Isaac Newton (January 4, 1643 to March 31, 1727) was an English physicist and mathematician who developed the principles of modern physics, including the laws of motion, and is credited as one of the great minds of the 17th century Scientific Revolution.
The Apple Myth
Between 1665 and 1667, Newton returned home from Trinity College to pursue his private study, as school was closed due to the Great Plague. Legend has it that, at this time, Newton experienced his famous inspiration of gravity with the falling apple. According to this common myth, Newton was sitting under an apple tree when a fruit fell and hit him on the head, inspiring him to suddenly come up with the theory of gravity. While there is no evidence that the apple actually hit Newton on the head, he did see an apple fall from a tree, leading him to wonder why it fell straight down and not at an angle. Consequently, he began exploring the theories of motion and gravity.
In 1687, following 18 months of intense and effectively nonstop work, Newton published Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), most often known as Principia. It is said to be the single most influential book on physics and possibly all of science. Its publication immediately raised Newton to international prominence.
Principia offers an exact quantitative description of bodies in motion, with three basic laws of motion:
1) A stationary body will stay stationary unless an external force is applied to it.
2) Force is equal to mass times acceleration, and a change in motion (i.e., change in speed) is proportional to the force applied.
3) For every action, there is an equal and opposite reaction.
In 1705, he was knighted by Queen Anne of England, making him Sir Isaac Newton.
He died on March 31, 1727, at the age of 84.