Its indivisable time-like aspect also extends from the instant that the universe flashed into existence, through the present moment, and on into the future. Astronomers who study the universe have developed a detailed model of its evolution called the Big Bang Theory. About 15 to 20 billion years ago, everything in the universe came into existence in an awesome explosion. The feeble light from the fireball of creation can still be detected by sensitive instruments as they peer into the depths of space. The magnitude of this event is truely mind boggeling.
Earthbound explosions begin with a bomb whose detonation sends debris flying out into space.
According to some recent theories, before the Big Bang, our particular spacetime simply did not exist. It is difficult and somewhat troubling to imagine that time and space had a beginning and may someday come to an end. Even among religeous cosmologies, both ancient and modern, this has been a common theme. Science may, in the next few decades, prove true what humans have long suspected, and perhaps even feared, about the fate of the universe. More amazing and profound than its scope and possible transcience are new discoveries that may portend even more remarkable revelations about the nature of spacetime.