Tuesday, February 23, 2010

The Invariance of the Speed of Light

I don't normally highlight a preprint on ArXiv, especially if it is still waiting for acceptance for publication (I do make some exceptions, especially by well-known authors). However, this is way too much fun to ignore. Besides, I want to keep a record of it here so that I can find it easily next time some crackpot point to me one of the papers as "evidence".

Early on, I came across this preprint that proclaimed to have found a variation in the speed of light that depends on the motion of the light detector. As is the case with any of these things, I wanted to wait until it gets accepted before mentioning anything about it. After all, there are many of these things that popped up regularly and went nowhere. As far as I know, this has not been published yet.

Still, a rebuttal to this work appeared on ArXiv today. And it's a good one! Read the conclusion:

In conclusion, because of the error we point out above, the claim in [1] that the velocity of light as measured by a moving detector does not equal c is wrong. It is particularly striking that the so called ‘measured’ discrepancy of 200 m/s between the light speed as calculated in the two frames does not depend at all on the measured time of flight of the laser pulse. That is, using the procedure of [1] to find cO, any random number put in for the time of flight T would give a result that is v0 larger than cS. Since the claimed anomalous result does not depend on the recorded time of flight, this experiment has, in fact, measured nothing.

I love it! :)

I think that actually, the original paper might be a good exercise for an advanced level physics course to pick apart and figure out what went wrong.

Now that this criticism has appeared, I wonder what is the fate of the submitted manuscript. Would the author write a response? Would the editor and/or referee of the journal be aware of this criticism?



Jarl said...

I couldn't agree with you more. An excellent refutation of this idiotic article!

Clem said...

The original paper was rejected by Il Nuovo Cimento, based in part on the negative comment on the arxiv.