isn't the same thing routinely done with fiberoptic
cable?
LL
Hi Good Elf,
I'm sorry, I must seem very stupid .. I still don't see the connection you are making between this
and this
Best wishes,
-C2.
I'm sorry, I must seem very stupid .. I still don't see the connection you are making between this
and this
Best wishes,
-C2.
QUOTE (Confused2+May 7 2007, 06:21 PM)
Hi Good Elf,
I'm sorry, I must seem very stupid .. I still don't see the connection you are making between this
and this
Best wishes,
-C2.
Hi C2,
the first example is the fourrier transform of the square packet i.m.h.o. This is something different from the actual wave packet. Especially when referring to a laser this packet has a very long coherent waveform. For one photon I have found no good reference to its lenght.
It apparently should illustrate something different from the wavepacket itself. As the refence (the URL) mentions it is the transformation of a wave through a single slit as it arrives at the detectionplate. The intensity should be calculated by using the square of this, resulting in the curves in the second picture denoted with the triangles.
Adding two versions of the first curve, where one is shifted by the same amount as the distance between two slits, we get a new curve. The square of this new curve can be seen as the curve with the round dots in the second picture.
So to conclude: if we could say f(x) is the result of slit one and its intensity is (f(x))^2 and g(x) the result of slit two with its respective intensity (g(x))^2 the combined result is not f(x))^2 + (g(x))^2 but it is (f(x)+g(x))^2.
If you like I can give the functions for f(x) and g(x) but that makes it less readable to start with.
Jan Rinze.
I'm sorry, I must seem very stupid .. I still don't see the connection you are making between this
and this
Best wishes,
-C2.
Hi C2,
the first example is the fourrier transform of the square packet i.m.h.o. This is something different from the actual wave packet. Especially when referring to a laser this packet has a very long coherent waveform. For one photon I have found no good reference to its lenght.
It apparently should illustrate something different from the wavepacket itself. As the refence (the URL) mentions it is the transformation of a wave through a single slit as it arrives at the detectionplate. The intensity should be calculated by using the square of this, resulting in the curves in the second picture denoted with the triangles.
Adding two versions of the first curve, where one is shifted by the same amount as the distance between two slits, we get a new curve. The square of this new curve can be seen as the curve with the round dots in the second picture.
So to conclude: if we could say f(x) is the result of slit one and its intensity is (f(x))^2 and g(x) the result of slit two with its respective intensity (g(x))^2 the combined result is not f(x))^2 + (g(x))^2 but it is (f(x)+g(x))^2.
If you like I can give the functions for f(x) and g(x) but that makes it less readable to start with.
Jan Rinze.
Hello all
Space-time resists change. It takes energy to overcome this resistance. The EM wave of a single frequency carries just enough energy to overcome this resistance. It takes more energy to overcome this resistance in a shorter period of distance/time. Hence higher frequencies have higher energy. E=hf is the equation for this energy and is also the equation for the energy of a photon. A photon is the measure of this space-time resistance. This implies to me that the photon does not move. The photon is stationary. The only thing moving is the EM wave. Each half cycle of the EM wave is a photon that can be measured at distance from the EM wave source. However, you are not measuring the same photon at different spacial locations.
The DSE and related experiments that involve EM waves are just the result of wave interference. There are no photons at the destructive interference because there is no energy available at that point to be resisted by space-time.
Space-time is not uniform. Matter affects space-time. These affects can be measured by gravitational/time changes and the changes in permittivity/permeability when compared to permittivity/permeability of a vacuum.
Just some thoughts open for discussion.
Space-time resists change. It takes energy to overcome this resistance. The EM wave of a single frequency carries just enough energy to overcome this resistance. It takes more energy to overcome this resistance in a shorter period of distance/time. Hence higher frequencies have higher energy. E=hf is the equation for this energy and is also the equation for the energy of a photon. A photon is the measure of this space-time resistance. This implies to me that the photon does not move. The photon is stationary. The only thing moving is the EM wave. Each half cycle of the EM wave is a photon that can be measured at distance from the EM wave source. However, you are not measuring the same photon at different spacial locations.
The DSE and related experiments that involve EM waves are just the result of wave interference. There are no photons at the destructive interference because there is no energy available at that point to be resisted by space-time.
Space-time is not uniform. Matter affects space-time. These affects can be measured by gravitational/time changes and the changes in permittivity/permeability when compared to permittivity/permeability of a vacuum.
Just some thoughts open for discussion.
Hi Good Elf,janrinze,LL Montec et al,
For a slit of width x we get a sinc thing like sin(x)/x
For two slits we need to shift one of both to the left and right .. for elegance we get
e^(iax) sin(x) /x and e^(-iax)sin(x)/x
janrinze says square this so ..
( e^(iax) sin(x) /x + e^(-iax)sin(x)/x ) ^2 = e^(i2ax) sin^2(x) /x^2 + sin^2(x) /x^2 + e^(-i2ax) sin^2(x) /x^2
Since we have smart plotters I'll try to plug this in directly and see what it looks like.
Best wishes,
-C2.
Time has passed and it looks like this (click)
Whoopee!
GE- we should have done that months ago - I couldn't see that final bit that janrinze added (many thanks) .. it works .. there is no time involved .. panic sets in.
Comments welcome.
For a slit of width x we get a sinc thing like sin(x)/x
For two slits we need to shift one of both to the left and right .. for elegance we get
e^(iax) sin(x) /x and e^(-iax)sin(x)/x
janrinze says square this so ..
( e^(iax) sin(x) /x + e^(-iax)sin(x)/x ) ^2 = e^(i2ax) sin^2(x) /x^2 + sin^2(x) /x^2 + e^(-i2ax) sin^2(x) /x^2
Since we have smart plotters I'll try to plug this in directly and see what it looks like.
Best wishes,
-C2.
Time has passed and it looks like this (click)
Whoopee!
GE- we should have done that months ago - I couldn't see that final bit that janrinze added (many thanks) .. it works .. there is no time involved .. panic sets in.
Comments welcome.
Jan Rinze.
QUOTE (Montec+May 7 2007, 09:25 PM)
Space-time resists change. It takes energy to overcome this resistance. The EM wave of a single frequency carries just enough energy to overcome this resistance. It takes more energy to overcome this resistance in a shorter period of distance/time. Hence higher frequencies have higher energy. E=hf is the equation for this energy and is also the equation for the energy of a photon. A photon is the measure of this space-time resistance. This implies to me that the photon does not move. The photon is stationary. The only thing moving is the EM wave. Each half cycle of the EM wave is a photon that can be measured at distance from the EM wave source. However, you are not measuring the same photon at different spacial locations.
The DSE and related experiments that involve EM waves are just the result of wave interference. There are no photons at the destructive interference because there is no energy available at that point to be resisted by space-time.
Space-time is not uniform. Matter affects space-time. These affects can be measured by gravitational/time changes and the changes in permittivity/permeability when compared to permittivity/permeability of a vacuum.
Just some thoughts open for discussion.
Hi Montec,
Resistance of space-time? I need to think about that. I agree with the concept
of permittivity and permeability of space/vacuum but the idea of resistance seems
counter-intuitive as it would, by necessity, generate secondary "side" effects
with energy transfer.
I will get back with you later on the topics/ideas that you have proposed.
LL
The DSE and related experiments that involve EM waves are just the result of wave interference. There are no photons at the destructive interference because there is no energy available at that point to be resisted by space-time.
Space-time is not uniform. Matter affects space-time. These affects can be measured by gravitational/time changes and the changes in permittivity/permeability when compared to permittivity/permeability of a vacuum.
Just some thoughts open for discussion.
Hi Montec,
Resistance of space-time? I need to think about that. I agree with the concept
of permittivity and permeability of space/vacuum but the idea of resistance seems
counter-intuitive as it would, by necessity, generate secondary "side" effects
with energy transfer.
I will get back with you later on the topics/ideas that you have proposed.
LL
Hi janrinze, Laserlight, Confused2, Yquantum, Neil Farbstein, Mate, Montec et al,
Thanks to Jan Rinze I think we are all on the same page now. Aside from the totally ideal nature of that packet transform, we now have the absolute simplest solution for single wave interference between two slits and an underlying mechanism. Of course there is the presumption that these two transforms refer to the one packet and its own internal interferences and not simply interference between two separate packets "each going their own way". The two "new" sources are identical but separated by the slit separation. So continuous waves can be depicted composed as a summation of these packet transforms differing only in spatial phase and as a bosonic superpositions like this.
... click to enlarge...
Each function is not limited spatially but overlap with its twin on the same wavefront. The squaring of the amplitude to obtain the intensity should not be such a surprise, it doubles the "observed peaks". Thus we end up with this image taken with real pinholes...
which matches your calculation rotated 90 degrees exactly"... well sort of?
By the way I have finally been able to obtain a copy of that previously referenced paper today...
Good Elf Earlier on yquantum's Gondran reference
This is a photocopy so I will need to be selective about what I later report.
Cheers
Thanks to Jan Rinze
I think we are all on the same page now. Aside from the totally ideal nature of that packet transform, we now have the absolute simplest solution for single wave interference between two slits and an underlying mechanism. Of course there is the presumption that these two transforms refer to the one packet and its own internal interferences and not simply interference between two separate packets "each going their own way". The two "new" sources are identical but separated by the slit separation. So continuous waves can be depicted composed as a summation of these packet transforms differing only in spatial phase and as a bosonic superpositions like this.... click to enlarge...
Each function is not limited spatially but overlap with its twin on the same wavefront. The squaring of the amplitude to obtain the intensity should not be such a surprise, it doubles the "observed peaks". Thus we end up with this image taken with real pinholes...
which matches your calculation rotated 90 degrees exactly"... well sort of?
By the way I have finally been able to obtain a copy of that previously referenced paper today...
QUOTE
Numerical simulation of the double slit interference with ultracold atoms
Michel Gondran
EDF, Research and Development, 1 av. du General de Gaulle, 92140 Clamart, France
Alexandre Gondran
Paris VI University, 60 av. Jean Jaures, 92190 Meudon, France
(Received 10 October 2003; accepted 17 December 2004)
We present a numerical simulation of the double slit interference experiment realized by F. Shimizu, K. Shimizu and H. Takuma with ultracold atoms. We show how the Feynman path integral method enables the calculation of the time-dependent wave function. Because the evolution of the probability density of the wave packet just after it exits the slits raises the issue of interpreting the wave/particle dualism, we also simulate trajectories in the de Broglie–Bohm interpretation. ©2005 American Association of Physics Teachers.
American Journal of Physics -- June 2005 -- Volume 73, Issue 6, pp. 507-515 (2005). pub Date: 06/2005
I have not been able to read it yet but I am sure it will be very interesting. I have been meaning to catch up on this since this post...Michel Gondran
EDF, Research and Development, 1 av. du General de Gaulle, 92140 Clamart, France
Alexandre Gondran
Paris VI University, 60 av. Jean Jaures, 92190 Meudon, France
(Received 10 October 2003; accepted 17 December 2004)
We present a numerical simulation of the double slit interference experiment realized by F. Shimizu, K. Shimizu and H. Takuma with ultracold atoms. We show how the Feynman path integral method enables the calculation of the time-dependent wave function. Because the evolution of the probability density of the wave packet just after it exits the slits raises the issue of interpreting the wave/particle dualism, we also simulate trajectories in the de Broglie–Bohm interpretation. ©2005 American Association of Physics Teachers.
American Journal of Physics -- June 2005 -- Volume 73, Issue 6, pp. 507-515 (2005). pub Date: 06/2005
Good Elf Earlier on yquantum's Gondran reference
This is a photocopy so I will need to be selective about what I later report.
Cheers
Montec, my thoughts on your prior propals...
IMO, space is dynamic and curved (non-linear), whereas time is linear and "event" based.
Space has multi-dimensional and exponential characteristics (length, width,
direction, volume, and energy content).
"Time" is relative to a change of state in the "space" being measured and requires
a start point and incremental points along a fixed linear timeline. So basically, space-time
is a sequential, continuous, and physical interdimensional change of volume,
energy state, or position. There must be some physical, measurable, and
quantifiable rate of "change" for space-time to co-exist.
If the volumetric, positional, or energy characteristics of "space" changes, it will be
over a linear period of time. Conversely, time being relative, requires a fixed
point of reference such as a change of "state" or position in the dynamics of space
or else it is not relative.
Since "time" is progressive and event based it requires an observable, measurable,
or quantifiable sequential change of state in the space being observed.
"Space", without a change of state, is not relative since time has no physical
references with which to gauge its passage.
-----
You are inferring that some physical attribute of space restricts or resists a change
of state on the event timeline. IMO, "space" is in a constant state of change and
is a "catalyst" or "medium" for it. The transport of energy thru space, over time,
is a dynamic event. The constant change in the energy level of volumetric space
insures a timeline.
IMO, space is dynamic and curved (non-linear), whereas time is linear and "event" based.
Space has multi-dimensional and exponential characteristics (length, width,
direction, volume, and energy content).
"Time" is relative to a change of state in the "space" being measured and requires
a start point and incremental points along a fixed linear timeline. So basically, space-time
is a sequential, continuous, and physical interdimensional change of volume,
energy state, or position. There must be some physical, measurable, and
quantifiable rate of "change" for space-time to co-exist.
If the volumetric, positional, or energy characteristics of "space" changes, it will be
over a linear period of time. Conversely, time being relative, requires a fixed
point of reference such as a change of "state" or position in the dynamics of space
or else it is not relative.
Since "time" is progressive and event based it requires an observable, measurable,
or quantifiable sequential change of state in the space being observed.
"Space", without a change of state, is not relative since time has no physical
references with which to gauge its passage.
-----
You are inferring that some physical attribute of space restricts or resists a change
of state on the event timeline. IMO, "space" is in a constant state of change and
is a "catalyst" or "medium" for it. The transport of energy thru space, over time,
is a dynamic event. The constant change in the energy level of volumetric space
insures a timeline.
The DSE and related experiments that involve EM waves are just the result of wave interference. There are no photons at the destructive interference because there is no energy available at that point to be resisted by space-time.
Photons are physical and dynamic energy events that expand to displace and fill
the non-physical "volume" of space. "Space" has a baseline reference energy
level, all other physical energy events operate above this threshold level.
