Approaching Absolute Zero

Read this interesting, short article about the temperature of absolute zero (–273.15°C / -459.67°F) and researchers who have gotten very close to it in the lab.

I visited Wolfgang Ketterle’s lab at the Massachusetts Institute of Technology in Cambridge. It 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.

That’s colder than the temperature in deep space, -455°F!

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.

The speed of light, as we’ve all heard, is a constant: 186,171 miles per second in a vacuum. But it is different in the real world, outside a vacuum; for instance, light not only bends but also slows ever so slightly when it passes through glass or water. Still, that’s nothing compared with what happens when Hau shines a laser beam of light into a BEC: it’s like hurling a baseball into a pillow. “First, we got the speed down to that of a bicycle,” Hau says. “Now it’s at a crawl, and we can actually stop it—keep light bottled up entirely inside the BEC, look at it, play with it and then release it when we’re ready.”

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2 Responses to Approaching Absolute Zero

  1. Marcus says:

    I think a couple of negative signs were omitted (i.e. temperature in deep space= -455°F)

  2. Scott says:

    Thanks, Marcus. I fixed them in the original post.

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