Unravelling the Mystery of Light's Constant Speed: Challenges and Proofs

  • #51
michael879 said:
I get the theory of special relativity, it is the logical conclusion drawn from the two facts that:
a) the laws of physics are the same in all reference frames
b) the speed of light is constant in all reference frames

what I don't get is why einstein thought the speed of light was constant in all reference frames. What proof of that is there even now? I know maxwell came up with c which is like 1/(m0*e0) or something which kinda suggests it but why couldn't that just be the initial velocity of light if the emitter was at rest with the "global reference frame".

Also, I am not convinced that theory is true. I mean, I've heard of all these experiments "proving" general and special relativity, but I've never seen any documentation of any or any real numbers. I've searched to... Can someone please give me some good links before I start talking about a giant physics conspiracy?

Here is a good synopsis of the experiments confirming relativity:

http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html

The actual list is about 10x bigger.
 
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  • #52
thanks man, Ill read that
 
  • #53
michael879 said:
first, aether, I just omitted the word inertial its what I meant, you didnt answer my question u just pointed out a mistake in it. I know what a postulate is but people don't just go around making up postulates out of nothing and use them in new theories. There must have been a significant amount of evidence that the speed of light is constant for einstein to create all of special relativity around it.
There is no physical evidence that the one-way speed of light is isotropic. What the postulates of SR are designed to exploit is the fact that there isn't any phyiscal evidence to the contrary. This is a mathematical issue, not a physical issue.
 
  • #54
Aether said:
There is no physical evidence that the one-way speed of light is isotropic. What the postulates of SR are designed to exploit is the fact that there isn't any phyiscal evidence to the contrary. This is a mathematical issue, not a physical issue.

You know that this isn't true, we went over this issue before, there are quite a few experiments that limit any potential anisotropy to very low limits. The experiments figure prominently in the list that I just gave. And you have been told that you are supporting an incorrect view countless times.

http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#one-way tests
 
  • #55
clj4 said:
Aether said:
There is no physical evidence that the one-way speed of light is isotropic. What the postulates of SR are designed to exploit is the fact that there isn't any phyiscal evidence to the contrary. This is a mathematical issue, not a physical issue.
You know that this isn't true, we went over this issue before, there are quite a few experiments that limit any potential anisotropy to very low limits. The experiments figure prominently in the list that I just gave. And you have been told that you are supporting an incorrect view countless times.

http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#one-way tests

3.2 One-Way Tests of Light-Speed Isotropy
Note that while these experiments clearly use a one-way light path and find isotropy, they are inherently unable to rule out a large class of theories in which the one-way speed of light is anisotropic. These theories share the property that the round-trip speed of light is isotropic in any inertial frame, but the one-way speed is isotropic only in an ether frame.
What is your major malfunction, clj4?!? Can you not read your own references?
 
  • #56
Aether said:
There is no physical evidence that the one-way speed of light is isotropic.
You can define some coordinate systems where the speed of light is not isotropic. But the question becomes, is that an inertial frame?

You might also be interested in this very recent conference talk:
http://www.zarm.uni-bremen.de/2forschung/gravi/laemmerzahl/MG11exp/
I came across it when searching for "one way light speed measurements".

All you can read is the abstract by Dr. Adrian Sfarti, but it seems to state that he strengthened some old data to experimentally prove the one-way light speed is isotropic. Strangely, the abstract doesn't describe the experiment at all.


Update: When searching to try to find the paper that goes with the abstract, it looks like this Dr. Sfarti may be a crackpot. Also it appears that the conference preceedings haven't been published yet. So we'll have to wait to see the paper (assuming that the referees don't decide he's a crackpot as well).
 
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  • #57
JustinLevy said:
You can define some coordinate systems where the speed of light is not isotropic. But the question becomes, is that an inertial frame?

You might also be interested in this very recent conference talk:
http://www.zarm.uni-bremen.de/2forschung/gravi/laemmerzahl/MG11exp/
I came across it when searching for "one way light speed measurements".

All you can read is the abstract by Dr. Adrian Sfarti, but it seems to state that he strengthened some old data to experimentally prove the one-way light speed is isotropic. Strangely, the abstract doesn't describe the experiment at all.Update: When searching to try to find the paper that goes with the abstract, it looks like this Dr. Sfarti may be a crackpot. Also it appears that the conference preceedings haven't been published yet. So we'll have to wait to see the paper (assuming that the referees don't decide he's a crackpot as well).

Kevin,Looks like the best you could muster in place of a scientific answer is a personal attack. This is what you learn at UCUI?
Last time we had a conversation on the same exact subject you were a pair of "sockpuppets" called "gregory_" and "NotForYou".
When "both" of you were banned you promptly re-registered yourself as "JustinLevy" and you "progressed" to personal attacks and cyberstalking as "scientific arguments". Looks like this type of unethical behavior is your standard mode of operation.
 
