Michelson-Morley experiments

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[hal]Does anybody know about tentatives to make MM type experiment using one way light travel?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

First, Sagnac experiments are the same as MM experiments, except that they are conducted on a rotating platform. The 1925 Michelson-Gale experiment, for example, is just an MM experiment conducted on the rotating Earth, showing a non-null result (i.e., it detected Earth's rotation).

Second, *all* questions and/or doubts about earlier experimental results were put to rest by the GPS system, which has done one-way and two-way lightspeed tests every second for ten years now with 1000 times more precision, and sees no variation with direction in space, time of day, or season of the year.

In particular, the non-null Miller experiments in the 1930s were very likely the result of failing to control for atmospheric pressure variations. So today, it is widely considered that there is no controversy about experimental results, even though many who are still trying to disprove relativity do not accept that.

Meta Research's position is that both the relativity of motion and the effect of gravitational potential on clocks are well-established. However, the particular version of relativity that best describes nature is probably LR rather than SR, and the field interpretation of GR rather than its geometric interpretation. -|Tom|-

tom

the only thing i wonder about this experiment is this,could light be to "heavy" if i can put it this way,much the same way that if i were to put a train moving at say 50,000mph throuh air would air effect it.could the mass of light relative to ether be the cause of no detectable effect.
just a thought.

Dear Mr. Van Flandern,

I am not trying to disprove anything, least of all chalenge theories, which, right or wrong as they may be, give, up to now, good agreements with what is observed.

I did not make comments on Miller's work - you did so, repeating somehow the Shankland and company's story - then there was the temperature, now it is the pressure, tomorrow will be something else. Miller started his work with no intention to prove or disprove anything. This note I put in memory of Dayton Miller, who was a real scientist, independently of his results which could eventually be proven to contain periodic errors of some kind, but until this is done with something else than simple suppositions, the doubt will remain.

The GPS system can hardly be considered an experiment - usually the experiments are performed to verify or falsify something. I would rather call it an application, based on SR(if we consider the Sagnac effect incorporated) and GR, which performs in good agreement with what expected.

In breaf, I was just asking about MM type experiments using different or "strange" setups - not trying to ridiculise Einstein. If somebody knows something, or is just interrested on the matter, please, let me know. [hal]

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[hal]: I did not make comments on Miller's work - you did so, repeating somehow the Shankland and company's story - then there was the temperature, now it is the pressure, tomorrow will be something else.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

I know nothing of Shankland or his story. I investigated the pressure matter personally, found that it had not been controlled for, then found that normal pressure variations were quantitatively of the right size and qualitatively of the right type to explain Miller's experimental findings.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Miller started his work with no intention to prove or disprove anything. This note I put in memory of Dayton Miller, who was a real scientist, independently of his results which could eventually be proven to contain periodic errors of some kind, but until this is done with something else than simple suppositions, the doubt will remain.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

I intend no criticism of Miller, but only of those who have done him a great injustice by continuing to advocate an interpretation of his results that has now been experimentally ruled out. Inasmuch as you did not mention Miller, I made no assumption about your position.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>The GPS system can hardly be considered an experiment - usually the experiments are performed to verify or falsify something.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

This betrays an unfortunate unfamiliarity with GPS data. I am not referring to the uses of GPS with receivers to locate positions on the Earth. These receivers are relatively crude and do not measure the speed of light, one-way or two-way. Instead, I refer to the continual dual-one-way, round-trip communications between Air Force tracking stations and GPS satellites, which take new readings roughly once per second of every day for every GPS (or GLONASS) satellite in orbit. This data is perhaps the grandest relativity experiment ever conducted, and verifies the invariance of lightspeed to the small limits I cited.

Published results by other scientists put much tighter limits on this -- They claim lightspeed is invariant to within 10 or so cm/sec. In my own analysis, I made the most pessimistic assumptions possible about systematic errors that might lie hidden in the system, and estimated more conservatively that errors up to 12 m/s might exist. But that is the outside upper limit.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>I was just asking about MM type experiments using different or "strange" setups - not trying to ridiculise Einstein. If somebody knows something, or is just interested on the matter, please, let me know.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

I took your message precisely that way -- as an inquiry for information. I provided some. Think about it. If the speed of propagation of the signals from GPS satellites to the ground, or the uplink speeds, varied at all, the system would give non-repeatible results for locations by the amounts of the variations, where light propagates one foot per nanosecond and GPS measures the one-way propagation times each way (ground to satellite plus satellite to ground) to a precision of one nanosecond. -|Tom|-

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[north]could light be to "heavy" ... much the same way that if i were to put a train moving at say 50,000mph throuh air would air effect it. Could the mass of light relative to ether be the cause of no detectable effect.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

The measured effect <i>is</i> the speed of light. It does not matter how "heavy" light is. The experiment proves its speed is invariant to 1000 times more precision than older experiments. -|Tom|-

[hal]
Nobody puts in doubt the constancy of the speed of light, nor the first postulate (which is nothing outstanding, considering the independency on the speed of the source is a common feature for waves - example, sound waves. The speed of sound, however, depends on the speed of the medium in which it propagates - the same conjecture was made by Michelson, considering the ether as the medium for the propagation of light, and considering it immobile with respect to the Earth movement. The experiment, then, left two possibilities -1.there is no such thing like ether, 2. ether is moving together with Erath. Many texbooks describe the Michelson experiment as a tentative to prove the light speed dependant on its source speed. Michelson was not that stupid.).

The time dilation and frame contraction, predicted by SR are second order effects and become significant with speeds approaching the speed of light. There may be first order effects which cancel in two way light travel. For example, did somebody measure the time for the light travel between two immobile clocks, then between the same clocks, traveling with the same velocity (speed and direction)? [hal]