I’ve had a nagging question for a while. Although I understand the Big Bang theory, it has never been made clear to me where the “singularity” that exploded came from. Therefore, I don’t get the Big Bang theory as a theory to explain the origin of the Universe, but only an explanation of its current state.
Also, I would like to know “where” this singularity of whatever was before it exploded.
Please enlighten me.
To add to the question. . .
The “Big Bang” as best as we understand it was just a “quantum fluctuation” that just happened.
OK.
What was the medium, then, in which this quantum fluctuation fluctuated?
However, since our understanding of physics seems to break down at that magical Planck time, is this just an irrelevant question?
As a Big Banger, myself, I wanna know.
Mjollnir - LOL at your “north of the North Polers” comment.
Techincally speaking, the quantum fluctuation that created our universe underwent a period of inflation that started its growing to its current size. Talking about a “big bang” is rather passe thse days, since the period of inflation that involved space itself expanding is not the same thing as an explosion taking place inside of space-time.
The Big Bang wasn’t an explosion in the sense we normally think of one. I.e. There wasn’t a ball of something (however small) that exploded in a spherical fashion. The Big Bang essentially happened everywhere at once.
The only theory I’ve heard for what was ‘caused’ the Big Bang (which in some ways of thinking is a meaningless question) was the separation of ten dimensional space into the three space and one time dimension we all know and love. The other six dimensions snapped down into a tenny-tiny ‘ball’. Tiny as the other dimensions are they also have the funky characteristic of touching all points in our three dimensions.
Of course, there is no evidence for any of this. Worse, even the notion of multidimensional space beyond our four is highly debatable so take all of this with a Universe sized grain of salt.
EXAPNO: Although I must say I did not know this, my OP still holds.
Darren: I had seen the thread before, but since there was only two replies, I thought someone else might have a different take on the subject. Alas, it seems that the answer is: Don’t know, can’t tell, will never be able to tell… Therefore, I assume that my statement Big Bang (or quantum fluctuation/inflation) does not explain the origin of the Universe, but its current state.
Mjollnir: I don’t get the “magical Planck” bit. Are you saying this question is irrelevant?
I should note that it isn’t quite fair to say there is no evidence for multidimensional space. While there is no experimental evidence String Theorists like to use multiple dimensions beyond our four for their calculations. Of course, String Theory itself is by no means universally accepted but it has enough going for it that some serious physicist types are trying to flesh it out. The multiple dimensions allows for easier management of some equations necessary to unify gravity and quantum mechanics (or so they hope). So, are multiple dimensions just a handy construct for doing some wiggy math or do they really exist? I have no idea myself as even touching that stuff for real would melt my brain (at least further than it already has been). Nevertheless it is something at least a bit more real than a premise for a nifty episode of Star Trek.
The ‘magical Planck’ bit refers to the Planck limits (Planck Time, Planck Length, Planck Mass) which set lower bounds on what we can describe. This isn’t to say there aren’t things or lengths smaller than the Planck limits but it is at those points that our ability to understand or predict what is going on thoroughly breaks down. So, if the Big Bang singularity was smaller than the Planck size then you could say it was made of peanut butter and you would be as right as any other possible answer.
This also goes with "Don’t know, can’t tell, will never be able to tell… ". That is essentially correct as what was before the Big Bang is by definition unknowable. You are asking what was around ‘before’ the Big Bang occurred and again you might as well say a booger or peanut butter or anything else.
Still, that doesn’t mean it isn’t fun to speculate.
If I may, I’ll refer you to a salient discussion on the origins of the origins of the universe
Mu.
I just sat down and both of my knees now have a 90[sup]o[/sup] bend in them; where did this angle come from and where does it go when I stand up?
JS: Thanks, I hadn’t seen this thread.
God said, “What would happen if I had a quantum vacuum fluctuation with these parameters?” and it was so.
Word.
Today on Book TV, Janna Levin discussed her book How the Universe Got Its Time Diary of a Finite Time and a Finite Space. During Q&A she said that before the Big Bang there was no space or time and therefore there was no “where” for it to come from. As to where the universe is going she said that if you could point to a spot and say that is “where” it is going then that space already exists. 
[sup]This all sounds like something Yogi Berra would say.[/sup]
:mad: [sup]Definitely not peanut butter without jelly[/sup]