I am trying to be more formal, and so on the way of proving Carlips formula is wrong (which contains the relative velocity) I stumbled accidentally on a finding that space must be absolute :-)
Let me know if you find a flaw :-)
_____________________________
The foundation for SR is the relativity principle. It requires that the laws of physics are the same for different observers. An object that is in fact moving relative to an observer might as well consider itself at rest, since it has no way of detecting if it is moving, or if the observer is moving instead.
Postulate 1: “Special Principle of Relativity”
The laws of physics are the same in any inertial frame, regardless of position or velocity
Postulate 2: “Relative Motion”
All uniform motion is relative
Definition 1: Signal
A signal is defined as information or any type of physical entity that can be emitted from a source which propagates with a finite speed.
Examples include: a photon beam, EM waves, particles, virtual particles, density or pressure change (as in solid objects), change in spacetime geometry
Definition 2: Retardation
A retardation is any amount of passage of time in any coordinate system.
Corollary 3: Retardation
Any signal that is emitted from a source A and propagates with a finite speed is retarded when it arrives at a target B.
Proof 3: Given observers A and B with positions R_A and R_B. Any signal that is emitted by A that propagates with speed |v_s| takes some amount of time |R_B-R_A|/|v_s| to get from source to target. Thus, the signal that B receives is retarded.
Corollary 4: Knowledge about an objects state
If signals propagate at finite speed, then an observer A cannot know the current state of an observer B that is some distance away.
Proof 4:
This follows from the “retardation” corollary: because a signal that propagates with finite speed, the target B receives the information about the state of A in a retarded fashion. The target B can only know the state of the source A at previous point in time defined by |R_B-R_A|/|v_s| (where |v_s| is the speed of the signal).
Corollary 5:
A signal that is sent from an object cannot contain any information about the velocity of the source.
Proof 5.1.: This follows from Corollary 4 and Postulates 1 and 2:
Suppose observer A and B some distance apart at time t0 where all clocks are reset.
A is moving relative to B. At point t0 A has no knowledge of the current state of A, and B has no knowledge of the current sate of B.A sends a signal with finite speed to B. Because A cannot know that B is moving relative to A yet, the signal cannot contain the relative velocity.
Proof 5.2.:
Suppose object A and any number of observers O_1..O_n moving at various velocities v_1..v_n relative to A. At the time t0 all clocks are reset.
A signal is emitted with finite speed |v_s| from A. At the time t0, A has no knowledge about current state and velocities of the observers O_1..O_n. Any information that A has about the observers is retarded by |R_A- O_i|/|v_s| (i=1..n). The signal that is sent from A can thus only contain retarded information. If the signal contains velocity information, it must contain the information about all relative velocities v_1.. v_n for all observers in the system.
Another proof:
Proof 5.3:
Suppose a star A explodes 6 billion light years away from earth, 6 billion years ago, at the time when earth did not exist yet. On earth the light from this explosion is measured 6 billion years later, when A no longer exists.
Hence when the light was emitted from the supernova 6 billion years ago, it could not contain any information about its relative velocity to earth, since earth did not exist then yet.
Doppler effect:
How can we then measure the relative motion towards a star that no longer exists, and where earth did not exist at the time the light was emitted?
Answer:
The doppler effect happens in two phases:
a) at the time the light is emitted by A, the light pulse is doppler shifted by the relative velocity of A to “space"
b.) at the time the light pulse is measured by B, the light pulse is doppler shifted again by the relative velocity of B to “space".
So in total, the frequency shift corresponds to the relative velocity of A vs B.
And this also proves two things:
a) the existence of an "absolute" space
b.) that the speed of light is constant in an "absolute" sense in space
Chantal :-)
Hi Korosten
I agree. There have to be an absolute background. A gravitational field may distort this background and we observe Vacuum Energy distorted close to a massive body. There is Sagnac effect, GPS time difference in west-east movement and other.
I agree. There have to be an absolute background. A gravitational field may distort this background and we observe Vacuum Energy distorted close to a massive body. There is Sagnac effect, GPS time difference in west-east movement and other.
Your disproof of the relativity principle by the use of Doppler shift is incorrect. Allow me to illustrate.
Imagine we are on a gigantic plain, with no wind, and constant atmospheric density and pressure.
Place a speaker at position P0. Emit a tone of frequency F0. Destroy said speaker. The speaker no longer exists.
Place a microphone M0 several miles from P0, at P1. The sound will be detected several minutes later, with the same frequency F0 since M0 is not moving.
Place a microphone M1 several miles from P0, and farther out than P1. Move M1 at velocity V, approaching P1 towards P0. At the point where M1 crosses M0 (at P1) it will also detect the sound wave, but with a frequency F1 > F0, due to Doppler shift.
If we ignore the fact that we can detect the movement of M1 relative to the air, we have no way of knowing whether M1 is moving, whether the speaker was moving, or at what frequency the original soundwave was at. In fact, we have no way of detecting the distance to the speaker either.
We haven't observed the speaker at all.
Let me switch back to the exploding star now...
We haven't observed the exploding star itself. We've only observed the light from it. That light is no longer part of the star. Only because we know the distance to said star a priori can we say that the explosion of the star, which this light conveyed to us, happened 6 billion years ago. The light itself does not tell us how far away or how old long ago the explosion happened. We figured out the distance to the star through other means, like relative brightness or parallax.
Imagine we are on a gigantic plain, with no wind, and constant atmospheric density and pressure.
