Newton

In the summer of 1665 the plague took London and Cambridge in the same season, and the colleges sent the undergraduates home. Isaac Newton went back to his mother's house at Woolsthorpe in Lincolnshire, where he had been born in the year his father died, and stayed for most of two years. He was twenty-two. He had read mathematics for one year. In the orchard at Woolsthorpe, by the tradition his niece Catherine Conduitt told to William Stukeley in 1726, he watched an apple fall from a tree and asked himself, in earnest and not for a moment, why it should fall straight down rather than sideways or up. The notebook from those two years contains the binomial theorem, the method of fluxions, the first formulation of the inverse-square law of gravity and the decomposition of white light. Cambridge calls them the anni mirabiles. Stukeley's account is the only first-hand source for the apple, and Stukeley wrote it down sixty years after the fact.

Read the story →

In August 1684 the astronomer Edmond Halley rode up to Cambridge on a question that had been arguing the Royal Society into a circle for eighteen months. If the planets are pulled toward the Sun by a force that diminishes with the square of the distance, what shape would their orbits take? Robert Hooke had said an ellipse and could not prove it. Christopher Wren had offered Halley a forty-shilling prize for the proof. Halley took the question to Newton, who had spent the years since Woolsthorpe in retreat from the world. Newton answered him at once. He had calculated it. He could not, on the spot, find the paper. He sent it down to London three months later as a nine-page treatise, De Motu Corporum in Gyrum, and Halley, reading it on a bench at the Society in November, sat very still for ten minutes before going to find the President.

Read the story →