What do physicists believe existed before the big bang?

Question

Please, if you don't know, or are just giving some fanciful 5 word answer, just don't answer

Answer 1

a big bomb.

Answer 2

What Physicists believe is that there existed a singularity(Highly condensed and very very small lump of ULTIMATE density) just before the big bang and that was the whole universe at that time.
and as we all know that there is no around, around universe.
so, SINGULARITY IS ALL WHAT EXISTED BEFORE THE BIG BANG.
The whole universe started expanding after the big bang and a time will come when again everything will start contracting and again a singularity will be formed and again another big bang...

Answer 3

I'll quote Wald's book on General Relativity:

"The big bang does not represent an explosion of matter concentrated at a point of a pre-existing, non-singular space-time, as it is sometimes depicted and as its name suggests. Since spacetime structure itself is singular at the big bang, it does not make sense either physically or mathematically, to ask about the state of the universe "before" the big bang; there is no natural way to extend the spacetime manifold and metric beyond the big bang singularity. Thus, general relativity leads to the viewpoint that the universe began at the big bang."

In other words, time is part of the universe. Asking what is before the big bang is like asking what is north of the north pole. There is simply no way to extend 'time' in a meaningful way to 'before' the big bang. This is the classical viewpoint from General Relativity.

Once Quantum mechanics comes into play, there are a couple of possibilities: One is that the singularity is still preserved so 'before the big bang' still is meaningless. The other, predicted by some theories of quantum gravity, is that there was a previousl universe that underwent a 'big bounce'. As stated above, M-theory describes the big bang as initiated by collision of 'branes'. *All* of this is highly speculative. We understand the universe to a very small fraction of a second after the big bang, but anything before that is extending our models past their breaking point.

Answer 4

They don't belive, they speculate. Current speculation revolves around something called M-theory where our universe was caused by a "membrane" of higher dimensional space colliding with our dimension. So as best I understand it, in one sense if the universe is a hole then all that existed was a zero dimensional "ground"

It really hard to tallk about this without using very complex math but thats a lay explanation.

The "big crunch" theory that the universe explodes and collapses and explodes again isn't in vogue anymore

Answer 5

little hydrogenes and stuff floatin around doing nothing. the big bang they suddenly 'sploded and became active. which is against physics since an object thats not moving wont suddenly start moving just on its own, with out some outside force, hmm makes ya think

Answer 6

In simplified terms, there was just a huge black hole filled with all the matter of the universe compressed into an incredibly dense core... when it reached critical mass, it exploded... and GOD had nothing to do with it.

Answer 7

They believe that their was a universe before this one that had decreased in someway and the pressure got so high it exploded

Answer 8

The Void.

Answer 9

GOD