The Mathematical Principles of Natural Philosophy

In this monumental work Newton presented his three laws of motion and the law of universal gravitation which collectively revolutionized the way scientists and thinkers understood the physical world. The key concepts in the Principia include: Three Laws of Motion: Newtons First Law (Law of Inertia): An object at rest stays at rest and an object in motion continues in motion with the same speed and in the same direction unless acted upon by an external force. Newtons Second Law (F = ma): The acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass. Newtons Third Law (Action and Reaction): For every action there is an equal and opposite reaction. Law of Universal Gravitation: Newton proposed that every mass attracts every other mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.