The Universe

          The Universe has no edge and nothing exists beyond it, not even space. In the vastness of the Universe, the Earth, the Sun and planets are tiny dots. The Sun is merely one star in a galaxy comprising 100,000 million stars. At least as many thousands of million of other galaxies, each with its own star system, extend as far as the largest and most sophisticated of optical and radio telescopes can reach.

          As the Universe expands, all galaxies and clusters of galaxies move apart from each other at speeds that depend upon their distances. The each other at speeds that depend upon their distances. The furthest ordinary galaxy yet detected, Abell 1835 IR is 13,230 million light years away and is receding at 45 per cent of the speed of light. The most distant object in the Universe as on 14 July 2004 is in background of Abell 2218. This corresponds to a distance greater than 2 billion light years. Beyond this, astronomers are looking back to a time when the Universe was born, and the detectable Universe fades out.

          Our present view of universe began with the findings of Copernicus, Galileo, and Newton. What they found was very much opposed by others at the time, mainly because established order was based on Aristotle's teachings. These "new" ideas were thought to diminish the role of humans in the universe, to undermine our importance we have expanded our vision since then by enormous effort, painstaking observations, and an ongoing desire to comprehend our surroundings.

Universe theory:

The Big Bang Theory:

          According to this theory, the Universe had its origin in a giant explosion about 18,000 million years ago. The Matter flung out from the explosion condensed into lumps called galaxies, which are still rushing outwards. As the Universe grows old, the matter in it thins out. The expansion continues indefinitely. The Big Bang theory received its strongest confirmation when 'cosmic background radiation' was discovered in 1964 by Amo Penzias and Robert Wilson, who won the Nobel Prize for this discovery. In 2003, NASA's Wilkinson Microwave Antisotropy Probe made measurements of the temperature of this 'cosmic microwave background' radiation to within millionth of a degree. From these measurements scientists were able to deduce that our universe is 13.7 billion years old and that first generation stars began to form a mere 200 million years after the Big Bang.  

Inflation Theory:

          Immediately following the Big Bang, the universe likely began a period of exaggerated outward expansion, with matter flying outward faster than the current speed of light. This is the inflation theory, widely accepted in the astrophysics community.

The Oscillating Universe Theory:

          This theory, a variation of the Big Bang Theory, suggests that expansion of the Universe will eventually slow down and stop, followed by contraction of the galaxies into another Big Bang. The Universe, therefore, continues in endless cycles of expansion and contraction; the laws of nature may differ in each cycle.

The Steady State Theory:

          An alternative view to the Big Bang Theory, this theory says that Universe never originated at any one instant, nor will it ever die. According to this theory, as the Universe expands new matter is created to fill the space left. Therefore, the appearance of the Universe remains constant with time.