Theories of relativity

Theories of relativity, mainly Einstein's special and general relativity, describe how space, time, and gravity work. Special relativity shows that when objects move close to the speed of light, time slows down and lengths contract for them. General relativity explains gravity not as a force but as the bending of spacetime caused by mass and energy—like how a heavy ball warps a stretched cloth. These theories revolutionized our understanding of the universe, showing that measurements of time and space depend on motion and gravity, especially in extreme conditions.