Scientific American recently published an article that suggests that perhaps the
fine structure constant isn't, in fact,
constant. More specifically,
astronomers have found
observational evidence that seems to indicate that the fine structure constant was weaker by one part in a thousand around 5 billion years ago.
One the one hand, this seems almost irrelevant. A difference of one part in a thousand, 5 billion years ago, doesn't affect us directly in any way. On the other hand, it makes all the difference; if one of the so-called constants of the Universe is changing, this pokes holes in all sorts of current theories in physics.
Before we get too excited, however, let's remember that something like this comes along just about every year. Physicists are constantly discovering bizarre results that seem, for a while, to disprove some long-standing theory, or provide evidence for some new theory that was, until that point, just some physicists pet speculation. 99 times out of 100, there turns out to be a relatively simple explanation, and the whole thing blows over. Recall the cold fusion fiasco. In any case, there is one detail that makes this particular claim rather sketchy; the same evidence that indicates that the fine structure constant was different ~5 billion years ago also indicates that it was the same as today when the Universe was young, ~12-15 billion years ago. One finds it difficult to imagine some elegant theory that would result in the fine structure constant weakening by 1 part in 1000, and then returning precisely to its original value. My opinion is that some alternate explanation for the data will be found shortly.