Bubble universes. Computer illustration of multiple 'bubble' universes as predicted by the Eternal Inflation theory. The inflationary theory proposes that after the Big Bang, a condition known as a false vacuum created a repulsive force that caused an incredibly rapid expansion, much faster than the ordinary expansion observed today. Since this expansion is faster than the speed of light, areas of inflation would form bubbles that would be completely isolated from each other. This artwork could also represent the creation of separate 'parallel' universes as fluctuations in a quantum foam.