Thermodynamic temperature in degrees Rankine are converted to kelvins by "dividing" by 1.8 ("T" = "T" ÷ 1.8). Although the kelvin and Celsius scales are defined using absolute zero (0 K) and the triple point of water (273.16 K and 0.01 °C), it is impractical to use this definition at temperatures that are very different from the triple point of water. ITS-90 is then designed to represent the thermodynamic temperature as closely as possible throughout its range. Many different thermometer designs are required to cover the entire range. These include helium vapor pressure thermometers, helium gas thermometers, standard platinum resistance thermometers (known
Absolute hot Absolute hot Absolute hot is a concept of temperature that postulates the existence of a highest attainable temperature of matter. The concept has been popularized by the television series "Nova". In this article, absolute hot is assumed to be the high end of a temperature scale starting at absolute zero, which is the temperature at which entropy is minimal and classical thermal energy is zero. Contemporary models of physical cosmology postulate that the highest possible temperature is the Planck temperature, which has the value . Above about , particle energies become so large that gravitational forces between them would become