Expert: Ed - 5/15/2008

Question
how was the big bang theory discover?
How will scientist obtain a new tool to search for the "fossil record" of the Big bang?
why do scientists believe in the "Big Bang theory"?

Answer
Adi,

I'm sorry I'm a little late.  I should have told AllExperts to put me on holiday.  I have a lot of projects that are due soon, so I have been busy.

The Big Bang theory wasn't exactly "discovered."  It developed over time, gradually, as the most reasonable way to interpret the data and information that early 20th century astronomers gathered with their telescopes.  The main idea began as a way to explain the fact that ALL distant nebulae and galaxies appear to be moving away from us.  This didn't seem possible, at first.  Astronomers wondered "why would these nebulae be doing this?"  Also, at the same time, mathematicians working on Einstein's theories proved that Einstein's theories implied that the universe could be expanding.

This meant, that if the universe was expanding, then at one time it must have been smaller.  Seems logical, right?  Well, in fact, they have proved that at one time it was VERY tiny, and exploded in the Big Bang, which created out universe.

All of these ideas took several decades to develop.  Astronomers, mathematicians and physicists spent a lot of time arguing about it, and gradually the Big Bang theory developed into the idea that we have today.

Look at these links:
http://en.wikipedia.org/wiki/History_of_the_Big_Bang_theory
http://universe.nasa.gov/

As for your second question, NASA is sending up lots of probes to work on this problem.  One of them was the FUSE probe.
http://www.sciencedaily.com/releases/1999/06/990609172213.htm

The COBE was another important tool, in the search for the fossil record of the Big Bang.  Here is a helpful NASA website about it:
http://lambda.gsfc.nasa.gov/product/cobe/

As for your third question, scientists don't "believe in" the Big Bang theory.  At the moment, it seems to be the best theory we have, to explain what we can observe about the universe.  If a better theory comes along, good scientists should test it, and if it seems better, then they should start trying to get it into our science textbooks.

I hope this is helpful.  Keep Looking Up!
--Ed