The point where equal but opposing forces "cancel" is a point of potential energy.
The energy is there, it is just in a temporary state of equilibrium and no work
function or energy displacement is occuring.
http://en.wikipedia.org/wiki/Phasor_%28physics%29
I agree with this concept.
Comments?
LL
QUOTE
Space-time resists change. It takes energy to overcome this resistance. The EM wave of a single frequency carries just enough energy to overcome this resistance. It takes more energy to overcome this resistance in a shorter period of distance/time. Hence higher frequencies have higher energy. E=hf is the equation for this energy and is also the equation for the energy of a photon. A photon is the measure of this space-time resistance. This implies to me that the photon does not move. The photon is stationary. The only thing moving is the EM wave. Each half cycle of the EM wave is a photon that can be measured at distance from the EM wave source. However, you are not measuring the same photon at different spacial locations.
IMO, space is dynamic and curved (non-linear), whereas time is linear and "event" based.
Space has multi-dimensional and exponential characteristics (length, width,
direction, volume, and energy content).
"Time" is relative to a change of state in the "space" being measured and requires
a start point and incremental points along a fixed linear timeline. So basically, space-time
is a sequential, continuous, and physical interdimensional change of volume,
energy state, or position. There must be some physical, measurable, and
quantifiable rate of "change" for space-time to co-exist.
If the volumetric, positional, or energy characteristics of "space" changes, it will be
over a linear period of time. Conversely, time being relative, requires a fixed
point of reference such as a change of "state" or position in the dynamics of space
or else it is not relative.
Since "time" is progressive and event based it requires an observable, measurable,
or quantifiable sequential change of state in the space being observed.
"Space", without a change of state, is not relative since time has no physical
references with which to gauge its passage.
-----
You are inferring that some physical attribute of space restricts or resists a change
of state on the event timeline. IMO, "space" is in a constant state of change and
is a "catalyst" or "medium" for it. The transport of energy thru space, over time,
is a dynamic event. The constant change in the energy level of volumetric space
insures a timeline.
QUOTE (->
| QUOTE |
| Space-time resists change. It takes energy to overcome this resistance. The EM wave of a single frequency carries just enough energy to overcome this resistance. It takes more energy to overcome this resistance in a shorter period of distance/time. Hence higher frequencies have higher energy. E=hf is the equation for this energy and is also the equation for the energy of a photon. A photon is the measure of this space-time resistance. This implies to me that the photon does not move. The photon is stationary. The only thing moving is the EM wave. Each half cycle of the EM wave is a photon that can be measured at distance from the EM wave source. However, you are not measuring the same photon at different spacial locations. |
IMO, space is dynamic and curved (non-linear), whereas time is linear and "event" based.
Space has multi-dimensional and exponential characteristics (length, width,
direction, volume, and energy content).
"Time" is relative to a change of state in the "space" being measured and requires
a start point and incremental points along a fixed linear timeline. So basically, space-time
is a sequential, continuous, and physical interdimensional change of volume,
energy state, or position. There must be some physical, measurable, and
quantifiable rate of "change" for space-time to co-exist.
If the volumetric, positional, or energy characteristics of "space" changes, it will be
over a linear period of time. Conversely, time being relative, requires a fixed
point of reference such as a change of "state" or position in the dynamics of space
or else it is not relative.
Since "time" is progressive and event based it requires an observable, measurable,
or quantifiable sequential change of state in the space being observed.
"Space", without a change of state, is not relative since time has no physical
references with which to gauge its passage.
-----
You are inferring that some physical attribute of space restricts or resists a change
of state on the event timeline. IMO, "space" is in a constant state of change and
is a "catalyst" or "medium" for it. The transport of energy thru space, over time,
is a dynamic event. The constant change in the energy level of volumetric space
insures a timeline.
The DSE and related experiments that involve EM waves are just the result of wave interference. There are no photons at the destructive interference because there is no energy available at that point to be resisted by space-time.
Photons are physical and dynamic energy events that expand to displace and fill
the non-physical "volume" of space. "Space" has a baseline reference energy
level, all other physical energy events operate above this threshold level.
The point where equal but opposing forces "cancel" is a point of potential energy.
The energy is there, it is just in a temporary state of equilibrium and no work
function or energy displacement is occuring.
http://en.wikipedia.org/wiki/Phasor_%28physics%29
QUOTE
Space-time is not uniform. Matter affects space-time. These affects can be measured by gravitational/time changes and the changes in permittivity/permeability when compared to permittivity/permeability of a vacuum.
I agree with this concept.
Comments?
LL
Good Elf wrote:
Good Elf,
this excerpt may be an answer on my most recent question? Would you please explain how?
Sorry about that, my layman knowledge can be and occasionally is an obstacle in conversation on these expert level topics.
Anton
QUOTE
YOUNG, Thomas. The Bakerian Lecture: "On the theory of light and colours," in Philosophical Transactions of the Royal Society, pts 1 & 2, pp 12-48; WITH: "An account of some cases of the production of colours, not hitherto described", in Philosophical Transactions, pp. 387-97. London: G. and G. Nicol, 1802.
Quoting directly from the article (this may also explain Mate's most recent
question)...
QUOTE (Philosophical Transactions)
"I therefore made a rectangular hole in a card, and bent its ends so as to support a hair parallel to the sides of the hole; then, upon applying the eye near the hole, the hair, of course, appeared dilated by indistinct vision into a surface, of which the breadth was determined by the distance of the hair and the magnitude of the hole, independently of the temporary aperture of the pupil. When the hair approached so near to the direction of the margin of a candle that the inflected light was sufficiently copious to produce a sensible effect, the fringes began to appear; and it was easy to estimate the proportion of their breadth to the apparent breadth of the hair across the image of which they extended. I found that six of the brightest red fringes, nearly at equal distance, occupied the whole of that image. The breadth of the aperture was 66/1000 [of an inch], and its distance from the hair 8/10 of an inch; the diameter of the hair was ... 1/600 [of an inch]. Hence, we have 11/1000 for the deviation of the first red fringe at the distance of 8/10; and as 8/10 / 11/1000 = 1/600 / 11/480000, or 1/43636 [of an inch] for the difference of the routes of the red light where it was most intense."
http://www.manhattanrarebooks-science.com/young.htm
Quoting directly from the article (this may also explain Mate's most recent
question)...
QUOTE (Philosophical Transactions)
"I therefore made a rectangular hole in a card, and bent its ends so as to support a hair parallel to the sides of the hole; then, upon applying the eye near the hole, the hair, of course, appeared dilated by indistinct vision into a surface, of which the breadth was determined by the distance of the hair and the magnitude of the hole, independently of the temporary aperture of the pupil. When the hair approached so near to the direction of the margin of a candle that the inflected light was sufficiently copious to produce a sensible effect, the fringes began to appear; and it was easy to estimate the proportion of their breadth to the apparent breadth of the hair across the image of which they extended. I found that six of the brightest red fringes, nearly at equal distance, occupied the whole of that image. The breadth of the aperture was 66/1000 [of an inch], and its distance from the hair 8/10 of an inch; the diameter of the hair was ... 1/600 [of an inch]. Hence, we have 11/1000 for the deviation of the first red fringe at the distance of 8/10; and as 8/10 / 11/1000 = 1/600 / 11/480000, or 1/43636 [of an inch] for the difference of the routes of the red light where it was most intense."
http://www.manhattanrarebooks-science.com/young.htm
Good Elf,
this excerpt may be an answer on my most recent question? Would you please explain how?
Sorry about that, my layman knowledge can be and occasionally is an obstacle in conversation on these expert level topics.
Anton
Hi Mate,
QUOTE (Mate+)
Moreover, perhaps the distance would not have to be a great one. Can you ( or anyone else here who knows mathematics better than moi, that is, everybody ) calculate at which distance between the slits and the detection screen the line from slit A would be indistinguishable from the line from the slit B, if the distance between slits themselves would be as smaller as it is allowed for DSE to work?
Sorry about that. I don't like mathematics. I will explain a bit more here. The original experiment by Young using a hair gives a practical minimum distance to observer for the DSE and the breadth of a single hair. While this is not the DSE it indicates a minimum distance from the hair where the effect could be physically observed (... for the DSE). Naturally everyones eye is different so this cannot be exact. The absolute minimum distance would be the finest filament that the human eye could see and still be opaque observed at the closest distance. Calculations are futile in this case since there is no answer to that exactly and it would also depend on wavelength. If the sources were not correlated then you would use the Rayleigh Criterion.
http://hyperphysics.phy-astr.gsu.edu/hbase...opt/raylei.html
Rayleigh Criterion is not appropriate in this case. A single or multiple distributed correlated source must be treated using Fraunhofer Diffraction (in the far field)...
http://www.phy.davidson.edu/StuHome/cabell...experiments.htm
Obviously the further away you are from the pair of sources the less likely you are able to resolve its parts. In that circumstance a "distributed" source can be considered the vector sum of a large number of smaller individual sources therefore any shaped source of any size can be generated from a number of these "smallest resolvable" individual sources... And that will depend on how far away you are observing from.
Cheers
http://hyperphysics.phy-astr.gsu.edu/hbase...opt/raylei.html
Rayleigh Criterion is not appropriate in this case. A single or multiple distributed correlated source must be treated using Fraunhofer Diffraction (in the far field)...
http://www.phy.davidson.edu/StuHome/cabell...experiments.htm
Obviously the further away you are from the pair of sources the less likely you are able to resolve its parts. In that circumstance a "distributed" source can be considered the vector sum of a large number of smaller individual sources therefore any shaped source of any size can be generated from a number of these "smallest resolvable" individual sources... And that will depend on how far away you are observing from.
Cheers
We seem to have more than one group in the same clearing in the forest - I don't see that as a problem if everyone else is happy - please complain if not happy.
Hi janrinze,Good Elf,Montec et al,
I suspect the Fourier thing is implicitly an e^(iwt) analysis .. I must admit I didn't expect the shift to work .. maybe a reson would be nice if possible.
I'm very much in favour of a pick and shovel approach to the maths so we can see where QM and classical analysis start to give different answers.
I started an analysis here :- http://forum.physorg.com/index.php?showtop...80&#entry183204 but gave up because nobody was interested. If anyone is interested (and checked or supplied better maths) I might be able to do snapshots of a time domain analysis for various 'photons'.
Best wishes,
-C2.
Hi janrinze,Good Elf,Montec et al,
I suspect the Fourier thing is implicitly an e^(iwt) analysis .. I must admit I didn't expect the shift to work .. maybe a reson would be nice if possible.
I'm very much in favour of a pick and shovel approach to the maths so we can see where QM and classical analysis start to give different answers.
I started an analysis here :- http://forum.physorg.com/index.php?showtop...80&#entry183204 but gave up because nobody was interested. If anyone is interested (and checked or supplied better maths) I might be able to do snapshots of a time domain analysis for various 'photons'.
Best wishes,
-C2.
QUOTE (Good Elf+May 8 2007, 11:28 AM)
A single or multiple distributed correlated source must be treated using Fraunhofer Diffraction (in the far field)...
http://www.phy.davidson.edu/StuHome/cabell...experiments.htm
Obviously the further away you are from the pair of sources the less likely you are able to resolve its parts. In that circumstance a "distributed" source can be considered the vector sum of a large number of smaller individual sources therefore any shaped source of any size can be generated from a number of these "smallest resolvable" individual sources... And that will depend on how far away you are observing from.
I see, Good Elf, thanks for the clarification.
Anton
http://www.phy.davidson.edu/StuHome/cabell...experiments.htm
Obviously the further away you are from the pair of sources the less likely you are able to resolve its parts. In that circumstance a "distributed" source can be considered the vector sum of a large number of smaller individual sources therefore any shaped source of any size can be generated from a number of these "smallest resolvable" individual sources... And that will depend on how far away you are observing from.
I see, Good Elf, thanks for the clarification.
Anton
Hi Confused2, janrinze, Laserlight, Yquantum, Neil Farbstein, Mate, Montec et al,
QUOTE (Confused2+)
Hi janrinze,Good Elf,Montec et al,
I suspect the Fourier thing is implicitly an e^(iwt) analysis .. I must admit I didn't expect the shift to work .. maybe a reason would be nice if possible.
I'm very much in favour of a pick and shovel approach to the maths so we can see where QM and classical analysis start to give different answers.
I suspect the Fourier thing is implicitly an e^(iwt) analysis .. I must admit I didn't expect the shift to work .. maybe a reason would be nice if possible.
I'm very much in favour of a pick and shovel approach to the maths so we can see where QM and classical analysis start to give different answers.
This is where I turn "radical" and suggest that quantum phenomena are ultimately entirely resolvable in terms of these "interferences" that represent the geometry of the space and are independent of the actual source of illumination (sources... primary and secondary). Please note this is a work in progress. What you have there with your maths function simulation is a single interference between two sources. These two sources carry encoded information from the 1/2 space on the laser side of the cavity. You have simplified this function somewhat by saying this can be represented by just two equally bright secondary sources that now become the source for the other 1/2 space by being a transform of the primary source.
In "general" these secondary sources could be equivalent to two single correlated spherical sources separated by that slit distance way way out in space only Young's Double Slit presents this as a 1/2 space pair of sources on a plane wall. The function would need to be generalized to be a three dimensional complex function instead of the one dimensional function you have there. In a very large "dark room cavity" other mirrors exist which are other "particles" or assemblies of "particles". These are likewise secondary sources just like the two you have nominated to process. While still recalling the fact that this is all inside each and every photon you may add secondary correlated "mirrors" from all surfaces within that "room" which sum with the first two secondary sources to carry additional information. This is the "seeking all paths" information that is missing from normal treatments. Instantaneously these secondary reflections are only a "statement" about the shape of the room at that one frequency. The distances between all secondary sources is like a three dimensional expression of the distance between all those "pinhole" sources of a very large number of distributed secondary mirror sources. In reality they are three dimensional sources. This represents a standing wave solution of the cavity at that nominated frequency. A single photon can be simply represented as that sync function which has a description as the Harmonic Oscillator for the upper sideband only. The source of coherent illumination propagates into the "dark room" with a mode characteristic of the source...
