Did Isaac Newton really discover gravity when an apple fell on his head?

Every so often – usually when I’m recounting the alleged thievery of biscuits belonging to an understanding high school Physics teacher – my brain reluctantly turns its attention towards science.

So today I decided to put the focus to good use and look at the truth behind a popular scientific legend – that Sir Isaac Newton discovered gravity when an apple fell on his head. And, like all the best myths from history, it seems to have at least a little grounding in reality.

I found one intriguing backgrounder on the topic at the Culture Lab blog at New Scientist, which profiled a historical manuscript that went on to become a biography of the scientist by William Stukeley, who was apparently told the following anecdote firsthand by Newton. He remembers the telling as such..

“After dinner, the weather being warm, we went into the garden and drank 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. It was occasioned 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…”

You can read the full manuscript here at the Newton Project, which is a non-profit group dedicated to making his unpublished and published works freely available online. If you have time, I do recommend it, as it offers some pretty interesting insights into the development of his theory on gravity and more.

Certainly he did more good with his apples than a certain snake ever did in the garden of Eden…