Albert Einstein (theory of relativity)

Albert Einstein's theory of relativity revolutionized our understanding of space, time, and gravity. It consists of the special relativity (1905), which shows that the laws of physics are the same for all observers moving at constant speeds and that time and space are linked—moving clocks run slower, and lengths contract at high speeds. General relativity (1915) describes gravity not as a force, but as the curvature of spacetime caused by mass and energy. Massive objects like stars create dents in spacetime, and other objects move along these curves, explaining the phenomena we observe as gravity.