Newton's 'apple story' online
London - An 18th-century account of how a falling piece of fruit helped Isaac Newton develop the theory of gravity is being posted to the web, making scans of the fragile paper manuscript widely available to the public for the first time.
Newton's encounter with an apple ranks among science's most celebrated anecdotes, and Britain's Royal Society said it was making the documents available online on Monday.
Royal Society librarian Keith Moore said the apple story has managed to keep its polish in part because it packs in so much - an illustration of how modern science works, an implicit reference to the solar system and even an allusion to the Bible.
When Newton describes the process of observing a falling apple and guessing at the principle behind it "he's talking about the scientific method", Moore said.
"Also the shape of the apple recalls the planet - it's round - and of course the apple falling from the tree does indeed hark back to the story of Adam and Eve, and Newton as a religious man would have found that quite apt."
Tea in the shade
The incident occurred in the mid-1660s, when Newton retreated to his family home in northern England after an outbreak of the plague closed the University of Cambridge, where he had been studying.
The Royal Society's manuscript, written by Newton's contemporary William Stukeley, recounts a spring afternoon in 1726 when the famous scientist shared the story over tea "under the shade of some apple trees".
"He told me, he was just in the same situation, as when formerly, the notion of gravitation came into his mind," Stukeley wrote.
"It was occasion'd by the fall of an apple, as he sat in contemplative mood. Why should that apple always descend perpendicularly to the ground, thought he to himself ... Why should it not go sideways, or upwards? But constantly to the earth's centre? Assuredly, the reason is, that the earth draws it. There must be a drawing power in matter."
Stukeley's account joins the long-lost notes of Newton's 17th-century scientific rival Robert Hooke on the Royal Society's website.
Users can flip through both documents using the same page-turning software used to browse Leonardo's sketches and Jane Austen's early work on the British Library's site.
The Royal Society is an academy of scientists founded in 1660 to gather, discuss and spread scientific knowledge. It is marking its 350th anniversary this year by putting more than 60 of its most important scientific papers online.