Place a speaker at position P0. Emit a tone of frequency F0. Destroy said speaker. The speaker no longer exists.
Place a microphone M0 several miles from P0, at P1. The sound will be detected several minutes later, with the same frequency F0 since M0 is not moving.
Place a microphone M1 several miles from P0, and farther out than P1. Move M1 at velocity V, approaching P1 towards P0. At the point where M1 crosses M0 (at P1) it will also detect the sound wave, but with a frequency F1 > F0, due to Doppler shift.
If we ignore the fact that we can detect the movement of M1 relative to the air, we have no way of knowing whether M1 is moving, whether the speaker was moving, or at what frequency the original soundwave was at. In fact, we have no way of detecting the distance to the speaker either.
We haven't observed the speaker at all.
Let me switch back to the exploding star now...
We haven't observed the exploding star itself. We've only observed the light from it. That light is no longer part of the star. Only because we know the distance to said star a priori can we say that the explosion of the star, which this light conveyed to us, happened 6 billion years ago. The light itself does not tell us how far away or how old long ago the explosion happened. We figured out the distance to the star through other means, like relative brightness or parallax.
cefarix,
Exactly :-).
Didn't I say the same thing?
My point is that the signal / sound wave cannot contain the "relative velcocity between A/B".
In otherwords: the source cannot "know" who will measure its signals.
This may sound obvious, but apparently some peole don't think so, so that that's why I had to prove it :-).
And I did NOT disprove the equivalence principle? What makes you think that???
I am USING the equivalence principle to show that a signal cannot "know" who will be measuring it.
Chantal
Exactly :-).
Didn't I say the same thing?
My point is that the signal / sound wave cannot contain the "relative velcocity between A/B".
In otherwords: the source cannot "know" who will measure its signals.
This may sound obvious, but apparently some peole don't think so, so that that's why I had to prove it :-).
And I did NOT disprove the equivalence principle? What makes you think that???
I am USING the equivalence principle to show that a signal cannot "know" who will be measuring it.
Chantal
This may seem like an unrelated and silly question:
Imagine A (stationary) sends out a light beam to a mirror that is moving away from A at a velocity v and is sent back to A.
What doppler shift does A measure?
a) the shift that corresponds to v
b.) the shift that corresponds to TWO times v
c.) something else
So the question boils down to: when the mirror reflects the light, does the frequence change in any way, and how much? (Since the mirror is moving away).
if the frequence changes, does it change once or twice?
(I would think twice, but I am not sure :-)
Chantal
Imagine A (stationary) sends out a light beam to a mirror that is moving away from A at a velocity v and is sent back to A.
What doppler shift does A measure?
a) the shift that corresponds to v
b.) the shift that corresponds to TWO times v
c.) something else
So the question boils down to: when the mirror reflects the light, does the frequence change in any way, and how much? (Since the mirror is moving away).
if the frequence changes, does it change once or twice?
(I would think twice, but I am not sure :-)
Chantal
I've been thinking about the doppler shift - let's use your speaker/microphone example.
Suppose the speaker S moves relative to a stationary microphone M and emits a sound.
M is stationary and measures the sound and notices the doppler effect.
I wonder about how it happens *exactly*, what happens exactly when the sound was emitted?
The sound speed is constant in (stationary) air, so no matter how fast the speaker moves, the sound speed is the same.
But the frequency of the sound shifted when the sound is emitted.
Never mind, it is clear :-). I guess I am just "typing out loud ":-).
Chantal
Suppose the speaker S moves relative to a stationary microphone M and emits a sound.
M is stationary and measures the sound and notices the doppler effect.
I wonder about how it happens *exactly*, what happens exactly when the sound was emitted?
The sound speed is constant in (stationary) air, so no matter how fast the speaker moves, the sound speed is the same.
But the frequency of the sound shifted when the sound is emitted.
Never mind, it is clear :-). I guess I am just "typing out loud ":-).
Chantal
I think you've got some terms mixed up ... the relativity principle is not the same as the equivalence principle. Also, you said you were trying to prove "absolute space", which, if proved, would disprove the relativity principle. I was merely showing that an absolute space is not needed to explain the observations in the star exploding scenario.
As for the moving mirror... I would think there should be zero shift in the reflected light. Now let me look this up on Google and see if I was right
Okay, I was wrong
The Doppler shift does happen, just once. I guess here's how you can understand why: Imagine the mirror moving towards the source, then the moving mirror crosses and reflects the incoming wavefronts faster than a mirror at rest, giving a higher frequency. The opposite obviously applies for a mirror moving away from the source.
As for the moving mirror... I would think there should be zero shift in the reflected light. Now let me look this up on Google and see if I was right
Okay, I was wrong
The Doppler shift does happen, just once. I guess here's how you can understand why: Imagine the mirror moving towards the source, then the moving mirror crosses and reflects the incoming wavefronts faster than a mirror at rest, giving a higher frequency. The opposite obviously applies for a mirror moving away from the source.
QUOTE (korosten+Jan 19 2007, 07:30 AM)
...I stumbled accidentally on a finding that space must be absolute...
By AWT the space is formed by inertial environment, which has a character of recursive foam. This foam can be considered as the result density fluctuations of inertial repulsive particle under high pressure. These particles can be considered as the result of condensation of another, even more dense foam, recursively. The higher pressure exist in such particle system, the more pronounced is the foamy character of density fluctuations and the character of transversal wave spreading of energy through such environment. This is why the sound spreads through vapor under low pressure via longitudinal waves, while in high density/pressure system the transversal wave spreading prevails.
