Joseph-Nicolas Delisle

Joseph -Nicolas Delisle ( born April 4, 1688 in Paris, † September 11, 1768 ) was a French astronomer and cartographer. He was the son of the historian and geographer Claude Delisle and the younger brother of the cartographer Guillaume Delisle.

Life and scientific achievements

Delisle was already in 1714 a member of the Academy of Sciences a student of Giacomo Filippo Maraldi. 1715 he observed a wave-optical effect, but largely forgotten and derived theoretically only about one hundred years later at the French Academy of Sciences by Augustin -Jean Fresnel, predicted by Siméon Denis Poisson, was detected by François Arago experimentally and now usually called Poisson spot is called.

1725 Delisle was called the Great as academics to Saint Petersburg by Tsar Peter, where he founded a school for Astronomy. There he observed the eclipses of Jupiter's moons and published his results. He fell particularly on the fact that it comprises data, correspondence and manuscripts copied, collected and compiled sorted. For this he received a salary and the title of " Astronomer of the Navy ." In 1725 he was elected a member of the Leopoldina.

Delisle suggested as an explanation for the rainbow in front of the refraction of sunlight by water droplets in clouds. He also worked on the calculation of the distance between the Sun and Earth by evaluated the observations of the transits of Mercury and Venus transits. He created a scale of temperature is named after him, the Delisle scale.

In 1747 he returned to Paris, where he was a supervisor of Charles Messier was involved in the Marine Observatory in finding Halley 's Comet.

On September 11, 1768, he died poor and forgotten.

Honor

According to him, a lunar crater was named (see Delisle (crater ) )