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  • #58
Aether said:
What is your major malfunction, clj4?!? Can you not read your own references?

The statement is made by Tom Roberts and is patently incorrect, sorry to disappoint you. It is refuted (multiiple times) by the papers of the much more respected expert in the field CMWill. Though Tom Roberts has been made aware that his statement is wrong, he never got around to editing his website. The same exact issue was refuted in a pair of multihundred posts threads between the two of us. How quickly you forget...
You need to read:

http://prola.aps.org/abstract/PRD/v45/i2/p403_1

I recommended it for you about 30 times.
 
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  • #59
clj4 said:
The statement is made by Tom Roberts and is patently incorrect, sorry to disappoint you. It is refuted (multiiple times) by the papers of the much more respected expert in the field CMWill. Though Tom Roberts has been made aware that his statement is wrong, he never got around to editing his website.
You are the one who referenced this website in post #54, and I don't see any problem with the passage that I quoted from it.
The same exact issue was refuted in a pair of multihundred posts threads between the two of us. How quickly you forget...
No, you lost that debate. You simply refuse to accept that.
You need to read:

http://prola.aps.org/abstract/PRD/v45/i2/p403_1

I recommended it for you about 30 times.
I would be happy to discuss C.M. Will's paper with you, but you won't make any specific points nor will you answer any of my questions. Therefore, your reference to this paper stands dismissed by unanimous consent. How can it be otherwise?
 
  • #60
Aether said:
You are the one who referenced this website in post #54, and I don't see any problem with the passage that I quoted from it.

Well, physics is about precision. had you read the referenced paper you would have understood that the complete quote is:

"Note that while these experiments clearly use a one-way light path and find isotropy, they are inherently unable to rule out a large class of theories in which the one-way speed of light is anisotropic provided that additional, ad-hoc assumptions are being made "The "provided that additional, ad-hoc assumptions are being made " are the Achille's heel of all the alternative "aether" theories.
That was the gist of my original counter from post 26. It is this exact "aetherist" position that you repeat every several months, only to be refuted every time, with the same arguments.
No, you lost that debate. You simply refuse to accept that.

Really? this is why you went away for such a long time? Just to come back with the same antiscientific statements that originated the threads? I
I would be happy to discuss C.M. Will's paper with you, but you won't make any specific points nor will you answer any of my questions.
Then read it and try to undewrstand it. CM Will makes his points quite clearly.

Therefore, your reference to this paper stands dismissed by unanimous consent. How can it be otherwise?
It can be otherwise if you took the time to read and understand rather than simply repeat stuff that you do not understand. As to the "unanimous", we have seen this from you in the past: it means you and yourself?
 
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  • #61
clj4 said:
Well, physics is about precision. had you read the referenced paper you would have understood that the complete quote is:

"Note that while these experiments clearly use a one-way light path and find isotropy, they are inherently unable to rule out a large class of theories in which the one-way speed of light is anisotropic provided that additional, ad-hoc assumptions are being made "

That was the gist of my original counter to your statement from post 53. This is a position that you repeat every several months, only to be refuted every time.
You are dreaming, clj4.
Really? this is why you went away for such a long time?
I destroyed your argument many times over, and nobody is left who agrees with you. Your arguments and references were all dismissed by unanimous consent. What's left undone? Continuing to "beat a dead horse" (your "argument") isn't necessary.
Then read it and try to undewrstand it. CM Will makes his points quite clearly.
If he comes here and makes his point quite clearly, then that would be fine. However, you have no standing whatsoever to simply invoke his name here as if that lends support to your case.
It can be otherwise if you took the time to read and understand rather than simply repeat stuff that you cleraly do not understand.
We are in disagreement about who clearly understands this subject, and who clearly does not understand it.
As to the "unanimous", we have seen this from you in the past. It means you and yourself?
It means every single person on this site who has read and understood what is being dismissed, and doesn't raise an objection.
 
  • #62
JustinLevy said:
You can define some coordinate systems where the speed of light is not isotropic. But the question becomes, is that an inertial frame?
Would you care to rephrase this? An inertial frame is a coordinate system in which Newton's laws hold true. Since Newton's laws do not hold true in a reference frame where one-way speeds are not isotropic, then the answer to your question as phrased here is: no, that is not an inertial frame.
You might also be interested in this very recent conference talk:
http://www.zarm.uni-bremen.de/2forschung/gravi/laemmerzahl/MG11exp/
I came across it when searching for "one way light speed measurements".

