How is absolute Zero defined? page 1

Absolute Zero is the theoretical temperature at which all substance have zero thermal energy. Originally conceived  as the temperature at which an ideal gas at constant pressure would contract to zero volume absolute temperature scales Absolute zero is equivalent to 0 K -459.67 F or 323.12 C. The velocity of a substance's molecules determines its temperature the faster the molecules move the more volume they require and the higher the temperature becomes The lowest actual temperature ever reached was two billionth of the degree above absolutes zero 2x10 80  by a team at the Low-Temperature Laboratory in the Helsinki University of Technology Finland in October 1989.