Anders Celsius (1701 - 1744) was a Swedish astronomer, physicist, and mathematician best known for proposing the centigrade temperature scale that today bears his name. [1] A professor of astronomy at Uppsala University, he made contributions to astronomy, geodesy, and the measurement of natural phenomena during the height of the Scientific Revolution.
Early life and education
Celsius was born on 27 November 1701 in Uppsala, Sweden, into a family with strong scientific ties; both of his grandfathers were professors. [1] He studied at Uppsala University, where he showed early promise in mathematics and the natural sciences.
Academic career
In 1730 Celsius was appointed professor of astronomy at Uppsala University. [2] During the 1730s he travelled through Europe, visiting notable astronomical observatories and collaborating with leading scientists of the day. He was elected a Fellow of the Royal Society in recognition of his scientific standing. [1]
Celsius took part in the French Geodesic Expedition to Lapland (1736 to 1737), organized to measure the length of a degree of latitude near the pole. The results helped confirm Isaac Newton's theory that the Earth is flattened at the poles. [2]
The temperature scale
In 1742 Celsius presented a paper to the Royal Swedish Academy of Sciences describing a temperature scale based on two fixed points: the freezing and boiling points of water. [1] In his original design the scale was inverted relative to modern usage, with 0 degrees representing the boiling point of water and 100 degrees its freezing point. The scale was later reversed to its familiar form, and after standardization it became known as the Celsius, or centigrade, scale.
Observatory and other work
Celsius founded the Uppsala Astronomical Observatory, one of the earliest in Sweden, and used it to advance astronomical observation in the country. [2] He also studied the aurora borealis and was among the first to suggest a connection between it and changes in the Earth's magnetic field. His careful measurements extended to gauging the brightness of stars.
Legacy
Celsius died of tuberculosis on 25 April 1744 in Uppsala, at the age of 42. [1] Though his life was short, the temperature scale bearing his name became one of the most widely used measurement systems in the world, adopted for science, meteorology, and everyday life across most of the globe. The unit for temperature, the degree Celsius, remains a standard in the modern International System of Units.
