Newton’s laws

In 1687 Isaac Newton publishes Principia. The three laws of motion and a law of gravity put falling apples and orbiting moons under one math. He did not work alone. Kepler's orbits, Galileo's experiments, and Hooke's ideas are in the background. The book is the synthesis people could calculate with.

The contribution is prediction. If you know the forces, you can work out the motion before you build the machine. Steam engines, bridges, artillery, and later rockets are designed this way. A robot arm's path is Newton's laws plus a controller.

Newton's gravity is not the last word. Einstein replaces it in strong gravity and at high speed. For engines, trains, and factories, Newton is still the working tool.

The year is the publication, not the day he understood it. The math he co-developed, calculus, is the other half of the gift, and Leibniz built it independently.