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
... Shackleton, (1874-1922), attempted to reach the South Pole and came further south than anyone before him
John Hanning Speke, (1827-1864), discovered Lake ...