1782 - John Goodricke[?] notices that the brightness variations of Algol are periodic and proposes that it is partially eclipsed by a body moving around it
1964 - Subrahmanyan Chandrasekhar and Richard Feynman develop a general relativistic theory of stellar pulsations and show that supermassive stars are subject to a general relativistic instability
... (died 1592), English sailor and explorer.
Samuel de Champlain, (c. 1567-1635), established the French colony in Canada; discovered the Great Lakes
William Clark, ...