Anders Celsius

Anders Celsius (; 27 November 170125 April 1744) 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 'mound').

As the son of an astronomy professor, Nils Celsius, nephew of botanist Olof Celsius and the grandson of the mathematician Magnus Celsius and the astronomer Anders Spole, Celsius chose a career in science. He was a talented mathematician from an early age. Anders Celsius studied at Uppsala University, where his father was a teacher, and in 1730 he, too, became a professor of astronomy there. Noted Swedish dramatic poet and actor Johan Celsius was also his uncle.

Career In 1730, Celsius published the (New Method for Determining the Distance from the Earth to the Sun). His research also involved the study of auroral phenomena, which he conducted with his assistant Olof Hiorter, and he was the first to suggest a connection between the aurora borealis and changes in the magnetic field of the Earth. He observed the variations of a compass needle and found that larger deflections correlated with stronger auroral activity. At Nuremberg in 1733, he published a collection of 316 observations of the aurora borealis made by himself and others over the period 1716–1732.

Celsius traveled frequently in the early 1730s, including to Germany, Italy and France, when he visited most of the major European observatories. In Paris he advocated the measurement of an arc of the meridian in Lapland. In 1736, he participated in the expedition organized for that purpose by the French Academy of Sciences, led by the French mathematician Pierre Louis Maupertuis (1698–1759) to measure a degree of latitude. The observatory was equipped with instruments purchased during his long voyage abroad, comprising the most modern instrumental technology of the period. In 1742 he proposed the Celsius temperature scale in a paper to the Royal Society of Sciences in Uppsala, the oldest Swedish scientific society, founded in 1710. His thermometer was calibrated with a value of 0 for the boiling point of water and 100 for the freezing point. In 1745, a year after Celsius's death, the scale was reversed by Carl Linnaeus to facilitate more practical measurement.

Celsius conducted many geographical measurements for the Swedish General map, and was one of the earliest to note that much of Scandinavia is slowly rising above sea level, a continuous process which has been occurring since the melting of the ice from the latest ice age. However, he wrongly posed the notion that the water was evaporating.

In 1725 he became secretary of the Royal Society of Sciences in Uppsala, and served at this post until his death from tuberculosis in 1744. He supported the formation of the Royal Swedish Academy of Sciences in Stockholm in 1739 by Linnaeus and five others, and was elected a member at the first meeting of this academy. It was in fact Celsius who proposed the new academy's name.

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