Biography of Anders Celsius

A staircase from the sky

27 November 1701
25 April 1744
Physicist, mathematician and astronomer, Anders Celsius was born in Uppsala, Sweden, on 27 November 1701. His father is a Professor of astronomy at the University of Uppsala. Anders Celsius is formed through the study of mathematics and astronomy, without neglecting experimental physics that affect his research in the field of Thermometry. Following in the footsteps of his father, Anders teaches mathematics and astronomy in Uppsala. In the years between 1732 and 1736 makes long journeys by establishing personal contacts with other scholars and observing the operation and organizational methods of various centres of astronomical research, such as observers in Berlin and Nürnberg.
In Paris knows LWB Maupertuis and joined the Group of scholars who will prepare the famous Meridian arc measurements, pursuing the aim to define, in terms of experimental observations, the long-running controversy which saw arrayed into separate fields supporters of Newtonian and Cartesian conceptions about the shape of the globe. The first argued that the globe was flattened at the poles: the measurements above mentioned would have precisely confirmed the validity of the Newtonian theses. The first investigations concerning the interest of Anders Celsius for temperature measurement related problems dating from 1733-1734. In 1733 his European route also touches the Italy.
And from Italy the following year comes a letter asking him explanations about how to build mercury thermometers, topic discussed during the Italian trip. You also know that barometric observations had already accomplished in 1731 and Celsius measurements using tools of Hauksbee. Then-as it appears from his correspondence as well as some of his handwritten notes – Anders Celsius uses a thermometer built by Nollet according to the method proposed by r. a. de Réaumur and another thermometer due to j. n. Delisle. In 1742 Celsius publishes a popular memory, issues of Thermometry where proposes to use a centigrade scale referred to two fixed points: the one that corresponds to the temperature of melting snow and reported it to the boiling State water temperature.
Taking into account the dependence of the boiling point of water by pressure, Celsius suggests 100 indicate the temperature of boiling water, and 0 to 751.16 torr atmospheric pressure, and provide a rule to fix freezing at different values of pressure. A thermometer with centigrade scales was inverted compared to the usual scale into operation in December of 1741. Anders Celsius died on 25 April 1744 in his hometown. In his career as an astronomer Celsius cataloged over 300 stars. With his assistant Olof Hiorter discovered the magnetic bases of the northern lights. Instruments with a centigrade scale as we know them today were built, after 1746, Ekström, adept scientific-instrument maker who worked in Stockholm, and from Strömer. In addition to note Fahrenheit scale proposed in 1724, other temperature scales are: Newton (circa 1700), Romer (1701), Réaumur (1731), Delisle (1738), Rankine (1859), Kelvin (1862).
Article contributed by the team of collaborators.