In 1684, Sir Christopher Wren (the architect who built St. Paul's Cathedral in London and who is pictured here at left), Sir Edmund Halley (of Halley's Comet fame and pictured here below), and Robert Hooke (of the famous Hooke's Law for the harmonic motion in springs) were seated together in a pub in England discussing celestial mechanics. Hooke asserted that the motion of the planets could be explained by assuming a force which varied as the inverse square of the distance between the bodies. Wren challenged Hooke to prove his inverse square law and offered a prize to him if he could do it. After two months he was unable to provide a mathematical proof.
 

Halley went to his friend and colleague, Isaac Newton, to ask him if he had ever consider the problem. Newton informed him that he had proved it many years earlier but had just never bothered to actually write it down somewhere. (Newton didn't handle criticism well and became very hesitant to ever publish because of run-ins with others over his early work). Halley urged his brilliant friend to write these things down and he also put up the money to publish the resultant work - the classic work of classical mechanics and moodern mathematics - Principia. It is for this work that Newton is most famous and it became the foundation for celestial mechanics and Newton's Laws.