the big bang

[fatgaz]

i sort of know what the big bang theory is, where 2 particales collided exploded and formed what we now know as the universe. But in "THEORY" could this happen again and wipe everything out and if so could that have happend the last time

will be interested to here what the replys are

thanks gaz

[ll_billym]

Nobody knows how the universe began but by observing the universe today and by using telescopes that effectively allow us to look back in time the most widely accepted theory is the Big Bang theory.

This theory suggests that at one time all matter was compressed into a single point, not two points or anything else, everything was contained in one single point that exploded into the universe.

Could that happen again? Well there is a theory called the Big Crunch that suggests that at sometime in the future the universe will stop expanding and begin to contract and that it will continue to contract until all matter is a singularity again, this singularity could explode again into a completely new universe.

There are many other theories about universes, both ours and many, perhaps infinite others sometimes existing in parellel dimensions to ours but none that I know of that suggest that our universe will be wiped out by two ordinary particles colliding.

[Robb Phoenix]

Well lets correct you theory first.........
We don't know and will never know what happened before a point called Planck epoch ie from 0 to 10^ -43 seconds in the existence of the universe.At this interval all the forces were unified and all laws of physics break down. We cannot speak of what happened before or during this time because time didn't exist.
After about one picoseconds all the forces separated as we know them today.
But the universe was still incredibly small with immense density and temperature. Some of this energy was converted into matter and anti matter which again eliminated each other to form energy back, this cycle continued but lucky for us at one point there was a very small excess of matter compared to antimatter. The matter then formed quarks,then electrons, the protons and so on. The immensely large amount of energy helped in beginning the expansion of our Universe.Mind you there was NO EXPLOSION.The story continues but i stop here.

This could never happen again in our universe as according to new research the Big Crunch will never come to pass, as no force is strong enough to stop the current expansion of the universe. The universe will continue to expand and will never have the same initial conditions again. But a new universe could be born in the same way elsewhere in the multiverse (which is the hypothetical superset of all the universes).But we can never know about or be influenced by them.