Why is the speed of light believed to be an absolute constant?

Question

I don't believe it is, and I have a pretty good argument for this conclusion. If you aren't on that level then please keep your opinions to yourself.

Some thoughts:

Are any of you aware of the political issues that surrounded the scientific "conclusion" that the speed of light is a constant?

Newton's laws put men on the moon even though we now know they start to break down at "relativistic" velocities. Just because something works, doesn't mean it's 100% correct all the way down a curve into infinity.

From what I've read, the "evidence" that the speed of light is an absolute constant is pretty weak, based mostly on experiments conducted before modern equipment was available, and a political momentum that won't allow anyone to question the assumption.

Answer 1

To see is to believe. Experiments have showed that the speed of light is constant in vacuum. (At least under the conditions of the experiments.) Science work like this. First we observe something and then we try to explain how it works. You can not just think out a theory that ignores what can be observed. If you want people to believe your argument you have to explain why the experiments show constant light speed, or invent an experiment that shows some case of light traveling at other speeds.

PS. I don't mean to put you down. It is great that you try to understand, rather than just take somebody else's word for it.

Answer 2

I can't argue against your particular argument without knowing it, but it would be a hard argument for you to make. There's a great deal of experimental evidence for the speed of light as a constant in a vacuum.

The Michelson-Morley experiment convinced most of the scientific communuty. Further, there are whole fields that wouldn't exist without this assumption -- quantum physics, most astrophysics, and subatomic physics, to name just three.

Here's an overview of the experiment, if you ned a refresher:
http://scienceworld.wolfram.com/physics/Michelson-MorleyExperiment.html

Answer 3

It is a prediction of Einstein's theory of special relativity, which is now established science, as the inhabitants of Hiroshima and Nagasaki learned all too well in 1945. The first indication that the speed of light was constant was the Michelson-Morley experiment, which attempted (unsuccessfully) to show that the earth's motion through space would affect the measured speed of light. Lorentz proposed a space transformation to explain this result, and Einstein used Lorentz's transformation in his theory.
I would be interested in seeing your argument; you may contact me directly at [e-mail].

Answer 4

The speed of light is only a constant at the instant of emission/absorption with respect to the emitting/absorbing particle of matter. Despite what relativity says, light is NOT always measured to be constant from any observer's perspective. That idea was proven wrong back in the sixties when powerful radar signals were bounced off the planet Venus from multiple radar stations around the globe simultaneously. As Bryan G. Wallace showed, signals from the side of the earth rotating towards Venus came back sooner than those from the side rotating away, to a degree that fits source-dependent models: http://www.ritz-btr.narod.ru/wallace.pdf

This suggests that [as common sense would have it] the speed of light is additive, i.e. light emitted from a source with velocity v, will have a velocity of c+v on emission. Light is capable of travelling through space with differing velocities. Wallace's observation refutes relativity but unfortunately, by this time relativity had already become more like a religion than science. No career-minded physicist could be seen to be paying heed to a "relativity-denier", so Wallace's paper did not get the attention it deserved and no further investigation was made. The mainstream scientific community carried on believing in the fallacy that the speed of light is always constant.

There have been other astronomical observations that suggest source-dependence too like this: http://www.news.ucdavis.edu/search/news_detail.lasso?id=8364
But such observations are seen as some minor curiosity and the theorists will bend over backwards to invent any kind of fantastical nonsense to explain them so that they can avoid ditching relativity.

The time-dilation seen in type 1a supernova is likely down to light being source-dependent too (rather than expanding spacetime!). And, many apparently variable stars may well be binaries in which light bunching is occurring as faster light emitted from a star moving at it's maximum velocity towards us in it's orbit, catches up with slower light it emitted later: http://www.datasync.com/~rsf1/binaries.htm

Experiments on earth can give the illusion of source-independence but that is due to the EM fields of the earth's matter interfering and effectively normalizing the speed of light from a moving source (i.e. slowing it down to c almost as soon as it is emitted). You have to look at astronomical and interplanetary observations to see how light really behaves. It's planet-bound behaviour is the special case.

Answer 5

the speed of light in a vacuum is reported to be consistent. There aren't any counterexamples. In different media, the speed of light is slower, yet it truly is an interplay between the gentle and the fabric.

Answer 6

I can prove that it is a constant.

Answer 7

Because it is a "pro"-portion.