The highly pronounced of transversal wave spreading in vacuum demonstrates, how extremely dense system the vacuum is, in fact. The AWT assumes, the vacuum is formed by the interior of some dense star - sort of black hole, which persists inside of another Universe generation, recursively.
Nevertheless, as the model of the capillary waves at the water surface demonstrates, the absolute reference frame can be still detected by using of waves with low frequency, i.e. the microwaves together with the evidence of absolute reference frame and Lorentz symmetry violation - compare the COBE/WMAP Doppler dipole anisotropy and some later experiments (1, 2).
By AWT the space is formed by inertial environment, which has a character of recursive foam. This foam can be considered as the result density fluctuations of inertial repulsive particle under high pressure. These particles can be considered as the result of condensation of another, even more dense foam, recursively. The higher pressure exist in such particle system, the more pronounced is the foamy character of density fluctuations and the character of transversal wave spreading of energy through such environment. This is why the sound spreads through vapor under low pressure via longitudinal waves, while in high density/pressure system the transversal wave spreading prevails.
The highly pronounced of transversal wave spreading in vacuum demonstrates, how extremely dense system the vacuum is, in fact. The AWT assumes, the vacuum is formed by the interior of some dense star - sort of black hole, which persists inside of another Universe generation, recursively.
Nevertheless, as the model of the capillary waves at the water surface demonstrates, the absolute reference frame can be still detected by using of waves with low frequency, i.e. the microwaves together with the evidence of absolute reference frame and Lorentz symmetry violation - compare the COBE/WMAP Doppler dipole anisotropy and some later experiments (1, 2).
cefarix,
then explain to me, step by step in all detail, how the doppler shift happens if there is no absolute space :-).
1. star explodes and emits light (star is moving)
2. question: does light already have a frequence shift or not?
2.1 if yes, how would that work if there was no absolute space?
3. earth receives the signal (earth is moving)
4. question: is there another frequence shift or not?
4.1 if yes, how would that work if there was no absolute space?
If your answers to 2.1 and 4.1 are NO, then you would observe NO frequency shift whatsoever!
We can do the same for the sound:
1. speaker explodes and emits a sound (speaker is moving)
2. question: does sound already have a frequence shift or not?
2.1 if yes, how would that work if there was no AIR?
3. microphone receives the signal (microphone is moving)
4. question: is there another frequence shift or not?
4.1 if yes, how would that work if there was no AIR?
Re Mirror:
- is it really just once? And not twice?
Chantal
then explain to me, step by step in all detail, how the doppler shift happens if there is no absolute space :-).
1. star explodes and emits light (star is moving)
2. question: does light already have a frequence shift or not?
2.1 if yes, how would that work if there was no absolute space?
3. earth receives the signal (earth is moving)
4. question: is there another frequence shift or not?
4.1 if yes, how would that work if there was no absolute space?
If your answers to 2.1 and 4.1 are NO, then you would observe NO frequency shift whatsoever!
We can do the same for the sound:
1. speaker explodes and emits a sound (speaker is moving)
2. question: does sound already have a frequence shift or not?
2.1 if yes, how would that work if there was no AIR?
3. microphone receives the signal (microphone is moving)
4. question: is there another frequence shift or not?
4.1 if yes, how would that work if there was no AIR?
Re Mirror:
- is it really just once? And not twice?
Chantal
Korosten: I've come to the conclusion that space is absolute too. I'm not sure if you've got a proof there though.
Look at this way korosten...
We take a frame of reference based on the Earth. In this reference frame, the star is receding from Earth, and the light emitted is red-shifted because of the recession. I.e., in this frame of reference, the light is red-shifted from the beginning.
On the other hand, we can take a reference frame based on the star. In this frame, the Earth is receding. In this case, the light emitted by the star is "normal". But when the light is observed on Earth, the wavefronts of the light take longer to register with the observer on Earth, because the observer is moving in the same direction the light is. From this reference frame, the speed difference between Earth and the light is less than c (note that this doesn't violate the constancy of the speed of light... the light is still moving at c).
In fact, we can take any arbitrary reference frame and do the same thing. The light will be red/blue shifted at emission at the star. This light will then travel, where we will see the wavefronts crossing Earth at either less than c or greater than c, resulting in a second frequency shift at the detection station. Note that the light does not undergo a frequency change upon hitting Earth, but rather the observation is of a different frequency, because of the relative movement between the light and Earth.
There is no notion of absolute space. The absolute is the "zero" basis, which is defined by the frame of reference. If there were a preferred frame of reference, we could talk of an absolute space, but as I just illustrated above, any frame of reference is equally valid.
And about the mirror...
You again seem to be confusing a perceived frequency shift as an actual frequency shift. Let's switch back to our speaker-and-microphone analogy. Remember the moving microphone? The moving microphone detects a different frequency than we (the observer, at rest) do. We don't see the sound waves shift in frequency as they hit the microphone. Instead, we see the microphone cross the wavefronts a bit faster than the sound waves are crossing us, because the microphone is moving. So in this reference frame, the sound waves are shifted at the source (or not shifted if the source is still), and then they remain at that frequency. The microphone only observes a higher frequency because of its motion through the sound wave. Replace sound waves with radio waves, speaker with transmitter, and microphone with a receiver, and you have your situation in a vacuum.
