I was reading about the quantum entanglement ...
"Quantum entanglement is a quantum mechanical phenomenon in which the quantum states of two or more objects have to be described with reference to each other, even though the individual objects may be spatially separated. This leads to correlations between observable physical properties of the systems. For example, it is possible to prepare two particles in a single quantum state such that when one is observed to be spin-up, the other one will always be observed to be spin-down and vice versa, this despite the fact that it is impossible to predict, according to quantum mechanics, which set of measurements will be observed. As a result, measurements performed on one system seem to be instantaneously influencing other systems entangled with it."
A question. If we have two or more objects for which we KNOW that they are in the "mirror" state correlation between themselves to begin with, that is, if one of them has a spin on the axis "x" upward then another has a spin on the axis "x" downward, that is, we know that those two particles cannot both have the same spin on the certain axis, how exactly an observation of the one particle to be with a spin upward makes an observation of another particle's spin to be downward as nonlocal phenomenon, if we have not know which spin particular particle had until we have observed one or another?
"However, classical information cannot be transmitted through entanglement faster than the speed of light."
I think in regard of this statement that we are , possibly, neglecting the big picture.
Anton
Let us say that we have produced a two entaglemented photons, each with opposite spin.
As I understand the only one photon with it's particular spin would be able to pass through some medium, field, material, while other photon with opposite spin would not be able to pas through that medium, field, material.
If, hypothetically, both of the photons would pass that would mean that both of them has the same spin ( hey, it is a strange world of internet forums).
Would that mean:
1) the end of the world is near?
2) that cannot happen because so called entanglement is a consequence of the universe which "follows" the law of conservation of energy?
Anton
As I understand the only one photon with it's particular spin would be able to pass through some medium, field, material, while other photon with opposite spin would not be able to pas through that medium, field, material.
If, hypothetically, both of the photons would pass that would mean that both of them has the same spin ( hey, it is a strange world of internet forums).
Would that mean:
1) the end of the world is near?
2) that cannot happen because so called entanglement is a consequence of the universe which "follows" the law of conservation of energy?
Anton
QUOTE (Mate+Jun 16 2007, 06:07 AM)
I was reading about the quantum entanglement ...
"Quantum entanglement is a quantum mechanical phenomenon in which the quantum states of two or more objects have to be described with reference to each other, even though the individual objects may be spatially separated. This leads to correlations between observable physical properties of the systems. For example, it is possible to prepare two particles in a single quantum state such that when one is observed to be spin-up, the other one will always be observed to be spin-down and vice versa, this despite the fact that it is impossible to predict, according to quantum mechanics, which set of measurements will be observed. As a result, measurements performed on one system seem to be instantaneously influencing other systems entangled with it."
A question. If we have two or more objects for which we KNOW that they are in the "mirror" state correlation between themselves to begin with, that is, if one of them has a spin on the axis "x" upward then another has a spin on the axis "x" downward, that is, we know that those two particles cannot both have the same spin on the certain axis, how exactly an observation of the one particle to be with a spin upward makes an observation of another particle's spin to be downward as nonlocal phenomenon, if we have not know which spin particular particle had until we have observed one or another?
"However, classical information cannot be transmitted through entanglement faster than the speed of light."
I think in regard of this statement that we are , possibly, neglecting the big picture.
Anton
Haha, I can see the headlines now: A century of confusion comes to a close after someone finally points out the obvious.
I get the feeling that a lot of people in the field spend their time thinking of the elegance of the math rather than what the math actually describes.
"Quantum entanglement is a quantum mechanical phenomenon in which the quantum states of two or more objects have to be described with reference to each other, even though the individual objects may be spatially separated. This leads to correlations between observable physical properties of the systems. For example, it is possible to prepare two particles in a single quantum state such that when one is observed to be spin-up, the other one will always be observed to be spin-down and vice versa, this despite the fact that it is impossible to predict, according to quantum mechanics, which set of measurements will be observed. As a result, measurements performed on one system seem to be instantaneously influencing other systems entangled with it."
A question. If we have two or more objects for which we KNOW that they are in the "mirror" state correlation between themselves to begin with, that is, if one of them has a spin on the axis "x" upward then another has a spin on the axis "x" downward, that is, we know that those two particles cannot both have the same spin on the certain axis, how exactly an observation of the one particle to be with a spin upward makes an observation of another particle's spin to be downward as nonlocal phenomenon, if we have not know which spin particular particle had until we have observed one or another?
"However, classical information cannot be transmitted through entanglement faster than the speed of light."
I think in regard of this statement that we are , possibly, neglecting the big picture.
Anton
Haha, I can see the headlines now: A century of confusion comes to a close after someone finally points out the obvious.
I get the feeling that a lot of people in the field spend their time thinking of the elegance of the math rather than what the math actually describes.
It points out that no matter what we can eventually know, we will never be able to predict or control the future exactly.
QUOTE (Eric England+Jun 16 2007, 10:59 AM)
It points out that no matter what we can eventually know, we will never be able to predict or control the future exactly.
I think you missed his point. Entangled particles are essentially mirror images of each other, so once you observe one you have information on both of them.
It's akin to flipping a coin and getting heads, then having your mind blown because its tails on the other side.
I think you missed his point. Entangled particles are essentially mirror images of each other, so once you observe one you have information on both of them.
It's akin to flipping a coin and getting heads, then having your mind blown because its tails on the other side.
QUOTE (Wulf+Jun 16 2007, 05:14 PM)
I think you missed his point. Entangled particles are essentially mirror images of each other, so once you observe one you have information on both of them.
It's akin to flipping a coin and getting heads, then having your mind blown because its tails on the other side.
Wulf,
correct, that is what I meant. You said it more simply.
Anton
It's akin to flipping a coin and getting heads, then having your mind blown because its tails on the other side.
Wulf,
correct, that is what I meant. You said it more simply.
Anton
QUOTE (Wulf+Jun 16 2007, 10:14 AM)
I think you missed his point. Entangled particles are essentially mirror images of each other, so once you observe one you have information on both of them.
It's akin to flipping a coin and getting heads, then having your mind blown because its tails on the other side.
But isn't this after the fact, of having observed both of the sides? If you're already at the stage of flipping the coin, then there's no reason to have your mind blown.
So let's say you can predict the future, by saying it's going to be one side or the other. Can you say which side will come up, that it won't land on its edge, or what location it will be in when it happens?
It's akin to flipping a coin and getting heads, then having your mind blown because its tails on the other side.
But isn't this after the fact, of having observed both of the sides? If you're already at the stage of flipping the coin, then there's no reason to have your mind blown.
So let's say you can predict the future, by saying it's going to be one side or the other. Can you say which side will come up, that it won't land on its edge, or what location it will be in when it happens?
QUOTE (Eric England+Jun 16 2007, 11:32 AM)
But isn't this after the fact, of having observed both of the sides? If you're already at the stage of flipping the coin, then there's no reason to have your mind blown.
So let's say you can predict the future, by saying it's going to be one side or the other. Can you say which side will come up, that it won't land on its edge, or what location it will be in when it happens?
The crazy thing is that the act of observing the coin flip determines the face of the coin on the opposite side. Statistically the odds of the face being heads or tails is 1:2, however when we observe one side the probability of the opposite side having the opposing face becomes 1:1.
It is almost as if the act of observing the outcome of the coin flip determines the face on the unobserved side.
So let's say you can predict the future, by saying it's going to be one side or the other. Can you say which side will come up, that it won't land on its edge, or what location it will be in when it happens?
The crazy thing is that the act of observing the coin flip determines the face of the coin on the opposite side. Statistically the odds of the face being heads or tails is 1:2, however when we observe one side the probability of the opposite side having the opposing face becomes 1:1.
It is almost as if the act of observing the outcome of the coin flip determines the face on the unobserved side.
I have come to one idea about an experiment about so called quantum entanglement, but this imaged set up can only work under certain circumstances, about which I was trying to find a relevant information on the net, but with no luck. Too much results and pages, which amounted to an avalanche of irrelevant informations which very efficiently buried my initial enthusiasm to search through that gigantic pile of everything.
After some thinking what to do I concluded that instead torturing myself with this that it would be much better for me if I pass that job on you.
So, the question is..
Is it possible to change a spin of photon at will, so to speak?
Anton
Edit...I removed another question.
After some thinking what to do I concluded that instead torturing myself with this that it would be much better for me if I pass that job on you.
So, the question is..
Is it possible to change a spin of photon at will, so to speak?
Anton
Edit...I removed another question.
QUOTE (Wulf+Jun 16 2007, 10:44 AM)
The crazy thing is that the act of observing the coin flip determines the face of the coin on the opposite side. Statistically the odds of the face being heads or tails is 1:2, however when we observe one side the probability of the opposite side having the opposing face becomes 1:1.
It is almost as if the act of observing the outcome of the coin flip determines the face on the unobserved side.
Is it really so crazy that the once you've arrived at 1 of 2, the other always comes up? What would actually be crazy, is if you have a coin with heads and tails, heads came up and you turned it over, and heads was on the other side too.
What you're observing is the fundamental nature of the RELATIVE. Two things that never change, but infinitely intermingle with each other.
It is almost as if the act of observing the outcome of the coin flip determines the face on the unobserved side.
Is it really so crazy that the once you've arrived at 1 of 2, the other always comes up? What would actually be crazy, is if you have a coin with heads and tails, heads came up and you turned it over, and heads was on the other side too.
What you're observing is the fundamental nature of the RELATIVE. Two things that never change, but infinitely intermingle with each other.
QUOTE (Eric England+Jun 16 2007, 04:59 PM)
It points out that no matter what we can eventually know, we will never be able to predict or control the future exactly.
That sounds like a good prediction of the future.
That sounds like a good prediction of the future.
WHAT IS PHASE?
WHAT KIND OF WAVE GETS ENTANGLED?
WHAT KIND OF WAVE GETS ENTANGLED?
QUOTE (NoCleverName+Jun 17 2007, 06:27 PM)
That sounds like a good prediction of the future.
Yes. It's a "certain uncertainty".
Yes. It's a "certain uncertainty".
QUOTE (Mate+Jun 17 2007, 09:01 AM)
Is it possible to change a spin of photon at will, so to speak?
I think the power of the observer is highly overrated. We too easily assume that our observations affect the phenomenon we observe. To take it a step further and assume we can add our will to this process, is just another short-coming in our ability to be objective.
How can we even begin to say that what we observe is different, that what it actually is before we observe it?
Physics is far too subjective (ego-centric) at this point.
I think the power of the observer is highly overrated. We too easily assume that our observations affect the phenomenon we observe. To take it a step further and assume we can add our will to this process, is just another short-coming in our ability to be objective.
How can we even begin to say that what we observe is different, that what it actually is before we observe it?
Physics is far too subjective (ego-centric) at this point.
QUOTE (Eric England+Jun 18 2007, 01:00 AM)
Is it really so crazy that the once you've arrived at 1 of 2, the other always comes up? What would actually be crazy, is if you have a coin with heads and tails, heads came up and you turned it over, and heads was on the other side too.
What you're observing is the fundamental nature of the RELATIVE. Two things that never change, but infinitely intermingle with each other.
Eric England,
but the underlying point IS that they never change. If they never change, about what so called quantum entanglement nonlocal phenomenon we are talking about?
The most simple assumption ( in the line of Ockham's Razor ) would be that there is no nonlocal "causation" between two entanglemented photons, but there is only a simple correlation between two photons which are the "mirror" images of themselves.
Should not we take Ockham's Razor instead assuming some nonlocal phenomenon here, while there is no, as far as I know, some direct experimental evidence which would validate the hypothesis of so called quantum entanglement?
What would validate QME hypothesis would be, for example....
We produced two entanglemented photons, A and B, and they went in a different directions.
On the path of the photon A is a barrier made from some material through which the photon A can pass through only if it's spin is up on the certain axis( for example ).
On the path of the photon B is also a barrier through which the photon B also can pass only if it's spin is up on the certain axis.
But the path of the photon A to a barrier is significantly shorter, so when the photon A eventually passes it's barrier the photon B is still propagating to it's barrier.
If the photon A passes it's barrier that would mean that the photon B would not pass it's barrier because the spin of photon B is down if the the spin of the photon A is up.
Now, if it would be possible to change the spin of the photon A from up to down after the photon A passed it's barrier, but before the photon B approached its barrier, and if that change of the spin of the photon A from up to down would , apparently, change the spin of the photon B from down to up, and we observe that in the manner that the photon B also passes it's barrier, then that would be, indeed, a nonlocal phenomenon observed.
Is it possible to arrange an experiment alike this?
Anton
What you're observing is the fundamental nature of the RELATIVE. Two things that never change, but infinitely intermingle with each other.
Eric England,
but the underlying point IS that they never change. If they never change, about what so called quantum entanglement nonlocal phenomenon we are talking about?
The most simple assumption ( in the line of Ockham's Razor ) would be that there is no nonlocal "causation" between two entanglemented photons, but there is only a simple correlation between two photons which are the "mirror" images of themselves.
Should not we take Ockham's Razor instead assuming some nonlocal phenomenon here, while there is no, as far as I know, some direct experimental evidence which would validate the hypothesis of so called quantum entanglement?
What would validate QME hypothesis would be, for example....
We produced two entanglemented photons, A and B, and they went in a different directions.
On the path of the photon A is a barrier made from some material through which the photon A can pass through only if it's spin is up on the certain axis( for example ).
On the path of the photon B is also a barrier through which the photon B also can pass only if it's spin is up on the certain axis.
But the path of the photon A to a barrier is significantly shorter, so when the photon A eventually passes it's barrier the photon B is still propagating to it's barrier.
If the photon A passes it's barrier that would mean that the photon B would not pass it's barrier because the spin of photon B is down if the the spin of the photon A is up.
Now, if it would be possible to change the spin of the photon A from up to down after the photon A passed it's barrier, but before the photon B approached its barrier, and if that change of the spin of the photon A from up to down would , apparently, change the spin of the photon B from down to up, and we observe that in the manner that the photon B also passes it's barrier, then that would be, indeed, a nonlocal phenomenon observed.
