The Kelvin temperature scale is based upon the kelvin, a unit of thermodynamic temperature, that is defined as the fraction 1/273.16 of the thermodynamic temperature of the triple point of water. The triple point is the temperature at which all three phases of water, solid, liquid, and gas, can coexist. The kelvin temperature scale is named after Scottish physicist William Thomson Kelvin who first described an absolute temperature scale based upon the thermodynamic defintions of absolute zero. The kelvin and the degree Celsius are both units of the International Temperature Scale of 1990 (ITS-90) adopted by the International Committee for Weights and Measures and the General Conference on Weights and Measures (CGPM, Conférence Générale des Poids et Mesures). When referring to the Kelvin temperature scale, the kelvin (symbol K) should be used instead of the term "degree Kelvin" (°K...