Let's add the mirror to that and see what happens. We'll make the mirror a reflecting set of antennae, and imagine that its ideal and it reflect the wave back with no distortion or loss of amplitude. Imagine that the mirror is receding from the transmitter, which is at rest. The receiver is co-located with the transmitter to receive the reflected signal (a radar setup). Suppose the transmitter emits 3 waves, so there are 3 wavefronts W1, W2, and W3. W1 reaches the reflector at time T1 and is reflected back. We'll call the reflected wavefront W1'. At time T1 the position of the reflector is P0 meters from the transmitter. W2 crosses the position P0 N seconds later, at time T1+N. But during this time, the reflector has moved an additional distance NV, where V is the recession velocity of the reflector. Therefore the position of the reflector at time T1+N is P0+NV, and as we saw before, at time T1+N, W2 is at P0, not at P0+NV. W2 arrives at P0+NV some time later, at T2, and is reflected back. The time difference between W1 and W2 is less than the time difference between W1' and W2', because of the additional distance W2 had to travel before being reflected. This is what causes the frequency red-shift at reflection. The reflected waves then travel back to the receiver, which is at rest, at the shifted frequency, and they do not change their frequency at all. If the receiver were moving, there would be an additional perceived frequency shift, not an actual from the reference point of our frame.
We take a frame of reference based on the Earth. In this reference frame, the star is receding from Earth, and the light emitted is red-shifted because of the recession. I.e., in this frame of reference, the light is red-shifted from the beginning.
On the other hand, we can take a reference frame based on the star. In this frame, the Earth is receding. In this case, the light emitted by the star is "normal". But when the light is observed on Earth, the wavefronts of the light take longer to register with the observer on Earth, because the observer is moving in the same direction the light is. From this reference frame, the speed difference between Earth and the light is less than c (note that this doesn't violate the constancy of the speed of light... the light is still moving at c).
In fact, we can take any arbitrary reference frame and do the same thing. The light will be red/blue shifted at emission at the star. This light will then travel, where we will see the wavefronts crossing Earth at either less than c or greater than c, resulting in a second frequency shift at the detection station. Note that the light does not undergo a frequency change upon hitting Earth, but rather the observation is of a different frequency, because of the relative movement between the light and Earth.
There is no notion of absolute space. The absolute is the "zero" basis, which is defined by the frame of reference. If there were a preferred frame of reference, we could talk of an absolute space, but as I just illustrated above, any frame of reference is equally valid.
And about the mirror...
You again seem to be confusing a perceived frequency shift as an actual frequency shift. Let's switch back to our speaker-and-microphone analogy. Remember the moving microphone? The moving microphone detects a different frequency than we (the observer, at rest) do. We don't see the sound waves shift in frequency as they hit the microphone. Instead, we see the microphone cross the wavefronts a bit faster than the sound waves are crossing us, because the microphone is moving. So in this reference frame, the sound waves are shifted at the source (or not shifted if the source is still), and then they remain at that frequency. The microphone only observes a higher frequency because of its motion through the sound wave. Replace sound waves with radio waves, speaker with transmitter, and microphone with a receiver, and you have your situation in a vacuum.
Let's add the mirror to that and see what happens. We'll make the mirror a reflecting set of antennae, and imagine that its ideal and it reflect the wave back with no distortion or loss of amplitude. Imagine that the mirror is receding from the transmitter, which is at rest. The receiver is co-located with the transmitter to receive the reflected signal (a radar setup). Suppose the transmitter emits 3 waves, so there are 3 wavefronts W1, W2, and W3. W1 reaches the reflector at time T1 and is reflected back. We'll call the reflected wavefront W1'. At time T1 the position of the reflector is P0 meters from the transmitter. W2 crosses the position P0 N seconds later, at time T1+N. But during this time, the reflector has moved an additional distance NV, where V is the recession velocity of the reflector. Therefore the position of the reflector at time T1+N is P0+NV, and as we saw before, at time T1+N, W2 is at P0, not at P0+NV. W2 arrives at P0+NV some time later, at T2, and is reflected back. The time difference between W1 and W2 is less than the time difference between W1' and W2', because of the additional distance W2 had to travel before being reflected. This is what causes the frequency red-shift at reflection. The reflected waves then travel back to the receiver, which is at rest, at the shifted frequency, and they do not change their frequency at all. If the receiver were moving, there would be an additional perceived frequency shift, not an actual from the reference point of our frame.
cefarix, read this:
http://home.att.net/~SolidUniverse/Relativ...Relativity.html
"Einstein’s special theory of relativity postulates that the speed of light is a constant for all inertial observers. This postulate can be used to derive the Lorenz transformations relating length and time measurements by different observers. In this paper it is shown that the Lorentz transformations can be obtained for any type of wave simply by defining distance to be proportional to wave propagation time. The special nature of light is that length and time measured by light propagation correspond exactly with length and time measured by material rulers and clocks. This suggests that material objects consist of waves propagating at the speed of light. Taking this as an alternative postulate for special relativity implies constancy of the measured speed of light without any recourse to non-Euclidean geometry of physical space-time. This alternative postulate is consistent with de Broglie’s wave hypothesis, with the Dirac velocity operator of quantum mechanics, and with experimental observations of transformations between matter and light..."
http://home.att.net/~SolidUniverse/Relativ...Relativity.html
"Einstein’s special theory of relativity postulates that the speed of light is a constant for all inertial observers. This postulate can be used to derive the Lorenz transformations relating length and time measurements by different observers. In this paper it is shown that the Lorentz transformations can be obtained for any type of wave simply by defining distance to be proportional to wave propagation time. The special nature of light is that length and time measured by light propagation correspond exactly with length and time measured by material rulers and clocks. This suggests that material objects consist of waves propagating at the speed of light. Taking this as an alternative postulate for special relativity implies constancy of the measured speed of light without any recourse to non-Euclidean geometry of physical space-time. This alternative postulate is consistent with de Broglie’s wave hypothesis, with the Dirac velocity operator of quantum mechanics, and with experimental observations of transformations between matter and light..."
