Anders Celsius—Temperature Scale

Abstract

Anders Celsius, regarded as the founder of Swedish astronomy, is best remembered as the inventor of the Celsius temperature scale (often called the centigrade scale), in which 0°C is the freezing point of water and 100°C is the boiling point. The centigrade thermometer (described in 1742) is commonly used throughout most of the world, especially in scientific laboratories. Celsius, the most distinguished member of a well-known scientific family, was born on Nov. 27, 1701, in Uppsala, Sweden (eastern Sweden, 40 miles northwest of Stockholm). He studied astronomy, mathematics, and experimental physics at the University of Uppsala, where his father was professor of astronomy. In 1726, young Anders became secretary of the Uppsala Scientific Society. In 1730, after teaching at the university for several years as professor of mathematics, he succeeded his father as professor of astronomy. He remained in that position until his death in 1744. From 1732 to 1736, Celsius traveled extensively in other countries; he visited famous astronomers and observatories in Berlin and Nuremberg (Germany), Paris (France), and Italy. While in Paris, he met a famous French mathematician-astronomer, Pierre-Louis Moreau de Maupertuis (1698-1759). In 1736, Celsius joined Maupertuis' expedition to Tornea in northern Sweden (now Tornio, Finland). During 1736 and 1737, as an astronomer, Celsius helped with the planned meridian measurements in the polar region, measurements that confirmed the theory of Sir Isaac Newton (1642-1727) that the earth is flattened at its poles. Celsius was the first person to associate northern lights with the magnetic field of the earth. In 1733, he published a collection of 316 observations of the aurora borealis (northern lights) made by himself and others from 1716 to 1732. In 1735, Celsius became a fellow of the Royal Society. In 1740, he was the instigator of the building of the Uppsala Observatory, the first modern installation of its kind in Sweden, which was completed in 1742. He died in Uppsala on Apr. 25, 1744, when he was only 42 years old. He was honored on a stamp issued by Sweden in 1982.