How Is “Absolute Zero” Defined?
In tribute to the Large Hadron Collider, we learn today that absolute zero is the theoretical temperature at which all substances have zero thermal energy. Absolute zero is equivalent to 0 degrees Kelvin, -459.67 degrees F, or -273.15 degrees C.
Originally conceived as the temperature at which an ideal gas at constant pressure would contract to zero volume, absolute zero is of great significance in thermodynamics and is used as the fixed point for absolute temperature scales.
The Large Hadron Collider supercools the magnets it uses to 1.9 degrees K. That’s pretty darn cold!
[Source : Wikipedia and The Handy Science Answer Book]