Video: Hawking's 'Brief History of Time' in two minutes
Stephen Hawking in his best-selling book 'A Brief History of Time' described black holes as incredibly dense objects, with gravity so strong even light cannot escape from it. At their edges, black holes capture one of particle-antiparticle pair, releasing one of them as 'Hawking Radiation'. Before the Big Bang, everything was squeezed into "singularity", which exploded to form the universe.