# Does the Universe have a centre?

Asked by flutherother (19407 ) June 6th, 2012

The Universe is expanding so surely it must be expanding from some central point. If there is a central point it must be where the Big Bang originated, but where is that point today?

Observing members: 0 Composing members: 0

Yep! You’re looking at her ;)

sliceswiththings (11627 )

My understanding is that there is no center of the universe, since the big bang was a quick expansion of matter and space. So, from wherever you are in the universe, it appears to be at the center. This hurts my head a bit, and I could be way off. I’ll see if I can dig up a good link.

EDIT: This might help.

tom_g (14410 )

There can be no centre of infinity, so no.

ucme (34942 )

@tom_g Good article if a bit mind bending. It seems that maybe it does and maybe it doesn’t.

flutherother (19407 )

The universe isn’t expanding from one central point, that’s a common misconception. Rather, every point in space is getting farther away from every other point in space. Think of it as what a marker drawing on the surface of a balloon would look like as you blew air into the balloon.

Mariah (17398 )“Great Answer” (10 )

Yes, my giant cat, Chewbacca. He is the center of everything, and his fluffy cuddles are the answer to everything.

Here.

rebbel (23072 )

If the Universe is infinite and has no centre how do you find the exit?

flutherother (19407 )

Quick question guys: is there direction in the universe? From what I understand, the universe isn’t some sphere, so there’s really no north and south etc?

Blackberry (27938 )

It’s exactly 42 from the edge.

Nullo (21496 )
Rarebear (18444 )

@Blackberry Since north and south are directions we assign along earth’s axis of rotation, it doesn’t really make sense to apply them to anything that doesn’t have an axis of rotation. I may not be correct on this, but I don’t think it’s known what “shape” the universe is.

Mariah (17398 )

@Mariah Yeah, I thought so as well.

Blackberry (27938 )

@Mariah @Blackberry Unless you are referring to positions as they relate to the Earth.

Nullo (21496 )

@flutherotherIf the Universe is infinite and has no centre how do you find the exit?

Is this one of those: “If a tree falls in a forest and no one’s around to hear it, does it make a sound?” questions?

@Keep_on_running Doesn’t sound like it. The tree-and-forest question boils down to differences in observation, whereas leaving effectively doorless rooms tends to be an exercise in lateral thinking.

Nullo (21496 )

@flutherother Great question. And the accurate answer is we have no idea. The observable Universe appears to be 96 billion light years in diameter and would—from Earth—appear to have us as its center. But we know from sending space telescopes out and observing from other points of view that it appears the same size and centered on that point of observation instead of Earth. Interestingly, no new observable objects appear when we view the Universe from a distant point.

So how is it really shaped? Can it even be described in 4 dimensional spacetime? Does it reach beyond the part we can observe? We simply do not know.

ETpro (30628 )

Some say the Universe is infinite, but how can something grow from nothing to an infinite size in a finite amount of time?

I like the balloon analogy which explains why the Universe doesn’t have a centre. But it means that everywhere in the Cosmos is the centre. But our Universe didn’t begin from a smaller version of itself but from a single point and everywhere can trace its origins back to that single point. All this makes me wonder if distance and space even exist in any fundamental sense.

flutherother (19407 )

Does the surface of the Earth have a center? Is it Punxsutawney, Pennsylvania? Of course not.

The same goes for the Universe with its warped spacetime. But the human mind wasn’t designed to picture this.

mattbrowne (30074 )

@Nullo Yeah, I was just kidding. :P …and maybe you were too, damn I can’t tell.

@flutherother You asked, ”…[H]ow can something grow from nothing to an infinite size in a finite amount of time?” Obviously, by growing infinitely fast. But measurements tell us that did not happen, so unless the Universe is even more illogical that I think it is at the macro scale, it’s finite.

ETpro (30628 )

@ETpro I just came across this. It is possible that the universe was not concentrated into a point at the time of the Big Bang but only the observable universe was.

flutherother (19407 )

@flutherother I see that the link is on UCLA, but I haven’t a clue how we could actually know that. Sadly, the author just makes these bold assertions without any supporting evidence or footnotes. Interestingly, he does provide a link to this page which states that we can “see” 47 billion light years in any given direction. That gives us a observable universe that’s 94 billion light years in diameter, which matches more closely with my understanding of 96 billion light years, but very poorly with the above link’s 78 billion years. So take it for what it’s worth.

ETpro (30628 )

If you are a Flatlander on an inflating balloon, where is the center of your universe? ;)