All you can read is the abstract by Dr. Adrian Sfarti, but it seems to state that he strengthened some old data to experimentally prove the one-way light speed is isotropic. Strangely, the abstract doesn't describe the experiment at all.
Yes, that's interesting. Did you write this abstract clj4?
Update: When searching to try to find the paper that goes with the abstract, it looks like this Dr. Sfarti may be a crackpot. Also it appears that the conference preceedings haven't been published yet. So we'll have to wait to see the paper (assuming that the referees don't decide he's a crackpot as well).
Please let me know if you ever see this paper anywhere.
 
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  • #63
Aether said:
You are dreaming, clj4.I destroyed your argument many times over, and nobody is left who agrees with you. Your arguments and references were all dismissed by unanimous consent.

Duh, "unanimous consent" is Aether, you and yourself.

If he comes here and makes his point quite clearly, then that would be fine. However, you have no standing whatsoever to simply invoke his name here as if that lends support to your case.

You mean that you want C.M.Will to come on this website to teach you physics? This is ridiculous, read his paper. In the meanwhile, can you stop trying to propagate your "aetherist" theories? This is a scientific website, not a platform for your antiscientific propaganda.
 
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  • #64
Aether said:
There is no physical evidence that the one-way speed of light is isotropic. What the postulates of SR are designed to exploit is the fact that there isn't any phyiscal evidence to the contrary. This is a mathematical issue, not a physical issue.
This statement sounds like nonsense to me. It is certainly a physical matter, not a purely mathematical one, that all the fundamental laws of physics are Lorentz-invariant; and given that they are, it is guaranteed that if you use the set of coordinate systems defined by the Lorentz transformation, the one-way speed of light will be the same in each inertial system. Of course you could use a different set of coordinate systems where the speed of light would not be isotropic, and the laws of physics would look different in each coordinate system. But this is not an experimental issue at all, it just has to do with the fact that "one-way speed" is a coordinate dependent quantity rather than a physical one, there is no more of a "real truth" about one-way speed than there is about where the origin of your coordinate axes should be located.
 
  • #65
JesseM said:
This statement sounds like nonsense to me. It is certainly a physical matter, not a purely mathematical one, that all the fundamental laws of physics are Lorentz-invariant; and given that they are, it is guaranteed that if you use the set of coordinate systems defined by the Lorentz transformation, the one-way speed of light will be the same in each inertial system. Of course you could use a different set of coordinate systems where the speed of light would not be isotropic, and the laws of physics would look different in each coordinate system. But this is not an experimental issue at all, it just has to do with the fact that "one-way speed" is a coordinate dependent quantity rather than a physical one, there is no more of a "real truth" about one-way speed than there is about where the origin of your coordinate axes should be located.

Thank you, looks like Aether's "unanimous consent" has fallen apart rather quickly. You need to understand Aether's motivation, he really has a "theory" that is (in his mind) a valid replacement for SR. This is the reason why he comes back in this forum every few months spewing the same nonsense only to be beaten back. He(Aether) has promised a "deciding" experiment which he has never run (at least, up to this point).
 
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  • #66
clj4 said:
You mean that you want C.M.Will to come on this website to teach you physics? This is ridiculous, read his paper.
If you want to cite his paper, then you need to explain the point that you are trying to make, apply this reference to support your case, and then answer reasonable direct questions about what you have claimed.
In the meanwhile, can you stop trying to propagate your "aetherist" theories? This is a scientific website, not a place for antiscientific propaganda.
It is not your place to continually contradict me here, and I will now ask you to stop interfering with me. In the future, if you disagree with me on a topic that we have already discussed at length, then please address your comments to someone other than me (either as advice to someone else who I am speaking with, or as a complaint to the PF staff).

It is the responsibility of PF staff to correct me if I were propagating "antiscientific propaganda". If you feel strongly that I'm doing that, then report me to the PF staff; but do not continue to argue with me about it.
 
  • #67
Aether said:
If you want to cite his paper, then you need to explain the point that you are trying to make, apply this reference to support your case, and then answer reasonable direct questions about what you have claimed.

I have, over hundreds of other posts and three other threads. Now, you want CM Will to come over here and teach you physics? You need to read his paper on your own, his point is pretty clear.

It is not your place to continually contradict me here, and I will now ask you to stop interfering with me.

Why not? If you try to use this forum to push 'aetherist" propaganda I think that it is my duty to debunk your statements. I am not "interfering with you" , I am simply debunking your incorrect statements.

In the future, if you disagree with me on a topic that we have already discussed at length, then please address your comments to someone other than me (either as advice to someone else who I am speaking with, or as a complaint to the PF staff).

Why? I am addressing your repeated attempts to push antiscientific theories in this forum (and in others).

It is the responsibility of PF staff to correct me if I were propagating "antiscientific propaganda". If you feel strongly that I'm doing that, then report me to the PF staff; but do not continue to argue with me about it.