Is it possible to arrange an experiment alike this?
Anton
QUOTE
but the underlying point IS that they never change. If they never change, about what so called quantum entanglement nonlocal phenomenon we are talking about?
Which is what I just said. Two relatives that never change, that intermingle with each other. The intermingling does not change the two relatives, but it changes their location (space and time) in respect to each other. This can happen not only as discrete point-likes in a larger field, but also as point-likes inside and outside of each other, at any scale.
As far as an experiment... don't know.
QUOTE (Eric England+Jun 18 2007, 06:44 PM)
Which is what I just said. Two relatives that never change, that intermingle with each other. The intermingling does not change the two relatives, but it changes their location (space and time) in respect to each other. This can happen not only as discrete point-likes in a larger field, but also as point-likes inside and outside of each other, at any scale.
As far as an experiment... don't know.
But where is the evidence that the fashion in which they change their location is the nonlocal causational consequence of their relationship between themselves?
Just because they are the mirror images of each other that alone does not make them intermingled with each other in nonlocal causational fashion.
Now, if it would be possible to set up the experiment alike one I proposed, and if we could observe that "imposed" change of one photon change other photon in nonlocal fashion , then we could say that influence of those two photons on their location is the consequence of the nonlocal causational relationship with each other.
Anton
As far as an experiment... don't know.
But where is the evidence that the fashion in which they change their location is the nonlocal causational consequence of their relationship between themselves?
Just because they are the mirror images of each other that alone does not make them intermingled with each other in nonlocal causational fashion.
Now, if it would be possible to set up the experiment alike one I proposed, and if we could observe that "imposed" change of one photon change other photon in nonlocal fashion , then we could say that influence of those two photons on their location is the consequence of the nonlocal causational relationship with each other.
Anton
Eric,
let me add another comment about this issue in order to achieve more clarity about the point I am making in case we still do not understand each other.
Let us say that two entanglemented photons have been created, and let us say that one of those two photons has been absorbed in the meantime by an electron, while other photon is still "free".
If we would now observe the remaining photon from two initially entanglemented , and if we would establish that that remaining photon has a spin up on the certain axis, we would know that if other photon has not been absorbed by an electron that that other photon would have a spin down on that particular axis.
If there would be some nonlocal causational interaction between those two photons then the absorption of one of the photons would have an influence on the remaining one, and that would be indeed a strange phenomenon.
But there is no such an influence, right?
If that is the case what is with all that fuss about so called quantum entanglement if the only "strange" thing is that if two photons were created as a mirror images of each other then that they are the mirror images of each other?
A quantum tautology?
Where is non-locality weirdness in all that ?
Anton
let me add another comment about this issue in order to achieve more clarity about the point I am making in case we still do not understand each other.
Let us say that two entanglemented photons have been created, and let us say that one of those two photons has been absorbed in the meantime by an electron, while other photon is still "free".
If we would now observe the remaining photon from two initially entanglemented , and if we would establish that that remaining photon has a spin up on the certain axis, we would know that if other photon has not been absorbed by an electron that that other photon would have a spin down on that particular axis.
If there would be some nonlocal causational interaction between those two photons then the absorption of one of the photons would have an influence on the remaining one, and that would be indeed a strange phenomenon.
But there is no such an influence, right?
If that is the case what is with all that fuss about so called quantum entanglement if the only "strange" thing is that if two photons were created as a mirror images of each other then that they are the mirror images of each other?
A quantum tautology?
Where is non-locality weirdness in all that ?
Anton
Hi,
I was just wondering,
If two photons get emitted and they are of opposing spin, isn't it obvious that if you measure the spin of either of them you will know the spin of the other?
Jan Rinze.
I was just wondering,
If two photons get emitted and they are of opposing spin, isn't it obvious that if you measure the spin of either of them you will know the spin of the other?
Jan Rinze.
To anyone possibly interested to settle this thing one way or another...
Is it possible to change a spin of particular photon on the certain axis from up to down, or vice versa , in experimental conditions, if we know which spin that particular photon has?
Is it possible to conduct the experiment I proposed or some other/similar experiment which if it would function would allow possibility to either observe nonlocal causational relationship between two entanglemented photons or to exclude non-locality as the factor in so called quantum entanglement?
Anton
Is it possible to change a spin of particular photon on the certain axis from up to down, or vice versa , in experimental conditions, if we know which spin that particular photon has?
Is it possible to conduct the experiment I proposed or some other/similar experiment which if it would function would allow possibility to either observe nonlocal causational relationship between two entanglemented photons or to exclude non-locality as the factor in so called quantum entanglement?
Anton
The Wiki article here might help to clarify..
http://en.wikipedia.org/wiki/Photon_entanglement
The crunch comes with photon pairs polarised at 45 degrees .. neither H nor V .. but if one passes through (a 45 degree filter) then the other won't..that's spooky where I come from.
Best wishes -C2.
Edit .. sorry . the '45 degree filter' should be at 45 degrees to the filter 'axis'.
http://en.wikipedia.org/wiki/Photon_entanglement
The crunch comes with photon pairs polarised at 45 degrees .. neither H nor V .. but if one passes through (a 45 degree filter) then the other won't..that's spooky where I come from.
Best wishes -C2.
Edit .. sorry . the '45 degree filter' should be at 45 degrees to the filter 'axis'.
Hmmm, I don't know much about optics. I'll need to do a bit of research.
At first glance it still seems to me that we should not be thinking of the entangled photons as seperate entities. They are two halves of a parent photon and should have an inherent symmetry that would affect the outcome.
At first glance it still seems to me that we should not be thinking of the entangled photons as seperate entities. They are two halves of a parent photon and should have an inherent symmetry that would affect the outcome.
I think most of you do not understand what the experiment is about.
The experiment goes like this: we create two entangled photons - then we keep one here and the other goes several light years away (for example). We measure the photon we have here and we instantly know the spin of the photon far away.
This would indicate that the information measured in here got transported instantly to the 'far away place' where the second of the pair of entangled photons was at the time of our measurement.
This experiment is tricky because it implies some superluminous means of transport for quantum information but we all know that's against the laws of physics. What we can assume is that local realism is incorrect. "Objects" (read: wavefunctions that represent objects) in fact can be in two places at the same time.
This simple assumption (postulated even in University of Vienna) solves the whole mistery. There would be no transport of information at a speed above the speed of light - there would be no transport of information at all because those two photons are in fact one wavefunction (after the process of entanglement through the means of breaking one photon into two photons of 1/2 the energy of the former using prism).
The experiment goes like this: we create two entangled photons - then we keep one here and the other goes several light years away (for example). We measure the photon we have here and we instantly know the spin of the photon far away.
This would indicate that the information measured in here got transported instantly to the 'far away place' where the second of the pair of entangled photons was at the time of our measurement.
This experiment is tricky because it implies some superluminous means of transport for quantum information but we all know that's against the laws of physics. What we can assume is that local realism is incorrect. "Objects" (read: wavefunctions that represent objects) in fact can be in two places at the same time.
This simple assumption (postulated even in University of Vienna) solves the whole mistery. There would be no transport of information at a speed above the speed of light - there would be no transport of information at all because those two photons are in fact one wavefunction (after the process of entanglement through the means of breaking one photon into two photons of 1/2 the energy of the former using prism).
The two particles don't allow the rest of the world to transmit information.
This solves the apparent paradox of instantaneous information transfer.
This solves the apparent paradox of instantaneous information transfer.
QUOTE (Enthalpy+Jul 2 2007, 08:40 AM)
The two particles don't allow the rest of the world to transmit information.
This solves the apparent paradox of instantaneous information transfer.
Could you elaborate on this? Interesting way to look at it.
This solves the apparent paradox of instantaneous information transfer.
Could you elaborate on this? Interesting way to look at it.
QUOTE (Confused2+Jun 29 2007, 12:55 PM)
The crunch comes with photon pairs polarized at 45 degrees .. neither H nor V .. but if one passes through (a 45 degree filter) then the other won't..that's spooky where I come from.
Best wishes -C2.
Edit .. sorry . the '45 degree filter' should be at 45 degrees to the filter 'axis'.
Hi to all,
I have been occupied recently with jumping from the horse on the donkey ( a national expression which is a subtle metaphor which illustrates a very very good judgment ) , when the horse is XP, the donkey is Vista, and result is that I am the victim. Therefore now I am in the mode to observe some photon with such intensity that it will entangle with itself and start running away.
C2,
those two polarized photons....are they entaglemented?
Assuming that they are entanglemented, that is, they are with opposite spins, but with the same polarization ( possible ? ), perhaps a combination of opposite spins and the same polarization is preventing one of the photons to rotate through?
Hey, what I know, I installed Vista.
Anton
Best wishes -C2.
Edit .. sorry . the '45 degree filter' should be at 45 degrees to the filter 'axis'.
Hi to all,
I have been occupied recently with jumping from the horse on the donkey ( a national expression which is a subtle metaphor which illustrates a very very good judgment ) , when the horse is XP, the donkey is Vista, and result is that I am the victim. Therefore now I am in the mode to observe some photon with such intensity that it will entangle with itself and start running away.
C2,
those two polarized photons....are they entaglemented?
Assuming that they are entanglemented, that is, they are with opposite spins, but with the same polarization ( possible ? ), perhaps a combination of opposite spins and the same polarization is preventing one of the photons to rotate through?
Hey, what I know, I installed Vista.
Anton
Let us say that two entanglemented photons, A and B , have been created in the state of QE because we did not have anything more useful to do at that time. And after that miraculous birth from a boredom the photon A went on its own in the direction of the filter, while the photon B went in different direction.
Then,the photon A has been observed to pass through that filter, for which we know that that filter is "allowing" through a photons with spin up, so we know that photon A has a spin up. Above that, after passing that filter the photon A continued on it's journey to be absorbed by an electron, then that electron has been absorbed by atom, and the atom participated in an nuclear explosion. All that just to be sure that once the photon A "chose" it's spin it was dead and buried, so it could not by any means have anything to say to the photon B. None. Ever. Period.
Now, the spin for recently deceased photon A was up, which implies by QE that photon B has the spin down, and if we would now measure the spin of the photon B it would be down. But the photon B run away and it continued to propagate for one million years with no interaction with anything on his "way". And as I understand what QM is saying if we would measure the spin of the photon B after one million years the spin would be down. So the photon B traveled one million years with defined spin, even an entanglement has been broken by the act of the photon A assuming the spin up one millions years ago.
This is what is interesting me.
The crucial precondition for the quantum entanglement is an assumption that photons do not have defined spins, but their spins are in the state of supposition, until they interact with environment in some way, which consequently determine what is the spin of particular photon from two possible.
If a "normal" photon has undefined spin, what would happened if such a photon would pass through the fitter through which the photon A passed? That "normal" photon would have the spin up like the photon A.
The question. Would that "normal" photon continue to propagate with defined spin up?
Rest of this litany is dependable on what is the answer on this question.
Anton
Then,the photon A has been observed to pass through that filter, for which we know that that filter is "allowing" through a photons with spin up, so we know that photon A has a spin up. Above that, after passing that filter the photon A continued on it's journey to be absorbed by an electron, then that electron has been absorbed by atom, and the atom participated in an nuclear explosion. All that just to be sure that once the photon A "chose" it's spin it was dead and buried, so it could not by any means have anything to say to the photon B. None. Ever. Period.
Now, the spin for recently deceased photon A was up, which implies by QE that photon B has the spin down, and if we would now measure the spin of the photon B it would be down. But the photon B run away and it continued to propagate for one million years with no interaction with anything on his "way". And as I understand what QM is saying if we would measure the spin of the photon B after one million years the spin would be down. So the photon B traveled one million years with defined spin, even an entanglement has been broken by the act of the photon A assuming the spin up one millions years ago.
This is what is interesting me.
The crucial precondition for the quantum entanglement is an assumption that photons do not have defined spins, but their spins are in the state of supposition, until they interact with environment in some way, which consequently determine what is the spin of particular photon from two possible.
If a "normal" photon has undefined spin, what would happened if such a photon would pass through the fitter through which the photon A passed? That "normal" photon would have the spin up like the photon A.
The question. Would that "normal" photon continue to propagate with defined spin up?
Rest of this litany is dependable on what is the answer on this question.
Anton
QUOTE (KaerbEmEvig+Jul 2 2007, 10:52 AM)
I think most of you do not understand what the experiment is about.
The experiment goes like this: we create two entangled photons - then we keep one here and the other goes several light years away (for example). We measure the photon we have here and we instantly know the spin of the photon far away.
This would indicate that the information measured in here got transported instantly to the 'far away place' where the second of the pair of entangled photons was at the time of our measurement.
This experiment is tricky because it implies some superluminous means of transport for quantum information but we all know that's against the laws of physics. What we can assume is that local realism is incorrect. "Objects" (read: wavefunctions that represent objects) in fact can be in two places at the same time.
This simple assumption (postulated even in University of Vienna) solves the whole mistery. There would be no transport of information at a speed above the speed of light - there would be no transport of information at all because those two photons are in fact one wavefunction (after the process of entanglement through the means of breaking one photon into two photons of 1/2 the energy of the former using prism).
Which is, of course, nonsense because photons cannot break in half. A photon being the smallest unit of radiant energy.
http://en.wikipedia.org/wiki/Photon_entanglement describes quantum entanglement in detail where at all times there are two photons. And this entanglement can occur when the two outer electrons of an atom (which themselves can be described as entangled) cascade to a lower energy state and thereby emitting two photons that are oppositely polarised. Entanglement can also be measured to occor between protons.
One can insist that there is no adequate explanation of entanglement in quantum theory since this would need to be causal and, at least from any evidence of matter and radiant energy on the smallest scale alone, enough details cannot be both justified and described of any cause that would act in addition to the known forces.
The experiment goes like this: we create two entangled photons - then we keep one here and the other goes several light years away (for example). We measure the photon we have here and we instantly know the spin of the photon far away.
