Ismael Bullialdus (his surname is a Latinized form of Boulliaud, Boulliau) (September 28, 1605 - November 25, 1694) was a French astronomer. He was born in Loudun, Vienne, France.

In 1640, he suggested that the force of gravity follows an inverse-square law. (Isaac Newton made this idea precise in his 1687 work, the Principia.)

Ismael Bullialdus died in Paris, France.

Bullialdus crater, on the Moon, is named after him.

External links

• Short biography
• Longer biography (in French)

1605 births | 1694 deaths | French astronomers | French mathematicians | 17th century astronomers | 17th century mathematicians

Ismaël Boulliau | Ismael Bullialdus