Friday 4 January 2013

WF HPPY BDAY 40

//////////////////////FRND , PHILOSPHR, GUIDE


//////////////////////Happiness is having a large, caring, close-knit family in another city." -- George Burns


//////////////////SCIAM= may sound less likely than hell freezing over, but physicists have created an atomic gas with a sub-absolute-zero temperature for the first time. Their technique opens the door to generating negative-Kelvin materials and new quantum devices, and it could even help to solve a cosmological mystery.

original, 19th Century definition of 'absolute' zero did not take quantum mechanics into account, because it wasn't described yet

Another peculiarity of the sub-absolute-zero gas is that it mimics 'dark energy', the mysterious force that pushes the Universe to expand at an ever-faster rate against the inward pull of gravity. Schneider notes that the attractive atoms in the gas produced by the team also want to collapse inwards, but do not because the negative absolute temperature stabilises them. “It’s interesting that this weird feature pops up in the Universe and also in the lab,” he says. “This may be something that cosmologists should look at more closely.”


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