Your claim is absurd, and your reply is not responsive to my question. Unless someone else here agrees with you, then your claim is dismissed by unanimous consent.clj4 said:You'll need to figure that one for yourself, I am not interested in restarting a multi-hundred post thread with you.
Again, your reply is not responsive to my question. Unless someone else here agrees with you, then your claim is dismissed by unanimous consent.You got that in the CMWill paper that was recommended to you hundreds of posts ago. I am not interested in running another multi-hundred post thread with you on the same exact subject. It was already discussed ad nauseaum with you in more than one thread.
Does anyone else remember it this way?Several other posters tried (and apparently failed) to explain the same thing to you. Try reading CM Will on your own.
alpaolo said:2. http://www.aip.org/enews/physnews/20...t/pnu484-1.htm . This is the most recent and accurate determination that the speed of light is independent of the speed of the source.
I don't know why are needed some experiment, I think is natural that the light speed is indipendent by the speed of the source.
Like a rain that fall down to the clouds.
If the cloud go down to sky with a certain speed, the drops fall at its speed, or not?
alpaolo said:Another strange question.
If the source S of light run with speed vs is on train with a speed Vt, the observer watch the speed as like a sum vs+vt, but the generated run with speed c.
Is not because the source of light lies on the train and the force drag the source, but the light is indipendent, is, in fact "suspended"?
alpaolo said:The speeed sum formula: (u+v)/[1+(u*v/c2)] for me appears a little trick to include a c in the formula.
About me there is a possibility to include gravity in the gallilean transformation.
Every object that don't lies on the "train" ( and stay suspended ) don't suffers the drag force.Then the ext observer can watch only the single speed...
I know I'm crazy, but this idea is a loop on my mind.
ZapperZ said:Er.. the frequencies don't separate because they travel different speeds in vacuum? Come again?
All you need to do is measure this and get it over with. We have measurements of c in vacuum ranging from low freq. radio waves all the way to gamma range. You demanded experimental evidence for the validity of SR. Now it is my turn to demand from you experimental evidence for what you are claiming. It is fair, is it not?
It is also ironic that you are using "photons are still going the constant speed of c" in your explanation of optical transport through matter, since you are arguing that they DON'T!
Zz.
michael879 said:Im not arguing that the speed of light isn't constant, I am asking for experimental evidence since the only proof I have is that a bunch of teachers have told me its constant. In my comment I was just telling you would a textbook would say: all frequencies of light travel at c in a vacuum. In media however they "travel" at different speeds. Its misleading to say that since in reality they are still traveling at c, they just are absorbed and reabsorbed by atoms in the medium that slow down different frequencies different amounts.
maybe its valid but its kinda irrelevent.ZapperZ said:But in all practical sense, they DO travel at different speeds in a medium. This is because the "light pulse" that is measured is always the group velocity. You don't measure the phase velocity, nor do you have a direct probe of the "photon velocity". The same is true for speed of light in a vacuum. Do you think you measured the "photon velocity" here? Thus, the comparison is perfectly valid.
huh? when have I countered SR? I think SR is right I am just trying to understand its postulates and get some clear evidence of it. what drag scenario are you talking about? I havnt mentioned anything like drag and I havnt given my own theory to counter SR... I think your confusing me with alpaolo..ZapperZ said:You were already given the experimental evidence that is consistent with SR. Yet, you continued to counter it with some made-up scenario of some "drag", which is neither formulated carefully, nor backed by any experimental evidence. Why aren't you as skeptical towards this scenario as you are with your textbooks and your teachers? To me, you're already nitpicking things that you don't like, while you turn on your blinders towards your explanation that is riddled with holes.
I have given you tons of experimental evidence. There are more. You haven't shown even one. Unless there's something you haven't told me, I'm sure you'll understand that I no longer wish to continue with this "discussion", because what I asked for, you refuse to provide.
Zz.
michael879 said:maybe its valid but its kinda irrelevent.
huh? when have I countered SR? I think SR is right I am just trying to understand its postulates and get some clear evidence of it. what drag scenario are you talking about? I havnt mentioned anything like drag and I havnt given my own theory to counter SR... I think your confusing me with alpaolo..
