An assignment on Bigbang Theory

AN ASSIGNMENT OF BIGBANG THEORY

It is the theory that all the matter and energy, of the universe, was concentrated in a compact, infinitely small volume that exploded some 15 to 20 billion years ago, giving rise to the present universe, still expanding from the initial explosion. The big bang theory is the most widely accepted cosmological theory today (the new Webster’s encyclopedia p.131.)

Big bang theory studies how eh universe originated. It pictures the universe as having been born, and as evolving and eventually dying. The big bang theory assumes, that all the material I the universe was at one time packed tightly together and was then flung outward by an enormous explosion. The Belgian Astrophysicist and priest Georges Lemaitre first put this theory forward in the 1920s.

It rested on the discovery by Edwin Hubble that the universe seemed to be expanding, like a balloon being blown up. Hubble showed that the galaxies are receding from each other with velocities increasing to nearly halt the speed of light as they get farther away.

After the world war II Hermann Bondi and Thomas Gold put forward the opposing steady theory, which says that new material is continually created to fill the space between the galaxies. Although the universe is expanding that matter in it was never concentrated. New galaxies and old galaxies would exist side by side, and the universe would always look the same. The English astronomer Fred Hoyle later developed the theory.

As one looks back in time, the character of the universe seems to altar. Instead of galaxies one sees, quasars, which may be galaxies in the process of formation. At distances past 8 billion light years, the number of objects seems to decrease, indicating a time when the universe was just forming. But I tend to think that everything is changing as Hiracletus said.

Some Data on Big Bang

Explosion took place, when universe was a few minutes old.
This explosion is still continues.
The temperature at the time of explosion was 1,000 million degrees and went up to 1,000 million degrees.
It cooled down, nuclear re-action took place and a material emerged from the fireball, which was consisting of 75% hydrogen, 25% helium by mass. This is what we call the universe today.