What experiment could we design that could determine if there really was an absolute space or not?
Then we could settle the question once and for all ;-).
The problem/challenge is this:
if matter is also composed of waves, then all our devices will ALSO contract when they move, just like light, and that's why we always measure c in all directions and independent of our velocity.
So, how would it work? Can we do something similar to the Morley experiment, but better, with our modern technology, that would decide this?
Chantal
Then we could settle the question once and for all ;-).
The problem/challenge is this:
if matter is also composed of waves, then all our devices will ALSO contract when they move, just like light, and that's why we always measure c in all directions and independent of our velocity.
So, how would it work? Can we do something similar to the Morley experiment, but better, with our modern technology, that would decide this?
Chantal
Sure... if we found the measured speed of light to be different for different scenarios, it would prove the existence of a preferred frame of reference, independent of whether matter is composed of waves or if the measuring device contracts or distorts in any manner.
so how could we do that then, exactly ;-).
Any ideas?
Chantal
Any ideas?
Chantal
QUOTE (korosten+Jan 20 2007, 06:31 AM)
What experiment could we design that could determine if there really was an absolute space or not? Then we could settle the question once and for all ;-)
Such experiments were done already (1, 2, 3). But the Nature doesn't require such categoric settlements. By AWT in Nature every concept is relative result of mutual dualities, the absolute reference frame concept as well. The real physic exhibits a number of examples, which are manifests itself as an absolute space for energy spreading sometimes, sometimes not, depending on the experimental conditions.
For example, for tiny waves at the water surface the absolute space doesn't exist by the same way, like for the light waves in vacuum. Whereas the long-wavelength waves exhibits the dependence to the absolute motion by the same way, like the Doppler shift anisotropy of microwave background Universe. Therefore we can say, for high energy spreading the absolute reference frame never would exist at all, whereas for the low energy density phenomena (the gravitational or radio waves in particular) the absolute reference frame should be always detectable.
By AWT the absolute frame of the whole Universe should always exist, but its detectability is infinitesimal. Because of our existence is very derived, we can say, the more general some concept/effect/phenomena appears, by the more subtle way it manifests itself in perceivable reality. Such insight brings the duality concept even into existence definition as some generalization of Heissenberg uncertainty principle.
So the answer to the question, whether the absolute space exist at all can sound: Sure, it does. But just in infinitesimal subtle way, because we aren't an absolute observers...
The way in better understanding of Universe is not always in building of high energy colliders and other giant apparatus, but in measurement of most subtle effects of reality. We should be very quiet to hear the breath of the God. And we should always avoid the premature decisions, because the reality can be a much more general, then we can even imagine.
Such experiments were done already (1, 2, 3). But the Nature doesn't require such categoric settlements. By AWT in Nature every concept is relative result of mutual dualities, the absolute reference frame concept as well. The real physic exhibits a number of examples, which are manifests itself as an absolute space for energy spreading sometimes, sometimes not, depending on the experimental conditions.
For example, for tiny waves at the water surface the absolute space doesn't exist by the same way, like for the light waves in vacuum. Whereas the long-wavelength waves exhibits the dependence to the absolute motion by the same way, like the Doppler shift anisotropy of microwave background Universe. Therefore we can say, for high energy spreading the absolute reference frame never would exist at all, whereas for the low energy density phenomena (the gravitational or radio waves in particular) the absolute reference frame should be always detectable.
By AWT the absolute frame of the whole Universe should always exist, but its detectability is infinitesimal. Because of our existence is very derived, we can say, the more general some concept/effect/phenomena appears, by the more subtle way it manifests itself in perceivable reality. Such insight brings the duality concept even into existence definition as some generalization of Heissenberg uncertainty principle.
So the answer to the question, whether the absolute space exist at all can sound: Sure, it does. But just in infinitesimal subtle way, because we aren't an absolute observers...
The way in better understanding of Universe is not always in building of high energy colliders and other giant apparatus, but in measurement of most subtle effects of reality. We should be very quiet to hear the breath of the God. And we should always avoid the premature decisions, because the reality can be a much more general, then we can even imagine.
QUOTE (korosten+Jan 20 2007, 03:31 AM)
What experiment could we design that could determine if there really was an absolute space or not?
I don't know korosten. But I've got a hunch it'll be something to do with gravity.
I don't know korosten. But I've got a hunch it'll be something to do with gravity.
Sorry, that's no good korosten. You'd get the same result if you moved 100km/s faster starting from any speed. No, I meant like what you were saying a while back about the speed of gravity. To prove that absolute space is the right concept you need to prove that spacetime is the wrong concept. And then you'd probably have to invent a hoverbike before anybody will believe you. Myself apart of course.
QUOTE (Farsight+Jan 22 2007, 03:38 AM)
To prove that absolute space is the right concept you need to prove that spacetime is the wrong concept.
