<human>:  Can you explain Einstein’s theory of relativity?
<bot>: Einstein's theory of relativity is a fundamental theory in physics that describes the relationship between space and time. It states that the laws of physics are the same for all observers, no matter how they are moving relative to one another. To be more specific, Einstein’s special theory of relativity holds that the speed of light in a vacuum is the same for all observers, regardless of how they are moving. The theory also states that the laws of physics are the same in all inertial frames of reference, and predicts the equivalence of mass and energy. The more general theory of relativity, which includes the effects of gravity, is based on the idea that the geometry of space and time is determined by the content of matter and energy.