The story of Isaac Newton and the falling apple is one of the most famous anecdotes in the history of science. According to the legend, Newton was sitting under an apple tree when an apple fell on his head, inspiring his theory of universal gravitation. But how much of this is true?
The apple story is not entirely fictional. Newton himself told the anecdote late in his life — including to his friend William Stukeley, who recorded it in a memoir in 1752. The key detail: the apple didn't hit Newton on the head. Rather, Newton saw an apple fall and began wondering why it fell straight down rather than sideways or upward.
This 'why' question — why does any object always fall toward the Earth, in any direction — led Newton to the insight that the same force pulling the apple down might extend much further, even to the Moon. If gravity extended to the Moon, it could explain why the Moon orbits the Earth rather than flying off in a straight line.
Newton had likely been thinking about gravity for some time before the apple incident, during his productive plague years of 1665–1666. The apple story describes a moment of crystallization rather than a bolt from the blue. The tree — identified as a Flower of Kent apple tree — still stands at Woolsthorpe Manor, Newton's birthplace.
The story illustrates something true about creative insight: major discoveries often happen when an ordinary observation is paired with an extraordinary question. Newton didn't see anything unusual in a falling apple. He asked an unusual question about it.
常见问题
Did the apple really fall on Newton's head?
No — that's the popular myth. The actual story, confirmed by Newton himself to William Stukeley, is that Newton observed an apple falling and wondered why it fell perpendicular to the ground rather than sideways or upward.
Where is Newton's apple tree today?
The original tree at Woolsthorpe Manor in Lincolnshire, England, still stands. It is a Flower of Kent variety. Cuttings have been propagated at Cambridge University and other institutions worldwide.