Cold Molecules Beat the Shakes.

This article reports on laser cooling of atoms. It discusses that laser cooling of atoms began more than 25 years ago which has led to spectacular advances in areas such as Bose-Einstein condensation, atomic clocks, ultracold collisions, and degenerate Fermi gases. Molecules have been slower to jump on the ultracold bandwagon but are now firmly on board due to their complexity relative to atoms. Temperature describes the transitional motion of molecules, but they also have internal energy due to vibration and rotation.