Where is the center of the universe?

Radrook

I agree that every observer sees the universe receding from his position. That doesn't justify the observer to conclude he holds the universal central position. It only proves that from his perspective it seems as if he does. Neither does it prove there is no central position. If indeed the relativity of perspective justifies concluding that no central position is possible then please explain how.

Chronos

Science is derived from observation. If it appears you are at the center of the universe, you must derive an experiment that attempts to disprove this theory. Lacking any such evidence means either you are at the center, or no center exists. We can say with fair certainty we are at the temporal edge of the universe, yet we observe the same distribution of galaxies [at large scales] in every direction. That too is compelling evidence the notion of any 'edge' to the universe is an illusion. An unbounded region has no 'center' according to the rules of geometry.

DLuckyE

So basically, you're saying if i'm drifting somewhere in a big ocean and can see the distance of water to the horizon is equal in every direction I have to conclude that i'm either at the center of that there's no center to the ocean at all? That makes no sense at all... It just means that the ocean is bigger than your horizon and thus you can't determine if there's a center and if you're at that center.

petm1

Unbounded may be what we "see", but bounded is what we feel. We are bounded by gravity which is a true center connection and the center of gravity is a real direction in time. Relative to my "now" the path back through time is inward opposite of the flow set into each atom. I "think" big bang was a little twist, a focal point of motion, because it formed our atoms, like a little focal point that broke into all of our dilating massive points. Time does not contract it is still dilating outward from big bang, and even though relative to my now I do not know where its center is in space, I "think" time's center was big bang the original dilating entity.

bytecash

This still does not make sense, there HAS to be a "center" of the Universe under the big bang theory, even if it is a ball or balloon blowing up, there is still a CENTER or middle of the ball or balloon. Even if there are no "edges" of the universe there is still a geometrical point of center. If the universe started from one point in space and expanded in all directions there is a center even if it is a moving central point.

Greylorn

IMO you are correct. Your analysis is one of others which expose the absurdity of Big Bang theory.

I can afford to agree with you because my theory of the beginnings, which would never be allowed here, does not incorporate a singularity (which would represent absurd physics, no different from claiming that God did it) and has a different explanation for both the observed expansion of the universe as well as its acceleration.

None of this will help you any unless I publish, but at least you know that you are not alone. Keep thinking!

nonequilibrium

I think you're simply misunderstanding the balloon analogy. The balloon actually tells the story for a two-dimensional universe. In that case the "center of the balloon" isn't a part of space at all! If people were to live in a 2D world, the balloon analogy would be exact (but then again, people in a 2D world can't imagine an inflating balloon, so they would use the analogy of a closed loop getting bigger).

Anyway, for our 3D spatial universe you have to inflate a "balloon" in 4D instead of 3D. You see that the "center of the balloon" isn't a part of our physical reality at all.

(To be exact, you'd probably need a 5D space, as time is an extra dimension, but that's besides the point in this discussion.)

DaveC426913

In fact, not only do you not need a 5th dimension, you do not even need a 4th. The mathematics of a curved 3D space work out just fine without needing to invoke a 4th dimension in the equations.

nonequilibrium

Hello Dave. Can it be that you misread my post? Otherwise I don't understand your objection. I was saying that the correct balloon analogy should be a 3 dimensional balloon in a 4 dimensional space (the 3D balloon then playing the role of our 3D space), but of course such an analogy would be useless due to not being able to imagine it :p

DaveC426913

No, and I wasn't objecting.

Pointing out that the 2D balloon analogy is like our 3D universe expanding into a 4th dimension is tantamount to suggesting that our universe would have a center - in that 4th dimension. That is going to send bytecash the wrong message.

The balloon analogy is simply an analogy because it shows someone how it is possible to have an object that is finite yet has no centre. But you don't want to carry the analogy too far, or you defeat the lesson. We don't want bytecash thinking our universe has a center in some 4th dimension.

Imax

Expansion from a center is not compatible with the notion of a homogeneous and isotropic Universe. If the Universe did expand from a center, then the observed expansion rate would depend on how far you are from the center.

Chronos

What part of seeing the universe as it appeared in the past is escaping notice here?

nonequilibrium

True, I should have noted that, but bytecash's post seemed to suggest, at least to me, that he thought that our universe was actually expanding like the balloon does, i.e. as a 2D sphere expanding in 3D space, and that is why I wanted to point out that the balloon analogy was merely a substitute for something we can't imagine.

petm1

I agree with this. Do you think that every observer also perceives they are as close as possible to the 'center' of the 'big bang', 'now', given the finite speed of mass?

salvestrom

I was immensely please with myself when I finally got to grips with this question a few days ago. I think I deserved to be, having been struggling with it for two decades. =D

What I realised was that since the universal singularity consisted of all space and all matter/energy then that energy occupied all of space. So when it went up like an intergalactic roman candle, all energy was evenly distributed and blown apart. Essentially, the entire universe, at every point 'exploded'. While the universe, or more specifically, space may yet turn out to have a center, an edge, or neither, the location of the Big Bang itself was everywhere.

xrx1113

OK i'm new to this site but i was wondering why: if we can see the red shift/blue shift of galixies and we know they are moving can't we tell by the degree of red shift/blue shift which direction they are going . If galixies are going in a strait line they are leaving where they were, if you drew lines backwards from them at some point they would all intersect at the center of the universe, dosn't that tell us where to point the telescope .
Am i totally wrong?

Cosmo Novice

Yes.

If we trace all motion for everything we can see - the center is our galaxy - all galaxies are moving away from our galaxy. If we were in Andromeda then we would see Andromeda as the center.

This can only ever tell us the Observable Universes center - the point is this; most mass in the Universe has not moved a great deal since the Big Bang (barring individual kinematic motion which is almost negligible on large scales) , the BB was not an explosion in the traditional sense but can be explained by expansion of the scale factor.

Scale expansion does not require a center. You can attribute a center to the Observable Universe but as we know the Universe is much much larger than the Observable (even if still finite) then this has no relevance to the U as a whole.

If the Universe is infinite then it cant possibly have a center and if it infinite it is bounded in a way that any point can be the center.

The only centers are for observables and the only edges are for temporals, there can be no centers or edges to the Universe as a whole - it would contradict the Cosmological Principle.