These have both transverse and longitudinal modes of propagation... The source supplies transverse modes as shown above. These are the result of collimation of the source that in turn "illuminates" the structure, in some cases being absorbed and in others cases reflected or transmitted.
This has a wave function solution at each of the harmonic frequencies that is always there.
Admittedly this is an illustration of "sound" not "light" but optical cavities have a similar mostly unseen response.
http://en.wikipedia.org/wiki/Cymatics
This is the result of matter waves forming standing waves in this cavity even when there is no "illumination" by photons. The matter waves are the underlying reality that we think of as matter. Potentially you could determine this "structure" through direct calculation or through experimentally probing the volumetric space like this...
This is a solution of Shrödinger's Wave Equation (... or Dirac's Wave Equation) for the cavity, for a single excitation frequency (or interference). As you might gather these "states" of the cavity are all superimposed and simply grade imperceptibly into the walls and pervade through all reachable space. Where these interferences cannot reach represent boundaries to our dimensions. These interferences exist one on top of the other like this sonogram of a violin excitation spectrum...
Once again this is sound but illustrates the principle for sound of the base frequency along the bottom row and the harmonically related "resonances" additional to the primary frequency.
These represent electromagnetic phenomena that ultimately underly all atomic theory such as solutions for the Hydrogen Atom (stripped of electrons and photons). For ordinary phenomena the information from sources cannot be transferred from within the evanescent region using ordinary electromagnetic theory. The source information remains behind in that evanescent region and this band limits the behavior of photons. Perfect copies of the sources were never thought possible and this was built into the quantum mechanics at the bottom level axiomatically. Information that was thought to be forever lost. What was not understood was the essential underlying negative refractive index of primary "spacetime" that is taking this electromagnetic signature as a template for primary geometry. These provide "perfect lenses" for what seemed an otherwise imperfect Universe. These are regions where the electric permitivity and magnetic susceptibility both take on negative values.
In "general" these secondary sources could be equivalent to two single correlated spherical sources separated by that slit distance way way out in space only Young's Double Slit presents this as a 1/2 space pair of sources on a plane wall. The function would need to be generalized to be a three dimensional complex function instead of the one dimensional function you have there. In a very large "dark room cavity" other mirrors exist which are other "particles" or assemblies of "particles". These are likewise secondary sources just like the two you have nominated to process. While still recalling the fact that this is all inside each and every photon you may add secondary correlated "mirrors" from all surfaces within that "room" which sum with the first two secondary sources to carry additional information. This is the "seeking all paths" information that is missing from normal treatments. Instantaneously these secondary reflections are only a "statement" about the shape of the room at that one frequency. The distances between all secondary sources is like a three dimensional expression of the distance between all those "pinhole" sources of a very large number of distributed secondary mirror sources. In reality they are three dimensional sources. This represents a standing wave solution of the cavity at that nominated frequency. A single photon can be simply represented as that sync function which has a description as the Harmonic Oscillator for the upper sideband only. The source of coherent illumination propagates into the "dark room" with a mode characteristic of the source...
These have both transverse and longitudinal modes of propagation... The source supplies transverse modes as shown above. These are the result of collimation of the source that in turn "illuminates" the structure, in some cases being absorbed and in others cases reflected or transmitted.
This has a wave function solution at each of the harmonic frequencies that is always there.
Admittedly this is an illustration of "sound" not "light" but optical cavities have a similar mostly unseen response.
http://en.wikipedia.org/wiki/Cymatics
This is the result of matter waves forming standing waves in this cavity even when there is no "illumination" by photons. The matter waves are the underlying reality that we think of as matter. Potentially you could determine this "structure" through direct calculation or through experimentally probing the volumetric space like this...
This is a solution of Shrödinger's Wave Equation (... or Dirac's Wave Equation) for the cavity, for a single excitation frequency (or interference). As you might gather these "states" of the cavity are all superimposed and simply grade imperceptibly into the walls and pervade through all reachable space. Where these interferences cannot reach represent boundaries to our dimensions. These interferences exist one on top of the other like this sonogram of a violin excitation spectrum...
Once again this is sound but illustrates the principle for sound of the base frequency along the bottom row and the harmonically related "resonances" additional to the primary frequency.
These represent electromagnetic phenomena that ultimately underly all atomic theory such as solutions for the Hydrogen Atom (stripped of electrons and photons). For ordinary phenomena the information from sources cannot be transferred from within the evanescent region using ordinary electromagnetic theory. The source information remains behind in that evanescent region and this band limits the behavior of photons. Perfect copies of the sources were never thought possible and this was built into the quantum mechanics at the bottom level axiomatically. Information that was thought to be forever lost. What was not understood was the essential underlying negative refractive index of primary "spacetime" that is taking this electromagnetic signature as a template for primary geometry. These provide "perfect lenses" for what seemed an otherwise imperfect Universe. These are regions where the electric permitivity and magnetic susceptibility both take on negative values.
QUOTE (Wikipedia: Metamaterial - Negative refractive index+)
Although the optical properties of a transparent material are fully specified by the parameters ε and μ, in practice the refractive index N is often used. N may be determined from 
All known transparent materials possess positive values for ε and μ. By convention the positive square root is used for N.
However, some engineered metamaterials have ε < 0 and μ < 0; because the product εμ is positive, N is real. Under such circumstances, it is necessary to take the negative square root for N. Physicist Victor Veselago proved that such substances can transmit light.
Metamaterials with negative N have numerous startling properties:
* Snell's law (N1sinθ1 = N2sinθ2) still applies, but as N2 is negative, the rays will be refracted on the same side of the normal on entering the material.
* The Doppler shift is reversed (that is, a light source moving toward an observer appears to reduce its frequency)
* Cherenkov radiation points the other way
* The time-averaged Poynting vector is antiparallel to phase velocity. This means that unlike a normal right-handed material, the wave fronts are moving in the opposite direction to the flow of energy.
For plane waves propagating in such metamaterials, the electric field, magnetic field and Poynting vector (or group velocity) follow a left-hand rule, thus giving rise to the name left-handed (meta)materials. It should be noted that the terms left-handed and right-handed can also arise in the study of chiral media, however this is an unrelated effect.
The effect of negative refraction is analogous to wave propagation in a left-handed transmission line, and such structures have been used to verify some of the effects described here.
http://en.wikipedia.org/wiki/Negative_refraction
All known transparent materials possess positive values for ε and μ. By convention the positive square root is used for N.However, some engineered metamaterials have ε < 0 and μ < 0; because the product εμ is positive, N is real. Under such circumstances, it is necessary to take the negative square root for N. Physicist Victor Veselago proved that such substances can transmit light.
Metamaterials with negative N have numerous startling properties:
* Snell's law (N1sinθ1 = N2sinθ2) still applies, but as N2 is negative, the rays will be refracted on the same side of the normal on entering the material.
* The Doppler shift is reversed (that is, a light source moving toward an observer appears to reduce its frequency)
* Cherenkov radiation points the other way
* The time-averaged Poynting vector is antiparallel to phase velocity. This means that unlike a normal right-handed material, the wave fronts are moving in the opposite direction to the flow of energy.
For plane waves propagating in such metamaterials, the electric field, magnetic field and Poynting vector (or group velocity) follow a left-hand rule, thus giving rise to the name left-handed (meta)materials. It should be noted that the terms left-handed and right-handed can also arise in the study of chiral media, however this is an unrelated effect.
The effect of negative refraction is analogous to wave propagation in a left-handed transmission line, and such structures have been used to verify some of the effects described here.
http://en.wikipedia.org/wiki/Negative_refraction
You can understand if spacetime had complementary properties for ε < 0 and μ < 0 (in particular where they have the value of -1 in a vacuum then the speed of light is unaltered but the properties of the space is "anomalous" resulting in reciprocal properties. Presently metamaterials are undergoing incredible technical developments resulting in optical cloaks and electromagnetic wormholes and other photonic properties such as optical anti-matter and electromagnetic induced transparency. It is no wonder that the properties of these materials attempt to form lenses with “perfect” properties that communicate source information to other places with or without magnification as “real images” or "virtual particles" that actually translate the physics of the primary event to the other alternate location, this is because the physics is actually only the action of "virtual photons". We have previously discussed Quantum Corrals and Kondo Phantoms and other quantum mirages. These are so real that they can actually partake in chemical reactions with real molecules. Because they are only images you can create as many of these as you want or need. You may want to research some of this background...
Remember folks .... work in progress. Comments welcome.
Cheers
QUOTE
A spherical perfect lens
Authors: S. Anantha Ramakrishna (IIT, Kanpur), J.B. Pendry (Imperial College London)
(Submitted on 10 Nov 2003)
It has been recently proved that a slab of negative refractive index material acts as a perfect lens in that it makes accessible the sub-wavelength image information contained in the evanescent modes of a source. Here we elaborate on perfect lens solutions to spherical shells of negative refractive material where magnification of the near-field images becomes possible. The negative refractive materials then need to be spatially dispersive with ε® = 1/r and μ® = 1/r. We concentrate on lens-like solutions for the extreme near-field limit. Then the conditions for the TM and TE polarized modes become independent of ε and μ respectively.
Comments:
Revtex4, 9 pages, 2 figures (eps)
Subjects:
Disordered Systems and Neural Networks (cond-mat.dis-nn)
Cite as:
arXiv:cond-mat/0311203v1 [cond-mat.dis-nn]
Submission history
From: S. Anantha Ramakrishna [view email]
[v1] Mon, 10 Nov 2003 08:30:11 GMT (16kb)
http://arxiv.org/abs/cond-mat/0311203
What works for “spherical solutions” will also work for any other solutions as well including all shells ... s, p, d, f etc. These are all optical cavities and also relate to the structure filling and surrounding the cavity at different frequencies. Note the speed of light in a vacuum remains C but we can vary between regions of positive and negative refractive space depending on the "optical curvature" being positive or negative. Between the two regions the refractive index may vary (in free space) between positive and negative. Remember this was one of the consequences of Dr. Taco Visser's studies. Sufficiently optically curved regions of spacetime result in "bright matter solitons" and instantons connect the surface as described in the literature. These behave as deBroglie Waves and are intimately related to Special Relativity and exhibit "mass". This geometry has overall "anti-symmetric" symmetry but all gravity describe regions of arbitrarily positive curvature only. With a continuous theory of the quantum there is no longer the need to quantize the manifold and so this is a huge simplification and has the potential to unify gravity with the other "electromagnetic" forces in nature. This changes nothing in many other respects leaving intact current theory as a subset of a more complete description.Authors: S. Anantha Ramakrishna (IIT, Kanpur), J.B. Pendry (Imperial College London)
(Submitted on 10 Nov 2003)
It has been recently proved that a slab of negative refractive index material acts as a perfect lens in that it makes accessible the sub-wavelength image information contained in the evanescent modes of a source. Here we elaborate on perfect lens solutions to spherical shells of negative refractive material where magnification of the near-field images becomes possible. The negative refractive materials then need to be spatially dispersive with ε® = 1/r and μ® = 1/r. We concentrate on lens-like solutions for the extreme near-field limit. Then the conditions for the TM and TE polarized modes become independent of ε and μ respectively.
Comments:
Revtex4, 9 pages, 2 figures (eps)
Subjects:
Disordered Systems and Neural Networks (cond-mat.dis-nn)
Cite as:
arXiv:cond-mat/0311203v1 [cond-mat.dis-nn]
Submission history
From: S. Anantha Ramakrishna [view email]
[v1] Mon, 10 Nov 2003 08:30:11 GMT (16kb)
http://arxiv.org/abs/cond-mat/0311203
Remember folks .... work in progress. Comments welcome.
Cheers
GE,
I liked your discussion. I think that we agree that the nature of "space"/vacuum
has a negative index of refraction, while most physical matter possesses a positive
index of refraction.
If correct, this implies that "space"/vacuum must have some baseline
threshold energy level that complements and promotes energy transfer thru it,
unless EM energy itself possesses a negative index of refraction. This concept
could be very radical.
Your thoughts?
LL
I liked your discussion. I think that we agree that the nature of "space"/vacuum
has a negative index of refraction, while most physical matter possesses a positive
index of refraction.
If correct, this implies that "space"/vacuum must have some baseline
threshold energy level that complements and promotes energy transfer thru it,
unless EM energy itself possesses a negative index of refraction. This concept
could be very radical.
Your thoughts?
LL
Hi Good Elf,
QUOTE (GE+)
This is where I turn "radical" and suggest that quantum phenomena are ultimately entirely resolvable in terms of these "interferences" that represent the geometry of the space and are independent of the actual source of illumination (sources... primary and secondary).
If you are referring to the DSE then the 'ray' maths model gives a good match to the experimental results.
An experiment that is insensitive to a particular variable is probably not the best experiment to choose to demonstrate the significance of such a variable.
The transform arises somewhat accidentally as a result of integrating e^(ix) across the width of the slit - this just happens to be the Fourier transform of the slit (by definition). Having established the principle it is now easy to add in extra sources, phase changes, amplitude changes and so on. The e^(ix) is the excitation .. the analysis implicitly assumes a plane wave and Huygens type spreading at the slit. I can try to lay a plot on top of the Teachspin results if you wish - my guess is it will be a very good match. We could tweak the analysis to allow for a point source at (say) 1 meter from the slits instead of a plane wave - but do you honestly think it would make a noticeable difference?
The transform arises somewhat accidentally as a result of integrating e^(ix) across the width of the slit - this just happens to be the Fourier transform of the slit (by definition). Having established the principle it is now easy to add in extra sources, phase changes, amplitude changes and so on. The e^(ix) is the excitation .. the analysis implicitly assumes a plane wave and Huygens type spreading at the slit. I can try to lay a plot on top of the Teachspin results if you wish - my guess is it will be a very good match. We could tweak the analysis to allow for a point source at (say) 1 meter from the slits instead of a plane wave - but do you honestly think it would make a noticeable difference?
This represents a standing wave solution of the cavity at that nominated frequency. A single photon can be simply represented as that sync function which has a description as the Harmonic Oscillator for the upper sideband only. The source of coherent illumination propagates into the "dark room" with a mode characteristic of the source...
Again .. the DSE does not seem to be the right experiment to demonstrate the significance of this claim.
