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Center of the Univers

by The Grimmus
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The Grimmus
#1
Jul4-03, 10:56 PM
P: 205
I have heard very little about what is suposedly there. I heard one perosn say a black hole...ok actulay that is all i heard.

But what is there and what causes all of the galxy clusters to revolve around it
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CrystalStudios
#2
Jul4-03, 11:00 PM
P: n/a
Solar systems have suns around them.

The stars (no matter if they have planets or not) make up a galaxy.

At the center of every galaxy discovered so far, is a black hole.

A galaxy is rotating.

The step up from a galaxy is far just the universe itself.

I have never ever heard any scientific experimentation or theory that talks about what is at the center.

Based on the big bang I was say nothing is at the center.

The universe is not rotating at all = it's just expanding - so there's nothing there.

that's all the input I have! I have yet to read any scientific data about the center of the U.

But as far as I know - it's way to far away to detect even anything that would give an answer
Hurkyl
#3
Jul4-03, 11:07 PM
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The universe is hypothesized to be boundaryless; thus "center of the universe" is a nonsensical term.

IOW there is no center to the universe.

CrystalStudios
#4
Jul4-03, 11:19 PM
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Center of the Univers

Originally posted by Hurkyl
The universe is hypothesized to be boundaryless; thus "center of the universe" is a nonsensical term.

IOW there is no center to the universe.

Nah - the universe has already been proven to be of finite size.

Any other theory is old-world.
marcus
#5
Jul5-03, 01:50 AM
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Originally posted by CrystalStudios
Nah - the universe has already been proven to be of finite size.

Any other theory is old-world.
I'm curious. Why do you think it has been "proven" to be of finite size?
CrystalStudios
#6
Jul5-03, 02:48 AM
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Originally posted by marcus
I'm curious. Why do you think it has been "proven" to be of finite size?
Good question.

The big bang has been proven. As the big bang expanded, it continueed to expand the size of the universe - as far as the matter and light of the big bang stretched, that was the size of the universe at that moment.

So right this second, the universe is exactly the radius in light years, the years of which is the exact age of the universe, since the big bang.

Simple as that.

In other words, you cannot have the big bang and have an infinite universe. Because the universe is defined by how far light has traveled since the big bang.

The big bang created space - space did not exist before it.
physicskid
#7
Jul5-03, 04:21 AM
P: 78
I thought that the universe's center is unacessible because it does not have a dimension, like Earth with an unbreakable crust. We only live on the surface of it.
r637h
#8
Jul5-03, 06:56 AM
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Good subject>

Is the Universe finite? Probably.
Does it have a center. Well, probably not quite: The curvature of space-time prevents us from defining a center.
A center is based upon 'anthropic' views. It probably does not have an independant physical location.
We have discovered "laws" of Physics which are probably a reflection of the true state of matter-energy. But the universe could care less.

Basically, all we have is Logic/Scientific Method, an artificial system of iteration/measurement and, possibly, insight/intuition.
These are probably puny weapons in a quest for understanding.

Mankind has aquired bodies of knowledge which, to us, are quite impressive. But how does this knowledge compare to that obtainable? Probably miniscule.

We are very, very far from a Theory of Everything. But perhaps the search, the game itself, is the point.

Thanks, Rudi
jcsd
#9
Jul5-03, 07:29 AM
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The univberse doesn't have a centre, though it is thought be closed(i.e. be of finite size) it is also thought to be boundless (i.e. without boundaries) like Hurkyl said. The best analogy is the surface of a sphere as it is finite in size but lacks any boundaries.
drag
#10
Jul5-03, 07:47 AM
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Greetings !

TG,
The Universe does not have a center. Like jcsd said, think
of all the Universe being located on the surface of
a sphere. The sphere expans and points on the sphere
get further apart from each other, but there's no location
in the Universe that is central.

CS,
The Universe may be infinite. The Universe does
not expand at c but rather faster which is why it does
not have a radius in LYs equal to its age. As for the BB,
it is scientificly proven to a certain extent, but not
all the way, of course.

Live long and prosper.
marcus
#11
Jul5-03, 12:14 PM
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Originally posted by CrystalStudios
Good question.

The big bang has been proven. As the big bang expanded, it continueed to expand the size of the universe - as far as the matter and light of the big bang stretched, that was the size of the universe at that moment.

So right this second, the universe is exactly the radius in light years, the years of which is the exact age of the universe, since the big bang.

Simple as that.

In other words, you cannot have the big bang and have an infinite universe. Because the universe is defined by how far light has traveled since the big bang.

The big bang created space - space did not exist before it.
The accepted picture of the big bang, at least to the best of my knowledge, is that it is infinite in spatial extent.

At least this is what is assumed in every recent article I've seen.

So talking about the big bang would seem to confirm that the universe is infinite.

A good recent (May 2003) overview of cosmology is in

Lineweaver "Inflation and the Cosmic Microwave Background"

arxiv: astro-ph/0305179

a good spacetime diagram suggesting the infinite extent of space is Lineweaver's figure 5, in which figure 1 (showing our finite horizon) is a small insert.

Lineweaver was one of those in charge of COBE which mapped the CMB and has a firsthand knowledge of the new dataset on which cosmology is based, IMO it's well worth checking out what he has to say about the universe---its infinite extent is only one of several interesting features
subtillioN
#12
Jul5-03, 12:22 PM
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Originally posted by marcus
The accepted picture of the big bang, at least to the best of my knowledge, is that it is infinite in spatial extent.

The oxymoronic mantra is "finite but unbounded". This nonsense notion is stolen directly from abstract mathematics (curved space) as is the nonsense notion of a "singularity". Neither of those terms have any causally definable meaning wrt physical reality.
jcsd
#13
Jul5-03, 12:30 PM
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ermmm, yes the conventional model of the universe is finite and unbounded, but curved space has been observed at our own sun and the large scale curvature of the universe has supporting physical evidence in the shape of the reshift magnitude test (i.e. the lensing of the furthest redshifted sources which increases their apparent magnitude).

That said, I believe no sugnificant curvature was found by COBE.
Eh
#14
Jul5-03, 12:31 PM
P: 683
It's a common misconception that the big bang implies the universe is finite. In actual, the theory says nothing about the overall size of the universe, only that it began to expand from a much denser, hotter state.
Eh
#15
Jul5-03, 12:33 PM
P: 683
Originally posted by subtillioN
The oxymoronic mantra is "finite but unbounded". This nonsense notion is stolen directly from abstract mathematics (curved space) as is the nonsense notion of a "singularity". Neither of those terms have any causally definable meaning wrt physical reality.
Why is the notion of curved spaces nonsense while flat Euclidean space is acceptable?

Awaiting your well reasoned and logical response.
subtillioN
#16
Jul5-03, 12:40 PM
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Originally posted by Eh
Why is the notion of curved spaces nonsense while flat Euclidean space is acceptable?

Awaiting your well reasoned and logical response.
Space is a metrical abstraction. In reality the Universe is neither flat not curved.
Eh
#17
Jul5-03, 12:41 PM
P: 683
So the universe has no structure or size at all? If it does, what is the geometry of it?
subtillioN
#18
Jul5-03, 12:43 PM
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Originally posted by jcsd
ermmm, yes the conventional model of the universe is finite and unbounded, but curved space has been observed at our own sun
The "spatial curvature" found was much more complex than the model of relativity could explain. And the notion of curvature is simply a method of quantifying the increased density of the field surrounding the sun.


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