Wednesday, November 6, 2013

Absolute Zero? Here on Earth? That's cold baby!

how close to absolute zero are we on Earth?

Wolfgang Ketterle holds the record for creating the coldest temperature on Earth...

Where's the coldest spot in the universe? Not on the moon, where the temperature plunges to a mere minus 378 Fahrenheit. Not even in deepest outer space, which has an estimated background temperature of about minus 455°F. As far as scientists can tell, the lowest temperatures ever attained were recently observed right here on earth.  Wolfgang Ketterle's lab at the Massachusetts Institute of Technology in Cambridge currently holds the record—at least according to Guinness World Records 2008—for lowest temperature: 810 trillionths of a degree F above absolute zero. Ketterle and his colleagues accomplished that feat in 2003 while working with a cloud—about a thousandth of an inch across—of sodium molecules trapped in place by magnets.

Ketterle's achievement came out of his pursuit of an entirely new form of matter called a Bose-Einstein condensate (BEC). The condensates are not standard gases, liquids or even solids. They form when a cloud of atoms—sometimes millions or more—all enter the same quantum state and behave as one. Albert Einstein and the Indian physicist Satyendra Bose predicted in 1925 that scientists could generate such matter by subjecting atoms to temperatures approaching absolute zero. Seventy years later, Ketterle, working at M.I.T., and almost simultaneously, Carl Wieman, working at the University of Colorado at Boulder, and Eric Cornell of the National Institute of Standards and Technology in Boulder created the first Bose-Einstein condensates. The three promptly won a Nobel Prize. Ketterle's team is using BECs to study basic properties of matter, such as compressibility, and better understand weird low-temperature phenomena such as superfluidity. Ultimately, Ketterle, like many physicists, hopes to discover new forms of matter that could act as superconductors at room temperature, which would revolutionize how humans use energy. For most Nobel Prize winners, the honor caps a long career. But for Ketterle, who was 44 years old when he was awarded his, the creation of BECs opened a new field that he and his colleagues will be exploring for decades.

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