Many of the new materials and phenomena seem (to me) to involve resonances and many photons - this is a known way round the HUP .. effectively using many measurements to reduce the uncertainty inherent in a single measurement. The results may be 'not wrong' but they may also be unhelpful and some claims may seek to mislead.
We need an agreed mathematical model to test the performance of photons. If janrinze is willing to help then this is WIP.
Best wishes,
-C2.
If you are referring to the DSE then the 'ray' maths model gives a good match to the experimental results.
An experiment that is insensitive to a particular variable is probably not the best experiment to choose to demonstrate the significance of such a variable.
QUOTE
You have simplified this function somewhat by saying this can be represented by just two equally bright secondary sources that now become the source for the other 1/2 space by being a transform of the primary source.
The transform arises somewhat accidentally as a result of integrating e^(ix) across the width of the slit - this just happens to be the Fourier transform of the slit (by definition). Having established the principle it is now easy to add in extra sources, phase changes, amplitude changes and so on. The e^(ix) is the excitation .. the analysis implicitly assumes a plane wave and Huygens type spreading at the slit. I can try to lay a plot on top of the Teachspin results if you wish - my guess is it will be a very good match. We could tweak the analysis to allow for a point source at (say) 1 meter from the slits instead of a plane wave - but do you honestly think it would make a noticeable difference?
QUOTE (->
| QUOTE |
| You have simplified this function somewhat by saying this can be represented by just two equally bright secondary sources that now become the source for the other 1/2 space by being a transform of the primary source. |
The transform arises somewhat accidentally as a result of integrating e^(ix) across the width of the slit - this just happens to be the Fourier transform of the slit (by definition). Having established the principle it is now easy to add in extra sources, phase changes, amplitude changes and so on. The e^(ix) is the excitation .. the analysis implicitly assumes a plane wave and Huygens type spreading at the slit. I can try to lay a plot on top of the Teachspin results if you wish - my guess is it will be a very good match. We could tweak the analysis to allow for a point source at (say) 1 meter from the slits instead of a plane wave - but do you honestly think it would make a noticeable difference?
This represents a standing wave solution of the cavity at that nominated frequency. A single photon can be simply represented as that sync function which has a description as the Harmonic Oscillator for the upper sideband only. The source of coherent illumination propagates into the "dark room" with a mode characteristic of the source...
Again .. the DSE does not seem to be the right experiment to demonstrate the significance of this claim.
Many of the new materials and phenomena seem (to me) to involve resonances and many photons - this is a known way round the HUP .. effectively using many measurements to reduce the uncertainty inherent in a single measurement. The results may be 'not wrong' but they may also be unhelpful and some claims may seek to mislead.
We need an agreed mathematical model to test the performance of photons. If janrinze is willing to help then this is WIP.
Best wishes,
-C2.
janrinze,
This is a link into a John Baez thread - usually worth following http://www.lns.cornell.edu/spr/1999-02/msg0014603.html
Best wishes,
-C2.
This is a link into a John Baez thread - usually worth following http://www.lns.cornell.edu/spr/1999-02/msg0014603.html
Best wishes,
-C2.
QUOTE (Confused2+May 8 2007, 11:35 PM)
janrinze,
This is a link into a John Baez thread - usually worth following http://www.lns.cornell.edu/spr/1999-02/msg0014603.html
Best wishes,
-C2.
Hi C2,
from a mathematical perspective these statements made by John Baez are completely correct (as one would indeed presume with a man of his caliber)
There remains a more philosophical question whether the universe is a perfectly logical construct. Mathematics are 'perfect' in the sense of completely logical and deterministic environments (disputable though..) but reality seems to have some strange aces up its sleeve. The Fourier transform shows that any signal can be made up of a (infinite) series of sines and cosines. IF frequencies can be infinite and wavelengths can be below the planck constant this would be perfectly ok. (remains the problem of 'photons' with infinite energies..) Apart from those philosophical questions these are very powerful tools to describe and calculate QM effects.
To add to the reasoning done by John Baez, there should be waves of all frequencies everywhere adding to an infinite amount of energy or simply zero energy.. depending on whether a wave has any energy or none. And a 'holographic' universe as in an infinite interference pattern of all frequencies in all phases should be an interesting interpretation..
leaves one question: can all functions be fourier transformed? how about discontinuous functions or explicit non periodical functions like sin(x^2)?
I am not an expert on these matters so I may be completely off the chart on this one. However within my knowledge the descriptions of QM, Relativity, Quantum field theory and more, are complex mathematical constructs which fit current experiments but fail to be consistent over the 'full domain' They zoom in on parts of the puzzle and describe the pieces very accurately. The image depicted by the puzzle itself remains a mistery i.m.h.o.
On the part where we would talk about wavepackets the matter is debatable from the parspective of 'what is a photon' but the same can be said about electrons, protons etc. If we do our math with either a wavelet (my preference) or continuous sinewaves the result will be the same. The DS experiment has no different results but if we want to create a hologram the rules are a bit different. The speed of light itself combined with the temporal coherence becomes a measure of the maximum volumetric size of the holograpic image. This should violate the idea that photons should be seen as infinite length 'particles that 'touch' everything at once and interfere only with themselves on a photographic plate.
Guess I could say it does not add up for me yet ..
Jan Rinze.
This is a link into a John Baez thread - usually worth following http://www.lns.cornell.edu/spr/1999-02/msg0014603.html
Best wishes,
-C2.
Hi C2,
from a mathematical perspective these statements made by John Baez are completely correct (as one would indeed presume with a man of his caliber)
There remains a more philosophical question whether the universe is a perfectly logical construct. Mathematics are 'perfect' in the sense of completely logical and deterministic environments (disputable though..) but reality seems to have some strange aces up its sleeve. The Fourier transform shows that any signal can be made up of a (infinite) series of sines and cosines. IF frequencies can be infinite and wavelengths can be below the planck constant this would be perfectly ok. (remains the problem of 'photons' with infinite energies..) Apart from those philosophical questions these are very powerful tools to describe and calculate QM effects.
To add to the reasoning done by John Baez, there should be waves of all frequencies everywhere adding to an infinite amount of energy or simply zero energy.. depending on whether a wave has any energy or none. And a 'holographic' universe as in an infinite interference pattern of all frequencies in all phases should be an interesting interpretation..
leaves one question: can all functions be fourier transformed? how about discontinuous functions or explicit non periodical functions like sin(x^2)?
I am not an expert on these matters so I may be completely off the chart on this one. However within my knowledge the descriptions of QM, Relativity, Quantum field theory and more, are complex mathematical constructs which fit current experiments but fail to be consistent over the 'full domain' They zoom in on parts of the puzzle and describe the pieces very accurately. The image depicted by the puzzle itself remains a mistery i.m.h.o.
On the part where we would talk about wavepackets the matter is debatable from the parspective of 'what is a photon' but the same can be said about electrons, protons etc. If we do our math with either a wavelet (my preference) or continuous sinewaves the result will be the same. The DS experiment has no different results but if we want to create a hologram the rules are a bit different. The speed of light itself combined with the temporal coherence becomes a measure of the maximum volumetric size of the holograpic image. This should violate the idea that photons should be seen as infinite length 'particles that 'touch' everything at once and interfere only with themselves on a photographic plate.
Guess I could say it does not add up for me yet ..
Jan Rinze.
Hi Jan,
It appears that there are some questions about the physical nature and
structure of a photon.
Do you agree that a propagating photon travels as energy in the form of a wave
and radiates from an atomic dipole source?
If you agree to this concept then we should be able to apply known physical wave
dynamics as a likely mechanism to explain how the wave energy of a photon
acts and responds when interacting with physical "obstructions".
I will review some common traits of waves to illustrate similarities that should
be consistent and applicable to photons.
1. Waves radiate radially/spherically from a centerpoint of physical disturbance
in a medium and have complementary vertical and lateral energy
displacements that sustain wave propagation.
2. Waves are the displacement of energy that propagate at a fixed speed which
depends on the energy characteristics of the medium in which they are
travelling.
3. Propagating wave energy follows the rule of the ISL.
4. Waves propagate uniformly until they are influenced/blocked by a fixed physical
obstruction with a higher net energy content.
5. Waves will reflect back onto themselves, slow down, speed up, or divert the
direction of their travel when influenced by a physical obstruction or a change
of medium.
6. Wave energy will distribute itself uniformly in all directions as long as the
medium and geometry in which it is propagating is consistent. If the physical
geometry receiving the wave energy changes then the wave will
change/conform to match the shape of the geometry obstructing its path and
will attempt to flow around the obstruction and continue to uniformly radiate
its energy content.
7. A wave will change its propagation characteristics including its size, direction,
speed and shape to accomodate a change of physical geometry of the
medium in which the wave energy is propagating. When meeting an obstruction
that blocks its forward propagation (at right angles) it will reflect back toward
the source.
8. The energy contained in a wavefront is coherent with itself and it can interfere
with itself if its direction of propagation or timing is altered when influenced by
a physical obstruction or change of geometry that redirects the wave energy
from different directions.
I have probably missed/overlooked a few other wave characteristics that should
be included.
If we agree that a photon has wave characteristics then it should follow the
basic attributes listed above.
Energy always distributes itself into its surrounding environment over some
interval of time and responds to the physical characteristics of that environment.
Discrete photons have their own origination time stamp and do not interfere with
other photons in free space unless the energy that they individually possess
superpose across a physical "catalyst" that can absorb the total energy applied.
Comments, discussion, disagreement?
LL
QUOTE
On the part where we would talk about wavepackets the matter is debatable from the parspective of 'what is a photon' but the same can be said about electrons, protons etc....
The speed of light itself combined with the temporal coherence becomes a measure of the maximum volumetric size of the holograpic image. This should violate the idea that photons should be seen as infinite length 'particles that 'touch' everything at once and interfere only with themselves on a photographic plate.
The speed of light itself combined with the temporal coherence becomes a measure of the maximum volumetric size of the holograpic image. This should violate the idea that photons should be seen as infinite length 'particles that 'touch' everything at once and interfere only with themselves on a photographic plate.
It appears that there are some questions about the physical nature and
structure of a photon.
Do you agree that a propagating photon travels as energy in the form of a wave
and radiates from an atomic dipole source?
If you agree to this concept then we should be able to apply known physical wave
dynamics as a likely mechanism to explain how the wave energy of a photon
acts and responds when interacting with physical "obstructions".
I will review some common traits of waves to illustrate similarities that should
be consistent and applicable to photons.
1. Waves radiate radially/spherically from a centerpoint of physical disturbance
in a medium and have complementary vertical and lateral energy
displacements that sustain wave propagation.
2. Waves are the displacement of energy that propagate at a fixed speed which
depends on the energy characteristics of the medium in which they are
travelling.
3. Propagating wave energy follows the rule of the ISL.
4. Waves propagate uniformly until they are influenced/blocked by a fixed physical
obstruction with a higher net energy content.
5. Waves will reflect back onto themselves, slow down, speed up, or divert the
direction of their travel when influenced by a physical obstruction or a change
of medium.
6. Wave energy will distribute itself uniformly in all directions as long as the
medium and geometry in which it is propagating is consistent. If the physical
geometry receiving the wave energy changes then the wave will
change/conform to match the shape of the geometry obstructing its path and
will attempt to flow around the obstruction and continue to uniformly radiate
its energy content.
7. A wave will change its propagation characteristics including its size, direction,
speed and shape to accomodate a change of physical geometry of the
medium in which the wave energy is propagating. When meeting an obstruction
that blocks its forward propagation (at right angles) it will reflect back toward
the source.
8. The energy contained in a wavefront is coherent with itself and it can interfere
with itself if its direction of propagation or timing is altered when influenced by
a physical obstruction or change of geometry that redirects the wave energy
from different directions.
I have probably missed/overlooked a few other wave characteristics that should
be included.
If we agree that a photon has wave characteristics then it should follow the
basic attributes listed above.
Energy always distributes itself into its surrounding environment over some
interval of time and responds to the physical characteristics of that environment.
Discrete photons have their own origination time stamp and do not interfere with
other photons in free space unless the energy that they individually possess
superpose across a physical "catalyst" that can absorb the total energy applied.
Comments, discussion, disagreement?
LL
Hi LL,
I am curious about the fact that you propose that photons can only interfere with themselves.
This would only be so if they would be in different 'planes' so the actual wavefronts are not in the same dimension or something..
With two waves coming from different two sources but both have the same wavelength there is intereference between those two waves (can be verified within various media)
So what makes light different in this aspect?
Jan Rinze.
P.S. the rest of all the points I agree with, it shows wave theory is n't that difficult i.m.h.o.
I am curious about the fact that you propose that photons can only interfere with themselves.
This would only be so if they would be in different 'planes' so the actual wavefronts are not in the same dimension or something..
With two waves coming from different two sources but both have the same wavelength there is intereference between those two waves (can be verified within various media)
So what makes light different in this aspect?
Jan Rinze.
P.S. the rest of all the points I agree with, it shows wave theory is n't that difficult i.m.h.o.
Hi Jan,
Here is a still image of an event that happened 6000 light years ago as seen by
the Hubble Space Telescope. All of the individual photons emitted were detected
as a detailed composite picture of the event that occurred then. Even though
the photons travelled a tremendous distance and crossed thru innumerable
photons enroute, there is no observable interference caused by photons
crossing. No interference occured to disturb the perfect clarity of the image.
Each photon has its own discrete time stamp and internal phasing. For
constructive or destructive interference to occur the wave phasing must be exactly
the same at fixed points in space. Waves can superpose at random coincidental
points in space, but the energy they contain continues propagating unobstructed
from the source.
Some applets:
http://id.mind.net/~zona/mstm/physics/wave...erference2.html
http://www.walter-fendt.de/ph14e/beats.htm
http://webphysics.davidson.edu/applets/Sou...t/SoundOut.html
Wave energy only collapses when it resonantly couples the force it is carrying to
displace matter, that is the point of 'detection". It is the transition in time when the
potential energy of stationary mass is influenced by the kinetic energy of
wave movement. Energy conversion takes place as wave energy induces a
change in the physical location of mass and "work" is accomplished.
Some of my previous "arguments":
http://forum.physorg.com/index.php?showtop...45&#entry154526
http://forum.physorg.com/index.php?act=ST&...ndpost&p=154399
Comments? Discussion? Alternative views?
