Discover how Einstein’s theory of special relativity reshaped physics by linking space, time, mass, and energy in a universe governed by the speed of light. Albert Einstein's 1905 theory of ...

Einstein's theory of special relativity unified energy, matter and the speed of light in a famous equation: E = mc^2. The equation describes the relationship between mass and energy — small ...

But that year, the British physicist Paul Dirac wrote down an equation that described an electron travelling at close to the speed of light and noticed that it contained something odd. Dirac was ...