Nope, it means to prove the violation of Lorentz symmetry. Here's nothing wrong on the space-time concept as such even in context of Aether theory. The space-time is simply the synonym for Aether environment - the Aether theory just adds the insintric inertia property (background of Newtonian dynamic) to this concept.
Even the water surface can serve as an example of some local space-time, why not. The purpose of AWT is not to replace the relativity theory, just to explain it and to extend it towards the other theories.
Nope, it means to prove the violation of Lorentz symmetry. Here's nothing wrong on the space-time concept as such even in context of Aether theory. The space-time is simply the synonym for Aether environment - the Aether theory just adds the insintric inertia property (background of Newtonian dynamic) to this concept.
Even the water surface can serve as an example of some local space-time, why not. The purpose of AWT is not to replace the relativity theory, just to explain it and to extend it towards the other theories.
farsight,
why would you get the same result?
If c is constant as an ABSOLUTE, then the forward speed relative to the moving apparatus is slower than the speed backwards.
Think of a speaker in a wind tunnel, and 2 microphones, one in front, one in the back, same distance apart, microphones not moving, and speaker not moving relative to the tunnel.
The sound travels faster in the direction of the wind.
So the Mic on one side registers the sound sooner than the other.
Example: engineers can create a sonic boom in the wind tunnel. the speed of sound is constant in AIR, and if air moves faster, so does the sound.
For light, IF there is a medium, it should be the same:
if the apparatus moves, then light cannot travel with the same speed in both directions, that would violate the constancy of the speed of light.
yes, there would be time dilation. But all 3 clocks would experience the same dilation,and both distances d would be shortened by the same amount.
So that's why it is important to just measure the time in ONE direction each, and to measure the time DIFFERENCE.
It think it should even work in fiberoptic cable, although I am not sure by how much it would differ.... but it would be cheap and doable!
http://chantal.nobilitas.com/gravity/light/light.doc
Chantal
why would you get the same result?
If c is constant as an ABSOLUTE, then the forward speed relative to the moving apparatus is slower than the speed backwards.
Think of a speaker in a wind tunnel, and 2 microphones, one in front, one in the back, same distance apart, microphones not moving, and speaker not moving relative to the tunnel.
The sound travels faster in the direction of the wind.
So the Mic on one side registers the sound sooner than the other.
Example: engineers can create a sonic boom in the wind tunnel. the speed of sound is constant in AIR, and if air moves faster, so does the sound.
For light, IF there is a medium, it should be the same:
if the apparatus moves, then light cannot travel with the same speed in both directions, that would violate the constancy of the speed of light.
yes, there would be time dilation. But all 3 clocks would experience the same dilation,and both distances d would be shortened by the same amount.
So that's why it is important to just measure the time in ONE direction each, and to measure the time DIFFERENCE.
It think it should even work in fiberoptic cable, although I am not sure by how much it would differ.... but it would be cheap and doable!
http://chantal.nobilitas.com/gravity/light/light.doc
Chantal
According to reevaluations of the Morley experiment and CMB, we are moving at about 380 or so km/s!
http://redshift.vif.com/JournalFiles/V10NO2PDF/V10N2CAH.pdf
http://redshift.vif.com/JournalFiles/V10NO2PDF/V10N2CAH.pdf
Korosten: you get the same result because the distances aren't both 10km when the whole appartus moves. For one clock it's less, for the other it's more. You also get problems trying to synchronise your clocks in the first place, and time dilation and length contraction creep in. Hey don't get me wrong, I agree with you about absolute space. But I also hold Special Relativity in high regard and think you need a more radical experiment to explain the postulate therein, and show that what appears to be spacetime is demonstrably absolute space.
farsight,
Clocks CAN be synchronized to that accuracy - for GPS they need to do that all the time! And even a few ns difference would be a disaster!
Also the WHOLE apparatus moves at the same velocity.
So WHY should the distances d front/back not be the same?
Can you explain it to me :-)?
They ALL move with the SAME velocity, ALL clocks, BOTH distances.
So there is NO relative velocity inside the apparatus.
It seems a simple enough experiment and doable, so why not do it?
Do you agree that if we DO in fact measure a time difference, that this proves that c is constant in an absolute sense?
So a good question is: what accuracy do we need?
Actually, not that much!
For say 10km cable as in the example, where we would expcet 22 ns difference, even if the cables are off by 10 cm (and we CAN do this probably do much more precicse, I'd say down to 1mm at least), then that would be a deviation in dt of only 0.3ns.
As for the time, the accuracy must be around += 2 ns.
So that should be doable.
Chantal
Clocks CAN be synchronized to that accuracy - for GPS they need to do that all the time! And even a few ns difference would be a disaster!
Also the WHOLE apparatus moves at the same velocity.
So WHY should the distances d front/back not be the same?
Can you explain it to me :-)?
They ALL move with the SAME velocity, ALL clocks, BOTH distances.
So there is NO relative velocity inside the apparatus.
It seems a simple enough experiment and doable, so why not do it?
Do you agree that if we DO in fact measure a time difference, that this proves that c is constant in an absolute sense?
So a good question is: what accuracy do we need?
Actually, not that much!
For say 10km cable as in the example, where we would expcet 22 ns difference, even if the cables are off by 10 cm (and we CAN do this probably do much more precicse, I'd say down to 1mm at least), then that would be a deviation in dt of only 0.3ns.
As for the time, the accuracy must be around += 2 ns.
