Anders Celsius was a Swedish astronomer, physicist and mathematician.
Background
Anders Celsius was born in Uppsala, Sweden on 27 November 1701. His family originated from Ovanåker in the province of Hälsingland. Their family estate was at Doma, also known as Höjen or Högen (locally as Högen 2). The name Celsius is a latinization of the estate's name (Latin celsus "mound").
As the son of an astronomy professor, Nils Celsius, and the grandson of the mathematician Magnus Celsius and the astronomer Anders Spole, Celsius chose a career in science.
Education
Anders was a talented mathematician from an early age. Anders Celsius studied at Uppsala University, where his father was a teacher.
Career
Anders became a professor of astronomy at the University of Uppsala. His earliest research concerned the aurora borealis (northern lights), and he was the first to suggest a connection between these lights and changes in the earth's magnetic field.
Celsius traveled for several years, including an expedition into Lapland with French astronomer Pierre-Louis Maupertuis (1698-1759) to measure a degree of longitude. Upon his return he was appointed steward to Uppsala's new observatory. He began a series of observations using colored glass plates to record the magnitude of certain stars. This constituted the first attempt to measure the intensity of starlight with a tool other than the human eye.
Celsius invented the celcius temperature scale the most widely used in the world today, although he was not the first to have done so since several hundred-point scales existed at that time. Celsius' unique and lasting contribution was the modification of assigning the freezing and boiling points of water as the constant temperatures at either end of the scale. When the Celsius scale debuted in 1747 it was the reverse of today's scale, with zero degrees being the boiling point of water and one hundred degrees being the freezing point.
A year later the two constants were exchanged, creating the temperature scale we use today. Celsius originally called his scale centigrade (from the Latin for "hundred steps"), and for years it was simply referred to as the Swedish thermometer. In 1948 most of the world adopted the hundred-point scale, calling it the Celsius scale. He died on April 25, 1744 at the age of 42.
Membership
He was a Member of the Royal Swedish Academy of Sciences.
He was a Fellow of the Royal Society.