Newton and the Apple

Every school child has heard the story of Newton and the apple. It sounds apocryphal. But it was as a real incident, as William Stukeley in his "Memories of Sir Issac Newton", of 1752 records; ON 15 April 1726 I paid a visit to Sir Issac at his lodgings in Orbels building in Kensington, denied with him and spent the whole day with him, alone.

After dinner, the weather being warm, we went into the garden and drank tea, under the shade of the apple trees, only he and myself. Amidst other discourse, he told me, he was just in the same situation, as when formerly, the notion of gravitation came into his mind. It was occasion by the fal of an apple, always descend perpendicularly to the ground, thought he to him self. Why should ti 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 the matter of the earth; and must be in the earth's center not only in any side of the earth. Therefore does this apple fall perpendicularly or towards the centre. If the matter thus draws matter, it must be in proportion of its quantity. Therefore the apple draws the earth as well as the earth draws the apple. That there is a power; like that we here call gravity which extends itself through the universe.

And thus by degrees he began to apply this property of gravitation to the motion of the earth and of the heavenly bodies, to consider their distances, their magnitudes and their periodical revolutions; to find out, that this property conjointly with progressive motion impressed on them at the beginning, perfectly solved their circular courses; kept the planets from falling upon the another or dropping all together into one center; and thus he unfolded and universe. This was the birth of those amazing discoveries, where by he built philosophy on a solid foundation to the astonishment of all Europe.