So that should be doable.
Chantal
I'll have to think about it some more and get back to you properly korosten.
Alright, korosten, let's see exactly why the setup won't detect an absolute space. Firstly, let me re-iterate the setup just to make sure I've got it correct. The apparatus consists of a laser in the center. This laser is sent in two directions simultaneously: forwards and backwards. At the front end is detector A and at the back end is detector B. The whole apparatus moves in the direction of A with velocity V.
We'll consider the simple case of an observer riding the apparatus. The answer in this case should be trivial: the same time will be observed for both A and B. This case is equivalent to you conducting this experiment in your lab.
On the other hand, we have the case where the apparatus is moving with velocity V, in the direction of A, relative to the observer. Things get complicated here. It is not sufficient to simply apply length contraction and time dilation to get the correct answer. Instead, understand that length contraction and time dilation are not the whole picture. There are other relativistic effects at work, like aberration. If the observer somehow sits in the center of the apparatus as it passes him, then when the observer is at the mid-point of the device (at the laser), he will see the distance to A to be shorter than the distance to B. The light emitted by the laser will be going at the same constant speed c. As the apparatus continues to move, the distance between the laser and the forward-emitted light pulse will increase at the rate of c-V, while the distance between the laser and backward-emitted light pulse will increase at the rate of c+V. The distance to A is also appropriately shortened, and the distance to B appropriately lengthened, such that even though the light pulses close on A and B at different rates, they still hit them after having travelled for the same amount of time. Note that the observer won't see the pulses hit at the same time, as it takes time for that information to travel from the detectors to the observer, and the distance to A and B is not the same. However, the elapsed time from emission to absorption is the same for both pulses. A similar scenario happens if the apparatus is off-center from the observer, but the calculation are more complicated. The end result is the same, however.
We'll consider the simple case of an observer riding the apparatus. The answer in this case should be trivial: the same time will be observed for both A and B. This case is equivalent to you conducting this experiment in your lab.
On the other hand, we have the case where the apparatus is moving with velocity V, in the direction of A, relative to the observer. Things get complicated here. It is not sufficient to simply apply length contraction and time dilation to get the correct answer. Instead, understand that length contraction and time dilation are not the whole picture. There are other relativistic effects at work, like aberration. If the observer somehow sits in the center of the apparatus as it passes him, then when the observer is at the mid-point of the device (at the laser), he will see the distance to A to be shorter than the distance to B. The light emitted by the laser will be going at the same constant speed c. As the apparatus continues to move, the distance between the laser and the forward-emitted light pulse will increase at the rate of c-V, while the distance between the laser and backward-emitted light pulse will increase at the rate of c+V. The distance to A is also appropriately shortened, and the distance to B appropriately lengthened, such that even though the light pulses close on A and B at different rates, they still hit them after having travelled for the same amount of time. Note that the observer won't see the pulses hit at the same time, as it takes time for that information to travel from the detectors to the observer, and the distance to A and B is not the same. However, the elapsed time from emission to absorption is the same for both pulses. A similar scenario happens if the apparatus is off-center from the observer, but the calculation are more complicated. The end result is the same, however.
Isn't this just the Mitchelson-Morley experiment revisited? And if we consider that "matter is made out of light" as per the Robert Close paper, those 10km lengths are going to measured in terms of light.
:-)
The observers(s) are the 100% synchronized atomic clocks.
We can LATER move them back to the observer (human) who can check the results ;-).
So it doesn't matter what the human observer really sees.
The 10km cable we can measure here on earth and make sure they are , in fact,10 km, side by side.
Yes they are contracted along the moving axis, but THE SAME way BOTH sides.
And yes there is time dilation, but again, the SAME way for all clocks.
So the distances d are then d' for instance in the moving case. It doesn't matter, as long as d' is the same front/back.
DIFFERENCES TO MORLEY:
================
The measured an interference pattern, NOT THE TIME.
Also, the light beam went BOTH ways! This is important, because then on AVERAGE, the light will travel with c again...
(We just do it ONE way each!)
Also, they had the right angle etc - a very different experiment in total!
But they did NOT HAVE atomic clocks then!
Now we can actually measure the time difference down to a few ns!
In addition, we can probably do this on EARTH, not in space, we can use CABLES.
YEs if we do this in SPACE, then how do we know the satellites are 10km apart. With lasers ;-). So then there is this issue with length. Although we can still do it, if we measure the distance using a laser going back AND forth...
Chantal
The observers(s) are the 100% synchronized atomic clocks.
We can LATER move them back to the observer (human) who can check the results ;-).
So it doesn't matter what the human observer really sees.
The 10km cable we can measure here on earth and make sure they are , in fact,10 km, side by side.
Yes they are contracted along the moving axis, but THE SAME way BOTH sides.
And yes there is time dilation, but again, the SAME way for all clocks.
So the distances d are then d' for instance in the moving case. It doesn't matter, as long as d' is the same front/back.
DIFFERENCES TO MORLEY:
================
The measured an interference pattern, NOT THE TIME.
Also, the light beam went BOTH ways! This is important, because then on AVERAGE, the light will travel with c again...
(We just do it ONE way each!)
Also, they had the right angle etc - a very different experiment in total!
But they did NOT HAVE atomic clocks then!
Now we can actually measure the time difference down to a few ns!
In addition, we can probably do this on EARTH, not in space, we can use CABLES.
