There are two primary units of temperature in the world: Fahrenheit, used primarily by the United States, and Celsius, used by pretty much everyone else. Scientists, however, use a third scale: Kelvins. A Kelvin degree is the same “size” as a Celsius degree, but the Kelvin scale defines 0 degrees as Absolute Zero, the lowest temperature possible; the temperature at which all kinetic motion stops and matter is (metaphorically) frozen. Thus, there are no “negative” degrees in the Kelvin scale.
Unlike other temperature systems, temperatures are NOT expressed as “degrees Kelvin”, but rather “Kelvins”, like other kinds of measurements (e.g. “miles” or “kilometers”, not “lengths Mile”), so if it were a warm sunny day, you might say the temperature was “300 Kelvins”.
In the Kelvin scale, the freezing point of water (0 ℃; 32 ℉) is defined as 273.15 K, while the boiling point of water (100℃; 212℉) is defined as 373.15 K; by this system, a warm day (28 ℃, ~80 ℉) would be 300 K, while a cold day (8 ℃, ~45 ℉) would be 280 K.
The Kelvin scale was named after British physicist and engineer William Thomson, 1st Baron Kelvin, who lived in the late 19th Century. He wrote of the need for an “absolute thermometric scale”.
Tags: absolute, boiling, cold, freezing, Kelvin, Kelvins, point, scale, temperature, thermometric, warm, William Thomson
