The following stuff from the Beta-atmosphere Yahoo group seems to have been largely covered by other people but I may as well include if for completeness of the archive
===================================================== From: "fgrimer" <[EMAIL PROTECTED]> Date: Tue Dec 6, 2005 5:17 am Subject: The Hafele and Keating Experiments I am sorry to have to subject the readers of this B-atm. group to a chunk of relativity stuff but the point which Webster Kehr expresses so clearly will be crucial to understanding the working of servomechanisms within materials. I confess I was so impressed with the clarity of Kehr's explanation that I congratulated him by e-mail and received an acknowledgement the very next day (ain't the Net a wonderful asset for expediting research). ----------------------------------------------------------- http://pages.sbcglobal.net/webster.kehr/files/Detection.pdf The Hafele and Keating Experiments The Hafele-Keating experiments of 1971 are among the most famous experiments in the history of physics. Their experiments were designed to test the validity of Einstein's SR and his General Theory of Relativity ("GR"). Hafele and Keating twice flew four cesium atomic clocks around the world in commercial jets, first eastbound, then westbound. Their experiments proved that "time," as measured by atomic clocks, is a function of the direction, velocity and altitude of jet airplanes. The direction and velocity of the airplanes were factors of the SR and the altitude of the jets was a factor of the GR.[8,9,10,11] I should note that "time" in this case is the "actual time" as measured by the atomic clocks. Compared to the time kept by a stationary atomic clock at the U.S. Naval Observatory ("USNO"), which stayed on the ground, the eastbound clocks measured time slower than the stationary clock and the westbound clocks measured time faster than the stationary clock. Prior to their experiments, Hafele correctly predicted that the westbound clocks would measure time faster than the stationary clock.[8,9] The Hafele-Keating experiment is considered a proof that the SR and GR are valid theories. But the H-K used a very different version of the SR than was proposed by Einstein in 1905. For example, in the "old SR" of 1905, every element in the experiment was considered, or could be considered, an "at rest" relative reference frame. This was the entire intent of the concept of "relative reference frames." For example, if there were ten jet airplanes flying at ten different velocities in ten different directions, any one of these ten airplanes could be used as the "at rest" reference frame, for the formulas of relativity, to determine the "relative time" between it and any of the other planes. ========================================= Comment Now this assumption of "ten jet airplanes flying at ten different velocities in ten different directions" is always what I understood Special Relativity to claim - but as you can see, those slimy bastard relativists shifted the goalposts. Frank ========================================= By 1971, however, the concept of "relative reference frames" had been totally eliminated. In the "new SR," used by Hafele and Keating, none of the two sets of jet airplanes or atomic clocks in the experiment were allowed to be considered "at rest." Not even the stationary atomic clock at the USNO could be considered "at rest." In the "new SR" used in the H-K, only one "at rest" reference frame was allowed and that was "a nonrotating observer looking down on the North pole from a great distance" [9] or to put it more simply: "a nonrotating point high above the North Pole." ========================================= comment In other words, an absolute reference frame for rotation with respect to the stars - with respect to the non-curvature of water surface in a bucket to bring it down to the most mundane level. Frank ========================================= This "at rest" reference point was not part of the experiment, meaning there was no atomic clock at that point. The "at rest" point in the H-K was many thousands of kilometers from any of the atomic clocks that were part of the experiment! The entire concept of "relative reference frames" was that any object that was part of the experiment could be considered "at rest." No object in the experiment was ever considered "at rest" by Hafele and Keating. It is important to emphasize that the observer or point is "nonrotating." If the observer rotated with the earth, then a stationary point on the equator, for example, would be viewed as being "at rest" relative to the observer's viewpoint. However, because the observer is not rotating, then a stationary point on the equator would be moving at a velocity equal to the (angular) rotation velocity of the earth at that latitude (i.e. zero degrees north). Thus, the "stationary" clock at the USNO was considered to be in motion due to the rotation of the earth (i.e. its velocity was measured relative to the rotation velocity of the earth at its latitude) because the observer was not rotating.[9] Thus, the "stationary" clock was actually in "motion." Let's call a spade a spade. Hafele and Keating could be said to have used a "local or localized Absolute Reference Frame ("local ARF") and a local or localized Absolute Time." By "absolute" I mean that the "at rest" reference frame they chose was not part of the experiment and did not move (relative to other objects), and did not rotate, during the experiment. By "local" I mean that they did not use the URF of CMBR (which had not been discovered by 1971), or the reference frame of the sun's barycenter (which Hafele and Keating obviously would have known about), or the galactic barycenter (which they should have known about), but instead they used a reference frame within the ionosphere, which is "local" to the earth, meaning it travels with the earth in its motions in the universe. The choice of an "at rest" reference frame thousands of kilometers from the experiment was clearly not the intent of the original SR, but was added by Einstein before or during 1920 when he started talking about the center of a rotating disc as the one and only allowable "at rest" reference point.[12] Einstein's change of mind from using "at rest" reference frames that were part of the experiment, to using a single local ARF that was thousands of kilometers from the objects in the experiment, was undoubtedly due to empirical data. Einstein was known to have been working on the Doppler effect of canal rays (a predecessor to today's atomic clocks) prior to 1908.[13] In fact, the 1919 Nobel Prize was awarded to Johannes Stark for the discovery of the Doppler effect in canal rays, which discovery was made by Stark in 1905.[14] Hafele and Keating did not invent the concept of using an "at rest" reference frame on the extended axis of the earth, they knew what they had to use before they did their experiments. The two articles written by Hafele before the experiment prove that. They knew that if they used the stationary USNO atomic clock as their "at rest" reference point the formulas of the SR would not have worked with the actual data. Even before the H-K it was known that in order to get the formulas of the SR to work it was necessary to pick a localized ARF on the extended axis of the earth. It is probable that the reason Hafele and Keating used "a nonrotating point high above the North Pole," instead of the center of the earth, is because its use made it easier to visualize and explain why the stationary USNO atomic clock had to be in motion. =================================================== As usual with "independent thinkers", Webster Kehr has a lot of nutty other ideas which I certainly don't subscribe to. But credit where credit's due - he seems to have nailed the essentials of the HK experiment firmly to the doors of relativity's cathedral - for which insight I am very grateful.
