Gravitational lensing, conceptual image. Computer illustration representing how light rays from a distant object (here, a galaxy) are bent as they pass through the gravitational field of another massive object (here, another galaxy). The light is deflected from its original path. This bending of light by a massive object was predicted by Einstein in 1916 in his General theory of Relativity. The light from a distant object can be lensed into a variety of shapes and forms, including arcs, multiple images, or an 'Einstein ring'. In Einstein's theory, gravity is the warping of space-time by mass.