Where in space did the Big Bang happen?

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SharidB

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Recently I've asked myself where did the Big Bang happen? Have Astronomers found a paticular region of space where this single point might of been? Even if so think about this... Astronomers are looking deep into space and trying to map out the Universe. The Deeper they look the further in the past they see. I've read books and seen TV shows about Astronomers looking 12 to 13 billion years in the past, even observing some of the remnants of the Big Bang. So, Which direction are they looking? And if you look in the opposite direction you would still see far in the past. So, if you are at a single point in space and all around you and as far as we can observe is the known past, how is it possible for one region of space to have this single point? I don't know if I have explained my question very well to give a good enough picture of what I'm talking about or asking. But all I know is in every direction around us we can only see so far and so far in the past. Where is this region of space where the Big Bang happened? Does anyone know?
 
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MeteorWayne

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The answer is, it happened everywhere. The entire universe was the size of an atom, and has been expanding (not exploding, which is the common misperception) from everywhere that exists ever since. So the space at the tip of your finger is expanding just as fast as any other place in the Universe.

There are already dozens of other threads discussing this.

Welcome to Space.com

Wayne
 
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nimbus

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Think about where the center of 3D space would be, if this 3D space is such that you seamlessly move from one "edge" of this 3D shape (whatever the shape, sphere, ovoid, hydra, etc) to the opposite end, anytime you try to move past the "boundary" of the 3D shape. In effect the universe has no shape, because (think about it, picture yourself in that position) at any given time (e.g. when just before the "edge") there's a same amount of space in all directions. A same amount of space in all directions as there was when you first started off (say from here on Earth) toward "the edge".

This is what you get with a "closed" universe. The terminology's pretty hairy at first, but that's basically it. If the universe were made of just 1 dimension, then an analogy would be travelling over a string. Close this string into a circle and you've made it so that there's no "center" of the 1D string universe. No matter where you are, you're no closer to or further from the edge or center. And this works with both a finite universe and an infinite one.

http://en.wikipedia.org/wiki/Shape_of_the_Universe

So, in this universe, the big bang didn't happen in one particular spot. It happened everywhere at once. The big bang was the expansion of space itself. There was no space ("space" that belonged to our universe) that wasn't part of the big bang.

http://www.atlasoftheuniverse.com/bigbang.html
 
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SpaceTas

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The big bang created space and time so there was no space (or time) to be in.

This is more than semantics, the idea of no-thing is a very hard concept to imagine. It can keep yo awake at night!

The only analogy I have found; is what is the image out the back of your head? Darkness no, that is the absence of light, but you don't have a dark patch when you think of what is behind your eyeball; just no-thing, no information.
 
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B_Cary

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To think about this unthinkable, remember that when you're dealing with the universe, you're dealing not with space but with space-time. Three points can identify a position in space, but you need a fourth point to identify a position in space-time.

Given that the Big Bang happened in the middle of everything, the question becomes "What is the middle of time?" The answer is, now. Because we are in the middle of time (as we feebly know it), we exist at the middle of space-time. This gives rise to the answer that the Big Bang is everywhere. The unique point is our now.

Two disclaimers: I didn't think this up; I absorbed it slowly. I also don't grasp what it means otherwise--I don't have the education. But this concept allows me to accept "The Big Bang is everywhere."

Courage.
 
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Captain_Salty

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nimbus":33zkt67h said:
Think about where the center of 3D space would be, if this 3D space is such that you seamlessly move from one "edge" of this 3D shape (whatever the shape, sphere, ovoid, hydra, etc) to the opposite end, anytime you try to move past the "boundary" of the 3D shape. In effect the universe has no shape, because (think about it, picture yourself in that position) at any given time (e.g. when just before the "edge") there's a same amount of space in all directions. A same amount of space in all directions as there was when you first started off (say from here on Earth) toward "the edge".
Sounds like Pacman :?
I'm having a hard time getting my head around this. I have always imagined the universe as an expanding 3 dimensional bubble that we are somewhere floating inside of. But this is wrong geometrically speaking, no matter what shape the bubble ?
I've see the spherical/flat/hyperbolic depictions of the universe, but how can you visualise these in 3 dimensions and without a center?
 
