What is known:
* Newton developed his theory of universal gravitation over many years, influenced by observations and calculations.
* The apple story likely originated from a letter Newton wrote to a friend where he mentioned an apple falling from a tree while he was thinking about gravity.
* The location of the apple incident, if it happened at all, is believed to be Woolsthorpe Manor in Lincolnshire, England, where Newton was staying during the Great Plague of London.
The important point is that Newton's discovery of gravity was not a sudden "Aha!" moment. It was a result of years of research and contemplation.
