The speed of light need not be constant
Abstract
Description
Recent observations of the fine structure of spectral lines in the early universe have been interpreted as a variation of the fine structure constant.
From the assumed validity of Maxwell equations in general relativity and well known experimental facts, it is proved that $e$ and $\hbar$ are absolute constants. On the other hand, the speed of light need not be constant.
3 pages revtex, comments welcome
3 pages revtex, comments welcome