the theory of special relativity was published by einstein in 1905, in the paper "on the electrodynamics of moving bodies". it says that both distance measurements and time measurements change near the speed of light. this means that as one get closer to the speed of light (nearly 300,000 kilometres per second), lengths appear to get shorter, and clocks tick more slowly. einstein said that special relativity is based on two ideas. the first is that the laws of physics are the same for all observers that are not moving in relation to each other.