The other day I was wondering about the Big Bang Theory particularly this part of it.-> About 15 billion years ago a tremendous explosion started the expansion of the universe. This explosion is known as the Big Bang. At the point of this event all of the matter and energy of space was contained at one point. What exisisted prior to this event is completely unknown and is a matter of pure speculation. ->http://www.umich.edu/~gs265/bigbang.htm
I dont know if the Big Bang is actually the way it happened(and I dont believe in creationism or god for that matter so keep it scientific) but they have found evidence of radiation that travels away from us that could have been left by the initial explosion
Supposedlyall of the matter and energy of space was contained at one point. I know matter and energy can be neither created nor destroyed but I still had to wonder why it would be there, or why space is there and so on. I wondered if you guys new any theories or jut had any ideas about the subject
:smack:
I think it’s unfortunate that the authors of the website worded it this way, because it really confuses the issue. My understanding of the theory is that time literally began at the moment of the big bang. Time is a property of the universe; in fact it is often thought of as a fourth dimension. At the singularity before the big bang, all of the universe would have been collapsed to a single point with infinite density. At that point, time would not exist. So the phrase “prior to this event” is really a misnomer. You can’t ask what came before the big bang any more than you can ask what was to the left of the big bang, or what was underneath the big bang. Such questions are nonsensical. I’ve heard it succinctly explained this way: Asking what came before the big bang is like asking what’s North of the North Pole.
That’s not to say there can’t be anything outside of our universe; it just doesn’t make any sense to define such a thing in terms of our time.
blowero has it right on the money. It is literally meaningless to ask what came before the Big Bang. From our position inside this universe such a question is unknowable. You can speculate all you like about it but any answer you care to come up with is as good as the next. I used to like to think the Universe cycled through Big Bang to Big Crunch to Big Bang to Big Crunch ad naseum. It had a certain aesthetic appeal to me but unfortunately it seems like the Big Crunch is not what will happen (rather the heat death of the universe which I find disturbing). Even were the cycle I mentioned actually the case we could know nothing of previous universes…the Big Bang singularity would essentially erase and reset everything.
As to where it all came from is a problem. You can endlessly go around the cause and effect loop saying that every event must have a prior cause. You can do this on to infinity and never resolve the question.
The only explanation I’ve heard as to where the stuff for our universe came from was the splitting of multidimensional space (IIRC 11 dimensions) into our three spatial dimensions and the other eight snapped down into a point (that also happens to be everywhere in our universe at the same time). The energy released from this event was what ultimately made us. This idea however is FAR from proven and requires a few (as far as we know today) assumptions not least of which is the actual existence of 11-dimensional space and what would cause it to split. In short take this notion with a healthy amount of skepticism.
i have to disagree here. my understanding (and i don’t think this is where i found it, but it was said this way in hawking’s ‘a brief history of time’, if you want a cite) is that “time began at the big bang” is a scientific convenience.
due to the nature of the big bang, nothing before it could be deduced by anything that happened after it. so we cannot (even in theory) know what happened before. therefore it is convenient to set the first instant of the big bang to t=0.
in fact, it is nonsensical to say that time even had a beginning, since the concept of beginning is a matter of time dependence.
as for the big bang, the radiation you referred to is the microwave background radiation, and its existence was predicted by the big bang theory and later discovered. that’s why it’s often considered strong evidence in support of the big bang. theories about what came before the big bang tend to rely on speculation about what will happen at the end of the universe. if (as many people hope, for reasons of faith) the universe eventually “crunches” back down due to gravity, it will likely be so massive that it would collapse to a single point. who knows what happens after that? but hell, it might be a big bang.