Looking deep into the universe to analyze light from long ago, astronomers have found that one of the most prominent basic constants of physics may not always have been so constant.
The fine structure constant, known as "alpha," is a measure of the strength of the electromagnetic force, which governs everything from radio waves and light to electricity and magnetism. Alpha is one of nature's most mysterious numbers, roughly equal to one divided by 137. It is a number without units, and is therefore the same regardless of the measurement system.
Alpha ought to have been the same throughout the history of the universe, physicists have believed. But observations of distant gas clouds by the Keck telescope in Hawaii suggest otherwise, astronomers from Australia, Pennsylvania and England reported last week.
Analysis of light absorbed in the clouds from distant objects known as quasars showed strange anomalies indicating that alpha was slightly smaller in earlier epochs of the universe. (Since the light was emitted from quasars billions of years ago, it reveals conditions in the universe at that time.)
The astronomers acknowledge that some unknown error or effect could be causing the strange results, but their effort to find an alternate explanation was fruitless. Therefore, they say, the results are consistent with a non-constant value for alpha.
-- Dallas Morning News