Fight over changing constants reaches stalemate
10:46 26 January 2012 by Stuart Clark
It's time to declare a ceasefire in the fight to find out whether the constants of nature vary. What was supposed to be a new superweapon in the battle has turned into something of a damp squib.
Some observations of how hydrogen gas in space absorbs light at ultraviolet wavelengths have hinted that the fine structure constant, responsible for the strength of electromagnetism, is not the same throughout the universe. That would point to exotic new physics, including the existence of extra dimensions and universes other than our own.
Constantly changing? (Image: ESA/Hubble and NASA)
But the measurement is tricky, and researchers had hoped that studying how hydroxyl molecules emit and absorb light at radio wavelengths would give a more precise, independent measurement of the effect.
In theory, radio instruments can measure wavelengths 50 to 100 times more accurately than those that detect hydrogen absorption, says Nissim Kanekar at the National Centre for Radio Astrophysics in Pune, India.
But he and colleagues discovered the reality is more complicated. They observed the emission and absorption of radio waves from hydroxyl molecules in a gas cloud 6.7 billion light years from Earth that was absorbing light from a more distant galaxy.
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Read more here/Leia mais aqui: New Scientist
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