General Relativity

Einstein's Geometric Theory of Gravitation

A revolutionary theory that describes gravity not as a force, but as the curvature of spacetime itself— fundamentally changing our understanding of the cosmos.

What is General Relativity?

General Relativity (GR) is Albert Einstein's 1915 theory that revolutionized our understanding of gravity, space, and time. Unlike Newton's theory where gravity is a force between masses, Einstein showed that gravity is the curvature of spacetime caused by mass and energy.

The theory's central insight: mass tells spacetime how to curve, and curved spacetime tells mass how to move. This elegant geometrical picture explains phenomena from planetary orbits to black holes and the expansion of the universe itself.

Key Insight

Gravity is not a force pulling objects together...

It's the natural motion of objects following the straightest possible paths through curved spacetime.

Newtonian

Gravity as force

Einstein

Geometry of spacetime

Historical Context

1905

Special Relativity

Einstein showed space and time are relative, unified into spacetime

1915

General Relativity

Extended to include gravity and accelerated reference frames

1919

First Confirmation

Eddington's eclipse expedition confirmed gravitational light bending