Celsius Celsius The Celsius scale, also known as the centigrade scale, is a temperature scale used by the International System of Units (SI). As an SI derived unit, it is used by all countries except the United States, the Bahamas, Belize, the Cayman Islands and Liberia. It is named after the Swedish astronomer Anders Celsius (1701–1744), who developed a similar temperature scale. The degree Celsius (°C) can refer to a specific temperature on the Celsius scale or a unit to indicate a difference between two temperatures or an uncertainty. Before being renamed to honor Anders Celsius in 1948, the unit was
Introduction to the metric system volt and farad in honour of Georg Ohm, Alessandro Volta and Michael Faraday respectively. This proposal had the support of William Thomson (Lord Kelvin) who had been instrumental in forming the Committee of Electrical Standards of the British Association for the Advancement of Science. The use of scientists' names for such units was subsequently extended to other units, including the watt named after James Watt and the degree Celsius named after Anders Celsius. Historically, individual units evolved which were based on the size and context of what was being measured. These units could avoid the need to use large numbers