This would indicate that the information measured in here got transported instantly to the 'far away place' where the second of the pair of entangled photons was at the time of our measurement.
This experiment is tricky because it implies some superluminous means of transport for quantum information but we all know that's against the laws of physics. What we can assume is that local realism is incorrect. "Objects" (read: wavefunctions that represent objects) in fact can be in two places at the same time.
This simple assumption (postulated even in University of Vienna) solves the whole mistery. There would be no transport of information at a speed above the speed of light - there would be no transport of information at all because those two photons are in fact one wavefunction (after the process of entanglement through the means of breaking one photon into two photons of 1/2 the energy of the former using prism).
Which is, of course, nonsense because photons cannot break in half. A photon being the smallest unit of radiant energy.
http://en.wikipedia.org/wiki/Photon_entanglement describes quantum entanglement in detail where at all times there are two photons. And this entanglement can occur when the two outer electrons of an atom (which themselves can be described as entangled) cascade to a lower energy state and thereby emitting two photons that are oppositely polarised. Entanglement can also be measured to occor between protons.
One can insist that there is no adequate explanation of entanglement in quantum theory since this would need to be causal and, at least from any evidence of matter and radiant energy on the smallest scale alone, enough details cannot be both justified and described of any cause that would act in addition to the known forces.
QUOTE (OutoftheWood+Jul 2 2007, 10:56 PM)
Which is, of course, nonsense because photons cannot break in half. A photon being the smallest unit of radiant energy.
http://en.wikipedia.org/wiki/Photon_entanglement describes quantum entanglement in detail where at all times there are two photons. And this entanglement can occur when the two outer electrons of an atom (which themselves can be described as entangled) cascade to a lower energy state and thereby emitting two photons that are oppositely polarised. Entanglement can also be measured to occor between protons.
One can insist that there is no adequate explanation of entanglement in quantum theory since this would need to be causal and, at least from any evidence of matter and radiant energy on the smallest scale alone, enough details cannot be both justified and described of any cause that would act in addition to the known forces.
I think you are wrong and you jump to conclusions way too fast.
You give Wikipedia as your source. I give an academic article:
4th paragraph.
Link (can't use the URL option, I'm unregistered at the moment):
grad.physics.sunysb.edu/~amarch/
I think you forgot about the fact photons are also waves. You should work on your attitude and not attack people when you think they are wrong. It may turn out that it was you who was wrong.
http://en.wikipedia.org/wiki/Photon_entanglement describes quantum entanglement in detail where at all times there are two photons. And this entanglement can occur when the two outer electrons of an atom (which themselves can be described as entangled) cascade to a lower energy state and thereby emitting two photons that are oppositely polarised. Entanglement can also be measured to occor between protons.
One can insist that there is no adequate explanation of entanglement in quantum theory since this would need to be causal and, at least from any evidence of matter and radiant energy on the smallest scale alone, enough details cannot be both justified and described of any cause that would act in addition to the known forces.
I think you are wrong and you jump to conclusions way too fast.
You give Wikipedia as your source. I give an academic article:
QUOTE
The entangled photons are produced by a process called spontaneous parametric down conversion. This takes place in a special nonlinear crystal called beta-barium borate (BBO). A photon from an argon ion pump laser (351.1 nm) is converted to two longer wavelength (702.2 nm) photons. The two photons go off in two different directions. In this experiment, we call one direction p and the other s. The photons that go down path p are called p photons and those that go down s are called s photons.
4th paragraph.
Link (can't use the URL option, I'm unregistered at the moment):
grad.physics.sunysb.edu/~amarch/
I think you forgot about the fact photons are also waves. You should work on your attitude and not attack people when you think they are wrong. It may turn out that it was you who was wrong.
KaerbEmEvig: I hope you stick around, enjoying your posts so far.
Now back to the discussion. Is anyone here able to address the point that C2 brought up regarding the 45 degree polarization? I don't understand his point well enought to even speculate at this point, but I have no doubt he knows what he is talking about.
Any thoughts?
Now back to the discussion. Is anyone here able to address the point that C2 brought up regarding the 45 degree polarization? I don't understand his point well enought to even speculate at this point, but I have no doubt he knows what he is talking about.
Any thoughts?
I am also not quite sure what C2 is saying. Perhaps a clarification with some illustration would be useful?
Now, let me ask again. If a photon is considered that it has undefined spin until it interact/being observed in some fashion, and if in that assumption of a photon having undefined spin is the whole "magic" of the quantum entanglement, what is happening if some previously entanglemented photon continued to propagate after it's spin has been determined by. for example, passing through some filter? Does that previously entanglemented photon assume it's usual state of undefined spin after the previous act of determining it's spin in the moment of time and space, in the past?
What would happen with a photon which was not entanglemented and which also had determined spin in the moment of time and space by passing through that filter? Would that photon assume it's usual state of undefined spin after passing the filter or would that photon continue to propagate with defined spin like other , still unobserved, photon from two initially entanglemented?
Let me also ask about one analogical situation. In the Stern/Gerlach experiment particles are passing between two magnets.
The question.
Once a particle in the experiment assumes , for example a spin down, how long it propagates in the state of defined spin?
If on the other hand a particle after assuming particular spin is staying in the same state of the spin down , how we can be sure that particles are propagating in the state of undefined spin to begin with?
Moreover, if a particle after assuming particular spin is getting back in it's usual state of undefined spin, should not some particle which assumed a spin down and went toward lower part of the screen now be observed with spin up if we would instead the lower part of the screen put a filter which is letting through particles with spin up?
Anton
Now, let me ask again. If a photon is considered that it has undefined spin until it interact/being observed in some fashion, and if in that assumption of a photon having undefined spin is the whole "magic" of the quantum entanglement, what is happening if some previously entanglemented photon continued to propagate after it's spin has been determined by. for example, passing through some filter? Does that previously entanglemented photon assume it's usual state of undefined spin after the previous act of determining it's spin in the moment of time and space, in the past?
What would happen with a photon which was not entanglemented and which also had determined spin in the moment of time and space by passing through that filter? Would that photon assume it's usual state of undefined spin after passing the filter or would that photon continue to propagate with defined spin like other , still unobserved, photon from two initially entanglemented?
Let me also ask about one analogical situation. In the Stern/Gerlach experiment particles are passing between two magnets.
The question.
Once a particle in the experiment assumes , for example a spin down, how long it propagates in the state of defined spin?
If on the other hand a particle after assuming particular spin is staying in the same state of the spin down , how we can be sure that particles are propagating in the state of undefined spin to begin with?
Moreover, if a particle after assuming particular spin is getting back in it's usual state of undefined spin, should not some particle which assumed a spin down and went toward lower part of the screen now be observed with spin up if we would instead the lower part of the screen put a filter which is letting through particles with spin up?
Anton
QUOTE (Wulf+Jul 3 2007, 11:26 PM)
KaerbEmEvig: I hope you stick around, enjoying your posts so far.
Now back to the discussion. Is anyone here able to address the point that C2 brought up regarding the 45 degree polarization? I don't understand his point well enought to even speculate at this point, but I have no doubt he knows what he is talking about.
Any thoughts?
Personally:
I think that matter is not a vessel for information. Rather - it's information that codes matter (this is view postulated even at University of Wien - nonlocal nonrealism, if I recall correctly - I can be wrong).
This would mean that matter (which is infact information expressed as matter) does not influence/change matter when they interefere with eachother - it influences the information 'behind' the matter thus 'erasing' the 'information' in the quantum eraser experiment would not be spooky at all - even the slightest.
It would simply mean that the information that codes the interference (spelling?) fringes has been changed/modified (the 'where from' information) so that matter exhibis the corpuscular nature - it certainly can be changed back because the information is still there, just not expressed.
Think of it as with genetics. Matter equals to proteins, information equals to DNA. Each cell has the whole genome present but only some parts of it are expressed. I take genes as a good analogy to matter. I see matter as coded by information.
___________________________
This way the 45 dg. paradox has been easily solved. Light goes through the V polarizer - only V polazired (or is it H? doesn't really matter at the moment), it then goes through the H polarizer - no light passes through.
I come to a bit different conclusions than most scientists. If my hypothesis is correct - and information codes the matter (and not: matter transports information) - then in reality all the light passes through, not only V polarized. But non-V light is not expressed anymore.
If it then goes through the H polarizer - V polarized light is no longer expressed: we see no light.
If we set a 45 dg. (a polarizer positioned at 45 dg. to the remaining polarizers, that is) polarizer inbetween - we will measure 50% H polarized and 50% V polarized light passing through (but the intensity will be only 1/4 of the source light, if I recall correctly). Then the light will go through the H polarizer and we see only H polarized light with 1/8 intensity of the source light.
With the assumption that everything is coded by information - this experiment becomes simply [probability] mathematics. H polarizers to V polarizer is nothing else but a V polarizer at 90 dg. - correct?
This means that 0 dg. shift = 100% of light passing through the second polarizer; 45 dg. shift = 50% light passing through (the light passing through the 45 dg. polarizer has been already polarized - so it equals to 1/4 of the former light passing through); 90 dg. = 0%.
I may have explained it badly and unclearly, so here's a link to a site explaining it alot better than I could:
upscale.utoronto.ca/GeneralInterest/Harrison/SternGerlach/Polarisation.html
Now back to the discussion. Is anyone here able to address the point that C2 brought up regarding the 45 degree polarization? I don't understand his point well enought to even speculate at this point, but I have no doubt he knows what he is talking about.
Any thoughts?
Personally:
I think that matter is not a vessel for information. Rather - it's information that codes matter (this is view postulated even at University of Wien - nonlocal nonrealism, if I recall correctly - I can be wrong).
This would mean that matter (which is infact information expressed as matter) does not influence/change matter when they interefere with eachother - it influences the information 'behind' the matter thus 'erasing' the 'information' in the quantum eraser experiment would not be spooky at all - even the slightest.
It would simply mean that the information that codes the interference (spelling?) fringes has been changed/modified (the 'where from' information) so that matter exhibis the corpuscular nature - it certainly can be changed back because the information is still there, just not expressed.
Think of it as with genetics. Matter equals to proteins, information equals to DNA. Each cell has the whole genome present but only some parts of it are expressed. I take genes as a good analogy to matter. I see matter as coded by information.
___________________________
This way the 45 dg. paradox has been easily solved. Light goes through the V polarizer - only V polazired (or is it H? doesn't really matter at the moment), it then goes through the H polarizer - no light passes through.
I come to a bit different conclusions than most scientists. If my hypothesis is correct - and information codes the matter (and not: matter transports information) - then in reality all the light passes through, not only V polarized. But non-V light is not expressed anymore.
If it then goes through the H polarizer - V polarized light is no longer expressed: we see no light.
If we set a 45 dg. (a polarizer positioned at 45 dg. to the remaining polarizers, that is) polarizer inbetween - we will measure 50% H polarized and 50% V polarized light passing through (but the intensity will be only 1/4 of the source light, if I recall correctly). Then the light will go through the H polarizer and we see only H polarized light with 1/8 intensity of the source light.
With the assumption that everything is coded by information - this experiment becomes simply [probability] mathematics. H polarizers to V polarizer is nothing else but a V polarizer at 90 dg. - correct?
This means that 0 dg. shift = 100% of light passing through the second polarizer; 45 dg. shift = 50% light passing through (the light passing through the 45 dg. polarizer has been already polarized - so it equals to 1/4 of the former light passing through); 90 dg. = 0%.
I may have explained it badly and unclearly, so here's a link to a site explaining it alot better than I could:
upscale.utoronto.ca/GeneralInterest/Harrison/SternGerlach/Polarisation.html
To all,
I asked few questions in last few posts in this thread but noone answered/commented those questions, and I am not sure why.
Is it because there are already known answers on those questions and noone wants to bother answering/saying "elementary" stuff ( understandable attitude, of course ) or noone answered/commented those questions because there are no known, standard answers on those question?
Anton
I asked few questions in last few posts in this thread but noone answered/commented those questions, and I am not sure why.
Is it because there are already known answers on those questions and noone wants to bother answering/saying "elementary" stuff ( understandable attitude, of course ) or noone answered/commented those questions because there are no known, standard answers on those question?
Anton
QUOTE (Mate+Jul 8 2007, 02:58 AM)
To all,
I asked few questions in last few posts in this thread but noone answered/commented those questions, and I am not sure why.
Is it because there are already known answers on those questions and noone wants to bother answering/saying "elementary" stuff ( understandable attitude, of course ) or noone answered/commented those questions because there are no known, standard answers on those question?
Anton
I'm not sure that the nature of spin is that well understood. I'd assume that those in the know would be hesitant to answer if the best they could offer is speculation.
I asked few questions in last few posts in this thread but noone answered/commented those questions, and I am not sure why.
Is it because there are already known answers on those questions and noone wants to bother answering/saying "elementary" stuff ( understandable attitude, of course ) or noone answered/commented those questions because there are no known, standard answers on those question?
Anton
I'm not sure that the nature of spin is that well understood. I'd assume that those in the know would be hesitant to answer if the best they could offer is speculation.
QUOTE (Wulf+Jul 8 2007, 09:20 AM)
I'm not sure that the nature of spin is that well understood. I'd assume that those in the know would be hesitant to answer if the best they could offer is speculation.
Wulf,
I am searching for some experimental evidence which cannot be interpreted in any other way but as an evidence which validates the hypothesis that photons have undefined spin. I am sure that there are experimental findings which support or it is widely considered to support the hypothesis about the spin of a photon to be in the state of supposition until an act of observation in some fashion. But I have not found such a paper yet.
If there is someone here who can point out such a material it will be appreciated if he will do so.
Anton
Wulf,
I am searching for some experimental evidence which cannot be interpreted in any other way but as an evidence which validates the hypothesis that photons have undefined spin. I am sure that there are experimental findings which support or it is widely considered to support the hypothesis about the spin of a photon to be in the state of supposition until an act of observation in some fashion. But I have not found such a paper yet.
