Born on 27 November 1701 in Uppsala, Sweden, Anders Celsius was an astronomer and inventor of the Celsius temperature scale. He studied at Uppsala University, where his father was an astronomy professor, and in 1730 Celsius also became an astronomy professor there. Most of his early career was spent studying the aurora borealis, and he was the first to suggest a connection with changes in Earth’s magnetic field. Between 1732 and 1736 Celsius made a grand tour of European observatories, then joined French astronomer Pierre Louis Maupertuis’s Lapland expedition to measure a degree of latitude and thus verify Earth’s ellipsoidal shape. In 1741 Celsius founded the Uppsala Astronomical Observatory with instruments purchased during his travels. Celsius is best known for proposing the centigrade temperature scale that bears his name. Unlike other temperature scales of the time, Celsius based his on the freezing and boiling points of water, with 0° as the boiling point and 100° as the freezing point. After he died from tuberculosis in 1744, that scale was reversed, creating the scale still used today.
