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Fight over changing constants reaches stalemate

IT’S time to declare a ceasefire in the fight to find out whether the constants of nature vary.

Some observations of how cosmic molecules emit and absorb light at ultraviolet wavelengths have hinted that the fine structure constant, responsible for the strength of electromagnetism, is not the same throughout the universe. But the measurement is tricky, and researchers had hoped that studying radio wavelengths would give a more precise result.

Not so, says a team including Chris Carilli of the National Radio Astronomy Observatory in New Mexico (arxiv.org/abs/1201.3372v1). “It didn’t pan out,” he says, adding that it could take 20 years to make enough observations to settle the question.