On this day in 1687 - July 5th - Edmond Halley published the Principia of Isaac Newton.

PhilosophiƦ Naturalis Principia Mathematica (Latin for 'Mathematical Principles of Natural Philosophy') states Newton's laws of motion and of universal gravitation. It's regarded as one of the most important works in the history of science.

Mona Evans
For news, activities, pictures and more, sign up to the Astronomy Newsletter!