Where is the center of the universe?

Fuzzy Logic

Absolutely. I don't recall anybody suggesting otherwise. The model doesn't change until there is evidence. You don't base practical application on something hypothetical. In no way does that mean we should discount everything that conflicts with the model though. Within reason of course.

Science should never be dogmatic.

Flustered

What would the core of the earth be in your situation?

Fuzzy Logic

You miss the point. What is the center of the circumference of a circle? Forget that it's a circle and realize that it is just a line that connects to itself.

DaveC426913

Yes. Note that just because you walk along a line and find yourself back at your starting point does not mean you are on a circle. There are many other ways this can happen, and they don't all involve an extra dimension.

Likewise, you can walk along a surface and find yourself back where you started without the surface having to enclose anything, thus without it having to have a centre at all.

salvestrom

As I stated in an above post using the ballon analogy, the core of the earth might represent zero time to the present (at the surface). Beyond the present is the future. This is as close to any 'center' as is possible for you to ever get, unless something very radical comes along in the future that shows our universe to be contrary to what our best minds have concluded our best data to mean.

Flustered

So what i'm getting out of this, is that the universe is flat and it connects to its self in a line. But there is no center, even though I can move in 3D? Also the circumference argument is only 2D. The universe is not 2D.

salvestrom

The universe is 3D. The effect we are describing occurs in every possible direction. You will, in a finite, unbound universe, always end up back where you started. Someone stood 6 feet to your left can see 6 feet further left than you can, however, all he sees in that extra 6 feet is the 6 feet extra that you can see to the right, that he cannot (assuming, for the sake of explanation, that the observable universe is equal to the actual universe).

If you follow this through for every possible point in spacetime you have a bunch of overlapping spheres that give you the view from each point, but no point has any special property that makes it the center. It isn't too dissimilar from the notion of the earth having a top or bottom. This presupposes it's possible to have a 'right way up', but such a thing is entirely arbitrary.

DaveC426913

That is because we poor humans cannot actually imagine 3D volumes without boundaries. But we can imagine 2D surfaces without boundaries and extrapolate to 3D.

Back when computer programs were carved on stone tablets with sharpened bone, there used to be all manner of dungeons games comprised of nothing more than 10x10 rooms with stuff in them. There were 10 levels to the dungeon, making for a 1000 room dungeon, 10x10x10. What's cool is that you can walk (or climb) in any direction without limit. Walk 10 rooms West and you find yourself back in the same room. Climb ten floors up and you're back in the same room.

Some interesting things about this arrangement:

• it is finite in extent - no more than 10 units in any dimension
• it is unbounded - there are no borders, no edges
• there is no centre - no room can claim to be at the centre - in fact, no room can claim to have any special privilege over any other
• from any room, you can see the same distance in every direction i.e. every room exhibits the appearance of being at the centre
• if the entire thing doubled in dimensions (every room underwent mitosis into 2), the entire dungeon would double in size yet it would not grow from any centre
• it is perfectly mathematically trivial
  

salvestrom

I dunno about you, but I'm out of analogies, so let's hope he gets it this time around...

Cosmo Novice

The animations are representations only and no they do not accurately reflect the overall topology or intinsic manifold of the Universe. Trying to imagine or visualise the entire Universe from an external vantage point is...well...pointless. Asking for the center is like standing at the north pole and asking which way is north, it has no meaning.

The reason you find general popularizations like this is because they are popular and accessable, but they should be taken at face value and for the popularizations that they are.

To better understand the early universe then I would recommend you read Steven Weinbergs the first 3 minutes.

Additionally you can discard the idea you have on multiverses, if indeed there are multiverses (which I think is speculative at very best) then it is probably unlikely they have any causal connection to our Universe .

Try to remember the BB is not a ballistic explosion in a pre-existing background but was the rapid expansion of the Universe itself - not into a pre-existing empty space as the space itself is part of the expansion. Reality expanded from > plancke time and this is well understood physics, now before plancke time is anyones guess and a different ballgame.

If you have any other questions please ask, I understand it is a difficult concept but honestly is one well worth sticking with

Cosmo

DaveC426913

Another way of thinking about is this:

The universe is all there was and is. At one time in the very far past, distances between points were very very small (smaller than an atom). Then rapidly, distances between points became much larger, and distances between points have been increasing ever since.

Flustered

This may be a dumb question but how do cosmologist know the BB was smaller than an atom? What if it was the exact size as a proton. Does something in the acceleration say that it was smaller than an atom? If so what about the acceleration proves this?

Did the BB just pop into existence, or was the singularity existing there for some time, than decide to blow. Or did it expand the moment it popped into existence?

Rob D

Never mind, very off topic after giving it some thought.
RD

korben dallas

Hey? 'Sup? I was watching discovery channel the other day and they were showing a new mystery in space of a bunch of oddly behaving galaxies. They seemed to be orbiting something that was not there. The center of the universe perhaps? I believe the expansion of our universe is caused by the undetectable dark matter still being spewed into our dimension by the black-hole from which our universe was born into existence?? I'm asking if this is even remotely possible? That is the only uneducated explanation to me!! Peace Brothers and Sisters!!!!!

salvestrom

The size of the early universe is calculated by taking the current rate of expansion, assuming it has been the same, and working out what happens as you go backward. From this you end up with a very dense universe some 13.7 billion years ago.

Questions about the existance of the universe are as yet unanswerable. It might have been a cosmic egg laid by a cosmic chicken for all anyone can prove.

salvestrom

Galaxies are able to orbit around shared centers of gravity. It isn't necessary for anything to be there. An alternative is a large, old blackhole. Dark matter is actually thought to counteract space expansion, as it exerts a gravitational influence. There is no indication that dark matter comes from black holes, which exist in our dimension. And although I personally treat the starting universe as having been the mother of all black holes, whatever it was, it isn't it anymore.

phinds

MISLEADING BY FAR. What you are talking about is the observable universe, NOT the universe and this is an extraordinarily important distinction.