Understanding Temperature Scales
Temperature scales are systems for measuring temperature relative to a starting point and incremental units. The most common scales are Celsius, Fahrenheit, and Kelvin, each with different applications and historical origins.
The Celsius scale, used by most of the world, sets water's freezing point at 0°C and boiling point at 100°C. Fahrenheit, used primarily in the United States, sets water's freezing point at 32°F and boiling point at 212°F.
Why Kelvin is Important in Science
The Kelvin scale is an absolute temperature scale used widely in scientific applications because it starts at absolute zero, the theoretical point where all molecular motion ceases. This makes it ideal for scientific calculations where relative temperature differences matter.
Unlike Celsius and Fahrenheit, Kelvin doesn't use degrees, and its increments are the same size as Celsius degrees. This makes conversion between Celsius and Kelvin straightforward—simply add or subtract 273.15.
Historical Temperature Scales
Throughout history, many temperature scales have been proposed. The Réaumur scale, included in this converter, was widely used in Europe in the 18th and 19th centuries. It sets the freezing point of water at 0°Ré and boiling point at 80°Ré.
The Rankine scale is another historical scale that is still occasionally used in engineering systems in the United States. It is an absolute version of the Fahrenheit scale, similar to how Kelvin relates to Celsius.