Cold Atom Lab (CAL)

This series of graphs show the changing density of a cloud of atoms as it is cooled to lower and lower temperatures (going from left to right) approaching absolute zero. The emergence of a sharp peak in the later graphs confirms the formation of a Bose-Einstein condensate — a fifth state of matter — occurring here at a temperature of 130 nanoKelvin, or less than 1 Kelvin above absolute zero. (Absolute zero, or zero Kelvin, is equal to minus 459 degrees Fahrenheit or minus 273 Celsius).