Black hole. Computer model of distortions in the view of an accretion disc due to the immense gravity of the black hole it orbits. The view is looking directly away from the hole from the rotating accretion disc. The hole is the dark area at left, with space being the rounded dark area at centre, surrounded by the distorted view of the disc. The bending of light rays by gravity is known as gravitational lensing. Temperature is colour-coded: orange (cool) to blue/white (hot). A black hole is a region where the gravitational field is so strong that light cannot escape. Work done at Johns Hopkins University, Maryland, USA.