If the big bang was not an explosion, but an expansion, and nothing existed before it. What caused it, and where did the material that is currently expanding come from?

O.K, so the universe stared life as a primeval atom, or a similar object??Well what was that object in?Answer: well... it could be dark matter (or a substance unknown to us...which dark matter is)What if dark matter acted as normal matter, the large 'vacuum' which was 'outside the universe' is actually eternal dark matter and the grouping of this into a central point due to a gravity type force, if not gravity itself, could lead to collisions of dark matter.This in turn could transform energy and may create 'matter' as we know it today. The transformation of dark matter to normal matter could be what we would perceive as an expansion of matter, which could link in with theories of inflation and thus the continued transformation of dark to normal matter could explain why the universe is expanding.Therefore the expanding universe could be a result of a far greater infinite (perhaps) expanse of dark matter.Only a theory, not very well explained or backed up in anyway, but thought I could lay it out on the table for you all to prod and jab at the concepts that could make it work.

If all the matter in the universe was once in a singularity which expanded with the Big Bang to the size it is now, then surely the density of matter initially exceeded the threshhold to create a black hole.

If such is the case, then don't we all live within one massive black hole and the physics that we see are the physics that operate within a black hole?

And if there are smaller blackholes within our observable universe, then surely it is reasonable to assume that there is physics that operates within those blackholes that is similar to our own.

This leads me to think of 2 pretty cool outcomes.

1) there can be an infinite number of blackholes within blackholes and that our observable universe exists as a just one blackhole in a universe of a larger scale just as we have many black holes within our observable universe.  Kind of like infitie Russian Dolls.

and

2) it is possible that the observable universe can both expand to reach the scale and density equilibrium required to one day equalize with the space it occupies in the next higher up scale universe.  Balance could be achieved through the mechanism of matter falling into the Black Hole and hawking radiation out of it along with the gradual expansion.

Does it also mean that the gravity of the next higher scale universe is pulling the matter in this blackhole universe that we live in apart?  Is it the missing Dark Energy?  Is that the dimension where gravity leaks?

I wish I knew some cosmic mathematics to delve deeper into these ideas.  But I'm sure someone who does can tell me why I'm wrong and why a singularity can expand, can even inflate, without bending any rules of blackholes.

Regards,

Kevin

Sir,

Please can you explain why the moment of creation is referred to as The Big Bang? Surely, as all matter as we know it was compressed to a size smaller than an atom and that sound needs a medium to propogate through this event was neither big nor made a banging noise. Why is it not called "The moment of great repulsion" ?

I believe that this is a more technically accurate name and also that, judging by the girls reaction in the pub on Tuesday, that elements of "The moment of great repulsion" are still in existence today.

Yours,

David Redford

My Physics teacher says time started at the Big Bang. If time is the order of the sequence of events, surely there must have been time before the Big Bang in which the two antimatters collided to create it. Am I right?

Could the universe be expanding to our point of view but contracting in another ? i.e. an explosion on the surface of the Earth would create an expanding shock wave, but if it was large enough it would continue around the surface and would then start to meet up again. Depending on where the observer was it would be expanding or contracting.

As I understand it a black hole can be connected to several universes at once, does this mean that it could in theory consume enough matter to become a super dense and collapse to form a singularity which in turn could generate a Big Bang thus creating a new universe ? 

From NewScientist.com-

"This is a tale of two spacecraft. Pioneer 10 was launched in 1972; Pioneer 11 a year later. By now both craft should be drifting off into deep space with no one watching. However, their trajectories have proved far too fascinating to ignore.

That's because something has been pulling - or pushing - on them, causing them to speed up. The resulting acceleration is tiny, less than a nanometre per second per second. That's equivalent to just one ten-billionth of the gravity at Earth's surface, but it is enough to have shifted Pioneer 10 some 400,000 kilometres off track. NASA lost touch with Pioneer 11 in 1995, but up to that point it was experiencing exactly the same deviation as its sister probe. So what is causing it?"

Other things I have read about time have led me to wonder if maybe the craft aren't moving faster, but rather our perception of time is changing.

Another user on this site asked if time travel might be possible by further expanding or re-collapsing the universe to speed up or "rewind" time. I don't think traveling back in history could be done using this method, but it may be like flooring the gas or pushing the brake on time itself. He also pointed out that what we perceive as "time" is a dimension probably restricted to this universe, but because of that it may be pushing against the limits of its ever-expanding confines. If he's correct, then might time be "stretching" to fill the universe, thereby "stretching" our perception of it?

Just an idea to toss around.

At school the teacher said that before the Big Bang, the Universe was like a small tennis ball. But where WAS this ball?

Time has not been around forever. Most scientists believe it was created along with the rest of the universe in the Big Bang, 13.7 billion years ago.

Some physicists like Michael Berry, Thomas Gold, and Steven Hawking have also proposed that time may reverse when the universe begins to contract. Using this as our base grounds, could we go into future or fast forward the time if we could somehow increase the expansion rate of the universe?