If there is someone here who can point out such a material it will be appreciated if he will do so.
Anton
Hi Anton et al,
The reason for my lack of further contribution is that I can't find a link to the experiment which I believe I am correctly quoting the result of.
My unsubstantiated claim remains...
If we toss a coin the result should be 50:50 heads/tails. If we give one coin to Alice and another to Bob and they toss them we'd expect the results to be unrelated. If (every time) Alice gets 'tails' we found Bob gets 'heads' (and vice versa) then we'd start to suspect something strange about the two coins.
If we have a photon polarised at 45 degrees to a filter then the 'amplitude' for it to pass/absorb should be 50:50 (the intensity will therefore be 1/sqrt(2) .. let's not go there). With entangled photons .. if the Alice photon is absorbed then the Bob photon will pass and vice versa.
If anyone finds the experiment please post it .. meantime we must allow for the possibility that I have made up the result - but I don't think so.
Best wishes - C2.
The reason for my lack of further contribution is that I can't find a link to the experiment which I believe I am correctly quoting the result of.
My unsubstantiated claim remains...
If we toss a coin the result should be 50:50 heads/tails. If we give one coin to Alice and another to Bob and they toss them we'd expect the results to be unrelated. If (every time) Alice gets 'tails' we found Bob gets 'heads' (and vice versa) then we'd start to suspect something strange about the two coins.
If we have a photon polarised at 45 degrees to a filter then the 'amplitude' for it to pass/absorb should be 50:50 (the intensity will therefore be 1/sqrt(2) .. let's not go there). With entangled photons .. if the Alice photon is absorbed then the Bob photon will pass and vice versa.
If anyone finds the experiment please post it .. meantime we must allow for the possibility that I have made up the result - but I don't think so.
Best wishes - C2.
QUOTE (Mate+Jul 9 2007, 03:45 AM)
Wulf,
I am searching for some experimental evidence which cannot be interpreted in any other way but as an evidence which validates the hypothesis that photons have undefined spin. I am sure that there are experimental findings which support or it is widely considered to support the hypothesis about the spin of a photon to be in the state of supposition until an act of observation in some fashion. But I have not found such a paper yet.
If there is someone here who can point out such a material it will be appreciated if he will do so.
Anton
I wish I had time to research this properly. It is a really interesting way to look at entanglement, and knowing if it is valid or not would be nice.
I'm studying Japanese at the moment so all my energy has been going into learning to read the language. Once I get my head around that I'll go hunting for papers.
I am searching for some experimental evidence which cannot be interpreted in any other way but as an evidence which validates the hypothesis that photons have undefined spin. I am sure that there are experimental findings which support or it is widely considered to support the hypothesis about the spin of a photon to be in the state of supposition until an act of observation in some fashion. But I have not found such a paper yet.
If there is someone here who can point out such a material it will be appreciated if he will do so.
Anton
I wish I had time to research this properly. It is a really interesting way to look at entanglement, and knowing if it is valid or not would be nice.
I'm studying Japanese at the moment so all my energy has been going into learning to read the language. Once I get my head around that I'll go hunting for papers.
QUOTE (Confused2+Jul 9 2007, 10:33 AM)
Hi Anton et al,
The reason for my lack of further contribution is that I can't find a link to the experiment which I believe I am correctly quoting the result of.
My unsubstantiated claim remains...
If we toss a coin the result should be 50:50 heads/tails. If we give one coin to Alice and another to Bob and they toss them we'd expect the results to be unrelated. If (every time) Alice gets 'tails' we found Bob gets 'heads' (and vice versa) then we'd start to suspect something strange about the two coins.
If we have a photon polarised at 45 degrees to a filter then the 'amplitude' for it to pass/absorb should be 50:50 (the intensity will therefore be 1/sqrt(2) .. let's not go there). With entangled photons .. if the Alice photon is absorbed then the Bob photon will pass and vice versa.
If anyone finds the experiment please post it .. meantime we must allow for the possibility that I have made up the result - but I don't think so.
Best wishes - C2.
C2,
if a photons which are polarized at 45 degrees to a filter are passing that filter in 50 % of the cases that implies that polarization itself does not determine a priori would a photon pass or not through that that filter. Something else does. What is it?
If one from a two entanglemented photons, which are also polarized at 45 degrees to a filter, is passing while other entanglemented photon does not then that also implies that polarization itself does not determine, at least not solely, would a photon with certain polarization pass or not a filter. Something else does. What is it?
Again. The key assumption for QE to "work" is the assumption that spin of a photon is in the state of supposition before an observation.
If that is the case then....
If a photon assumes at a very act of observation a spin down ( or up ) on a certain axis, for example, does that photon remain in the state of spin down in regard to the axis indefinitely?
If yes, is not the most simple implication which springs from that that photon has a defined spin, if a photon stays in the same spin after an observation?
If a photon, indeed, has undefined spin that could be tested. Let us say that we have a line of 20 ( or more or less ) filters which are "letting" through a photons with spin up, for example.
If a particular photon in it's usual state has undefined spin in the state of supposition, and if that particular photon assumes it's spin unpredictably at the very moment of an act of observation, then that photon would not pass all 20 filters which are letting through photons with spin up because that particular photon would assume it's spin in unpredictable way at EVERY act of observation, which implies that that particular photon would, soon or later, assume a spin down instead a spin up if it's spin is indeed in the state of supposition. There is extremely small probability that that photon would in random manner assume the same spin up in 20 consequent act of observations/passing filters.
So, if every photon which passed first filter would came out from the last filter then the most simple interpretation from that finding would be that photons actually have a defined spin. And if that is the case there is no QE to talk about, but there are just two photons with defined opposite characteristics, which are consequently behaving in "opposite" manner in regard to those opposite characteristics.
Is it expensive to set up and try this experiment?
Anton
The reason for my lack of further contribution is that I can't find a link to the experiment which I believe I am correctly quoting the result of.
My unsubstantiated claim remains...
If we toss a coin the result should be 50:50 heads/tails. If we give one coin to Alice and another to Bob and they toss them we'd expect the results to be unrelated. If (every time) Alice gets 'tails' we found Bob gets 'heads' (and vice versa) then we'd start to suspect something strange about the two coins.
If we have a photon polarised at 45 degrees to a filter then the 'amplitude' for it to pass/absorb should be 50:50 (the intensity will therefore be 1/sqrt(2) .. let's not go there). With entangled photons .. if the Alice photon is absorbed then the Bob photon will pass and vice versa.
If anyone finds the experiment please post it .. meantime we must allow for the possibility that I have made up the result - but I don't think so.
Best wishes - C2.
C2,
if a photons which are polarized at 45 degrees to a filter are passing that filter in 50 % of the cases that implies that polarization itself does not determine a priori would a photon pass or not through that that filter. Something else does. What is it?
If one from a two entanglemented photons, which are also polarized at 45 degrees to a filter, is passing while other entanglemented photon does not then that also implies that polarization itself does not determine, at least not solely, would a photon with certain polarization pass or not a filter. Something else does. What is it?
Again. The key assumption for QE to "work" is the assumption that spin of a photon is in the state of supposition before an observation.
If that is the case then....
If a photon assumes at a very act of observation a spin down ( or up ) on a certain axis, for example, does that photon remain in the state of spin down in regard to the axis indefinitely?
If yes, is not the most simple implication which springs from that that photon has a defined spin, if a photon stays in the same spin after an observation?
If a photon, indeed, has undefined spin that could be tested. Let us say that we have a line of 20 ( or more or less ) filters which are "letting" through a photons with spin up, for example.
If a particular photon in it's usual state has undefined spin in the state of supposition, and if that particular photon assumes it's spin unpredictably at the very moment of an act of observation, then that photon would not pass all 20 filters which are letting through photons with spin up because that particular photon would assume it's spin in unpredictable way at EVERY act of observation, which implies that that particular photon would, soon or later, assume a spin down instead a spin up if it's spin is indeed in the state of supposition. There is extremely small probability that that photon would in random manner assume the same spin up in 20 consequent act of observations/passing filters.
So, if every photon which passed first filter would came out from the last filter then the most simple interpretation from that finding would be that photons actually have a defined spin. And if that is the case there is no QE to talk about, but there are just two photons with defined opposite characteristics, which are consequently behaving in "opposite" manner in regard to those opposite characteristics.
Is it expensive to set up and try this experiment?
Anton
QUOTE (Wulf+Jul 9 2007, 10:36 AM)
I wish I had time to research this properly. It is a really interesting way to look at entanglement, and knowing if it is valid or not would be nice.
I'm studying Japanese at the moment so all my energy has been going into learning to read the language. Once I get my head around that I'll go hunting for papers.
Japanese? You want to learn reading Japanese?
Ok, see you in few years.
Anton
I'm studying Japanese at the moment so all my energy has been going into learning to read the language. Once I get my head around that I'll go hunting for papers.
Japanese? You want to learn reading Japanese?
Ok, see you in few years.
Anton
QUOTE (Confused2+Jul 9 2007, 10:33 AM)
Hi Anton et al,
The reason for my lack of further contribution is that I can't find a link to the experiment which I believe I am correctly quoting the result of.
My unsubstantiated claim remains...
If we toss a coin the result should be 50:50 heads/tails. If we give one coin to Alice and another to Bob and they toss them we'd expect the results to be unrelated. If (every time) Alice gets 'tails' we found Bob gets 'heads' (and vice versa) then we'd start to suspect something strange about the two coins.
We don't give Alice one coin and Bob another. We give Alice, for example, tails (half of the former coin - we cut it in half so that one side is tails/heads and the other is blank) - covered so that she can't see whether it's tail or heads.
At the same time we give Bob heads covered so that he cannot he whether it's heads or tails.
At this point the chance that Bob will have heads is 50% - but the chance that at the same time Alice will have tails is now 100% (and that she will have heads is 0%) due to the fact we know Bob has tails. That's entanglement.
The reason for my lack of further contribution is that I can't find a link to the experiment which I believe I am correctly quoting the result of.
My unsubstantiated claim remains...
If we toss a coin the result should be 50:50 heads/tails. If we give one coin to Alice and another to Bob and they toss them we'd expect the results to be unrelated. If (every time) Alice gets 'tails' we found Bob gets 'heads' (and vice versa) then we'd start to suspect something strange about the two coins.
We don't give Alice one coin and Bob another. We give Alice, for example, tails (half of the former coin - we cut it in half so that one side is tails/heads and the other is blank) - covered so that she can't see whether it's tail or heads.
At the same time we give Bob heads covered so that he cannot he whether it's heads or tails.
At this point the chance that Bob will have heads is 50% - but the chance that at the same time Alice will have tails is now 100% (and that she will have heads is 0%) due to the fact we know Bob has tails. That's entanglement.
EDIT: he cannot see* - not "he". Can a moderator delete this post and edit my previous, please? Thanks in advance. Also - could an admin create me an account "KaerbEmEvig" - I would change the password when I get to it. The registration e-mail doesn't come.
QUOTE (Mate+Jul 9 2007, 01:14 PM)
So, if every photon which passed first filter would came out from the last filter then the most simple interpretation from that finding would be that photons actually have a defined spin. And if that is the case there is no QE to talk about, but there are just two photons with defined opposite characteristics, which are consequently behaving in "opposite" manner in regard to those opposite characteristics.
Is it expensive to set up and try this experiment?
If I recall correctly - QE has nothing to do with superposition, so no - those aren't just two oppositely characterised photons. They are entangled. They do have defined spins after they have been created but that does not mean we know what those spins are - we need to measure that.
After the meaurement we notice not only that the spins of those two entangled photons are opposite but also that the second spin has been measured through only measuring one of the entangled photons (vide: Double Slit Quantum Eraser experiment).
My "coin split in half" analogy works very well to describe entanglement.
Is it expensive to set up and try this experiment?
If I recall correctly - QE has nothing to do with superposition, so no - those aren't just two oppositely characterised photons. They are entangled. They do have defined spins after they have been created but that does not mean we know what those spins are - we need to measure that.
After the meaurement we notice not only that the spins of those two entangled photons are opposite but also that the second spin has been measured through only measuring one of the entangled photons (vide: Double Slit Quantum Eraser experiment).
My "coin split in half" analogy works very well to describe entanglement.
QUOTE (KaerbEmEvig+Jul 9 2007, 07:43 AM)
My "coin split in half" analogy works very well to describe entanglement.
Agreed, this is how I understood it as well.
Agreed, this is how I understood it as well.
We have a filter which allows vertically polarised photons to pass. Whatever the initial orientation of the photon - if it passes it is vertically polarised and will pass through any number of vertically polarised filters and will be blocked 100% by a horizontal filter.
We have two photons with entangled polarisation states at 90 degrees - we arrange for them to be at plus or minus 45 degrees to our test filters.
Our Alice photon passes through the vertically polarised filter and is now vertically polarised. The Bob photon can't pass through a vertically polarised filter because it is now horizontally polarised (it is still entangled at 90 degrees to the Alice photon). And vice versa.
I think this says the same thing but seems to take rather more words to do it in :- http://en.wikipedia.org/wiki/Photon_entanglement
Best wishes - C2.
We have two photons with entangled polarisation states at 90 degrees - we arrange for them to be at plus or minus 45 degrees to our test filters.
Our Alice photon passes through the vertically polarised filter and is now vertically polarised. The Bob photon can't pass through a vertically polarised filter because it is now horizontally polarised (it is still entangled at 90 degrees to the Alice photon). And vice versa.
I think this says the same thing but seems to take rather more words to do it in :- http://en.wikipedia.org/wiki/Photon_entanglement
Best wishes - C2.
QUOTE (KaerbEmEvig+Jul 9 2007, 01:30 PM)
We don't give Alice one coin and Bob another....
KaerbEmEvig,
that is what the quantum entanglement "magic" is saying. The magic is in the assumption that both Alice and Bob are having a coins which have the both sides, head and tail, and as soon Alice toss a coin and gets the head then if Bob would toss a coin he would have a tail, always.
