Celsiusskálát

Celsiusskálát, or the Celsius scale, is a widely used temperature scale for everyday measurement and many scientific applications. It is part of the International System of Units (SI) and uses the unit degree Celsius (°C). On this scale, the freezing point of water at standard atmospheric pressure is defined as 0 °C and the boiling point as 100 °C, creating a 100-degree interval between these two phase transitions.

One degree Celsius represents the same magnitude of temperature change as one kelvin. The relation between the Celsius and kelvin scales is T(K) = T(°C) + 273.15, so 0 °C equals 273.15 K. Conversely, T(°C) = T(K) − 273.15. The Celsius scale is the standard for most day-to-day temperature reporting, while kelvin is commonly used in scientific contexts, particularly for absolute temperatures.

History and naming: the scale is named after the Swedish astronomer Anders Celsius, who proposed a centigrade temperature scale in the 1740s. He initially published a reversed arrangement (0 at boiling, 100 at freezing), which was later inverted to the present convention of 0 at freezing and 100 at boiling. The term “centigrade” is still encountered in older texts, but “Celsius” is the official name in the SI system.