YEs if we do this in SPACE, then how do we know the satellites are 10km apart. With lasers ;-). So then there is this issue with length. Although we can still do it, if we measure the distance using a laser going back AND forth...
Chantal
I admire your enthusiasm korosten, and I don't mean to be skeptical. Like I said, I'll have to think this through properly to get back to you.
PS: what length of cable does the time difference equate to?
PS: what length of cable does the time difference equate to?
light travels 10m in 33ns
So if the time difference is 22ns, that is a difference of about 6m. Quite a lot :-)
And that's just for the velocity of earth at 100km/s. It is estimated to be more like 390km/s, then the time difference shoulld be about 86ns.
86ns is almost 40m! (Unless I did the calculatiions wrong ;-).
Here is the computation (see .doc file)
Speed of light in vacuum 299792 km/s
Speed forward d/(c-v)
Speed backward d/(c+v)
Time difference d / ( c-v) - d/(c + v)
Paste this in Excel:
(it looks horrible here)
Distance d of light ray (km) Speed of apparatus (km/s) Time forward Time backward Time difference between front/back in seconds Time differencein nanoseconds
1 100 3.33676E-06 3.33453E-06 2.22531E-09 2.225307159
10 100 3.33676E-05 3.33453E-05 2.22531E-08 22.25307159
100 1000 0.000334681 0.000332456 2.22533E-06 2225.331672
10 390 3.33999E-05 3.33131E-05 8.67871E-08 86.78711642
So if the time difference is 22ns, that is a difference of about 6m. Quite a lot :-)
And that's just for the velocity of earth at 100km/s. It is estimated to be more like 390km/s, then the time difference shoulld be about 86ns.
86ns is almost 40m! (Unless I did the calculatiions wrong ;-).
Here is the computation (see .doc file)
Speed of light in vacuum 299792 km/s
Speed forward d/(c-v)
Speed backward d/(c+v)
Time difference d / ( c-v) - d/(c + v)
Paste this in Excel:
(it looks horrible here)
Distance d of light ray (km) Speed of apparatus (km/s) Time forward Time backward Time difference between front/back in seconds Time differencein nanoseconds
1 100 3.33676E-06 3.33453E-06 2.22531E-09 2.225307159
10 100 3.33676E-05 3.33453E-05 2.22531E-08 22.25307159
100 1000 0.000334681 0.000332456 2.22533E-06 2225.331672
10 390 3.33999E-05 3.33131E-05 8.67871E-08 86.78711642
QUOTE (korosten+)
The observers(s) are the 100% synchronized atomic clocks.
This could be taken to be the first case in my example.
This could be taken to be the first case in my example.
QUOTE (korosten+)
We can LATER move them back to the observer (human) who can check the results ;-).
So it doesn't matter what the human observer really sees.
It does. The observer is the one who sees. Without an observer, there is no seeing
So it doesn't matter what the human observer really sees.
It does. The observer is the one who sees. Without an observer, there is no seeing
QUOTE (korosten+)
Yes they are contracted along the moving axis, but THE SAME way BOTH sides.
No, they are not. It depends on a number of factors how the lengths appear to a relatively moving observer. (length contraction + relativistic aberration)
No, they are not. It depends on a number of factors how the lengths appear to a relatively moving observer. (length contraction + relativistic aberration)
QUOTE (korosten+)
And yes there is time dilation, but again, the SAME way for all clocks.
That is correct.
That is correct.
QUOTE (korosten+)
So the distances d are then d' for instance in the moving case. It doesn't matter, as long as d' is the same front/back.
d' is not the same front and back.
Also notice that the clocks and the lengths are distorted relative to the frame of reference. If you want to keep the clocks the observers, then the apparatus is at rest, because the frame of reference is centered on the apparatus itself. If you want to know what the human observer sees, you must necessarily shift the frame of reference to the human observer. You can't keep your observer in one place and your frame of reference in another.
d' is not the same front and back.
Also notice that the clocks and the lengths are distorted relative to the frame of reference. If you want to keep the clocks the observers, then the apparatus is at rest, because the frame of reference is centered on the apparatus itself. If you want to know what the human observer sees, you must necessarily shift the frame of reference to the human observer. You can't keep your observer in one place and your frame of reference in another.
cefarix,
yes the observers are the clocks! Of course :-)
I meant the observer is not in the MIDDLE. but the 2 clocks on either end.
Now re length contraction:
the formula for length contraction is... the Lorentz transformation!
If both front and back cables are moving with the SAME VELOCITY relative to the "background", then BOTH are contracted the SAME way.
How could it be different?!
Picture 2 wooden sticks, each 1m long on each side of the indicated middle.
Both sticks move with velocity v.
Both sticks are contracted by the Lorentz contraction.
Note there is just ONE v.
Can you please compute it for me then if you disagree, how can these 2 wooden sticks be contracting in different ways?
Chantal
yes the observers are the clocks! Of course :-)
I meant the observer is not in the MIDDLE. but the 2 clocks on either end.
Now re length contraction:
the formula for length contraction is... the Lorentz transformation!
If both front and back cables are moving with the SAME VELOCITY relative to the "background", then BOTH are contracted the SAME way.
How could it be different?!
Picture 2 wooden sticks, each 1m long on each side of the indicated middle.
Both sticks move with velocity v.
Both sticks are contracted by the Lorentz contraction.
Note there is just ONE v.
Can you please compute it for me then if you disagree, how can these 2 wooden sticks be contracting in different ways?
Chantal
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