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nimbus

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Because there's no edge. The problem is picturing a finite universe, as it is when you're at your point of departure. You see it as a big sphere or whatever shape you assume it has. On the one hand it's an accurate picture because that's all the space there is, but on the other hand it's not accurate because the edge doesn't actually exist: If you did travel from that point of departure towards what appeared to be the furthest point, you'd reach that furthest point and then travel beyond it... to the point exactly opposite of it. Because the universe is "closed".

Look at the graphic on the atlasoftheuniverse.com webpage. You can picture it like that kind of dream/nightmare paradox where someone walks out of a room thru one door, and instead of exiting to another room, walks back into the same room from the opposite end.
 
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Captain_Salty

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nimbus":2nqzk2wd said:
If you did travel from that point of departure towards what appeared to be the furthest point, you'd reach that furthest point and then travel beyond it... to the point exactly opposite of it. Because the universe is "closed".
As seen from earth, would something travelling outward eventually make a 180' arc through the sky and come back from the opposite direction? at least in a very small universe.
 
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ramparts

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The short answer is: we don't know.

The long answer is this: the question is whether the universe is flat or curved. Flat means there's no "coming out the other side," closed means that there is. All evidence points to the universe being flat. But there are two caveats, and those are that we can never measure that flatness completely perfectly (there's always some margin of error; now it's about 2%, give or take), and that we can only say how the universe is within the visible part of it. We don't know about the universe in places where the light has never had time to reach us.

In fact, you can draw an analogy to the Earth's roundness. On small scales, the Earth's surface looks flat - it's not until you go out a bit that you begin to notice its curvature. However, I caution that this is an analogy and nothing more. The fact that when a similar situation we turned out to be wrong doesn't mean that the same thing will happen this time, and all the available scientific evidence points to the universe being perfectly flat. For example, if the universe in the beginning had even a teensy tiny deviation from flatness, as it expanded that curvature would be blown up to massive proportions. If the universe is curved today but only slightly, that would require the early universe to have had a curvature whose deviation from flatness was about a 1 preceded by 60 decimal points, but still wasn't exactly flat. And that's just not a natural thing to happen.
 
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nimbus

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So flat/closed is the correct terminology? I thought it was open/closed or bound/unbound, and that flat/convex/concave was to describe expansion?
 
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ramparts

Guest
The most basic distinction is open/flat/closed. An open universe is hyperbolically curved (that's a very difficult thing to visualize) and a closed universe is basically curved the way the Earth's surface is - around a sphere in higher dimension. Flat is what's exactly in between them, making it a very special type of universe. A closed universe is the only one where you can go one way and come out the other side. It's also the only universe which you expect to recollapse on itself: flat and open universes go on expanding forever, but in the closed universe the gravity of the stuff inside eventually causes everything to stop expanding and come back in a "Big Crunch." Luckily that doesn't appear to be in the cards for us :)
 
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nimbus

Guest
What key words should I look for to find an explanation for the relation between the two? For closed universe to be the only configuration expected to possibly collapse back on itself?
 
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ramparts

Guest
In general this sort of stuff is called the geometry of the universe, the curvature of the universe, or (more colloquially) the shape of the universe. This is a pretty important issue in very basic cosmology so wiki does have some good stuff about it. The best explanation I could find for what you're looking for is:

http://en.wikipedia.org/wiki/Ultimate_f ... e_universe

But see also:

http://en.wikipedia.org/wiki/Shape_of_the_Universe
Particularly the section called "spherical universe": http://en.wikipedia.org/wiki/Shape_of_t ... l_universe

That article gets kind of technical, especially in the sections about global geometry. I'd recommend you just read the introduction, the sections under "local geometry," and then the "flat universe," "spherical universe," and "hyperbolic universe" sections, ignoring some of the math you might not understand :)
 
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Woggles

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ramparts"quote said:
Hi ramparts.

Flat universe

"Absent of dark energy, a flat universe expands forever but at a continually decelerating rate, with expansion asymptotically approaching a fixed rate. With dark energy, the expansion rate of the universe initially slows down, due to the effect of gravity, but eventually increases. The ultimate fate of the universe is the same as an open universe."

A couple of questions.
1) Is dark energy actually (for lack of a better word) pushing the expansion?
And
2) As the universe keeps expanding would the effect of dark energy no longer be a cause of acceleration? Basically acceleration would stop and the universe would carry on expanding at a fix rate?

Thanks
Paul
 
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FlatEarth

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ramparts":3upadx8j said:
...the Earth's surface looks flat ...
I like this statement. ramparts, you are indeed a fine fellow. :ugeek:
 
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