8

The popular belief goes like this:

Isaac Newton was sitting in his garden under a tree when an apple falls on his head, and suddenly he came up with his theory of gravity.

Did this event really happen, or was it an invented story to explain his idea?

  • The Newtonian theory of gravity did not spring fully formed from his head in one instant. As a model of an aspect of the universe constructing the theory would have required a lot of hard work including observation (making notes about how objects behave), building a model based on those observations, using that model to make predictions and verifying those predictions in the real world. There would be no "Eureka" moment. What started him thinking about gravity from a scientific standpoint is another matter, though I've heard the apple story was probably false – GordonM Sep 18 '17 at 13:03
  • @GordonM I agree that whole theory shouldn't have formed in one instant, I was particularly interested in the story of the falling apple on his head, not the whole theory. – marcanuy Sep 18 '17 at 22:35
15

The idea of the apple falling on Newton's head was invented by Isaac Disraeli (father of British Prime Minister Benjamin Disraeli) in the early 19th century, nearly 150 years after the supposed event.

Newton, however, did himself relate the story (toward the end of his life) of his having observed an apple fall, which provided the impetus for his theory of universal* gravitation. As his friend William Stukely related:

"... the notion of gravitation ... was occasion'd by the fall of an apple, as he sat in a contemplative mood. Why should that apple always descend perpendicularly to the ground, thought he to him self. Why should it not go sideways or upwards, but constantly to the earths centre? Assuredly, the reason is, that the earth draws it ... there is a power, like that we here call gravity, which extends itself thro' the universe."

[See Newton's Apple and Other Myths about Science, edited by Ronald L. Numbers]

*Thanks to @jameslarge comment

  • 1
    ...for his theory of universal gravitation, which was the idea that the force that drew the apple to the ground was the same force that binds the Solar system. That was a revolutionary idea---bordering on heresy. Up until that point, everybody knew that objects in "the heavens" obeyed different laws from objects on Earth. – Solomon Slow Sep 14 '17 at 21:19
  • @jameslarge: Thanks, I've included that qualifier in the answer. – Robusto Sep 14 '17 at 21:54

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .