Oct 312013
 

ALMA Views the Coldest Place in the Universe: The Boomerang Nebula

This nebula, a mere 5,000 light years away, appears to have a temperature of 1 degree Kelvin. I admit to being confuzzled by this, given that the cosmic background radiation is at 2.8 degrees Kelvin. How can something be colder than that without an active cooling system, with energy being used to run a “heat pump?”

 Posted by at 2:30 am
  • John Simpson

    Since we’re including the Universe I’d have to point out that one of the coldest places is whenever the University of Michigan generates a Bose-Einstein condensate at or below 20 nano Kelvins http://www-personal.umich.edu/~graithel/bose.html

    • publiusr

      Making Stuff Colder (NOVA) had the D-WAVE set up often featured on next big future.

  • Geoffrey

    Who’s to say it isn’t ‘actively’ cooling? Perhaps it’s being adiabatically cooled by rapid expansion.

    • Anonymous

      I don’t that would apply n this situation. Once a gas has expanded far enough, the individual molecules aren’t banging into each other anymore, and it ceases to be a “gas” so much as a collection of very tiny, widely separated particles.