The Geometry of Space Time

Einstein theorized that the geometry of the universe (specifically space-time) should not be taken as fixed and rigid but rather as something that can change depending on the way matter is spread around. The geometry of space-time is determined by the metric, g_{\mu\nu} , which provides a way of measuring distance within that space. The distribution of matter, in turn, influences the metric and changes it. At points near large concentrations of mass, the metric will have higher curvature and space will be more curved.