Jean-Jacques d'Ortous de Mairan

Jean Jacques d' Ortous de Mairan (* November 26, 1678 in Beziers, † February 20, 1771 in Paris) was a French geophysicist.

His father, François d' Ortous, was a member of the landed gentry. He died when Jean Jacques was four years old.

The young d' Ortous attended school in Toulouse, where he put his focus on ancient Greek. In 1698 he went to Paris to study mathematics and physics.

In 1718 he became a member of the Académie Royal des Sciences, and until 1760 at various times held there between various functions, including the post of Secretary, Deputy Director, and finally the Director. He also gave the journal of the Scavans, a scientific journal out.

In 1731 he observed a fog-like appearance around a star near the Orion nebula. This was later referred to as M43.

De Mairan also conducted research on circadian rhythms. He was a former student of Malebranche and collaboration with this 1713/14, shortly before his death in an exchange of letters on the philosophy of Spinoza.

1771 He died in Paris of pneumonia.

Awards

• The crater Mairan on the Moon was named in 1935 by the IAU for him.

Writings (selection )

• Traité physique and historique de l' Aurore Boréale. 1733.