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Stellar aberation, a One way measurement of c?

by Tracer
Tags: aberation, measurement, stellar
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Feb11-12, 01:48 AM
P: 3,188
Quote Quote by Tracer View Post
The rain drop's closing velocity with the observer was calculated to be 39.051248meters/sec when he was at the top of the wheel and 30.413813 meters/sec when he was at the bottom of the wheel.

Since the closing velocity of the rain drops with the observer is different for measurements from the top and bottom of the wheel, what information would using the differences between velocities and angles between top and bottom of the wheel provide?
Again, that's the equivalence with your first post! Stellar aberration is the observation of the difference of two angles due to the different velocities of the Earth at two points of its orbit.

Do you think that based on the provided information, the guy in the giant wheel can determine the speed of the rain drops relative to himself, or relative to the wheel? I don't think so.
Feb11-12, 07:42 AM
P: 17,545
There is simply no way to measure the one way velocity of light using stellar aberration or any other means. In order to measure a one-way velocity of light you need to use a theory which allows it to vary (i.e. you cannot use special relativity), such as Edward's theory or the Mansouri-Sexl test theory. However, in both of those theories, the one way speed of light depends on the synchronization convention. So, any experimental result, including stellar abberation, is consistent with a range of one-way speed of light.
Feb13-12, 09:33 AM
P: 612
Quote Quote by PAllen View Post
While many of these differences are too small to detect, source motion dependence has been rigorously ruled out by measurement of aberration from rapidly orbiting binary stars.
Thanks for the nicely organized presentation of the different theoretically possible observed results. I'd like to see a good analysis of DeSitter's (very old) binary star observations and interpretations on their meaning. I spent a little time looking at his material and the impression I got was that his thinking was extremely crude - very, very, very far from either rigor or precision. I haven't seen any kind of real analytical reference to it - only the vague hand waving kind.

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