LL
Here is a still image of an event that happened 6000 light years ago as seen by
the Hubble Space Telescope. All of the individual photons emitted were detected
as a detailed composite picture of the event that occurred then. Even though
the photons travelled a tremendous distance and crossed thru innumerable
photons enroute, there is no observable interference caused by photons
crossing. No interference occured to disturb the perfect clarity of the image.
Each photon has its own discrete time stamp and internal phasing. For
constructive or destructive interference to occur the wave phasing must be exactly
the same at fixed points in space. Waves can superpose at random coincidental
points in space, but the energy they contain continues propagating unobstructed
from the source.
Some applets:
http://id.mind.net/~zona/mstm/physics/wave...erference2.html
http://www.walter-fendt.de/ph14e/beats.htm
http://webphysics.davidson.edu/applets/Sou...t/SoundOut.html
Wave energy only collapses when it resonantly couples the force it is carrying to
displace matter, that is the point of 'detection". It is the transition in time when the
potential energy of stationary mass is influenced by the kinetic energy of
wave movement. Energy conversion takes place as wave energy induces a
change in the physical location of mass and "work" is accomplished.
Some of my previous "arguments":
http://forum.physorg.com/index.php?showtop...45&#entry154526
http://forum.physorg.com/index.php?act=ST&...ndpost&p=154399
Comments? Discussion? Alternative views?
LL
Hi LL,
I do not see why interference implies collapse of a wavefunction. At the null nodes of the interference pattern you will not find any photons so none collapse there...
On top of that there is no reason for an interference pattern in the hubble telescope since none of the stars are coherent with each other...
Baffles me why you use that as an argument.
Interference has nothing to do with a stable pattern! The interference is there but integrated over the exposure time of the hubble image there can not be any visible interference pattern present.. The method of creating a picture of incoming light is far different from setting-up a plate in space and capture all incoming photons. It involves lenses and mirrors to converge the incoming waves to a point. If we do this we get amplification of the wavefronts that fit with the design of the lens/mirror setup.
so could you please explain your thoughts on this and if possible make it quantifyable through some theory or maths?
Jan Rinze.
P.S. the links you added clearly support my thoughts in this , see constructive and destructive interference in the documentation from the first link..
P.P.S. I found this link, the abstract shows that two photons from different sources CAN interfere. http://www.springerlink.com/content/h43732112402037t/
I do not see why interference implies collapse of a wavefunction. At the null nodes of the interference pattern you will not find any photons so none collapse there...
On top of that there is no reason for an interference pattern in the hubble telescope since none of the stars are coherent with each other...
Baffles me why you use that as an argument.
Interference has nothing to do with a stable pattern! The interference is there but integrated over the exposure time of the hubble image there can not be any visible interference pattern present.. The method of creating a picture of incoming light is far different from setting-up a plate in space and capture all incoming photons. It involves lenses and mirrors to converge the incoming waves to a point. If we do this we get amplification of the wavefronts that fit with the design of the lens/mirror setup.
so could you please explain your thoughts on this and if possible make it quantifyable through some theory or maths?
Jan Rinze.
P.S. the links you added clearly support my thoughts in this , see constructive and destructive interference in the documentation from the first link..
P.P.S. I found this link, the abstract shows that two photons from different sources CAN interfere. http://www.springerlink.com/content/h43732112402037t/
Hi LL,
another strong piece of evidence of two photons that can interfere is the implementation of the 'beat' modes you reference to in the second link.
These too are possible with two light sources. This would be absolutely impossible if two photons cannot interfere with each other.
So I would like to change your list and say that photons can interfere just like any other wave phenomenon with themselves as well as with other photons. On the quantum scale things do get more weird because identical photons emitted from two separate sources can coalese. This is not part of normal wave theory i.m.h.o.
Next to that a two photon interference pattern yields a detection of two photons at the same location. That also is pretty weird.
the part where you wrote:
Each photon has its own discrete time stamp and internal phasing. For
constructive or destructive interference to occur the wave phasing must be exactly
the same at fixed points in space. Waves can superpose at random coincidental
points in space, but the energy they contain continues propagating unobstructed
from the source.
is missing the understanding that destructive interference does not mean that the waves cannot propagate beyond a point of destructive interference. It just means that it is not possible to detect any wave at that point (and time), the waves are just passing 'through' each other and the energy is never 'lost'.
Your statement of 'fixed points' in space would result in a form of absolute reference frame and therefore would violate (special) relativity.
Maybe I should be a little more lenient and say that your notion of superposition has been disconnected from the word 'interference' but they imply the same thing..
Jan Rinze.
P.S. this is not an attempt to bash you with my arguments. As an extra please read this article: http://hal.archives-ouvertes.fr/docs/00/10...ature_arXiv.pdf
another strong piece of evidence of two photons that can interfere is the implementation of the 'beat' modes you reference to in the second link.
These too are possible with two light sources. This would be absolutely impossible if two photons cannot interfere with each other.
So I would like to change your list and say that photons can interfere just like any other wave phenomenon with themselves as well as with other photons. On the quantum scale things do get more weird because identical photons emitted from two separate sources can coalese. This is not part of normal wave theory i.m.h.o.
Next to that a two photon interference pattern yields a detection of two photons at the same location. That also is pretty weird.
the part where you wrote:
QUOTE
Each photon has its own discrete time stamp and internal phasing. For
constructive or destructive interference to occur the wave phasing must be exactly
the same at fixed points in space. Waves can superpose at random coincidental
points in space, but the energy they contain continues propagating unobstructed
from the source.
is missing the understanding that destructive interference does not mean that the waves cannot propagate beyond a point of destructive interference. It just means that it is not possible to detect any wave at that point (and time), the waves are just passing 'through' each other and the energy is never 'lost'.
Your statement of 'fixed points' in space would result in a form of absolute reference frame and therefore would violate (special) relativity.
Maybe I should be a little more lenient and say that your notion of superposition has been disconnected from the word 'interference' but they imply the same thing..
Jan Rinze.
P.S. this is not an attempt to bash you with my arguments. As an extra please read this article: http://hal.archives-ouvertes.fr/docs/00/10...ature_arXiv.pdf
Hi Jan
I do feel we haven't really got very far on this thread. I don't know how much time you would want to put into this thread - I can only say (from experience) that the more time you put in the more you get out of it - but you lose the time.
My suggestion would be that we start again at the source, give our ideas for what is happening there, through the first slit .. ideas again .. then the two slits and on to the (known) result. If there is anything wrong on the way then we should be predicting the wrong result .. if we have no predictions that match the result then we go round again.
My feeling is that the FT trick was fun but hides (imho reveals) the physical significance of what is actually happening. I would predict that a full wavelet analysis based on the assumed(?) value of the FT analysis will fail .
Imho properly played cards will inevitably take us into QFT and the Standard Model. But they have to be properly played.
Best wishes,
-C2.
I do feel we haven't really got very far on this thread. I don't know how much time you would want to put into this thread - I can only say (from experience) that the more time you put in the more you get out of it - but you lose the time.
My suggestion would be that we start again at the source, give our ideas for what is happening there, through the first slit .. ideas again .. then the two slits and on to the (known) result. If there is anything wrong on the way then we should be predicting the wrong result .. if we have no predictions that match the result then we go round again.
My feeling is that the FT trick was fun but hides (imho reveals) the physical significance of what is actually happening. I would predict that a full wavelet analysis based on the assumed(?) value of the FT analysis will fail .
Imho properly played cards will inevitably take us into QFT and the Standard Model. But they have to be properly played.
Best wishes,
-C2.
Hi C2,
I am not sure what you mean. The interference pattern is a superposition of waves. This can be computed quite easily. the fourier transform just happens as a result of integration and therefore is not a real surprise. (the definition of the fourier transform looks very similar to what is needed to calculate the interference pattern.)
Since the waves from both slits are coherent and the path lenght differences are within a few wavelengths there are no time dependent components necessary.
I will try and create a better and more precise formula which describes the interference pattern and which you can plot on the pgc.
The next step is to get back to the point where we try and reason our way into a 'which way' argument.
Jan Rinze.
I am not sure what you mean. The interference pattern is a superposition of waves. This can be computed quite easily. the fourier transform just happens as a result of integration and therefore is not a real surprise. (the definition of the fourier transform looks very similar to what is needed to calculate the interference pattern.)
Since the waves from both slits are coherent and the path lenght differences are within a few wavelengths there are no time dependent components necessary.
I will try and create a better and more precise formula which describes the interference pattern and which you can plot on the pgc.
The next step is to get back to the point where we try and reason our way into a 'which way' argument.
Jan Rinze.
Hi Jan,
QUOTE (JR+)
Since the waves from both slits are coherent and the path length differences are within a few wavelengths there are no time dependent components necessary.
I consider the DSE in the light of the Kennedy Thorndike (1932) experiment ( http://en.wikipedia.org/wiki/Kennedy-Thorndike_experiment ) . Unfortunately the original paper is still a pay and display item so I can't say how different the path lengths were. In the context that the K-T experiment was looking for Aether drift I guess the path length difference must have been of the order of a meter to have any physical significance. Obviously this is a guess - but if the guess is remotely correct we have interference over a considerable distance even from a non-laser source. Unproven - no evidence offered at this stage - dispute invited - is that the same interference effect would exist between paths from an individual photon from a star if the path has been divided by (say) a massive object - the path difference could be many light years - I would still back the sum over paths to give the right answer - would you?
Best wishes,
-C2.
I consider the DSE in the light of the Kennedy Thorndike (1932) experiment ( http://en.wikipedia.org/wiki/Kennedy-Thorndike_experiment ) . Unfortunately the original paper is still a pay and display item so I can't say how different the path lengths were. In the context that the K-T experiment was looking for Aether drift I guess the path length difference must have been of the order of a meter to have any physical significance. Obviously this is a guess - but if the guess is remotely correct we have interference over a considerable distance even from a non-laser source. Unproven - no evidence offered at this stage - dispute invited - is that the same interference effect would exist between paths from an individual photon from a star if the path has been divided by (say) a massive object - the path difference could be many light years - I would still back the sum over paths to give the right answer - would you?
Best wishes,
-C2.
Hi Jan,
It appears that we have a difference of "philosophy" about wave interference vs.
wave superposition. Perhaps it is just semantics..... I will read your posts
again and give them more contemplation.
Interference implies that if you move along the line of sight from the source
that at some point(s) you will observe interference where the superposition of
different waves interfere at the point of detection..... Interference is a
mismatch of wave timing/phase between separate sources which generates noise and
disrupts the pure shape and amplitude of the individual waveforms in the
medium or across a physical detector.
This only occurs when there is a physical medium or detector that
can detect and sum the energy of the two crossing waves at a fixed physical point of wave mixing.
The result is detected as wave shape distortion in the detector/medium.
IMO, you cannot measure or observe wave interference without having a physical
detector or physical medium to act as an energy summation point. This is a work function.
Without a physical detector to act as a work function summing point, the crossing
photon wavefronts will not "interfere" per se, because no work has been done.
The waves simply pass thru each other with no exchange of energy or disruption
of the wave shape. You cannot have "interference" which is a work function, if you
cannot detect it.
An example: If you play two different frequency musical notes the individual
frequencies mantain their discrete qualities which can be separated and isolated
by filtering, so no signal mixing is taking place. However, at a detector (ear or
o-scope) the energy of the 2 notes combines and the result is the combination of
the amplitude and phasing of the sounds at the point of mixing.
We hear a composite/summed sound because we cannot discriminate between the
phase energies of the sound waves. We hear/detect the interference of the waves
as harmonics.
If two separate instruments play the same frequency note we cannot separate/discriminate
a frequency difference and the total energy/amplitude
of the two individual wave frequencies is summed at the detector. The waves are
synchronous, or nearly so, and closely phase aligned across the medium of air
and the "detector". The total summed energy of the separate waves is detected at
the point of mixing. If the waves are arriving 180 degrees out of phase they will
cancel at the detector. If there is no physical detector to act as a summing
point the waves will simply pass thru each other out of phase and continue on their
way because no signal mixing has occurred.
My point being, that if there is no physical point of mixing or transfer of
energy(work function), there will be no signal interference.
Comments?
LL
It appears that we have a difference of "philosophy" about wave interference vs.
wave superposition. Perhaps it is just semantics..... I will read your posts
again and give them more contemplation.
Interference implies that if you move along the line of sight from the source
that at some point(s) you will observe interference where the superposition of
different waves interfere at the point of detection..... Interference is a
mismatch of wave timing/phase between separate sources which generates noise and
disrupts the pure shape and amplitude of the individual waveforms in the
medium or across a physical detector.
This only occurs when there is a physical medium or detector that
can detect and sum the energy of the two crossing waves at a fixed physical point of wave mixing.
The result is detected as wave shape distortion in the detector/medium.
IMO, you cannot measure or observe wave interference without having a physical
detector or physical medium to act as an energy summation point. This is a work function.
Without a physical detector to act as a work function summing point, the crossing
photon wavefronts will not "interfere" per se, because no work has been done.
The waves simply pass thru each other with no exchange of energy or disruption
of the wave shape. You cannot have "interference" which is a work function, if you
cannot detect it.
An example: If you play two different frequency musical notes the individual
frequencies mantain their discrete qualities which can be separated and isolated
by filtering, so no signal mixing is taking place. However, at a detector (ear or
o-scope) the energy of the 2 notes combines and the result is the combination of
the amplitude and phasing of the sounds at the point of mixing.
We hear a composite/summed sound because we cannot discriminate between the
phase energies of the sound waves. We hear/detect the interference of the waves
as harmonics.
If two separate instruments play the same frequency note we cannot separate/discriminate
a frequency difference and the total energy/amplitude
of the two individual wave frequencies is summed at the detector. The waves are
synchronous, or nearly so, and closely phase aligned across the medium of air
and the "detector". The total summed energy of the separate waves is detected at
the point of mixing. If the waves are arriving 180 degrees out of phase they will
cancel at the detector. If there is no physical detector to act as a summing
point the waves will simply pass thru each other out of phase and continue on their
way because no signal mixing has occurred.
My point being, that if there is no physical point of mixing or transfer of
energy(work function), there will be no signal interference.
Comments?
