Anders Celsius magnitude (a measure of brightness) of certain stars. This was the first attempt to measure the intensity of starlight with a tool other than the human eye. He made observations of eclipses and various astronomical objects and published catalogues of carefully determined magnitudes for some 300 stars using his own photometric system (mean error=0.4 mag). Celsius was the first to perform and publish careful experiments aiming at the definition of an international temperature scale on scientific grounds. In his Swedish paper "Observations of two persistent degrees on a thermometer" he reports on experiments to check that the freezing point is
Anders Sørensen Vedel Anders Sørensen Vedel Anders Sørensen Vedel (9 November 1542 – 13 February 1616) was a Danish priest and historian. He translated the "Gesta Danorum" by Saxo Grammaticus into Danish in 1575, and published the influential ""Hundredvisebogen"" in 1591. Anders Sørensen was born in Vejle, from which place the Vedel name comes. 14 years old he moved to study in Ribe, and after finishing his education he moved on to Copenhagen University in 1561. In 1562, he was the tutor of astronomer Tycho Brahe on Brahe's Grand Tour in Europe, forming a lasting bond of friendship with him. Vedel started studying