M1keh, light could logically be able to travel at speed greater than light while all frequencies still initially went the same speed. I think sound waves are like this, all frequencies travel 334 m/s (not sure) but can be viewed as going faster from different reference frames.
zapper, the frequencies don't separate because they travel different speeds in a vacuum, just because they travel different speeds in a medium which is pretty irrelevant since the photons are still going the constant speed of c (just being absorbed and reabsorbed by molecules).
michael879 said:I said logically, which means if light were like sound different frequencies would still travel at c but they could appear to travel at speeds greater than c from different reference frames. I didnt say light IS like sound I said logically it could be. I was just saying that the fact that all frequencies travel at the same speed doesn't prove that c is constant in all inertial frames.
also, all frequencies do travel at c in a vacuum, its only when they are in some medium that they separate.
The fact that the speed of light can vary in different media is irrelevant to this thread because the photons in that case never travel slower than c. The overall light "wave" has an average speed slower than c.
sorry I just reread what I wrote. I think my lack of commas made it mean something different from what I meant.ZapperZ said:So I actually imagined you saying what I quoted in BOLD?
I meant that the reason the frequencies separate in a medium isn't because they travel different speeds in a vaccuum. We both saying the same thing arent we?the frequencies don't separate because they travel different speeds in a vacuum
what paper are you talking about? I havnt cited any paper... and I get that the group velocity isn't c in a medium but it really has nothing to do with my original question. All I asked was for experimental evidence that the speed of light was constant. Since relativity is based around that fact I am just curious why einstein thought that. Why are you being so aggressive towards me? and why do you keep acting like I made most of these posts? I've only posted 3 or 4 times and I havnt said half of the things youve accused me of.ZapperZ said:You don't have to teach me that, especially if you have read our FAQ in the General Physics section. However, and I'm saying this again for the umpteeth time, you do NOT measure the speed of a photon. You detect the GROUP VELOCITY, be it in vacuum or in a medium. That is what we measure in optical transport measurement, it is what is measured in the paper that was cited, and it is what is being measured in that apparent superliminal NEC experiment a few years ago.
And where do you think are the sources of the gamma rays that were measured in the cited paper? In the Earth's reference frame? How about you give the paper a careful reading FIRST and figure out if they somehow managed to sneak into PRL with simply just that one result, or if they actually had a few more things to say?
Zz.
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?
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.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.
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.
clj4 said: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.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.
http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#one-way tests
What is your major malfunction, clj4?!? Can you not read your own references?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.
You can define some coordinate systems where the speed of light is not isotropic. But the question becomes, is that an inertial frame?Aether said:There is no physical evidence that the one-way speed of light is isotropic.
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).
Aether said:What is your major malfunction, clj4?!? Can you not read your own references?
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.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.
No, you lost that debate. You simply refuse to accept that.The same exact issue was refuted in a pair of multihundred posts threads between the two of us. How quickly you forget...
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?You need to read:
http://prola.aps.org/abstract/PRD/v45/i2/p403_1
I recommended it for you about 30 times.
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.
No, you lost that debate. You simply refuse to accept that.
Then read it and try to undewrstand it. CM Will makes his points quite clearly.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.
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?Therefore, your reference to this paper stands dismissed by unanimous consent. How can it be otherwise?
You are dreaming, clj4.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.
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.Really? this is why you went away for such a long time?
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.Then read it and try to undewrstand it. CM Will makes his points quite clearly.
We are in disagreement about who clearly understands this subject, and who clearly does not understand it.It can be otherwise if you took the time to read and understand rather than simply repeat stuff that you cleraly do not understand.
It means every single person on this site who has read and understood what is being dismissed, and doesn't raise an objection.As to the "unanimous", we have seen this from you in the past. It means you and yourself?
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.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?
Yes, that's interesting. Did you write this abstract clj4?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.
Please let me know if you ever see this paper anywhere.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).
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.
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.
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.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.
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.
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.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.
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).In the meanwhile, can you stop trying to propagate your "aetherist" theories? This is a scientific website, not a place for antiscientific propaganda.
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.
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.
I do not see any contradiction between your statement and mine. I accept your statement as valid. How does it invalidate mine?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.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.
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.
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.clj4 said:Thank you, looks like Aether's "unanimous consent" has fallen apart rather quickly.
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.You need to understand Aether's motivation, he really has a "theory" that is (in his mind) a valid replacement for SR.
Beaten "up", maybe; but not "back". Why is it that you always seem to be 90-degrees out of phase with reality, clj4?This is the reason why he comes back in this forum every few months spewing the same nonsense only to be beaten back.
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.He(Aether) has promised a "deciding" experiment which he has never run (at least, up to this point).