LL
Hi C2,
unfortunately the Plane Graphic Calculator does not have an integration method so I have not been able to give you a method to verify the sin(x)/x equivalence yet.
I am still working on it but I have gotten this far:
f = |i*ay+n|+cx,ay
g = cx,-dx*t -bx
h = re(e^(i*2*pi*(fx/by))) , ay
k = |e^(i*2*pi*(fx/by))|,ay
n = cx,(dx*t +bx)
now let t step from 0.0 to 1.0
cx is the distance of the two slits to the screen at x=0 (choose point c to the left of the center)
bx is half the distance between the slits
by is the wavelength
dx is the size of the slits
that should make fx the pathlenght difference for each point at the lower slit.
moving point 'a' will choose the point on the detection screen where we want to calculate the path difference.
h will show the real part a wave from the bottom slit arriving at the detection screen.
k shows that the intensity is the same of each wave arriving at the detection screen (which is 1 every where here since I still need to add the ISL)
This is as far as I got with this tool.. I would prefer to write a simple program for this though.. Maybe some other time.
If I could integrate f over t or average it maybe we could fully show the resulting arriving wave at the detection plate.
Probably using only 2 point sources and sweep t over the plate would be much easier... i'll try that too.
Jan Rinze.
unfortunately the Plane Graphic Calculator does not have an integration method so I have not been able to give you a method to verify the sin(x)/x equivalence yet.
I am still working on it but I have gotten this far:
f = |i*ay+n|+cx,ay
g = cx,-dx*t -bx
h = re(e^(i*2*pi*(fx/by))) , ay
k = |e^(i*2*pi*(fx/by))|,ay
n = cx,(dx*t +bx)
now let t step from 0.0 to 1.0
cx is the distance of the two slits to the screen at x=0 (choose point c to the left of the center)
bx is half the distance between the slits
by is the wavelength
dx is the size of the slits
that should make fx the pathlenght difference for each point at the lower slit.
moving point 'a' will choose the point on the detection screen where we want to calculate the path difference.
h will show the real part a wave from the bottom slit arriving at the detection screen.
k shows that the intensity is the same of each wave arriving at the detection screen (which is 1 every where here since I still need to add the ISL)
This is as far as I got with this tool.. I would prefer to write a simple program for this though.. Maybe some other time.
If I could integrate f over t or average it maybe we could fully show the resulting arriving wave at the detection plate.
Probably using only 2 point sources and sweep t over the plate would be much easier... i'll try that too.
Jan Rinze.
Hi LL,
http://en.wikipedia.org/wiki/Interference
it has no mention of it being necessary to be detected to exist..
It can thus be perceived as a 3d map of the resulting superposition of all waves within the 3d volume.. Superposition is a method. Interference just a term for the result when superposing waves.
Perhaps the problem is with the fact that English is not my native language. (I am Dutch)
Jan Rinze.
http://en.wikipedia.org/wiki/Interference
it has no mention of it being necessary to be detected to exist..
It can thus be perceived as a 3d map of the resulting superposition of all waves within the 3d volume.. Superposition is a method. Interference just a term for the result when superposing waves.
Perhaps the problem is with the fact that English is not my native language. (I am Dutch)
Jan Rinze.
Hi Jan,
I am enjoying your new and clean perspective on the DSE and physics. You are
challenging us to rethink our preconceptions and offer a logical approach to the
issues. It is refreshing and your command of English is excellent. I was
wondering if you were Dutch or German.
----
Ok, now I will revisit (for us) a topic that has cropped up numerous times.
Do you expect to observe interference at the point of beam intersection if two
laser pointers are aimed so that their beams cross?
IMO, there will be no observable energy loss or gain from either beam and
nothing to indicate or verify the existence of wave interference at the point of
intersection. The beams/waves will pass thru each other without delay,
interference, or loss because there is no work function or change of amplitude of
the individual beams.
However, if you place a physical detector at the point of beam intersection the
phase relationship/distribution and double intensity of the waves will be observable
and measurable because the individual wave energies are being summed by the detector.
IMO, unlimited photons in open space can occupy the same space without
interaction/interference until they are summed and perform a work function across
a detector.
an after thought: Interference is a non-linear byproduct of signal mixing.
Comments?
LL
I am enjoying your new and clean perspective on the DSE and physics. You are
challenging us to rethink our preconceptions and offer a logical approach to the
issues. It is refreshing and your command of English is excellent. I was
wondering if you were Dutch or German.
----
Ok, now I will revisit (for us) a topic that has cropped up numerous times.
Do you expect to observe interference at the point of beam intersection if two
laser pointers are aimed so that their beams cross?
IMO, there will be no observable energy loss or gain from either beam and
nothing to indicate or verify the existence of wave interference at the point of
intersection. The beams/waves will pass thru each other without delay,
interference, or loss because there is no work function or change of amplitude of
the individual beams.
However, if you place a physical detector at the point of beam intersection the
phase relationship/distribution and double intensity of the waves will be observable
and measurable because the individual wave energies are being summed by the detector.
IMO, unlimited photons in open space can occupy the same space without
interaction/interference until they are summed and perform a work function across
a detector.
an after thought: Interference is a non-linear byproduct of signal mixing.
Comments?
LL
Hi Jan,
Some responses to your prior posts.
Aren't standing waves "fixed points" in geometric space?
--------
Aren't standing waves "fixed points" in geometric space?
--------
I do not see why interference implies collapse of a wavefunction. At the null nodes of the interference pattern you will not find any photons so none collapse there...
If there is no collapse/change of the wavefunction is there interference, which is a
work function (a change of instantaneous energy level/signal summation)?
Aren't the null nodes of the sinewave the points of "mean" relative energy density/
amplitude
at "zero" rotational phase reference? IMO, it is the neutral phase point between
the positive and negative extremes of the amplitude of the photon sine wave. The "mean" threshold
energy level of the photon is there but it is out of phase with optical/dimensional
3-D space-time. Beat modes are the same thing, there is a wave energy "mean"
level between the +/- extreme amplitude levels.
---------
Hmmmm, IMO, interference of the wave energies at the point of detection is what
creates the pattern,
it is the integration/summation of the energy at fixed points on the detector. If
there were no wave interference at different atomic (pixel) points of the CCD
imager there would not be a clear crisp image. The intensity would be the same
across the imaging device. It is the summation of the standing wave energy
that creates interference at fixed locations on the CCD that creates the image.
Anyone else care to comment or correct my argument?
LL
Some responses to your prior posts.
QUOTE
Your statement of 'fixed points' in space would result in a form of absolute reference frame and therefore would violate (special) relativity.
Aren't standing waves "fixed points" in geometric space?
--------
QUOTE (->
| QUOTE |
| Your statement of 'fixed points' in space would result in a form of absolute reference frame and therefore would violate (special) relativity. |
Aren't standing waves "fixed points" in geometric space?
--------
I do not see why interference implies collapse of a wavefunction. At the null nodes of the interference pattern you will not find any photons so none collapse there...
If there is no collapse/change of the wavefunction is there interference, which is a
work function (a change of instantaneous energy level/signal summation)?
Aren't the null nodes of the sinewave the points of "mean" relative energy density/
amplitude
at "zero" rotational phase reference? IMO, it is the neutral phase point between
the positive and negative extremes of the amplitude of the photon sine wave. The "mean" threshold
energy level of the photon is there but it is out of phase with optical/dimensional
3-D space-time. Beat modes are the same thing, there is a wave energy "mean"
level between the +/- extreme amplitude levels.
---------
QUOTE
Interference has nothing to do with a stable pattern! The interference is there but integrated over the exposure time of the hubble image there can not be any visible interference pattern present.. The method of creating a picture of incoming light is far different from setting-up a plate in space and capture all incoming photons. It involves lenses and mirrors to converge the incoming waves to a point. If we do this we get amplification of the wavefronts that fit with the design of the lens/mirror setup.
so could you please explain your thoughts on this and if possible make it quantifyable through some theory or maths?
so could you please explain your thoughts on this and if possible make it quantifyable through some theory or maths?
Hmmmm, IMO, interference of the wave energies at the point of detection is what
creates the pattern,
it is the integration/summation of the energy at fixed points on the detector. If
there were no wave interference at different atomic (pixel) points of the CCD
imager there would not be a clear crisp image. The intensity would be the same
across the imaging device. It is the summation of the standing wave energy
that creates interference at fixed locations on the CCD that creates the image.
Anyone else care to comment or correct my argument?
LL
Hi JanRinze, laserlight, Confused2 et al,
Lets see if we can't straighten out the issue about "interference" between photons. This is a difficult topic and it takes time to grasp and sort out. Photons from different uncorrelated sources do not interfere (at least I do not think so... ). If two uncorrelated point sources are separated by a small angular displacement what is seen is Rayleigh Criterion amplitude summation. Internally each source may be spatially partially coherent but this will not aid the two to "interfere".
Illustrations come from here...
http://hyperphysics.phy-astr.gsu.edu/hbase...ffracon.html#c1
Here is a single monochromatic correlated source...
... click to enlarge...
You can replace the pinhole with a lens and the pattern will depend on the aperture of the lens or if you 'stop it down" will depend on the stop number ... maybe a pinhole. A "pinhole" and a stopped down lens of the same aperture (spatial filter) size will produce the same pattern. Close examination of a point source will show this monochromatic pattern.
Here we see two sources. They can be monochromatic light but spatially separated. Individually they can be focussed on a screen and we will obtain pinhole diffraction patterns.What you see are Airy disks. A second similar source (monochromatic) nearby can be made to overlap the sources such that their maxima falls on the first minimima of the other one like this...
... click to enlarge...
This could be created by two separate lasers fired at the card in the illustration above but separated by the critical distance of the "slit separation" in the Double slit experiment. Prevent the two sources from mixing using a strategically placed card and the effect will be no interference at all.
All things being equal there is no "interference" only summation since the sources are not correlated. Now ensure that these two pinholes have the same "divergent photons from the one single source fall on it" or alternatively we can "connect the two laser sources" linking the chambers of the lasers resonantly so they are correlated. We see a different process.
... click to enlarge...
The left image is due to one pinhole as before and when you have a second pinhole you obtain the interference pattern to the right. This is different to the Rayleigh Pattern above (even if you use two monochromatic lasers of the same intensity and wavelength). The only difference is they are now correlated. Now the pattern does not depend on two photons interfering with each other or any number of photons interfering with each other. The pattern is established photon by photon... even when there are large gaps in time between each individual photon.
One possible explanation for this is that photons are bosons and any number of correlated bosons can exist in the same state, they can be superimposed on each other occupying the same physical space. This means regardless of the number of photons emitted simultaneously... one or a billion... the interference pattern that builds up over time remains exactly the same. All the bosons exist in the same identical quantum state depending on "some other factor' individual photons distribute themselves the same way around the screen as they do collectively.
Regardless the way you cut this, photons from uncorrelated sources with spatial separation will only be correlated with photons from their own unique parent source (they are all "in step" with each other). A shuttered screen counting system would show that if you used two different laser sources, the two sets of photons would fall on separate and distinct interference patterns with an appropriate angular separation between them. Together their interference patterns would be related through a "Rayleigh pattern" even if we were using dual slits. Of course if you use the same pair of slits and if the sources have no angular separation there will be no way to immediately show that the two sets would fall on separate interference patterns. This is not because the photons are correlated necessarily... but the patterns would then be spatially physically "identical" and this is the result of not measuring phase but by only measuring intensity. as noted previously spatially correlated monochromatic photons will produce an interference pattern. Are spatially coherent photons interfering with other non-coherent photons but spatially related photons or only interfering with themselves? I don't think it is possible to say as Confused2 has stated.
The conclusion has always been, since Dirac originally stated it, that uncorrelated sources do not interfere with each other and that since individual photons singly produce the same interference pattern as many photons, each photon is only interfering with itself to build that consistent full pattern... the only caveat is it does it one 'speck" at a time. Extending this concept to Holograms, the photons are not interfering with each other at one frequency. It is each photon that is somehow carrying the information about "seeking all paths" that is "drawing" our interference fringes in the emulsion one "speck" at a time.
I saw that reference JanRinze but other than paying for that download I am unconvinced that parametric down-conversion is "simple interference" between photons as shown in the Double Slit Interference Experiment. Parametric Down-conversion is a process which splits high energy photons into doublets (takes a green photon and makes two "entangled" red ones out of it for instance), and this is not an interference phenomenon but something else related to quantum entanglement through non-linear processes in birefringent crystals. There are also exceptions to "everything" of course. What does everyone think about this idea... comments welcome.
Cheers
Lets see if we can't straighten out the issue about "interference" between photons. This is a difficult topic and it takes time to grasp and sort out. Photons from different uncorrelated sources do not interfere (at least I do not think so... ). If two uncorrelated point sources are separated by a small angular displacement what is seen is Rayleigh Criterion amplitude summation. Internally each source may be spatially partially coherent but this will not aid the two to "interfere".
Illustrations come from here...
http://hyperphysics.phy-astr.gsu.edu/hbase...ffracon.html#c1
Here is a single monochromatic correlated source...
... click to enlarge...
You can replace the pinhole with a lens and the pattern will depend on the aperture of the lens or if you 'stop it down" will depend on the stop number ... maybe a pinhole. A "pinhole" and a stopped down lens of the same aperture (spatial filter) size will produce the same pattern. Close examination of a point source will show this monochromatic pattern.
Here we see two sources. They can be monochromatic light but spatially separated. Individually they can be focussed on a screen and we will obtain pinhole diffraction patterns.What you see are Airy disks. A second similar source (monochromatic) nearby can be made to overlap the sources such that their maxima falls on the first minimima of the other one like this...
... click to enlarge...
This could be created by two separate lasers fired at the card in the illustration above but separated by the critical distance of the "slit separation" in the Double slit experiment. Prevent the two sources from mixing using a strategically placed card and the effect will be no interference at all.
All things being equal there is no "interference" only summation since the sources are not correlated. Now ensure that these two pinholes have the same "divergent photons from the one single source fall on it" or alternatively we can "connect the two laser sources" linking the chambers of the lasers resonantly so they are correlated. We see a different process.
... click to enlarge...
