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lockecole
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Please, take a look at the last paragraph of the http://www.aliasabur.com/nytimes.html then read the whole article and answer my question.
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Originally posted by lockecole
Please, take a look at the last paragraph of the http://www.aliasabur.com/nytimes.html then read the whole article and answer my question.
Originally posted by GRQC It's unfortunately for his contemporaries (Lorentz, Mach, etc...) that their contributions to the development of relativity theory are lost to the Einstein PR Machine...
Originally posted by Norman
Variable speed of light cosmologies are gaining ground. There are only a few people in the world working on them. Check around on the web and in the cosmology forum. I believe that the idea is that a varying speed of light might explain some interesting cosmological effects we are seeing today, such as an accelerating universe and why it is accelerating now (as in this point in time). If you are really interested someone will know on here about it.
cheers,
Norm
Originally posted by ZapperZ
If you're referring to the possible variation to the fine structure constant that may in turn suggest that c may have been different during the history of our universe, then you may want to hold back on jumping on this bandwagon just yet. There are three separate papers that have thrown serious doubt to the original "discovery" by J.K Webb et al. The first two can be found in the references at the end of this Nature science update piece at
http://www.nature.com/nsu/030428/030428-20.html
The 2nd one, and more recent, is the paper by T. Ashenfelter et al.[1] reporting that the observation made by Webb et al. from the globular clusters can be explained via the synthesis of various isotopes of Mg. This affects the absorption spectra of the quasars observed by Webb et al., and can be explained without invoking any variation in alpha.
Zz.
[1] T Ashenfelter et al., PRL v.92, p.041102 (2004).
Originally posted by Integral
The constant Speed of light is not Einstein's it is Maxwell's. Einstein only showed the RESULTS of a constant speed of light.
..., and also introduce an other postulate, which is only apparently irreconcilable with the former, namely, that light always propagates in empty space with a definite velocity c which is independant of the state of motion of the emitting body.
Originally posted by Integral
Why was Einstein able to POSTULATE this? Why did he not have to prove it? Because MAXWELL predicted it, and the entire Physics community had spend 40 yrs attempting to disprove it. Needless to say they were unable to. As soon as Maxwell derived an expression for the speed of Electro Magnetic waves consisting only of fundamental constants it became clear that this speed was independent of any motion of the source.
You cannot simply postulate something out of the blue, there must be some evidence, if you are attempting to create a meaningful physical theory, that is. Not only did Einstein have a sound tested theory predicting the constancy of c, he had direct experimental verification from Michelson and Morley. All that has changed in the last 100 yrs is a compounding of the evidence that c is indeed a constant.
We have yet to observe a phenomenon that shows C to not be constant.Originally posted by toasty
Maybe C like some other once called cosntants is banded - behaves like a constant in one condition but in another does not.
Originally posted by Integral
If Einstein was making a startling new claim in his 1905 paper concerning the speed of light, he would not have been able to postulate it. He would have had to back up this claim in some manner. The very fact that he did not do this, and that his contemporaries were not bothered by this claim is verification of my argument that speed of light was commonly accepted to be as Einstein postulated. The postulate was not and could not be a controversial claim at the time it was made. Only now after a century has passed when Einstein is either legendary hero or legendary heel is there any question of this issue.
Einstein has already drawn fire because of his lack of reference to the work of others, so you say that his failure to mention the M-M experiment is proof that he was unaware of it? I do not see that as proof of anything other then the fact that he does not speak of it. I find it hard to believe that, as involved in this issue as Einstein was, that he was unaware of M-M.
Originally posted by ZapperZ
By all accounts that I have read, this was singularly due to the "controversial" nature of Relativity.
Originally posted by Integral
Do not forget also that Einstein was a graduate of a Physics program of a reputable school. He had some conflicts with a prominent professor which made it very difficult for him to find a position in physics.
Good analogy and a good illustration of the most common misconception about how light propagates. Usually though, people connect that to a non-constant C, but brightness - no. Brightness is amplitude. With a train whistle, it doesn't sound louder or softer because of doppler shift, it just changes the pitch (frequency).Originally posted by toasty
Getting back to the question of the supposed 'constant' C, can we now again begin to think of experiments - isn't that what Science is supposed to do? - which explore other aspects of the illusion that we experience as light?
For example when I blow my whistle on a train it sounds to me as if it plays in G, but to a person on a bridge listening as I approach it sounds like A above G and on passing like E below G.
Thus is not the expected effect of perceived light moving towards one bound to be 'brighter' and on passing 'darker'?
And if so, can we now note it could only be so if like sound it had to have a medium by which it moves.
Originally posted by russ_watters
Good analogy and a good illustration of the most common misconception about how light propagates. Usually though, people connect that to a non-constant C, but brightness - no. Brightness is amplitude. With a train whistle, it doesn't sound louder or softer because of doppler shift, it just changes the pitch (frequency).
Light experiences motion related doppler shifts, but it doesn't affect speed of light measurements.
There are hundreds of permutations of M&M type experiments that have attempted for more than a hundred years to find an ether. All have failed.
Originally posted by Integral
Notice that in 2 years the "shell" has grown less then 2 light years, so what ever it is that is expanding is moving at less then c. What is the problem with this?
Since I made a mistake in it I removed the entry,
Originally posted by NateTG
Note that the assumtion is that the speed of light is constant in all inertial reference frames. The speed of light need not be constant in accelerated reference frames.
What I do notice here is that from precisely these kinds of events we shall soon learn many new things including what ends Einstein's account based as it was upon an unmeasurably small part of reality.
It's kinda tough working out what toasty posted then removed; it seems to be a reference to http://imgsrc.hubblesite.org/hu/db/2004/10/images/b/formats/web_print.jpg has also been seen.Originally posted by toasty
Since I made a mistake in it I removed the entry, but must clarify what I took notice of; Hubble object V838 images taken in May 2002 and again in Feb 2004 shows growth of 2-3 lightyears.
However we are looking at some kind of gas of debris and it is highly unlikely that such a thing could happen if C is constant and the limit of velocity in the universe.
At close to C nothing except light should be showing itself and this image shows something is happening at the same or a greater velocity.
Originally posted by Nereid
It's kinda tough working out what toasty posted then removed; it seems to be a reference to http://imgsrc.hubblesite.org/hu/db/2004/10/images/b/formats/web_print.jpg has also been seen.
Needless to say, no need for variable c, or any other new physics.
Originally posted by Integral
Zapper,
All good and fine but while the RESULTS of a constant c created some controversy, the postulate did not. Why? If the postulates were in question the entire work would be meaningless. The postulates HAD to be accepted physics, not new revelations, or the paper would have been rejected out of hand.
Nothing. So it would seem, you've painted yourself into a corner.Originally posted by toasty
If we cannot trust the evidence then what is left to investigate?