Celsius – temperature scale

Temperature is an intensive quantity and describes the energy state of the matter. All materials have atoms and molecules that are constantly moving, vibrating, or rotating. The Celsius temperature scale is a common System Internationale (SI) temperature scale (the official scale is Kelvin). The Celsius scale is a temperature scale based on 0° for the freezing point of water and 100° for the boiling point of water.

It is also known as the centigrade scale. It is named for the Swedish physicist, astronomer, and engineer Anders Celsius (1701–1744), who established the scale in 1742. William Thomson Kelvin used it as the basis of his absolute temperature scale, now known as the Kelvin temperature scale, in 1848.

Before being renamed in 1948 to honor Anders Celsius, the unit was called centigrade, from the Latin centum, which means 100, and gradus, which means steps.

The Celsius scale is defined by absolute zero and the triple point of pure water. This definition allows easy conversion between the Celsius and Kelvin temperature scales, such that absolute zero is defined to be precisely 0 K and −273.15 °C. The triple point of water is defined to be 273.16 K (0.01 °C; 32.02 °F).
Celsius – temperature scale