The left image is due to one pinhole as before and when you have a second pinhole you obtain the interference pattern to the right. This is different to the Rayleigh Pattern above (even if you use two monochromatic lasers of the same intensity and wavelength). The only difference is they are now correlated. Now the pattern does not depend on two photons interfering with each other or any number of photons interfering with each other. The pattern is established photon by photon... even when there are large gaps in time between each individual photon.
One possible explanation for this is that photons are bosons and any number of correlated bosons can exist in the same state, they can be superimposed on each other occupying the same physical space. This means regardless of the number of photons emitted simultaneously... one or a billion... the interference pattern that builds up over time remains exactly the same. All the bosons exist in the same identical quantum state depending on "some other factor' individual photons distribute themselves the same way around the screen as they do collectively.
Regardless the way you cut this, photons from uncorrelated sources with spatial separation will only be correlated with photons from their own unique parent source (they are all "in step" with each other). A shuttered screen counting system would show that if you used two different laser sources, the two sets of photons would fall on separate and distinct interference patterns with an appropriate angular separation between them. Together their interference patterns would be related through a "Rayleigh pattern" even if we were using dual slits. Of course if you use the same pair of slits and if the sources have no angular separation there will be no way to immediately show that the two sets would fall on separate interference patterns. This is not because the photons are correlated necessarily... but the patterns would then be spatially physically "identical" and this is the result of not measuring phase but by only measuring intensity. as noted previously spatially correlated monochromatic photons will produce an interference pattern. Are spatially coherent photons interfering with other non-coherent photons but spatially related photons or only interfering with themselves? I don't think it is possible to say as Confused2 has stated.
The conclusion has always been, since Dirac originally stated it, that uncorrelated sources do not interfere with each other and that since individual photons singly produce the same interference pattern as many photons, each photon is only interfering with itself to build that consistent full pattern... the only caveat is it does it one 'speck" at a time. Extending this concept to Holograms, the photons are not interfering with each other at one frequency. It is each photon that is somehow carrying the information about "seeking all paths" that is "drawing" our interference fringes in the emulsion one "speck" at a time.
I saw that reference JanRinze but other than paying for that download I am unconvinced that parametric down-conversion is "simple interference" between photons as shown in the Double Slit Interference Experiment. Parametric Down-conversion is a process which splits high energy photons into doublets (takes a green photon and makes two "entangled" red ones out of it for instance), and this is not an interference phenomenon but something else related to quantum entanglement through non-linear processes in birefringent crystals. There are also exceptions to "everything" of course. What does everyone think about this idea... comments welcome.
Cheers
Hello all
It is impossible to get interference from a point source. The aperture (real or synthetic) determines whether of not two point sources can be resolved. All types of lenses or curved mirrors convert plane EM waves to spherical EM waves and back. The size of the aperture also governs the light gathering power of the telescope. Summation of the light energy happens when two point sources cannot be resolved.
It is impossible to get interference from a point source. The aperture (real or synthetic) determines whether of not two point sources can be resolved. All types of lenses or curved mirrors convert plane EM waves to spherical EM waves and back. The size of the aperture also governs the light gathering power of the telescope. Summation of the light energy happens when two point sources cannot be resolved.
Hi Montec,
QUOTE (Montec+)
Summation of the light energy happens when two point sources cannot be resolved.
Not a critical point but obviously you do not mean that just because you are not able to resolve two monochromatic separately correlated sources they are "automatically" fully internally correlated with each other when they are not "resolved". In practical terms these two individually and separately correlated sources will produce the same "visible' interference pattern on the screen. This is because light sensors only measure the square of the amplitude (Intensity) and not the phase which do not add or subtract vectorially in this case because individual photons each "do their own thing" separately to produce interference patterns. If the two monochromatic separately correlated sources are too close to be physically resolved so will their combined double slit interference pattern.
What do you think?
Cheers
What do you think?
Cheers
Here's something I can't quite understand.
Let's say that single photons from a "correlated" source are emitted one at a time, pass through some "pinhole", and interfere with themselves to produce the interference pattern.
Now, let's consider each of these photons in isolation. Taken by itself, it is just one single photon, passing through a pinhole, and interfering with itself. It doesn't "know" anything about what emitted it, or what other photons might come in its wake at some later point in time. How is this "correlated" photon, then, different in any respect whatsoever from a single photon emitted by an "uncorrelated" source? It's still a photon, of a certain frequency, traveling in a certain direction through a certain point in space. But if there is no fundamental difference endemic to the photon itself, then shouldn't "uncorrelated" single photons also interfere with themselves when passing through a pinhole (or through a slit, for that matter)???
Let's say that single photons from a "correlated" source are emitted one at a time, pass through some "pinhole", and interfere with themselves to produce the interference pattern.
Now, let's consider each of these photons in isolation. Taken by itself, it is just one single photon, passing through a pinhole, and interfering with itself. It doesn't "know" anything about what emitted it, or what other photons might come in its wake at some later point in time. How is this "correlated" photon, then, different in any respect whatsoever from a single photon emitted by an "uncorrelated" source? It's still a photon, of a certain frequency, traveling in a certain direction through a certain point in space. But if there is no fundamental difference endemic to the photon itself, then shouldn't "uncorrelated" single photons also interfere with themselves when passing through a pinhole (or through a slit, for that matter)???
QUOTE (Confused2+May 9 2007, 10:25 PM)
Hi Jan,
QUOTE (JR+)
Since the waves from both slits are coherent and the path length differences are within a few wavelengths there are no time dependent components necessary.
I consider the DSE in the light of the Kennedy Thorndike (1932) experiment ( http://en.wikipedia.org/wiki/Kennedy-Thorndike_experiment ) . Unfortunately the original paper is still a pay and display item so I can't say how different the path lengths were. In the context that the K-T experiment was looking for Aether drift I guess the path length difference must have been of the order of a meter to have any physical significance. Obviously this is a guess - but if the guess is remotely correct we have interference over a considerable distance even from a non-laser source. Unproven - no evidence offered at this stage - dispute invited - is that the same interference effect would exist between paths from an individual photon from a star if the path has been divided by (say) a massive object - the path difference could be many light years - I would still back the sum over paths to give the right answer - would you?
Best wishes,
-C2.
we're getting closer to an answer to the two slit experiment; within a light wavelength is touching each other for all intents and purposes.
So, it is the phase of the photons that ensures formation of the interference pattern? After all, "path length" equals phase, doesn't it?
But then, what does it mean to "diverge" a light beam -- when the spatial extent of any given photon's cross-section cannot change? How do you "force" a single photon to pass through both slits vs. only one -- when the only things you can really control, are the direction in which you emit it, the phase at the moment you emit it, and its frequency?
I consider the DSE in the light of the Kennedy Thorndike (1932) experiment ( http://en.wikipedia.org/wiki/Kennedy-Thorndike_experiment ) . Unfortunately the original paper is still a pay and display item so I can't say how different the path lengths were. In the context that the K-T experiment was looking for Aether drift I guess the path length difference must have been of the order of a meter to have any physical significance. Obviously this is a guess - but if the guess is remotely correct we have interference over a considerable distance even from a non-laser source. Unproven - no evidence offered at this stage - dispute invited - is that the same interference effect would exist between paths from an individual photon from a star if the path has been divided by (say) a massive object - the path difference could be many light years - I would still back the sum over paths to give the right answer - would you?
Best wishes,
-C2.
we're getting closer to an answer to the two slit experiment; within a light wavelength is touching each other for all intents and purposes.
Hi Pink Elephant,
A complete hologram could be formed one photon at a time (to the best of my knowledge) where all photons originate from the same source... "path length". To "see" an entire room, it would be necessary to diverge the laser beam to "seek all paths" otherwise the light will only be concentrated on a very small object area... maybe only those two slits. Of course the photons have philosophically "sought all paths" but obviously some paths a lot more than some others... every "beam" has "side lobes".
Images of transverse optical modes...
Comments welcome.
Cheers
QUOTE
Let's say that single photons from a "correlated" source are emitted one at a time, pass through some "pinhole", and interfere with themselves to produce the interference pattern.
Now, let's consider each of these photons in isolation. Taken by itself, it is just one single photon, passing through a pinhole, and interfering with itself. It doesn't "know" anything about what emitted it, or what other photons might come in its wake at some later point in time. How is this "correlated" photon, then, different in any respect whatsoever from a single photon emitted by an "uncorrelated" source? It's still a photon, of a certain frequency, traveling in a certain direction through a certain point in space. But if there is no fundamental difference endemic to the photon itself, then shouldn't "uncorrelated" single photons also interfere with themselves when passing through a pinhole (or through a slit, for that matter)???
Sure, that is true... you can do that but you get the same interference with diverged coherent light. What is important is the light must spread for double slit interference to work. The single photon must pass through both slits or both pinholes. The question being asked is "are photons able to interfere with each other?" Answer: No!... as you have stated it is one photon at a time. "If the beam passes through only one slit and not the other will I get double slit interference?" Answer: No!... It is 'axiomatic" to get interference within that one photon, it must pass through both slits, so if you force it through only one slit you will not get that interference. The next question is "will photons from uncorrelated sources and even unresolvable separate interference patterns still produce a perfect hologram?" Answer : No! They can only be produced from a single wholly correlated source.... There can be many secondary mirrors and that will not affect the Hologram other than probably aesthetically improving it, but all photons must have the same source origin to within a fraction of a wavelength. Two uncorrelated sources will produce two separate Holographic images in a plate's emulsion separated by some fraction of a wavelength. These do not "construct" separate images since they cannot record separate phase in a single emulsion independently of each other. Thus when it comes time to illuminate the developed hologram only a "mess" will be seen equivalent to moving the emulsion during the exposure process.Now, let's consider each of these photons in isolation. Taken by itself, it is just one single photon, passing through a pinhole, and interfering with itself. It doesn't "know" anything about what emitted it, or what other photons might come in its wake at some later point in time. How is this "correlated" photon, then, different in any respect whatsoever from a single photon emitted by an "uncorrelated" source? It's still a photon, of a certain frequency, traveling in a certain direction through a certain point in space. But if there is no fundamental difference endemic to the photon itself, then shouldn't "uncorrelated" single photons also interfere with themselves when passing through a pinhole (or through a slit, for that matter)???
A complete hologram could be formed one photon at a time (to the best of my knowledge) where all photons originate from the same source... "path length". To "see" an entire room, it would be necessary to diverge the laser beam to "seek all paths" otherwise the light will only be concentrated on a very small object area... maybe only those two slits. Of course the photons have philosophically "sought all paths" but obviously some paths a lot more than some others... every "beam" has "side lobes".
Images of transverse optical modes...
Comments welcome.
Cheers
Hi Montec,
I'm not sure that I understand what you are implying. Please elaborate.
LL
QUOTE
Summation of the light energy happens when two point sources cannot be resolved.
I'm not sure that I understand what you are implying. Please elaborate.
LL
QUOTE
A complete hologram could be formed one photon at a time (to the best of my knowledge) where all photons originate from the same source... "path length".
So, it is the phase of the photons that ensures formation of the interference pattern? After all, "path length" equals phase, doesn't it?
But then, what does it mean to "diverge" a light beam -- when the spatial extent of any given photon's cross-section cannot change? How do you "force" a single photon to pass through both slits vs. only one -- when the only things you can really control, are the direction in which you emit it, the phase at the moment you emit it, and its frequency?
Hello Good Elf, et al.
This makes sense, but I what do you mean by "correlated sources". Two point sources that are close together will produce the same interference pattern as long as the wavefronts from each source are parallel. All the emitted EM wavelets (photons) of the same frequency that have parallel wave fronts will produce the same double slit interference pattern. The wavelets may not be in phase with each other but the resultant DSE pattern from the summed waves will be the same. This is where the phrase "a photon can only interfere with itself" comes from.
Parallel wave fronts implies that the point sources cannot be resolved.
Now the polarization of the wavelets can be used to further differentiate or resolve the point sources.
Comments welcome.
QUOTE
If the two monochromatic separately correlated sources are too close to be physically resolved so will their combined double slit interference pattern.
This makes sense, but I what do you mean by "correlated sources". Two point sources that are close together will produce the same interference pattern as long as the wavefronts from each source are parallel. All the emitted EM wavelets (photons) of the same frequency that have parallel wave fronts will produce the same double slit interference pattern. The wavelets may not be in phase with each other but the resultant DSE pattern from the summed waves will be the same. This is where the phrase "a photon can only interfere with itself" comes from.
Parallel wave fronts implies that the point sources cannot be resolved.
Now the polarization of the wavelets can be used to further differentiate or resolve the point sources.
Comments welcome.
Hi Pink Elephant,
QUOTE (Pink Elephant+)
But then, what does it mean to "diverge" a light beam -- when the spatial extent of any given photon's cross-section cannot change? How do you "force" a single photon to pass through both slits vs. only one -- when the only things you can really control, are the direction in which you emit it, the phase at the moment you emit it, and its frequency?
The individual photon does seek all paths and is "everywhere" in the 'cavity" or room... every photon is the same and they spread initially on the surface of a sphere.
Just set up the optical divergent lens and all photons "seek all paths" but when they are individually recorded in the hologram's emulsion, the record is a single flash of light or the changing of a single silver halide crystal. Each individual photon "senses" the entire optical cavity and through "internal self interference" decides where it will be deposited... It is like painting the "Mona Lisa" one tiny brush stroke at a time. Each "speck" has to be placed exactly in place to construct the whole image. Even one wrong brush stroke will spoil the overall result. This is in part how a camera actually works too. There is nothing "quantum statistical" about this underlying information.
This process (quantum statistics vs measurables) has been discussed earlier in this thread about the way quantum information differs from optical measurable information. Statistical data never painted the Mona Lisa and is missing "non-local cavity information" that is obtained from it's wavefront in the entire cavity. Empty space is not really empty and hold information about the cavity shape. Within a broad spread of quanta each and every photon knows exactly where it is going, you just do not know where a particular photon is going. Armed with a "knowledge" of the entire cavity a single photon will find a unique place to go to "paint" the "Mona Lisa".
