Invariance of Light

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21 years 3 months ago #6475 by tvanflandern
<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[LB]: Another difference between SR and LR is that in SR there is no aether, period.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Einstein was a pretty smart fellow. The problems with relativity can be largely attributed to his followers, not to E himself. For example, E never accepted the possibility of "black holes".

On the point about the aether, Einstein was finally driven by reason and experiment to accept the reality of some sort of aether, and even hinted at recognizing that it had to coincide with the local gravitational potential field. For example, we read in Einstein's "Ether and the theory of relativity", Springer, Berlin (1920), reprinted Dover (1983), p. 23: “According to the general theory of relativity space without ether is unthinkable.” According to Einstein, aether could be equated to the gravitational field. “The aether of the general theory of relativity is a medium without mechanical and kinematic properties, but which codetermines mechanical and electromagnetic events.” It was inferred that the aether must be incompressible so that longitudinal waves did not exist. Cf. "Albert Einstein: Philosopher-Scientist", Ed. P.A. Schilpp, Tudor Publ. (1951). Then in "Einstein: the first hundred years", Ed: M. Goldsmith, A. Mackay, J. Woudhuysen, Pergammon Press, Oxford (1980), pp. 58-59: “Thus [Einstein] regarded his field theory as in essence a kind of revival of the notion of a space-filling ether, which is, however, relativistic rather than non-relativistic. But somehow Bohr could never take such views seriously and probably regarded them as naïve, a return to ‘primitive realism’.” Einstein noted that Lorentz had taken over all the properties of the original aether except its immobility. -|Tom|-

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21 years 3 months ago #6239 by tvanflandern
<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[Jan]: Just to tease our minds again. Consider a high speed rotational platform with a laser mounted on the border and having it point towards the centre. Now, according to SR, the light should not intersect the centre since dragging should occur with high speeds. Any comments on this?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

It depends on how you aim the laser. The center suffers aberration. Its retarded and instantaneous positions differ. If you aim at the retarded position, the laser beam will go there. -|Tom|-

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21 years 3 months ago #6071 by Larry Burford
<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
[tvf]
The problems with relativity can be largely attributed to his followers, not to E himself.
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>
Understood. Einstein himself is still one of my heros, but I hold many of the current relativity experts (smart guys, in many ways) in somewhat less esteem. These followers (at least most of them) will tell you flat out that in SR there is and/or can be no aether. The rest lean that way but tend not to have a strong opinion.

It's been a busy morning. I hope you are even now considering further comments about the possiblilty of exploiting the aether/no-aether difference between the modern incarnations of LR and SR.

Even if my off-the-cuff suggestion isn't up to it, it seems logical that this difference should be exploitable in *some* way even with sub-FTL signals. (??)

It might require some time to come up with a scheme, if this hasn't already been considered.

Regards,
LB

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21 years 3 months ago #6072 by tvanflandern
Reply to LB:

In the first 150 years of trying, no one could find an experiment that could distinguish aether from non-aether beyond the original evidence that light had all the known properties of waves and therefore had to have a medium to "wave".

Then it was argued that such an experiment was impossible in the light-speed & slower domain. [AJP 41, 1068-1077 (1973), "The rod contraction-clock retardation ether theory and the special theory of relativity" by Herman Erlichson.] He concluded that:
(1) no experimental difference, predicted or realized, yet exists between the Lorentzian “ether” form of relativity and Einstein’s special relativity.
(2) The only possible experimental difference between the two theories may lie in a one-way experiment that is not a direct measurement of the speed of light.
(3) It may be that no experimental difference is possible.

The elimination of one-way experiments as candidates (because of clock synchronization requiring an assumption about light-speed), and the failure for all the people in the world (thinking hard about how to do this) to come up with an experiment, has convinced me and others that no such experiment is possible. But you are welcome to keep trying. If you succeeded, it wouldn't be the first time that something thought impossible was done. <img src=icon_smile_shock.gif border=0 align=middle> -|Tom|-

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21 years 3 months ago #6073 by Jan
Replied by Jan on topic Reply from Jan Vink
<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
[TVF]: It depends on how you aim the laser. The center suffers aberration. Its retarded and instantaneous positions differ. If you aim at the retarded position, the laser beam will go there.
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

I initially failed to see the aberration. Is this caused by the instantaneous tangential velocity component of the platform border? Suppose light waves were to travel independently through space, would aberration still occur?

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21 years 3 months ago #6375 by tvanflandern
<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[Jan]: Is this caused by the instantaneous tangential velocity component of the platform border? Suppose light waves were to travel independently through space, would aberration still occur?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Aberration is a consequence of relative motion, period. Ordinary (angular) aberration requires a tangential (transverse) component of motion, as distinct from radial or normal (meaning perpendicular out-of-plane) motion.

See Figure 3 in [url] www.metaresearch.org/cosmology/speed_of_gravity.asp [/url]. -|Tom|-

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