Mechanics is the physics of movement — why things speed up, slow down, fall, fly, spin and stop. It is the oldest branch of physics and the one you meet every single day: every time you throw a ball, ride a bike, or trip over the cat, you are doing mechanics.

The astonishing idea at its heart is that a tiny handful of rules — pushes and pulls we call forces — govern all of it. The same rules that decide how a dropped pencil hits the floor also swing the Moon around the Earth and fling a rocket to Mars.

Two branches to explore

Begin down on the ground with forces and motion — pushes, pulls, speed, and Newton's famous laws that tie force to movement. Then look up: the very same force of gravity reaches across space to hold the Earth, Sun, Moon and planets in their orbits. Mechanics stretches from a rolling marble all the way to the Solar System.