Anton
KaerbEmEvig,
that is what the quantum entanglement "magic" is saying. The magic is in the assumption that both Alice and Bob are having a coins which have the both sides, head and tail, and as soon Alice toss a coin and gets the head then if Bob would toss a coin he would have a tail, always.
Anton
QUOTE (Confused2+Jul 9 2007, 02:50 PM)
We have a filter which allows vertically polarised photons to pass. Whatever the initial orientation of the photon - if it passes it is vertically polarised and will pass through any number of vertically polarised filters and will be blocked 100% by a horizontal filter.
We have two photons with entangled polarization states at 90 degrees - we arrange for them to be at plus or minus 45 degrees to our test filters.
Our Alice photon passes through the vertically polarised filter and is now vertically polarised. The Bob photon can't pass through a vertically polarised filter because it is now horizontally polarised (it is still entangled at 90 degrees to the Alice photon). And vice versa.
I think this says the same thing but seems to take rather more words to do it in :- http://en.wikipedia.org/wiki/Photon_entanglement
Best wishes - C2.
C2,
actually, if we would have that filter which "allows" vertically polarized photons, and if we would pointed toward that filter a beam of photons with randomly distributed polarization, that is, between those photons are those which are polarized at every possible degree in regard to that filter, and those photons are not entanglemented, again would half of the photons pass and other half would not.
Therefore when entanglemented photon with polarization of 45 degree in regard to that filer passed that filter that does not necessarily mean that now it is vertically polarized because from the excerpt above is clear that half of a "circle" of all possible degrees of polarization is passing that vertical filter.
The question is what are and where are exactly the degrees which are passing through. They combined are "making" 180 degrees of polarization in regard to that filter, and it would be interesting to see where exactly are those degrees of polarization which are passing through distributed around the circle.
Also, what is other factor which is determining which photon would pass and which would not ?
You mentioned two entanglemented photons, one polarized to the left at 45 degree, so to speak, and other to the right at 45 degrees, so to speak. Can we know did "left" or "right" one passed, and more importantly does always, for example, right photon passes or not?
Also, if one entaglemented photon has polarization at certain degree different than other entanglemented photon, does that photon have additional difference in regard to it's "twin"?
I have more comments but there is no rush. : )
Anton
PS. Still, how we can assume that photons have undefined spin before observation if photons "keep" their spin after an observation?
We have two photons with entangled polarization states at 90 degrees - we arrange for them to be at plus or minus 45 degrees to our test filters.
Our Alice photon passes through the vertically polarised filter and is now vertically polarised. The Bob photon can't pass through a vertically polarised filter because it is now horizontally polarised (it is still entangled at 90 degrees to the Alice photon). And vice versa.
I think this says the same thing but seems to take rather more words to do it in :- http://en.wikipedia.org/wiki/Photon_entanglement
Best wishes - C2.
C2,
actually, if we would have that filter which "allows" vertically polarized photons, and if we would pointed toward that filter a beam of photons with randomly distributed polarization, that is, between those photons are those which are polarized at every possible degree in regard to that filter, and those photons are not entanglemented, again would half of the photons pass and other half would not.
Therefore when entanglemented photon with polarization of 45 degree in regard to that filer passed that filter that does not necessarily mean that now it is vertically polarized because from the excerpt above is clear that half of a "circle" of all possible degrees of polarization is passing that vertical filter.
The question is what are and where are exactly the degrees which are passing through. They combined are "making" 180 degrees of polarization in regard to that filter, and it would be interesting to see where exactly are those degrees of polarization which are passing through distributed around the circle.
Also, what is other factor which is determining which photon would pass and which would not ?
You mentioned two entanglemented photons, one polarized to the left at 45 degree, so to speak, and other to the right at 45 degrees, so to speak. Can we know did "left" or "right" one passed, and more importantly does always, for example, right photon passes or not?
Also, if one entaglemented photon has polarization at certain degree different than other entanglemented photon, does that photon have additional difference in regard to it's "twin"?
I have more comments but there is no rush. : )
Anton
PS. Still, how we can assume that photons have undefined spin before observation if photons "keep" their spin after an observation?
One more thing.
It would be interested to see what is happening if we would have two entanglemented photos with 90 degrees difference of polarization between themselves, but if the degree of polarization of those entanglemented photons would be , for example, for photon A 15 degrees to the right in regard to the vertical filter, and for the photon B 75 degrees to the left in regard to the vertical filter. And vice versa.
(Edit) or some other combination of degrees.
Perhaps, and considering what I wrote about the polarization in the previous post, would both of those entanglemewnted photons pass thought that filter.
Anton
It would be interested to see what is happening if we would have two entanglemented photos with 90 degrees difference of polarization between themselves, but if the degree of polarization of those entanglemented photons would be , for example, for photon A 15 degrees to the right in regard to the vertical filter, and for the photon B 75 degrees to the left in regard to the vertical filter. And vice versa.
(Edit) or some other combination of degrees.
Perhaps, and considering what I wrote about the polarization in the previous post, would both of those entanglemewnted photons pass thought that filter.
Anton
QUOTE (Mate+Jul 9 2007, 05:16 PM)
KaerbEmEvig,
that is what the quantum entanglement "magic" is saying. The magic is in the assumption that both Alice and Bob are having a coins which have the both sides, head and tail, and as soon Alice toss a coin and gets the head then if Bob would toss a coin he would have a tail, always.
Anton
It's not a simple assumption - it's a scientific fact proven with experiments. Entagled partles behave as if they were one 'object' - measuring one of them results in measuring the other (how else would you explain the lack of interference pattern in when it comes don to the second particle - it hasn't been measured at all, yet it exhibits the state after measurement).
that is what the quantum entanglement "magic" is saying. The magic is in the assumption that both Alice and Bob are having a coins which have the both sides, head and tail, and as soon Alice toss a coin and gets the head then if Bob would toss a coin he would have a tail, always.
Anton
It's not a simple assumption - it's a scientific fact proven with experiments. Entagled partles behave as if they were one 'object' - measuring one of them results in measuring the other (how else would you explain the lack of interference pattern in when it comes don to the second particle - it hasn't been measured at all, yet it exhibits the state after measurement).
EDIT: particles* - not "partles".
Hi Mate, KaerbEmEvig et al,
I'm no expert on this .. my interest was in the efficiency of BBO down-conversion rather than polarization
Here's an indication..
http://xqp.physik.uni-muenchen.de/publ/apl_79_869_2001.pdf
There's no drawing of the 'coincidence detector' - the usual thing is that it only counts if if it gets two pulses at the same time - these are assumed to be from the same down-conversion event. Without reading the text I'd guess they're looking for one one way and the other the other.
Best wishes - C2.
I'm no expert on this .. my interest was in the efficiency of BBO down-conversion rather than polarization
Here's an indication..
http://xqp.physik.uni-muenchen.de/publ/apl_79_869_2001.pdf
There's no drawing of the 'coincidence detector' - the usual thing is that it only counts if if it gets two pulses at the same time - these are assumed to be from the same down-conversion event. Without reading the text I'd guess they're looking for one one way and the other the other.
Best wishes - C2.
When I'm not busy I will find the exact experiment write-up I was talking about and link to it in here.
Can someone ask an admin to create me a "KaerbEmEvig" account? The registration e-mail isn't comming.
Can someone ask an admin to create me a "KaerbEmEvig" account? The registration e-mail isn't comming.
QUOTE (KaerbEmEvig+Jul 9 2007, 07:03 PM)
It's not a simple assumption - it's a scientific fact proven with experiments. Entagled partles behave as if they were one 'object' - measuring one of them results in measuring the other (how else would you explain the lack of interference pattern in when it comes don to the second particle - it hasn't been measured at all, yet it exhibits the state after measurement).
KaerbEmEvig ,
right, QE it is scientifically proven fact. But let me point one nuance of meaning regarding that assertion of yours.
"The fact" in science is not the same as "the truth". In the science there is no proving particular hypothesis but "just" validating, falsifying particular hypothesis. QE has experimental findings, which validate the hypothesis of QM.
However, QE is not indisputable truth because indisputable truths are not a science. It may be wrong. Perhaps something else is happening which might interpret experimental result even better than QM.
Anton
KaerbEmEvig ,
right, QE it is scientifically proven fact. But let me point one nuance of meaning regarding that assertion of yours.
"The fact" in science is not the same as "the truth". In the science there is no proving particular hypothesis but "just" validating, falsifying particular hypothesis. QE has experimental findings, which validate the hypothesis of QM.
However, QE is not indisputable truth because indisputable truths are not a science. It may be wrong. Perhaps something else is happening which might interpret experimental result even better than QM.
Anton
Hi KaerbEmEvig,
Your name does not appear in the members list .. I think it does even if you haven't used the account for the first time - I'd try again.
Best wishes - C2.
Your name does not appear in the members list .. I think it does even if you haven't used the account for the first time - I'd try again.
Best wishes - C2.
QUOTE (KaerbEmEvig+Jul 9 2007, 08:03 PM)
When I'm not busy I will find the exact experiment write-up I was talking about and link to it in here.
Can someone ask an admin to create me a "KaerbEmEvig" account? The registration e-mail isn't comming.
KaerbEmEvig,
does your browser accept cookies?
Anton
Can someone ask an admin to create me a "KaerbEmEvig" account? The registration e-mail isn't comming.
KaerbEmEvig,
does your browser accept cookies?
Anton
Hi Mate,
Looking back .. I think you need to know that the output of (say) a vertically polarizing filter is vertically polarized .. not at the input angle. Whatever it was before.. the output is vertically polarised. The probabilty of passing is determined by Malus's Law ( http://en.wikipedia.org/wiki/Polarizer#Mal...ther_properties )
Best wishes - C2.
Looking back .. I think you need to know that the output of (say) a vertically polarizing filter is vertically polarized .. not at the input angle. Whatever it was before.. the output is vertically polarised. The probabilty of passing is determined by Malus's Law ( http://en.wikipedia.org/wiki/Polarizer#Mal...ther_properties )
Best wishes - C2.
Thanks for the links C2. http://grad.physics.sunysb.edu/~amarch/
Take a look at the details of the Quantum Erasure DSE. In particular take a look at the coincidence counter.
Now adding a polarizer to the entangled photon that is not going through the slits somehow makes the interference pattern re-appear. Now this other photon is not entirely out of the experiment, it is used by the coincidence counter.
I'm not an expert, but I'm pretty sure that altering the sample set of detection events would have a noticable affect on the pattern that arises.
Take a look at the details of the Quantum Erasure DSE. In particular take a look at the coincidence counter.
Now adding a polarizer to the entangled photon that is not going through the slits somehow makes the interference pattern re-appear. Now this other photon is not entirely out of the experiment, it is used by the coincidence counter.
I'm not an expert, but I'm pretty sure that altering the sample set of detection events would have a noticable affect on the pattern that arises.
Finally! After 1 hour of waiting - it finally came. Welcome to me. 
QUOTE (KaerbEmEvig+)
Welcome to me
Welcome to you
Welcome to you
QUOTE (Wulf+Jul 9 2007, 04:48 PM)
Thanks for the links C2. http://grad.physics.sunysb.edu/~amarch/
Take a look at the details of the Quantum Erasure DSE. In particular take a look at the coincidence counter.
Now adding a polarizer to the entangled photon that is not going through the slits somehow makes the interference pattern re-appear. Now this other photon is not entirely out of the experiment, it is used by the coincidence counter.
I'm not an expert, but I'm pretty sure that altering the sample set of detection events would have a noticable affect on the pattern that arises.
Hmmm as far as I can tell no events are lost, so this line of reasoning might be a dead end. I'll revisit it later. Let me know your thoughts.
Take a look at the details of the Quantum Erasure DSE. In particular take a look at the coincidence counter.
Now adding a polarizer to the entangled photon that is not going through the slits somehow makes the interference pattern re-appear. Now this other photon is not entirely out of the experiment, it is used by the coincidence counter.
I'm not an expert, but I'm pretty sure that altering the sample set of detection events would have a noticable affect on the pattern that arises.
Hmmm as far as I can tell no events are lost, so this line of reasoning might be a dead end. I'll revisit it later. Let me know your thoughts.
QUOTE (Confused2+Jul 9 2007, 09:33 PM)
Hi Mate,
Looking back .. I think you need to know that the output of (say) a vertically polarizing filter is vertically polarized .. not at the input angle. Whatever it was before.. the output is vertically polarised. The probabilty of passing is determined by Malus's Law ( http://en.wikipedia.org/wiki/Polarizer#Mal...ther_properties )
Best wishes - C2.
C2,
in the experimental conditions with "uncontrolled" beam of a photons of various degrees of polarization it would be expected to get some deviation from ideal result.In fact, if we would get a perfect result expected in such a uncontrolled conditions then that result would suggest that we are wrong about something in our hypothesis.
Now, you emphasized that the output is uniformed, but that is not surprising. Once a photon with some degree of polarization in regard to the vertical filter enters the filter I guess passing through the filter is uniforming polarization of a photons which went through. However what is surprising is that, seemingly, 180 different degrees of polarization can "enter" that vertical filter ( assuming that polarizations of a photons in that uncontrolled beam are more less uniformly distributed around 360 degrees). Of course, dividing a circle in 360 degrees is also an arbitrary measurement. We can divide a circle in 1000 degrees to get a more precise result.
Coming back on which I wanted to say. Surely it would be interesting to see what are exactly the degrees of polarization which are entering/passing through, and vice versa.Perhaps we can get that information in this manner.Let us say that we have prepared a 360 filters ( or the one rotating around, if that is possible ), with each of the filter "arranged" for one degree of polarization around a full circle, that is, filter 0 degree ( vertical ), then 1,2,3 .....until the last of 359 degrees.
And we have a barrier where we can put one of those fitters ( or the rotating one ) so only a photons which are passing particular filter and a barrier are those photons which are passing through that particular filter.
And we have one controlling, let us say vertical filter, which is placed behind a barrier, just in front of particular filter placed in a barrier.
