At near absolute zero, molecules may start to exhibit exotic
states of matter.
(June 10, 2015) The
air around us is a chaotic superhighway of molecules whizzing through space and
constantly colliding with each other at speeds of hundreds of miles per hour.
Such erratic molecular behavior is normal at ambient temperatures.
But scientists have long suspected that if temperatures were
to plunge to near absolute zero, molecules would come to a screeching halt,
ceasing their individual chaotic motion and behaving as one collective body.
This more orderly molecular behavior would begin to form very strange, exotic
states of matter — states that have never been observed in the physical world.
Now experimental physicists at MIT have successfully cooled
molecules in a gas of sodium potassium (NaK) to a temperature of 500
nanokelvins — just a hair above absolute zero, and over a million times colder
than interstellar space. The researchers found that the ultracold molecules were
relatively long-lived and stable, resisting reactive collisions with other
molecules. The molecules also exhibited very strong dipole moments — strong
imbalances in electric charge within molecules that mediate magnet-like forces
between molecules over large distances.