Student Projects/The Big Bang
The Big Bang :-
About 14 billion years ago, the Universe materialized out of nothing reasons. Infinitely smaller than an atom to begin with, the Universe expanded to a trillion kilometers across in under a second-gen event called Big Bang. Time came into existence when the Universe began,so the question "what happened before?"has no meaning. Space also came into existence. The Big Bang was not an explosion of matter through space-it was an expansion of space itself. At first the Universe consisted of pure energy,but within a trillionth of a second some of this energy turned into matter,forming a vast soup of subatomic particles (particles smaller than atoms). It took nearly 400,000 years for the particles to cool down enough to form atoms,and then another 300 million years before the atoms formed planets,stars,and galaxies. The expansion that began in the Big Bang continues to this day,and most scientists think it will carry on forever.
Discovery of the Big Bang:- The first scientific evidence for the Big Bang was found in 1929,when astronomers discovered that light from distant galaxies is reddened. This colour change happens when objects are moving away from us making light waves stretch out and change colour. The more distant the galaxies are,the faster they are rushing away. This shows that the whole Universe is expanding.
Big Bang afterglow:- More evidence of Big Bang came in the 1960s,when astronomers detected faint microwave radiation coming from every point in the sky. This mysterious energy is the faded remains of the intense burst of energy released in the Big Bang.