Big Bang, The

Today the most widely accepted theory of the origin of the universe (see previous section on "alternate universes") is the Big Bang Theory. Lemaitre suggested the beginnings of the theory in 1931, and George Gamow added to it later.

The Big Bang Theory says that the universe as we know it began as a tiny mass of "primordial matter." At a point in time that marks the beginning of time as we know it, the density of the mass caused it to reach a temperature of 10 billion degrees.

At that critical temperature, the mass exploded. In less than one second, the matter began expanded into space, forming the elements we know today, starting with hydrogen.

About 4.6 billion years ago, much of the matter in the universe was contained in large clouds of hot gas. According to a new theory by astronomer Jeff Hester of Arizona State University, intense ultraviolet radiation created a bubble within one of these gas clouds.

A shock wave compressed the surrounding gas, triggering the formation of many of the low-mass stars in our universe today, including our own sun. Intense ultraviolet radiation from a nearby massive star evaporated much of the gas surrounding the star, leaving behind a small star and a flat disk of gas and dust. The gas and dusk in the disk formed the planets in our solar system.

David Langford's Earthdoom (1987) speculated that the Big Bang might have triggered by an unwitting time traveler, just as A.E. van Vogt's "The Seesaw" (1941) suggested that the solar system was created by a reporter swinging back and forth through time until he explodes with built-up energy.

In James Blish's The Triumph of Time (originally published in 1958 as A Clash of Cymbals), the Okies witness the end of the universe and the beginning of another. The same event takes place in Poul Anderson's Tau Zero (1970).

Physicists at the University of Chicago say that the Big Bang was not a one-time event, but that Big Bangs occasionally happen at different points in space and time. Their calculations show that another Big Bang is likely to occur, although the probability of it taking place at any particular time or location is exceedingly small: 1 divided by 10 to the power of 1056. Although this number is small, it is not zero, and since the universe is infinite, the next Big Bang will happen.