Special Relativity
Special Relativity is a fundamental theory in physics formulated by Albert Einstein in 1905, which describes the behavior of objects moving at constant high speeds, particularly close to the speed of light. The theory introduces key concepts such as the relativity of simultaneity, time dilation, and length contraction, demonstrating that measurements of time and space are relative to the observer's state of motion. It fundamentally altered the understanding of space and time, establishing that the laws of physics are the same for all observers, regardless of their relative motion, and leading to the famous equation E=mc², which expresses the equivalence of mass and energy.