(1642-1727) an English scientist. He is well known for discovering Newton's Laws, which explained the relationships between force, mass and movement. Many people know the story that he discovered the idea of gravity (= the force that attracts things towards the centre of the planet) when he saw an apple fall from a tree in his garden. He also discovered differential calculus, a branch of mathematics, at the same time as Leibniz discovered it in Germany, and made important discoveries about the nature of light and colour. He was made a knight in 1705.