Ismaël Bullialdus
Ismael Boulliau (also Boulliaud or Ismaël Bullialdus; * September 28, 1605 in Loudun, Vienne, † November 25, 1694 in Paris) was a French astronomer.
Life
At age 21, converted from Calvinism to Catholicism Boulliau and was ordained at the age of 26 years as a priest. In 1632 he became librarian at the Bibliothèque du Roi in Paris together with the brothers Pierre and Jacques Dupuy.
In 1657 he became secretary of the French ambassador in Holland.
In the last five years of his life he was a priest in the Abbey of St. Victor in Paris.
Boulliau was a friend of Pierre Gassendi, Christiaan Huygens, Marin Mersenne and Blaise Pascal. He supported the views of Galileo Galilei and Nicolaus Copernicus.
On April 4, 1667, he was elected a Fellow of the Royal Society.
Boulliau suggested in his work Astronomia philolaica (1645 ) before Isaac Newton before, that the gravitational force decreases with the square of the distance.
The lunar crater Bullialdus was named after him in 1935.