Cheers
Just set up the optical divergent lens and all photons "seek all paths" but when they are individually recorded in the hologram's emulsion, the record is a single flash of light or the changing of a single silver halide crystal. Each individual photon "senses" the entire optical cavity and through "internal self interference" decides where it will be deposited... It is like painting the "Mona Lisa" one tiny brush stroke at a time. Each "speck" has to be placed exactly in place to construct the whole image. Even one wrong brush stroke will spoil the overall result. This is in part how a camera actually works too. There is nothing "quantum statistical" about this underlying information.
This process (quantum statistics vs measurables) has been discussed earlier in this thread about the way quantum information differs from optical measurable information. Statistical data never painted the Mona Lisa and is missing "non-local cavity information" that is obtained from it's wavefront in the entire cavity. Empty space is not really empty and hold information about the cavity shape. Within a broad spread of quanta each and every photon knows exactly where it is going, you just do not know where a particular photon is going. Armed with a "knowledge" of the entire cavity a single photon will find a unique place to go to "paint" the "Mona Lisa".
Cheers
QUOTE (Pink Elephant+May 10 2007, 04:24 AM)
Here's something I can't quite understand.
Let's say that single photons from a "correlated" source are emitted one at a time, pass through some "pinhole", and interfere with themselves to produce the interference pattern.
Now, let's consider each of these photons in isolation. Taken by itself, it is just one single photon, passing through a pinhole, and interfering with itself. It doesn't "know" anything about what emitted it, or what other photons might come in its wake at some later point in time. How is this "correlated" photon, then, different in any respect whatsoever from a single photon emitted by an "uncorrelated" source? It's still a photon, of a certain frequency, traveling in a certain direction through a certain point in space. But if there is no fundamental difference endemic to the photon itself, then shouldn't "uncorrelated" single photons also interfere with themselves when passing through a pinhole (or through a slit, for that matter)???
the electromagnetic force has range up to infinity. Even though the wavelength of an EM wave or photon is defined as finite in extent, there is some part of the EM wave that is interacting at a greater distance than defined by the wavelenght where most of the action is taking place.
Let's say that single photons from a "correlated" source are emitted one at a time, pass through some "pinhole", and interfere with themselves to produce the interference pattern.
Now, let's consider each of these photons in isolation. Taken by itself, it is just one single photon, passing through a pinhole, and interfering with itself. It doesn't "know" anything about what emitted it, or what other photons might come in its wake at some later point in time. How is this "correlated" photon, then, different in any respect whatsoever from a single photon emitted by an "uncorrelated" source? It's still a photon, of a certain frequency, traveling in a certain direction through a certain point in space. But if there is no fundamental difference endemic to the photon itself, then shouldn't "uncorrelated" single photons also interfere with themselves when passing through a pinhole (or through a slit, for that matter)???
the electromagnetic force has range up to infinity. Even though the wavelength of an EM wave or photon is defined as finite in extent, there is some part of the EM wave that is interacting at a greater distance than defined by the wavelenght where most of the action is taking place.
Two lasers each with two (typically badly made) pinholes. One set of pinholes is in vertical plane .. the other horizontal.
Laser A says it is a 650nm device, laser B doesn't say anything.
Click
Some details of the C2 optics lab here
http://forum.physorg.com/index.php?showtop...ndpost&p=203449
To show interference I think we would be looking for an area where the fringe from one pattern makes the fringe from the other 'go away'. I don't see this so I conclude these two lasers are not interfereng with each other .. they simply sum.
Best wishes,
-C2.
Laser A says it is a 650nm device, laser B doesn't say anything.
Click
Some details of the C2 optics lab here
http://forum.physorg.com/index.php?showtop...ndpost&p=203449
To show interference I think we would be looking for an area where the fringe from one pattern makes the fringe from the other 'go away'. I don't see this so I conclude these two lasers are not interfereng with each other .. they simply sum.
Best wishes,
-C2.
Hi Montec, Pink Elephant, Laserlight, Neil Farbstein, Confused2, yquantum, janrinze et al,
QUOTE (Montec+)
This makes sense, but I what do you mean by "correlated sources". Two point sources that are close together will produce the same interference pattern as long as the wavefronts from each source are parallel. All the emitted EM wavelets (photons) of the same frequency that have parallel wave fronts will produce the same double slit interference pattern. The wavelets may not be in phase with each other but the resultant DSE pattern from the summed waves will be the same. This is where the phrase "a photon can only interfere with itself" comes from.
Parallel wave fronts implies that the point sources cannot be resolved.
Now the polarization of the wavelets can be used to further differentiate or resolve the point sources.
Parallel wave fronts implies that the point sources cannot be resolved.
Now the polarization of the wavelets can be used to further differentiate or resolve the point sources.
No ... "photons can only interfere with itself" comes from the fact that individual photons one at a time result in full interference patterns when allowed to build up in time... an experimental fact. I have partially resolved this question through an gedanken observation of the effect of creating a Hologram. Parallel wavefronts are not enough to create a hologram since interference paths must be consistent to less than a fraction of a wavelength of the light for the process to record clear and crisp holograms because the hologram is an exact in depth record of the interference fringes of the standing waves of light inside the emulsion depositing there from all of space. This will only work if we have a single primary coherent source.
While spatially coherent photons which are not correlated at source still produce individual self interference and provided they are within the Rayleigh Criterion can build on a Young's double slit interference pattern regardless of source, they will not be able to produce a Hologram unless they are also correlated at the source. A laser is spatially and source correlated in the resonant tube of the LASER Source through a process of Stimulated Emission of Radiation which could be loosely described as a "longitudinal Mexican wave" inside the laser tube gas molecules that synchronizes the photons to "release" not by source but by phase which in this case is even better than simple source correlation since the "Mexican wave" is very exact in its characteristics and times the release of the photons to within a hundred or so femtoseconds. The tube longitudinal and transverse modes undergo spontaneous electromagnetic emergent phenomena when undergoing stimulation. When the photons pass through the semi-reflecting dielectric window in the end of the tube the photons are longitudinally correlated on this semi-continuous wave. There is another process in which photons can become correlated and produce source coherent radiation other than through EM tank circuits, Klystron Resonators, Masers, Optical Stimulated Emission, Quantum Dots or other method... It is the way that the first holograms were produced... this is by a process of spontaneous coherence of co-moving photons from a compact monochromatic source, viewed in the far field. What seems to happen is the haphazard co-moving photons all the same wavelength moving in space spontaneously try to find a point on the surface of some spatial electromagnetic "geodesic" of a common wave where the path of least action and shortest path induces nearby spatial photons to form a common bosonic state. This is not unlike the situation with low temperature gas molecules forming a Bose-Einstein Condensate in fermions.
An infinite number of bosons can exist in the one boson state but with fermions must pair up in something like "Cooper Pairs" to numerically become a numerical quantum bosonic fluid with an even number of fermions in the state. Unlike Bosons they all cant occupy the one place in space though... but they try. The only practical difference is matter does this with a great deal of effort (extreme low temperatures to reduce the atoms to the lowest degenerate state of matter) while photons traveling at the speed of light do this a lot more easily. Originally the first holograms used sources of monochromatic light before the advent of continuous wave lasers. Since the photons interfere with themselves only if the path lengths originate from a compact source with monochromatic light, it is possible to make fuzzy holograms with ordinary light. Of course laser light is a lot easier to manipulate.
Cheers
While spatially coherent photons which are not correlated at source still produce individual self interference and provided they are within the Rayleigh Criterion can build on a Young's double slit interference pattern regardless of source, they will not be able to produce a Hologram unless they are also correlated at the source. A laser is spatially and source correlated in the resonant tube of the LASER Source through a process of Stimulated Emission of Radiation which could be loosely described as a "longitudinal Mexican wave" inside the laser tube gas molecules that synchronizes the photons to "release" not by source but by phase which in this case is even better than simple source correlation since the "Mexican wave" is very exact in its characteristics and times the release of the photons to within a hundred or so femtoseconds. The tube longitudinal and transverse modes undergo spontaneous electromagnetic emergent phenomena when undergoing stimulation. When the photons pass through the semi-reflecting dielectric window in the end of the tube the photons are longitudinally correlated on this semi-continuous wave. There is another process in which photons can become correlated and produce source coherent radiation other than through EM tank circuits, Klystron Resonators, Masers, Optical Stimulated Emission, Quantum Dots or other method... It is the way that the first holograms were produced... this is by a process of spontaneous coherence of co-moving photons from a compact monochromatic source, viewed in the far field. What seems to happen is the haphazard co-moving photons all the same wavelength moving in space spontaneously try to find a point on the surface of some spatial electromagnetic "geodesic" of a common wave where the path of least action and shortest path induces nearby spatial photons to form a common bosonic state. This is not unlike the situation with low temperature gas molecules forming a Bose-Einstein Condensate in fermions.
An infinite number of bosons can exist in the one boson state but with fermions must pair up in something like "Cooper Pairs" to numerically become a numerical quantum bosonic fluid with an even number of fermions in the state. Unlike Bosons they all cant occupy the one place in space though... but they try. The only practical difference is matter does this with a great deal of effort (extreme low temperatures to reduce the atoms to the lowest degenerate state of matter) while photons traveling at the speed of light do this a lot more easily. Originally the first holograms used sources of monochromatic light before the advent of continuous wave lasers. Since the photons interfere with themselves only if the path lengths originate from a compact source with monochromatic light, it is possible to make fuzzy holograms with ordinary light. Of course laser light is a lot easier to manipulate.
Cheers
Hi Confused2,
QUOTE (Confused2+)
Two lasers each with two (typically badly made) pinholes. One set of pinholes is in vertical plane .. the other horizontal.
Laser A says it is a 650nm device, laser B doesn't say anything.
Click
Some details of the C2 optics lab here
http://forum.physorg.com/index.php?showtop...10&#entry203449
To show interference I think we would be looking for an area where the fringe from one pattern makes the fringe from the other 'go away'. I don't see this so I conclude these two lasers are not interfereng with each other .. they simply sum.
Best wishes,
-C2.
Laser A says it is a 650nm device, laser B doesn't say anything.
Click
Some details of the C2 optics lab here
http://forum.physorg.com/index.php?showtop...10&#entry203449
To show interference I think we would be looking for an area where the fringe from one pattern makes the fringe from the other 'go away'. I don't see this so I conclude these two lasers are not interfereng with each other .. they simply sum.
Best wishes,
-C2.
Brilliant... That is a great illustration of this principle... thanks for that. The fringe spacing indicates the lasers are "similar". You won't find that result in books.
It is almost an "act of faith" to believe that individually each and every photon carries with it an almost complete description at that wavelength of the entire cavity in which it is interacting. This leads to only one tiny speck of light in the emulsion of a hologram. What Confused2 has demonstrated is the utter independence of photons from different sources and in some way the "identicality" of photons in the one boson state. You could "imagine" two correlated photons falling almost next to each other but as a result of the slight physical offset in position carries just a tiny bit of slightly different information that describes the cavity from that alternative position as if each photons position in the emulsion of a hologram will see the same cavity with all the same detail from that slightly offset position. In this way a fragment of a hologram carries the same description of the cavity as another fragment only offset physically. Our eyes view this ensemble of superimposed states "encoded" into the emulsion from the differing perspective of the offset of each of our eyes and interpret three dimensions. What a lot of information and some might say what a waste of information. Yet this is what we need to describe our dimensional reality. This is an example of the "strong" principle of Canonical Typicality of quantum ensembles.
http://www.math.rutgers.edu/~oldstein/papers/can.pdf
Cheers
It is almost an "act of faith" to believe that individually each and every photon carries with it an almost complete description at that wavelength of the entire cavity in which it is interacting. This leads to only one tiny speck of light in the emulsion of a hologram. What Confused2 has demonstrated is the utter independence of photons from different sources and in some way the "identicality" of photons in the one boson state. You could "imagine" two correlated photons falling almost next to each other but as a result of the slight physical offset in position carries just a tiny bit of slightly different information that describes the cavity from that alternative position as if each photons position in the emulsion of a hologram will see the same cavity with all the same detail from that slightly offset position. In this way a fragment of a hologram carries the same description of the cavity as another fragment only offset physically. Our eyes view this ensemble of superimposed states "encoded" into the emulsion from the differing perspective of the offset of each of our eyes and interpret three dimensions. What a lot of information and some might say what a waste of information. Yet this is what we need to describe our dimensional reality. This is an example of the "strong" principle of Canonical Typicality of quantum ensembles.
http://www.math.rutgers.edu/~oldstein/papers/can.pdf
Cheers
Hello Good Elf, et al.
I agree that a hologram requires planer EM waves with the same phase or time synched wave fronts. This is required to record both direction and distance information via interference into the emulsion.
I personally cannot tell the difference between two photons of the same frequency and polarization so when I read "photon" I mentally translate it to "wave front" and go on reading.
In the Mickelson interferometer the interference, with different length legs, requires a monochromatic light to produce fringes. The fringes are produced by different wave fronts. If the legs are the same length then any source will produce fringes because the same wave front is being used to produce the fringes.
I agree that a hologram requires planer EM waves with the same phase or time synched wave fronts. This is required to record both direction and distance information via interference into the emulsion.
I personally cannot tell the difference between two photons of the same frequency and polarization so when I read "photon" I mentally translate it to "wave front" and go on reading.
In the Mickelson interferometer the interference, with different length legs, requires a monochromatic light to produce fringes. The fringes are produced by different wave fronts. If the legs are the same length then any source will produce fringes because the same wave front is being used to produce the fringes.
Good Day everyone!
Could you describe how the cavity is made?
I'm sure that zephir would say that it's his bubbles.
I prefer to re-phrase:
The quantum structure of the cavity has a memory of of the photons.
It might be easier to experimentally demonstrate, (one day), this point of view, than to demonstrated that the photon is everywhere and that the photon can see into the future and into the past.
jal
QUOTE
Good Elf
It is almost an "act of faith" to believe that individually each and every photon carries with it an almost complete description at that wavelength of the entire cavity in which it is interacting
It is almost an "act of faith" to believe that individually each and every photon carries with it an almost complete description at that wavelength of the entire cavity in which it is interacting
Could you describe how the cavity is made?
I'm sure that zephir would say that it's his bubbles.
I prefer to re-phrase:
The quantum structure of the cavity has a memory of of the photons.
It might be easier to experimentally demonstrate, (one day), this point of view, than to demonstrated that the photon is everywhere and that the photon can see into the future and into the past.
jal
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