Curved space-time. Conceptual computer artwork of a twisted strip of grid lines representing space- time. Einstein described space-time in his Special Theory of Relativity, showing that space and time are not invariant. They actually change with an object's velocity, the changes becoming noticeable near the speed of light. Space and time need to be treated as a single space-time framework. In his General Theory of Relativity, Einstein explained the phenomenon of gravity as a distortion of this space-time. Gravitational calculations then become a problem in topology (surface geometry). This strip has two twists. One twist would produce an object with only one surface, a Mobius strip.