Convert kelvin to Reaumur

kelvin

Definition: The kelvin (symbol: K) is the base unit of thermodynamic temperature in the International System of Units (SI). It is defined as the energy equivalent of the triple point of water as given by Boltzmann's equation. It is also the unit of the Kelvin scale in which the null point (0 K) is the temperature at which all thermal motion ceases, known as absolute zero, or -273.15°C. The definition of the kelvin was changed in 2019. This new definition results in a fundamental change in the kelvin, such that it is now dependent on the definitions of the second, the meter, and the kilogram.

History/origin: The kelvin is named after British physicist William Thomson, who was known as Lord Kelvin. Thomson wrote a paper outlining the need for an absolute temperature scale. He calculated the value of absolute zero to be -273°C in 1848 which is only a 0.15°C deviation from the current accepted value. Until late 2018, the kelvin was defined as 1/273.16 of the thermodynamic temperature of the triple point of water (0.01°C or 32.018°F). This definition came about in 1954, when the General Conference on Weights and Measures designated the triple point of water as the second defining point of the Kelvin scale, defining the temperature as exactly 273.16 K. Although the definition of the kelvin has changed fundamentally in 2019, it does not affect how the kelvin is used, or its relationship to other temperature scales and units.

Current use: The kelvin is used worldwide, particularly in science and engineering, together with the Celsius. This is partially due to the kelvin and the Celsius degree having exactly the same magnitude. Unlike the Celsius and Fahrenheit, the kelvin is not used in meteorological contexts.

Reaumur

Definition: The Réaumur scale is a historical temperature scale on which water freezes at 0 °Ré and boils at 80 °Ré at standard atmospheric pressure. One degree Réaumur equals 1.25 kelvin intervals.