How emission theory was disproved by de sitter binary star experiment?

In summary, the author of the paper referenced in the FAQ claims that experiments using terrestrial sources show that c+v, rather than c-v, is the correct equation for describing the speed of light in a vacuum.
  • #1
techysafi
1
0
Actually I was studying on 2nd postulate of special relativity. There I saw Ritz's emission hypotheses says for an object moving directly towards (or away from) the observer at v metres per second, this light would then be expected to still be traveling at (c + v) or (c − v) metres.

Now let's imagine an orbiter (star) trows a photon from A, another from B, another from C and another from D. Also imagine that the velocity of the photon of A is (c + v) and of C is (c-v). If this happens we would get an weird picture of the orbiter because the the distance from the orbiter to the observer is sufficient enough then the faster photon (A) would reach to the observer faster than photon of C THOUGH PHOTON of C WAS RELEASED FIRST THEN D THEN A. (assuming the orbit is a->b->c->d->a) And this means we would often see the star at random places or at multiple position at a same time. but william de sitter didn't find any such thing...Am I right? If wrong then where I am wrong?

You see I'm noob so a nooby friendly answer will help me more :)
 
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  • #2
You need terrestrial experiments to address the extinction question, not astronomical ones.

See the appropriate section in the paper referenced by the FAQ
https://www.physicsforums.com/showthread.php?t=229034

stickied as the top thread in the relativity forum.

Experiments Using Terrestrial Sources

Alvaeger F.J.M. Farley, J. Kjellman and I Wallin, Physics Letters 12, 260 (1964). Arkiv foer Fysik, Vol 31, pg 145 (1965).

Measured the speed of gamma rays from the decay of fast π0 (~0.99975 c) to be c with a resolution of 400 parts per million. Optical extinction is not a problem for such high-energy gamma rays. The speed of the π0 is not measured, but is assumed to be similar to that measured for π+ and π−.
Sadeh, Phys. Rev. Lett. 10 no. 7 (1963), pg 271.

Measured the speed of the gammas emitted from e+e− annihilation (with center of mass v/c ~0.5) to be c within 10%.

This experiment was criticized in Lo Savio, Phys. Lett. A, 1988, Vol 133, pg 176. It is certainly true that at the instant of annihilation the e+ need not be traveling in the same direction it had initially, or have the same speed (most annihilations occur at very low energy as the positrons stop). This experiment is inconclusive at best.
Babcock and Bergmann, Journal Opt. Soc. Amer. Vol. 54, pg 147 (1964).

This repeat of Kantor's experiment in vacuum shows no significant variation in the speed of light affected by moving glass plates. Optical Extinction is not a problem. k < 0.02.
Filipas and Fox, Phys. Rev. 135 no. 4B (1964), pg B1071.

Measured the speed of gamma rays from the decay of fast π0 (~0.2 c) in an experiment specifically designed to avoid extinction effects. Their results are in complete disagreement with the assumption c+v, and are consistent with SR. k < 0.5 with a confidence level of 99.9%.
Beckmann and Mandics, “Test of the Constancy of the Velocity of Electromagnetic Radiation in High Vacuum”, Radio Science, 69D, no. 4, pg 623 (1965).

A direct experiment with coherent light reflected from a moving mirror was performed in vacuum better than 10−6 torr. Its result is consistent with the constant velocity of light. This experiment is notable because Beckmann was a perennial critic of SR. Optical Extinction is not a problem.
Operation of FLASH, a free-electron laser, http://vuv-fel.desy.de/.

A free-electron laser generates highly collimated X-rays parallel to the relativistic electron beam that is their source. If the region that generates the X-rays is L meters long, and the speed of light emitted from the moving electrons is c+kv (here v is essentially c), then at the downstream end of that region the minimum pulse width is k(L/c)/(1+k), because light emitted at the beginning arrives before light emitted at the downstream end. For FLASH, L=30 meters, v=0.9999997 c (700 MeV), and the observed X-ray pulse width is as short as 25 fs. This puts an upper limit on k of 2.5×10−7. Optical extinction is not present, as the entire process occurs in very high vacuum.
 

Related to How emission theory was disproved by de sitter binary star experiment?

1. What is emission theory?

Emission theory, also known as the luminiferous aether theory, was a scientific model proposed in the 19th century to explain the propagation of light. It suggested that light is a wave that travels through a medium called the "aether".

2. What is the de sitter binary star experiment?

The de sitter binary star experiment was an experiment conducted by Willem de Sitter in 1913 to test the validity of the emission theory. It involved observing the shift in the position of a binary star system as the Earth moved in its orbit around the Sun.

3. How did the de sitter binary star experiment disprove emission theory?

The de sitter binary star experiment showed that the speed of light is constant, regardless of the direction of the Earth's motion. This directly contradicted the predictions of emission theory, which suggested that the speed of light would vary depending on the Earth's motion.

4. What were the implications of the de sitter binary star experiment?

The de sitter binary star experiment played a crucial role in discrediting emission theory and paving the way for Albert Einstein's theory of relativity. It also led to the development of the theory of special relativity, which explains the constant speed of light and the absence of the aether.

5. Why was emission theory widely believed before the de sitter binary star experiment?

Before the de sitter binary star experiment, there was no definitive evidence to disprove emission theory. It was widely accepted by scientists because it provided a plausible explanation for the propagation of light, and it was consistent with Newton's laws of motion. However, the results of the de sitter binary star experiment ultimately proved its inadequacy in explaining the behavior of light.

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