Now, we let uncontrolled beam of photons with various polarizations through each of those 360 fitters, one by one. As you sad output from filter/ will be unformed with degrees of polarization of exiting photons depending of particular filter, that is, 0,1,2,3 etc. And now we will be able to see which photons with which polarization are passing the controlling vertical filter. I think that it would be very interesting to see ( if it is not done already ) which are and where are the degrees of polarization which are able to enter the vertical controlling filter.
Finally, let me ask these questions again no matter how cumulative affect of boredom they may produce considering how many times I asked these questions.
Quantum entanglement essence lies on the assumption/notion that photon's spin is in the state of supposition, that is, it is undefined until an act of observation. How we can falsify that notion if, seemingly, a photon keeps it's spin after an act of observation as it was in the moment and space when and where the observation occurred, and of a photon, seemingly, does not "get back" in the state of undefined spin ever again after it has been observed once?
Anton
Looking back .. I think you need to know that the output of (say) a vertically polarizing filter is vertically polarized .. not at the input angle. Whatever it was before.. the output is vertically polarised. The probabilty of passing is determined by Malus's Law ( http://en.wikipedia.org/wiki/Polarizer#Mal...ther_properties )
Best wishes - C2.
C2,
in the experimental conditions with "uncontrolled" beam of a photons of various degrees of polarization it would be expected to get some deviation from ideal result.In fact, if we would get a perfect result expected in such a uncontrolled conditions then that result would suggest that we are wrong about something in our hypothesis.
Now, you emphasized that the output is uniformed, but that is not surprising. Once a photon with some degree of polarization in regard to the vertical filter enters the filter I guess passing through the filter is uniforming polarization of a photons which went through. However what is surprising is that, seemingly, 180 different degrees of polarization can "enter" that vertical filter ( assuming that polarizations of a photons in that uncontrolled beam are more less uniformly distributed around 360 degrees). Of course, dividing a circle in 360 degrees is also an arbitrary measurement. We can divide a circle in 1000 degrees to get a more precise result.
Coming back on which I wanted to say. Surely it would be interesting to see what are exactly the degrees of polarization which are entering/passing through, and vice versa.Perhaps we can get that information in this manner.Let us say that we have prepared a 360 filters ( or the one rotating around, if that is possible ), with each of the filter "arranged" for one degree of polarization around a full circle, that is, filter 0 degree ( vertical ), then 1,2,3 .....until the last of 359 degrees.
And we have a barrier where we can put one of those fitters ( or the rotating one ) so only a photons which are passing particular filter and a barrier are those photons which are passing through that particular filter.
And we have one controlling, let us say vertical filter, which is placed behind a barrier, just in front of particular filter placed in a barrier.
Now, we let uncontrolled beam of photons with various polarizations through each of those 360 fitters, one by one. As you sad output from filter/ will be unformed with degrees of polarization of exiting photons depending of particular filter, that is, 0,1,2,3 etc. And now we will be able to see which photons with which polarization are passing the controlling vertical filter. I think that it would be very interesting to see ( if it is not done already ) which are and where are the degrees of polarization which are able to enter the vertical controlling filter.
Finally, let me ask these questions again no matter how cumulative affect of boredom they may produce considering how many times I asked these questions.
Quantum entanglement essence lies on the assumption/notion that photon's spin is in the state of supposition, that is, it is undefined until an act of observation. How we can falsify that notion if, seemingly, a photon keeps it's spin after an act of observation as it was in the moment and space when and where the observation occurred, and of a photon, seemingly, does not "get back" in the state of undefined spin ever again after it has been observed once?
Anton
QUOTE
Quantum entanglement essence lies on the assumption/notion that photon's spin is in the state of supposition
Superposition?
I don't think (and I'm quite sure of that) that entanglement has anything to do with superposition (I assume you misinterpret what entanglement is about - but I may always be wrong).
Just because we do not know the spin an entangled particle has after it has been created does not mean it is necessary for it to be in superposition. Even if it was to have a defined spin right after it has been created it does not change the peculiar results it gives - measuring one particle results in automatical and instant measurement of the paired entangled particle 'far away'.
This is the "spooky action at a distance" - that's what entanglement is all about. Supposedly separate and separated particles can interact with eachother no matter how long the distance between them is.
This is also why conservative physicist find these results very, very peculiar - it forces us to assume that either information can transfer superluminously (instantly, infact) or that locality assumption is incorrect. Both can't be true or there would be no "spooky action at a distance" whatsoever.
Bear in my this is only my opinion and point of view on the QE - nothing else.
QUOTE (KaerbEmEvig+Jul 10 2007, 12:34 PM)
Superposition?
I don't think (and I'm quite sure of that) that entanglement has anything to do with superposition (I assume you misinterpret what entanglement is about - but I may always be wrong).
Just because we do not know the spin an entangled particle has after it has been created does not mean it is necessary for it to be in superposition. Even if it was to have a defined spin right after it has been created it does not change the peculiar results it gives - measuring one particle results in automatical and instant measurement of the paired entangled particle 'far away'.
This is the "spooky action at a distance" - that's what entanglement is all about. Supposedly separate and separated particles can interact with eachother no matter how long the distance between them is.
This is also why conservative physicist find these results very, very peculiar - it forces us to assume that either information can transfer superluminously (instantly, infact) or that locality assumption is incorrect. Both can't be true or there would be no "spooky action at a distance" whatsoever.
Bear in my this is only my opinion and point of view on the QE - nothing else.
KaerbEmEvig,
it is possible that term "supposition" is not entirely adequate for describing the official notion about a spin of a photon but one thing about the quantum entanglement is certain.
If two entanglemented photons , A and B, would have defined spin on the certain axis, each of them, let us say A up and B down, before the measurement, then there is no magic of the quantum entanglement to wonder about. In this case we would have two photons which are mirror image/state of each other and of course that if we observe one of those photons with spin up on the certain axis then we would of course know that other has spin down on that axis because they were and they are in that correlation since they have been created, therfore nothing changed and there is nothing magical or nonlocal about that, that is a simple noncausal correlation.
The notion which makes the quantum entanglement magical is that either of those entaglemented photons MAY assume either of the possible spins, that is, A can be up or down and B can be up or down, that is, the spin of each of those photons is undefined since they have been created. It is not that we just do not know what is the spin for each of them, it is that each of them does not have defined spin UNTIL one of them is observed/measured, which by the way breaks entanglement.
There is a magic of nonlocality, and that is the reason why I am questioning the notion that A or B are in the state of undefined spin BEFORE an observation/measurement.
Anton
QUOTE
If two entanglemented photons , A and B, would have defined spin on the certain axis, each of them, let us say A up and B down, before the measurement, then there is no magic of the quantum entanglement to wonder about. In this case we would have two photons which are mirror image/state of each other and of course that if we observe one of those photons with spin up on the certain axis then we would of course know that other has spin down on that axis because they were and they are in that correlation since they have been created, therfore nothing changed and there is nothing magical or nonlocal about that, that is a simple noncausal correlation.
The notion which makes the quantum entanglement magical is that either of those entaglemented photons MAY assume either of the possible spins, that is, A can be up or down and B can be up or down, that is, the spin of each of those photons is undefined since they have been created. It is not that we just do not know what is the spin for each of them, it is that each of them does not have defined spin UNTIL one of them is observed/measured, which by the way breaks entanglement.
The notion which makes the quantum entanglement magical is that either of those entaglemented photons MAY assume either of the possible spins, that is, A can be up or down and B can be up or down, that is, the spin of each of those photons is undefined since they have been created. It is not that we just do not know what is the spin for each of them, it is that each of them does not have defined spin UNTIL one of them is observed/measured, which by the way breaks entanglement.
I think you misunderstood what the magic is about. The magic of entanglement is not the fact that characteristics of entangled particle pair are opposite - it's not that. The peculiarity of QE is the fact one particle influence the other.
Measuring one particle results in instantly measuring the other - that is: when you measure A, B's interference pattern (fringes) magically disappear, without any local measurement of the B particle.
That's what the magic of QE is about - not the fact the y bear opposite spins.
If they were simply separate particles with opposite characteristics after the creation, then we would not be witnessing the fact that one particle influence the other no matter how far the distance is.
Once again - QE has nothing to do with superposition. QE is all about one entangled particle influencing its counterpart instantly - even at the distance of hundreds of light years.
QUOTE (KaerbEmEvig+Jul 10 2007, 02:15 PM)
I think you misunderstood what the magic is about. The magic of entanglement is not the fact that characteristics of entangled particle pair are opposite - it's not that. The peculiarity of QE is the fact one particle influence the other.
Measuring one particle results in instantly measuring the other - that is: when you measure A, B's interference pattern (fringes) magically disappear, without any local measurement of the B particle.
That's what the magic of QE is about - not the fact the y bear opposite spins.
If they were simply separate particles with opposite characteristics after the creation, then we would not be witnessing the fact that one particle influence the other no matter how far the distance is.
Once again - QE has nothing to do with superposition. QE is all about one entangled particle influencing its counterpart instantly - even at the distance of hundreds of light years.
Now I have noticed that I am using "supposition" instead "superposition". Nonetheless it was understandable what I meant. I hope.
KaerbEmEvig,
what you are describing is the delayed choice quantum eraser experiment. Indeed that is a mystery.
Although what is troubling me about that experiment is that as soon as any of the entanglemented photons is observed in some manner then the entanglement between them is suppose to be broken, that is, one entanglemented photon can influence the other just once. But in DCQE one entanglemented photon hits the detector, in which moment that act of an observation in accordance with the quantum entanglement should determine the state of the one photon in regard to other, and vice versa.
However, in this experiment it is more chaotic than table tennis.
That other photon continues to be deflected by prism toward the beam splitter, through which that photon either passes or it is reflected by the beam splitter, and then that photon arrives at one of four possible detectors, and depending which detector it will hit that would determine is there an interference of not on the screen where the first photon hit the screen, long long time ago.
The question is. Again, as I understand quantum entanglement between two photons is broken after one of them is being observed once. In QCDE photon A hitting the detector, photon B reflects from prism, passing or reflecting by beam splitter, and finally hitting one from four possible detectors. When the entanglement has been broken between those two photons?
To go back on the subject matter.
http://en.wikipedia.org/wiki/Quantum_Entanglement
"Quantum entanglement is a quantum mechanical phenomenon in which the quantum states of two or more objects have to be described with reference to each other, even though the individual objects may be spatially separated. This leads to correlations between observable physical properties of the systems. For example, it is possible to prepare two particles in a single quantum state such that when one is observed to be spin-up, the other one will always be observed to be spin-down and vice versa, this despite the fact that it is impossible to predict, according to quantum mechanics, which set of measurements will be observed. As a result, measurements performed on one system seem to be instantaneously influencing other systems entangled with it."
It seems to me that what I am saying about spin up or down is what the quantum entanglement is saying.
And when it is said,
"..this despite the fact that it is impossible to predict, according to quantum mechanics, which set of measurements will be observed",
what is meant by that? Impossible to predict the spin because any of the entanglemented photons may assume randomly either spin up or spin down or impossible to predict which of entanglemented photons has spin up ( or down )?
Anton
QUOTE (Mate+Jul 10 2007, 03:46 PM)
Now I have noticed that I am using "supposition" instead "superposition". Nonetheless it was understandable what I meant. I hope.
KaerbEmEvig,
what you are describing is the delayed choice quantum eraser experiment. Indeed that is a mystery.
Although what is troubling me about that experiment is that as soon as any of the entanglemented photons is observed in some manner then the entanglement between them is suppose to be broken, that is, one entanglemented photon can influence the other just once. But in DCQE one entanglemented photon hits the detector, in which moment that act of an observation in accordance with the quantum entanglement should determine the state of the one photon in regard to other, and vice versa.
However, in this experiment it is more chaotic than table tennis.
That other photon continues to be deflected by prism toward the beam splitter, through which that photon either passes or it is reflected by the beam splitter, and then that photon arrives at one of four possible detectors, and depending which detector it will hit that would determine is there an interference of not on the screen where the first photon hit the screen, long long time ago.
The question is. Again, as I understand quantum entanglement between two photons is broken after one of them is being observed once. In QCDE photon A hitting the detector, photon B reflects from prism, passing or reflecting by beam splitter, and finally hitting one from four possible detectors. When the entanglement has been broken between those two photons?
To go back on the subject matter.
http://en.wikipedia.org/wiki/Quantum_Entanglement
"Quantum entanglement is a quantum mechanical phenomenon in which the quantum states of two or more objects have to be described with reference to each other, even though the individual objects may be spatially separated. This leads to correlations between observable physical properties of the systems. For example, it is possible to prepare two particles in a single quantum state such that when one is observed to be spin-up, the other one will always be observed to be spin-down and vice versa, this despite the fact that it is impossible to predict, according to quantum mechanics, which set of measurements will be observed. As a result, measurements performed on one system seem to be instantaneously influencing other systems entangled with it."
It seems to me that what I am saying about spin up or down is what the quantum entanglement is saying.
And when it is said,
"..this despite the fact that it is impossible to predict, according to quantum mechanics, which set of measurements will be observed",
what is meant by that? Impossible to predict the spin because any of the entanglemented photons may assume randomly either spin up or spin down or impossible to predict which of entanglemented photons has spin up ( or down )?
Anton
QUOTE
what is meant by that? Impossible to predict the spin because any of the entanglemented photons may assume randomly either spin up or spin down or impossible to predict which of entanglemented photons has spin up ( or down )?
It's the second answer (you can deduce it from the academic artles I have presented - I have many more on the subject, if you wish). It's impossible as in: the probability equals to 50% for either option and they it is assigned 'randomly' - thus there's no trace you could base your predictions on - impossible to predict.
The impossibility of prediction which photon has spin down does not imply that it's in superposition. It simply states that only means to determine which spin it posseses is to measure it.
QUOTE (KaerbEmEvig+Jul 10 2007, 04:33 PM)
It's the second answer (you can deduce it from the academic artles I have presented - I have many more on the subject, if you wish). It's impossible as in: the probability equals to 50% for either option and they it is assigned 'randomly' - thus there's no trace you could base your predictions on - impossible to predict.