The moderators can decide on their own. I prefer to challenge you directly as I have done it in the past when you came up with the same incorrect notions.

I told you then and I am telling you noe: the varu=ious aether theories are not equivalent with SR. Each one such theory needs, for each particular experiment additional ad-hoc assumptions. This is CM Will's (and the mainstream physics) point.
 
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  • #68
JesseM said:
Aether said:
There is no physical evidence that the one-way speed of light is isotropic. What the postulates of SR are designed to exploit is the fact that there isn't any phyiscal evidence to the contrary. This is a mathematical issue, not a physical issue.
This statement sounds like nonsense to me. It is certainly a physical matter, not a purely mathematical one, that all the fundamental laws of physics are Lorentz-invariant; and given that they are, it is guaranteed that if you use the set of coordinate systems defined by the Lorentz transformation, the one-way speed of light will be the same in each inertial system. Of course you could use a different set of coordinate systems where the speed of light would not be isotropic, and the laws of physics would look different in each coordinate system. But this is not an experimental issue at all, it just has to do with the fact that "one-way speed" is a coordinate dependent quantity rather than a physical one, there is no more of a "real truth" about one-way speed than there is about where the origin of your coordinate axes should be located.
I do not see any contradiction between your statement and mine. I accept your statement as valid. How does it invalidate mine?
 
  • #69
Aether said:
There is no physical evidence that the one-way speed of light is isotropic. What the postulates of SR are designed to exploit is the fact that there isn't any phyiscal evidence to the contrary. This is a mathematical issue, not a physical issue.

You already know that your statement above is false, in the past you have been given about 10 experiments that deal specifically with light speed isotropy. Do you need a refresher on the list? Here is a partial:

1. C.M.Will “Clock Synchronization and isotropy of one-way speed of light”, Phys.Rev. D, 45, 2 (1992)

2. D.R.Gagnon, D.G.Torr, P.T.Kolen, T.Chang “Guided-wave measurement of the one-way speed of light”, Phys.Rev. A, 38, 4 (1988)3. T.Krisher, L.Maleki, G.Lutes, L.Primas, R.Logan, J.Anderson, C.Will, Phys. Rev. D, 42, 2, (1990)

4. S. Herrmann, A. Senger, E. Kovalchuk, H. Müller, A. Peters: "Test of the isotropy of the speed of light using a continuously rotating optical resonator", Phys. Rev. Lett. 95, (2005)

You know how science goes, you only need one experiment to render your statement wrong. You have 4 listed above and you fully know that there are a few more.
 
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  • #70
clj4 said:
Thank you, looks like Aether's "unanimous consent" has fallen apart rather quickly.
No it hasn't. If JesseM says that you have a valid point, then it naturally falls apart. In that case, I would continue to listen to what you have to say.
You need to understand Aether's motivation, he really has a "theory" that is (in his mind) a valid replacement for SR.
I have recently posted an explanation of why I am interested in the aether topic at the PF Independent Research Forum. If the PF staff thinks that post is appropriate for this Relativity forum, then it may appear here eventually.
This is the reason why he comes back in this forum every few months spewing the same nonsense only to be beaten back.
Beaten "up", maybe; but not "back". Why is it that you always seem to be 90-degrees out of phase with reality, clj4?
He(Aether) has promised a "deciding" experiment which he has never run (at least, up to this point).
I described a "deciding" experiment in my post to the IR forum. Hopefully someone will authorize me to make that same post here so that we can discuss it openly.
 
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  • #71
Aether said:
I described a "deciding" experiment in my post to the IR forum. Hopefully someone will authorize me to make that same post here so that we can discuss it openly.

Until you have run your experiment and it has agreed with your "theory", please refrain from repeating your anti-mainstream views. This is not the "Against Mainstream Forum" , this is the "Physics Forum".1. C.M.Will “Clock Synchronization and isotropy of one-way speed of light”, Phys.Rev. D, 45, 2 (1992)

2. D.R.Gagnon, D.G.Torr, P.T.Kolen, T.Chang “Guided-wave measurement of the one-way speed of light”, Phys.Rev. A, 38, 4 (1988)3. T.Krisher, L.Maleki, G.Lutes, L.Primas, R.Logan, J.Anderson, C.Will, Phys. Rev. D, 42, 2, (1990)

4. S. Herrmann, A. Senger, E. Kovalchuk, H. Müller, A. Peters: "Test of the isotropy of the speed of light using a continuously rotating optical resonator", Phys. Rev. Lett. 95, (2005)

You know how science goes, you only need one experiment to render your statement wrong. You have 4 listed above and you fully know that there are a few more.
 
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  • #72
Well, this has certainly gone on long enough.

- Warren
 
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