Theory of Relativity The Theory of Relativity, proposed by Albert Einstein, revolutionized our understanding of space, time, and gravity in the early 20th century. Special Theory of Relativity The Special Theory of Relativity, proposed by Albert Einstein in 1905, is a groundbreaking scientific theory that has fundamentally changed our understanding of space, time, and motion. It postulates two key principles: first, the laws of physics are the same for all observers, no matter how fast they're moving; second, the speed of light in a vacuum is the same for everyone, regardless of their motion