crownboy

Did the universe suddenly appear and immediately start expanding, or was it an infinitesimally small piece of extremely dense matter (existing for who knows how long) that suddenly "exploded"? Or is there another theory? Or is it not known at this time?

scigirl

I think you'll get better responses to this question at <a href="http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=forum&f=57&SUBMIT=Go" target="_blank">Science and Skepticism</a>.

scigirl

Nat

The simple answer is that it is not known at this time, nor is it even possible to know the answer because a singularity destroys all information - no information can be passed through a singularity

The more complex answer is that Big Bang Cosmology doesn't just presuppose a beginning of space, matter, and energy at t=0, but a beginning of time as well. Hawking is famous for stating that asking what was before the Big Bang is like asking what is North of the North Pole - the question itself is non-sensical.

The even more complex answer goes into the very nature of time. Many noted quantum cosmologists would go so far as to suggest that the progression of time itself is simply an illusion created by our method of causal organization. There is a lot of merit to this case, because no moment in time really has an special significace in physics (i.e. the "present" is not all that exists - it is simply the point that we are currently percieving). I suggest you check out this month's copy of Scientific American for a well presented discussion of the nature of time and the issues that physicists are thinking about regarding it.

Hope this helps!

atrahasis

One thing that i know is that something must have existed always!! Im not trying to talk about about a god ar anything immortal here, what im trying to say is that it is plausable to claim that at least if not everything something was here from eternity.......

Nat

"One thing that i know is that something must have existed always!! "

Standard Big Bang Cosmology implies that the Universe itself has always existed, since time is a property of the Universe.

Paul2

since the big bang set time in motion, there was nothing before the big bang because there was no "before".


Another popular theory is that there is an infinite loop of big bangs and big crunches. the universe will expand and then colapse upon itself only to explode again.

Apikorus

What lies north of the North Pole?

Coragyps

Santa's patio, of course!

eh

Something has indeed existed for all eternity. But eternity does not need to need to be infinite in time.

Doubting Didymus

Ive often wondered about that, as a physics layman. If the universe could perpetually expand and collapse, wouldn't that contradict the second law of thermodynamics? Or does the theory suggest that it will run down sooner or later?