The impossibility of prediction which photon has spin down does not imply that it's in superposition. It simply states that only means to determine which spin it posseses is to measure it.
KaerbEmEvig,
but if it is the second then where is the nonlocality there? That is what motivated me to start this thread in the first place.
If it is the second then that is akin of having two chairs in some dark room, each of the chair placed near the opposite wall of that room. What we know is that one chair is red and another is green, but we do not know in which chair we are sitting until someone would put a light on the other chair near opposite wall of the room.
And we see that that chair is the red one. Now we know that we are siting in the green one even we still do not see the color of the chair we are sitting in.
Where is nonlocality in this metaphorical situation?
Anton
Hi Anton, KaerbEmEvig ,
This might help .. http://www.mtnmath.com/whatrh/node78.html
Best wishes, -C2.
Edit .. and the next page.
This might help .. http://www.mtnmath.com/whatrh/node78.html
QUOTE
An ideal polarizing filter only allows that component of light to be transmitted that is parallel to the axis of polarization of the filter. If the angle between the axis of polarization of light and the polarizing filter is then the amplitude of the transmitted light is 8.3. See Figure 8.2. If a a single photon encounters a polarizing filter it must either completely traverse the filter or be completely blocked. It cannot split into smaller particles. However the classical relationship must hold in a statistical sense. The probability that a single photon will traverse the filter must be such that statistically the predictions of quantum mechanics and classical physics will agree.
Best wishes, -C2.
Edit .. and the next page.
QUOTE (Mate+Jul 10 2007, 05:11 PM)
KaerbEmEvig,
but if it is the second then where is the nonlocality there? That is what motivated me to start this thread in the first place.
If it is the second then that is akin of having two chairs in some dark room, each of the chair placed near the opposite wall of that room. What we know is that one chair is red and another is green, but we do not know in which chair we are sitting until someone would put a light on the other chair near opposite wall of the room.
And we see that that chair is the red one. Now we know that we are siting in the green one even we still do not see the color of the chair we are sitting in.
Where is nonlocality in this metaphorical situation?
Anton
Nonlocality? The fact that particle here has an effect on the particle 'there' instantly (this is not superluminous information transfer because those particles can be/are described by one wavefunction from what I know - they are a singularity in two places at a time - nolocality).
You constantly commit the same mistake - you leave out the fact that the up particle, when measured, influences the down particle, so that the latter is now in the state after-the-measurement - without actually being measured (interference fringes disappear). Vide this: grad.physics.sunysb.edu/~amarch/
Where is the nonlocality in the analogy? Nowhere - the analogy is incorrect and does not resemble entangled system.
QUOTE (KaerbEmEvig+Jul 10 2007, 05:46 PM)
Nonlocality? The fact that particle here has an effect on the particle 'there' instantly (this is not superluminous information transfer because those particles can be/are described by one wavefunction from what I know - they are a singularity in two places at a time - nolocality).
You constantly commit the same mistake - you leave out the fact that the up particle, when measured, influences the down particle, so that the latter is now in the state after-the-measurement - without actually being measured (interference fringes disappear). Vide this: grad.physics.sunysb.edu/~amarch/
Where is the nonlocality in the analogy? Nowhere - the analogy is incorrect and does not resemble entangled system.
KaerbEmEvig,
I already addressed your remark about an interference fringes disappearing in few posts ago. That is different matter than relationship between the spins of a entanglemented photons. Disappearing fringes of an interference is matter of wave/particle duality. Here there is no post observation state of another photon after observing one photon, if that observed photon had determined spin of the certain axis BEFORE it has been measured.
If that is the case then there is no non locality when we measure/observe a photon A with spin up because photon A had a spin up on that axis since it has been created. And measuring it's spin does not influence a spin of a photon B because photon B had a spin down on that axis since it has been created.
Do you understand what I am saying here?
Now, I do not claim that that is really the "relationship between spins of the entanglemented photons, but if you hold opinion that they have defined spin before the measurement then that is the implication of that notion. Clearer now?
Anton
You constantly commit the same mistake - you leave out the fact that the up particle, when measured, influences the down particle, so that the latter is now in the state after-the-measurement - without actually being measured (interference fringes disappear). Vide this: grad.physics.sunysb.edu/~amarch/
Where is the nonlocality in the analogy? Nowhere - the analogy is incorrect and does not resemble entangled system.
KaerbEmEvig,
I already addressed your remark about an interference fringes disappearing in few posts ago. That is different matter than relationship between the spins of a entanglemented photons. Disappearing fringes of an interference is matter of wave/particle duality. Here there is no post observation state of another photon after observing one photon, if that observed photon had determined spin of the certain axis BEFORE it has been measured.
If that is the case then there is no non locality when we measure/observe a photon A with spin up because photon A had a spin up on that axis since it has been created. And measuring it's spin does not influence a spin of a photon B because photon B had a spin down on that axis since it has been created.
Do you understand what I am saying here?
Now, I do not claim that that is really the "relationship between spins of the entanglemented photons, but if you hold opinion that they have defined spin before the measurement then that is the implication of that notion. Clearer now?
Anton
I get the impression I haven't helped much. I'll try again - at least you can both blame me if I'm wrong.
Looking at http://grad.physics.sunysb.edu/~amarch/
Their 'x' polarisation is my Horizontal polarization and 'y' is my Vertical polarisation
Which-Way Marker diagram
The p photon cannot be vertically AND horizontally polarized at the point of detection so 'the system' must choose which one to go for... hence the path is also chosen:- QWP1 for pH and QWP2 for pV. No interference.
Quantum Erasure diagram
The source pH or pV polarisation is made indistinguishable by a polarizer so detection no longer forces s (the other photon) into a defined state. Now s isn't forced into a defined state it can take either path and we get interference.
Forcing 'the other' photon into a defined state is the entanglement, doing it somewhere else is the non-locality and doing it in the 'wrong order' is the erasure.
Looks very elegant to me. If you cannot be kind then please be gentle.
Best wishes - C2.
Looking at http://grad.physics.sunysb.edu/~amarch/
Their 'x' polarisation is my Horizontal polarization and 'y' is my Vertical polarisation
Which-Way Marker diagram
The p photon cannot be vertically AND horizontally polarized at the point of detection so 'the system' must choose which one to go for... hence the path is also chosen:- QWP1 for pH and QWP2 for pV. No interference.
Quantum Erasure diagram
The source pH or pV polarisation is made indistinguishable by a polarizer so detection no longer forces s (the other photon) into a defined state. Now s isn't forced into a defined state it can take either path and we get interference.
Forcing 'the other' photon into a defined state is the entanglement, doing it somewhere else is the non-locality and doing it in the 'wrong order' is the erasure.
Looks very elegant to me. If you cannot be kind then please be gentle.
Best wishes - C2.
QUOTE (Confused2+Jul 10 2007, 02:27 PM)
I get the impression I haven't helped much. I'll try again - at least you can both blame me if I'm wrong.
Looking at http://grad.physics.sunysb.edu/~amarch/
Their 'x' polarisation is my Horizontal polarization and 'y' is my Vertical polarisation
Which-Way Marker diagram
The p photon cannot be vertically AND horizontally polarized at the point of detection so 'the system' must choose which one to go for... hence the path is also chosen:- QWP1 for pH and QWP2 for pV. No interference.
Quantum Erasure diagram
The source pH or pV polarisation is made indistinguishable by a polarizer so detection no longer forces s (the other photon) into a defined state. Now s isn't forced into a defined state it can take either path and we get interference.
Forcing 'the other' photon into a defined state is the entanglement, doing it somewhere else is the non-locality and doing it in the 'wrong order' is the erasure.
Looks very elegant to me. If you cannot be kind then please be gentle.
Best wishes - C2.
No argument here, I'm just trying to look at things from different angles to see if something might have gone unnoticed.
Your description gives me an idea. We should look at the consequences of changing the wave packets to see how it all fits together. The polarizers used in the delayed choice dse don't block the energy, they reshape it.
Blah, no time to think on this, japanese to study.
C2: You've been plenty of help, thanks.
Looking at http://grad.physics.sunysb.edu/~amarch/
Their 'x' polarisation is my Horizontal polarization and 'y' is my Vertical polarisation
Which-Way Marker diagram
The p photon cannot be vertically AND horizontally polarized at the point of detection so 'the system' must choose which one to go for... hence the path is also chosen:- QWP1 for pH and QWP2 for pV. No interference.
Quantum Erasure diagram
The source pH or pV polarisation is made indistinguishable by a polarizer so detection no longer forces s (the other photon) into a defined state. Now s isn't forced into a defined state it can take either path and we get interference.
Forcing 'the other' photon into a defined state is the entanglement, doing it somewhere else is the non-locality and doing it in the 'wrong order' is the erasure.
Looks very elegant to me. If you cannot be kind then please be gentle.
Best wishes - C2.
No argument here, I'm just trying to look at things from different angles to see if something might have gone unnoticed.
Your description gives me an idea. We should look at the consequences of changing the wave packets to see how it all fits together. The polarizers used in the delayed choice dse don't block the energy, they reshape it.
Blah, no time to think on this, japanese to study.
C2: You've been plenty of help, thanks.
QUOTE (Mate+Jul 10 2007, 06:24 PM)
KaerbEmEvig,
I already addressed your remark about an interference fringes disappearing in few posts ago. That is different matter than relationship between the spins of a entanglemented photons. Disappearing fringes of an interference is matter of wave/particle duality. Here there is no post observation state of another photon after observing one photon, if that observed photon had determined spin of the certain axis BEFORE it has been measured.
If that is the case then there is no non locality when we measure/observe a photon A with spin up because photon A had a spin up on that axis since it has been created. And measuring it's spin does not influence a spin of a photon B because photon B had a spin down on that axis since it has been created.
Do you understand what I am saying here?
Now, I do not claim that that is really the "relationship between spins of the entanglemented photons, but if you hold opinion that they have defined spin before the measurement then that is the implication of that notion. Clearer now?
Anton
But the truth is - just because they have defined spins does not mean they exhibit the nature of measured particles. They will still create interference fringes but after measurement they will create a point. Measuring particle A results in particle B behaving as if it has also been measured. That's nonlocality (or superluminous information transfer).
QUOTE
I get the impression I haven't helped much. I'll try again - at least you can both blame me if I'm wrong.
Looking at grad.physics.sunysb.edu/~amarch/
Their 'x' polarisation is my Horizontal polarization and 'y' is my Vertical polarisation
Which-Way Marker diagram
The p photon cannot be vertically AND horizontally polarized at the point of detection so 'the system' must choose which one to go for... hence the path is also chosen:- QWP1 for pH and QWP2 for pV. No interference.
Quantum Erasure diagram
The source pH or pV polarisation is made indistinguishable by a polarizer so detection no longer forces s (the other photon) into a defined state. Now s isn't forced into a defined state it can take either path and we get interference.
Forcing 'the other' photon into a defined state is the entanglement, doing it somewhere else is the non-locality and doing it in the 'wrong order' is the erasure.
Looks very elegant to me. If you cannot be kind then please be gentle.
Best wishes - C2.
Looking at grad.physics.sunysb.edu/~amarch/
Their 'x' polarisation is my Horizontal polarization and 'y' is my Vertical polarisation
Which-Way Marker diagram
The p photon cannot be vertically AND horizontally polarized at the point of detection so 'the system' must choose which one to go for... hence the path is also chosen:- QWP1 for pH and QWP2 for pV. No interference.
Quantum Erasure diagram
The source pH or pV polarisation is made indistinguishable by a polarizer so detection no longer forces s (the other photon) into a defined state. Now s isn't forced into a defined state it can take either path and we get interference.
Forcing 'the other' photon into a defined state is the entanglement, doing it somewhere else is the non-locality and doing it in the 'wrong order' is the erasure.
Looks very elegant to me. If you cannot be kind then please be gentle.
Best wishes - C2.
This is exactly what I was saying all the time. I just didn't have time to back it up with the article like you did. Thanks for your effort. Your explanation clearly explains what entanglement is and when nonlocality occurs.
Just want to throw an idea I have out there.
Alright lets consider the Quantum erasure DSE, wether it is delayed or not dosent matter.
| /_ In the unobserved run of the experiment 3 states are reaching the target Spin up down and circular. So every detection event has the full spectrum of possible spins. We observe an interference pattern.
|_ In the wich way run detectors in place only 2 states are reaching the targets, for some reason the interference pattern dissapears.
|_ + / Finally in the erasure step we add a 45deg polarizer before the event counter and the pattern suddenly re-appears.
Notice anything different between these three runs of the experiment?
The / component being removed destroys the pattern. Re-introducing it brings it back.
Now in the Delayed choice DSE the distribution of detection events is based on both photons, adding a 45deg filter to the detector to destroy the wich way information also reduces the number of detection events by 2/3.
Let us consider a little more of my stunning ascii art:
|||||||||
|||||||||
| | |
| | |
This kind of looks like an interference pattern dosen't it?
So where is the spooky action at a distance? This looks more like a failure to consider the properties of the sample set you are basing the measurements off of.
This seems to do away with the whole spooky action at a distance and time travel effects. That is, unless I'm missing something.
This also seems to relate to the nature of the inerference pattern as well, but I'm too tired to think about it right now. Any thoughts or comments?
Alright lets consider the Quantum erasure DSE, wether it is delayed or not dosent matter.
| /_ In the unobserved run of the experiment 3 states are reaching the target Spin up down and circular. So every detection event has the full spectrum of possible spins. We observe an interference pattern.
|_ In the wich way run detectors in place only 2 states are reaching the targets, for some reason the interference pattern dissapears.
|_ + / Finally in the erasure step we add a 45deg polarizer before the event counter and the pattern suddenly re-appears.
Notice anything different between these three runs of the experiment?
The / component being removed destroys the pattern. Re-introducing it brings it back.
