Albert Einstein (in context of early theories)

Albert Einstein was a theoretical physicist who revolutionized our understanding of space, time, and gravity. Early in his career, he developed the special theory of relativity (1905), which showed that the laws of physics are the same for all observers moving at constant speeds and that the speed of light is constant. He proposed that gravity isn't just a force but the warping of spacetime caused by mass and energy, later elaborated in his general theory of relativity (1915). These ideas transformed physics, replacing Newtonian concepts with a more accurate understanding of the universe's fundamental structure.