Portal:Denmark/Selected biography/2011/42
Ole Rømer (September 25, 1644 – September 19, 1710) was a Danish astronomer who made the first quantitative measurements of the speed of light (1676).
Rømer was employed by the French government: King Louis XIV made him teacher for the Dauphin, and he also took part in the construction of the magnificent fountains at Versailles.
In 1681, he returned to Denmark and was appointed professor of Astronomy at Copenhagen University. He was active also as an observer, both at the University Observatory at the Rundetårn and in his home, using improved instruments of his own construction. Unfortunately, his observations have not survived: they were lost in the great fire of Copenhagen in 1728. However, a former assistant (and later an astronomer in his own right), Peder Horrebow, loyally described and wrote about Rømer's observations.
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