Jean-Jacques d'Ortous de Mairan

Jean-Jacques d'Ortous de Mairan
Engraving by Pierre-Charles Ingouf (1746–1800)
Born	26 November 1678 Béziers, France
Died	20 February 1771(1771-02-20) (aged 92) Paris, France
Education	University of Toulouse
Known for	Studies of circadian rhythm
Awards	Elected to the French Academy of Sciences, Fellow of the Royal Society, Foreign Member of the Royal Swedish Academy of Sciences
Scientific career
Fields	Geophysics, astronomy, chronobiology
Patrons	Cardinal de Fleury, Louis XV, Prince of Conti, Duke of Orléans
Doctoral advisor	Nicolas Malebranche

Jean-Jacques d'Ortous de Mairan (26 November 1678 – 20 February 1771) was a French natural philosopher (physicist), born in the town of Béziers on 26 November 1678.^[1] De Mairan lost his father, François d'Ortous, at age four and his mother twelve years later at age sixteen.^[1] Over the course of his life, de Mairan was elected into numerous scientific societies and made key discoveries in a variety of fields including ancient texts and astronomy. His observations and experiments also inspired the beginning of what is now known as the study of biological circadian rhythms. At the age of 92, de Mairan died of pneumonia in Paris on 20 February 1771.