Now in the Delayed choice DSE the distribution of detection events is based on both photons, adding a 45deg filter to the detector to destroy the wich way information also reduces the number of detection events by 2/3.
Let us consider a little more of my stunning ascii art:
|||||||||
|||||||||
| | |
| | |
This kind of looks like an interference pattern dosen't it?
So where is the spooky action at a distance? This looks more like a failure to consider the properties of the sample set you are basing the measurements off of.
This seems to do away with the whole spooky action at a distance and time travel effects. That is, unless I'm missing something.
This also seems to relate to the nature of the inerference pattern as well, but I'm too tired to think about it right now. Any thoughts or comments?
QUOTE (Confused2+Jul 10 2007, 05:35 PM)
Hi Anton, KaerbEmEvig ,
This might help .. http://www.mtnmath.com/whatrh/node78.html
Best wishes, -C2.
Edit .. and the next page.
C2,
thanks for the papers you are posting but there was not enough time to read them thoroughly because yesterday I was playing a polo with my friends , and I can tell you that it is difficult to read about a physics and ride a horse simultaneously.
A few comments nonetheless...
"The strangeness of quantum mechanics makes it difficult to describe these experiments coherently. On the one hand the photon does not have a definite polarization until and unless it is detected."
Now, this is a guess. How we can be reasonably sure that photon does not have a definitive polarization until and unless it is detected? On which experimental finding that assertion lies?
Snip......
"Consider a single quantum event that creates a pair of photons. Conservation laws require a correlation in properties like polarization for the elements of such pairs. The probability that both will pass though a pair of polarizers is $\cos(\theta)$ where $\theta$ is the angle between the polarizers. Note this says nothing about the polarization angle of the photons. That does not exist until it is observed!"
Is my proposal of the experiment of using one fitter to have perfectly polarized beam of photons exiting that filter at precise angle of polarization as the fitter is set up, and other filter through which ( or not ) would particular angles of polarization pass that vertical filter, a possible solution? Now we can experiment with photons for which we know exactly what is their angle of polarization in regard to that other filter.
Yes? No? We do not know? Go back and play polo?
Anton
This might help .. http://www.mtnmath.com/whatrh/node78.html
Best wishes, -C2.
Edit .. and the next page.
C2,
thanks for the papers you are posting but there was not enough time to read them thoroughly because yesterday I was playing a polo with my friends , and I can tell you that it is difficult to read about a physics and ride a horse simultaneously.
A few comments nonetheless...
"The strangeness of quantum mechanics makes it difficult to describe these experiments coherently. On the one hand the photon does not have a definite polarization until and unless it is detected."
Now, this is a guess. How we can be reasonably sure that photon does not have a definitive polarization until and unless it is detected? On which experimental finding that assertion lies?
Snip......
"Consider a single quantum event that creates a pair of photons. Conservation laws require a correlation in properties like polarization for the elements of such pairs. The probability that both will pass though a pair of polarizers is $\cos(\theta)$ where $\theta$ is the angle between the polarizers. Note this says nothing about the polarization angle of the photons. That does not exist until it is observed!"
Is my proposal of the experiment of using one fitter to have perfectly polarized beam of photons exiting that filter at precise angle of polarization as the fitter is set up, and other filter through which ( or not ) would particular angles of polarization pass that vertical filter, a possible solution? Now we can experiment with photons for which we know exactly what is their angle of polarization in regard to that other filter.
Yes? No? We do not know? Go back and play polo?
Anton
QUOTE (Wulf+Jul 11 2007, 08:35 AM)
Just want to throw an idea I have out there.
Alright lets consider the Quantum erasure DSE, wether it is delayed or not dosent matter.
| /_ In the unobserved run of the experiment 3 states are reaching the target Spin up down and circular. So every detection event has the full spectrum of possible spins. We observe an interference pattern.
|_ In the wich way run detectors in place only 2 states are reaching the targets, for some reason the interference pattern dissapears.
|_ + / Finally in the erasure step we add a 45deg polarizer before the event counter and the pattern suddenly re-appears.
Notice anything different between these three runs of the experiment?
The / component being removed destroys the pattern. Re-introducing it brings it back.
Now in the Delayed choice DSE the distribution of detection events is based on both photons, adding a 45deg filter to the detector to destroy the wich way information also reduces the number of detection events by 2/3.
Let us consider a little more of my stunning ascii art:
|||||||||
|||||||||
| | |
| | |
This kind of looks like an interference pattern dosen't it?
So where is the spooky action at a distance? This looks more like a failure to consider the properties of the sample set you are basing the measurements off of.
This seems to do away with the whole spooky action at a distance and time travel effects. That is, unless I'm missing something.
This also seems to relate to the nature of the inerference pattern as well, but I'm too tired to think about it right now. Any thoughts or comments?
Hello, Wulf
Look, the photon in the experiment will exhibit two nature - but only one at a time - it will either exhibit the corpuscular nature or the wave nature. The wave nature is present when we do not place which'way detectors between the slits and the targeted area - we can clearly see fringes.
When we place a which-way detector, so that we are able to obtain the information through which slit the photon went, the photon will exhibit its corpuscular nature - correct?
Now comes the nonlocality and quantum entanglement.
Quantum entanglement means that if we observe/measure one of the entangled particles to have a specific spin, the other will have an opposite spin.
We obtain the which-way information through measuring the spin of the photon (it doesn't matter whether the photon has a defined spin right after it has been created or not - it's not superposition that defines interference fringes, it's the lack of which-way information - lack of the measurement of the spin).
This means that obtaining (or rather being able to obtain it - doesn't matter whether we look at the collected data or not) the 'which-way information, the information about what the spin is, forces the photon to 'change' the exhibited nature from wave-like to particle-like.
Where's the entanglement? When we obtain which-way information for photon A by measuring its spin we simultaneously obtain the information on the B photon's spin - thus we also obtain the which-way information for the latter photon. This means that by influencing photon A (to change the exhibited nature from wave-like to particle-like) we have at the same time influenced photon B - without actually measuring. One photon influenced the other.
Where's the nonlocality? When one entangled photon influences the other the distance doesn't matter - it all happens instantly (this means we would either have to assume that information is transfered superluminously or that entangled photons are actually on 'being' in two places - nonlocality). Scientists assume it's nonlocality becase there's alot more goin' against the former assumption.
Alright lets consider the Quantum erasure DSE, wether it is delayed or not dosent matter.
| /_ In the unobserved run of the experiment 3 states are reaching the target Spin up down and circular. So every detection event has the full spectrum of possible spins. We observe an interference pattern.
|_ In the wich way run detectors in place only 2 states are reaching the targets, for some reason the interference pattern dissapears.
|_ + / Finally in the erasure step we add a 45deg polarizer before the event counter and the pattern suddenly re-appears.
Notice anything different between these three runs of the experiment?
The / component being removed destroys the pattern. Re-introducing it brings it back.
Now in the Delayed choice DSE the distribution of detection events is based on both photons, adding a 45deg filter to the detector to destroy the wich way information also reduces the number of detection events by 2/3.
Let us consider a little more of my stunning ascii art:
|||||||||
|||||||||
| | |
| | |
This kind of looks like an interference pattern dosen't it?
So where is the spooky action at a distance? This looks more like a failure to consider the properties of the sample set you are basing the measurements off of.
This seems to do away with the whole spooky action at a distance and time travel effects. That is, unless I'm missing something.
This also seems to relate to the nature of the inerference pattern as well, but I'm too tired to think about it right now. Any thoughts or comments?
Hello, Wulf
Look, the photon in the experiment will exhibit two nature - but only one at a time - it will either exhibit the corpuscular nature or the wave nature. The wave nature is present when we do not place which'way detectors between the slits and the targeted area - we can clearly see fringes.
When we place a which-way detector, so that we are able to obtain the information through which slit the photon went, the photon will exhibit its corpuscular nature - correct?
Now comes the nonlocality and quantum entanglement.
Quantum entanglement means that if we observe/measure one of the entangled particles to have a specific spin, the other will have an opposite spin.
We obtain the which-way information through measuring the spin of the photon (it doesn't matter whether the photon has a defined spin right after it has been created or not - it's not superposition that defines interference fringes, it's the lack of which-way information - lack of the measurement of the spin).
This means that obtaining (or rather being able to obtain it - doesn't matter whether we look at the collected data or not) the 'which-way information, the information about what the spin is, forces the photon to 'change' the exhibited nature from wave-like to particle-like.
Where's the entanglement? When we obtain which-way information for photon A by measuring its spin we simultaneously obtain the information on the B photon's spin - thus we also obtain the which-way information for the latter photon. This means that by influencing photon A (to change the exhibited nature from wave-like to particle-like) we have at the same time influenced photon B - without actually measuring. One photon influenced the other.
Where's the nonlocality? When one entangled photon influences the other the distance doesn't matter - it all happens instantly (this means we would either have to assume that information is transfered superluminously or that entangled photons are actually on 'being' in two places - nonlocality). Scientists assume it's nonlocality becase there's alot more goin' against the former assumption.
Quantum entanglement as every crank knows is purley due to higher dimensional geometry/ recursive duality, created by endo event horizon transit in an non-temporal transdimensional energy propagating instant.
QUOTE (fivedoughnut+Jul 11 2007, 11:00 AM)
Quantum entanglement as every crank knows is purley due to higher dimensional geometry/ recursive duality, created by endo event horizon transit in an non-temporal transdimensional energy propagating instant.
I thoroughly agree!
I thoroughly agree!
QUOTE (KaerbEmEvig+Jul 10 2007, 09:10 PM)
But the truth is - just because they have defined spins does not mean they exhibit the nature of measured particles. They will still create interference fringes but after measurement they will create a point. Measuring particle A results in particle B behaving as if it has also been measured. That's nonlocality (or superluminous information transfer).
KaerbEmEvig,
noone really knows for sure what is the state/condition of a photon before it is observed
in comparison with a photon being observed/measured. The "official" notion about a nature of still unmeasured photon is, well, a speculation.
Anton
KaerbEmEvig,
noone really knows for sure what is the state/condition of a photon before it is observed
in comparison with a photon being observed/measured. The "official" notion about a nature of still unmeasured photon is, well, a speculation.
Anton
QUOTE (Confused2+Jul 10 2007, 08:27 PM)
I get the impression I haven't helped much. I'll try again - at least you can both blame me if I'm wrong.
Looking at http://grad.physics.sunysb.edu/~amarch/
Their 'x' polarisation is my Horizontal polarization and 'y' is my Vertical polarisation
Which-Way Marker diagram
The p photon cannot be vertically AND horizontally polarized at the point of detection so 'the system' must choose which one to go for... hence the path is also chosen:- QWP1 for pH and QWP2 for pV. No interference.
Quantum Erasure diagram
The source pH or pV polarisation is made indistinguishable by a polarizer so detection no longer forces s (the other photon) into a defined state. Now s isn't forced into a defined state it can take either path and we get interference.
Forcing 'the other' photon into a defined state is the entanglement, doing it somewhere else is the non-locality and doing it in the 'wrong order' is the erasure.
Looks very elegant to me. If you cannot be kind then please be gentle.
Best wishes - C2.
C2,
a really nice presentation of various experiments. However, it seems to me that that my proposal is much simple, there is no entanglement, nor changing of polarization, there is no disturbance whatsoever before an electron hits the screen The only "device" with which it MAY be possibly to deduce backward, so to speak, which way information is a "hole" in the middle of the area on which an electrons hits in an interference pattern.
Anton
Looking at http://grad.physics.sunysb.edu/~amarch/
Their 'x' polarisation is my Horizontal polarization and 'y' is my Vertical polarisation
Which-Way Marker diagram
The p photon cannot be vertically AND horizontally polarized at the point of detection so 'the system' must choose which one to go for... hence the path is also chosen:- QWP1 for pH and QWP2 for pV. No interference.
Quantum Erasure diagram
The source pH or pV polarisation is made indistinguishable by a polarizer so detection no longer forces s (the other photon) into a defined state. Now s isn't forced into a defined state it can take either path and we get interference.
Forcing 'the other' photon into a defined state is the entanglement, doing it somewhere else is the non-locality and doing it in the 'wrong order' is the erasure.
Looks very elegant to me. If you cannot be kind then please be gentle.
Best wishes - C2.
C2,
a really nice presentation of various experiments. However, it seems to me that that my proposal is much simple, there is no entanglement, nor changing of polarization, there is no disturbance whatsoever before an electron hits the screen The only "device" with which it MAY be possibly to deduce backward, so to speak, which way information is a "hole" in the middle of the area on which an electrons hits in an interference pattern.
Anton
QUOTE (Mate+Jul 11 2007, 12:42 PM)
KaerbEmEvig,
noone really knows for sure what is the state/condition of a photon before it is observed
in comparison with a photon being observed/measured. The "official" notion about a nature of still unmeasured photon is, well, a speculation.
Anton
That was not the point I was trying to make. I was saying that even if they had a defined spin before the measurement they would still create interference fringes because not the fact that the spin is defined breaks the interference but the which-way information.
I'm sorry but it gets irritating already.
How many times do we (me, Wulf and C2) have to explain what entanglement is and when it appears in the DCQE experiment?
Entanglement means that one p
noone really knows for sure what is the state/condition of a photon before it is observed
in comparison with a photon being observed/measured. The "official" notion about a nature of still unmeasured photon is, well, a speculation.
Anton
That was not the point I was trying to make. I was saying that even if they had a defined spin before the measurement they would still create interference fringes because not the fact that the spin is defined breaks the interference but the which-way information.
QUOTE
a really nice presentation of various experiments. However, it seems to me that that my proposal is much simple, there is no entanglement, nor changing of polarization, there is no disturbance whatsoever before an electron hits the screen The only "device" with which it MAY be possibly to deduce backward, so to speak, which way information is a "hole" in the middle of the area on which an electrons hits in an interference pattern.
I'm sorry but it gets irritating already.
How many times do we (me, Wulf and C2) have to explain what entanglement is and when it appears in the DCQE experiment?
Entanglement means that one p