Where is the center of the universe?

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The discussion centers on the concept of a "center" of the universe in relation to the Big Bang and cosmic inflation. Participants argue that there is no definitive center, as the universe expands uniformly in all directions, similar to the surface of an expanding balloon. The cosmic microwave background radiation appears consistent in all directions, supporting the idea that every point in the universe could be considered a center. Some contributors express confusion about how we can observe the beginning of time from different directions without a specific origin point. Ultimately, the consensus leans toward the understanding that the universe does not have a singular center, challenging traditional notions of expansion and origin.
  • #151
DaveC426913 said:
This is not at all true.

You are standing on the surface of the Earth - a 2-dimensional plane with a finite area. Where is the centre of the Earth's surface?

would it be that there is no center or that every point is the center? Or is there a difference between those two?
 
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  • #152
The center of the Earth's surface is not the center of the Earth as a whole. A solid 3-d shape like the Universe does have a center. And the center of the Earth's surface could be said to have infinite centers as each point can be reached by going around the Earth, and the path you follow has a midpoint. But as I said, the Earth does have a center. Also, the surface of the Earth can not be made into a 2-d shape, the surface of the Earth is also a sphere and the center of the spheres mass would be at the center of the sphere. If you laid the Earth out flat, then it would have a defined center since you would have to chose a latitude or longitude to define as the edge, no matter where you cut a globe and lay it out, you will end up with a center.
 
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  • #153
SHISHKABOB said:
would it be that there is no center or that every point is the center? Or is there a difference between those two?

If you view it at a single point, the center would be the opposite pole to you. If you did it for every point on a sphere, there would be infinite centers on the sphere.
 
  • #154
ynot1 said:
So where would you find the center of an infinite universe, if such a thing exists? Or did I miss something?

This is presuming that the universe is finite. If it were infinite, then there would be no center.
 
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  • #155
If the Universe is not truly infinite would this suggest that there is something else besides the Universe?
I don't mean the observable universe here, I mean the whole Universe which is a continuum of our own observable Universe.
By something else I mean more Universes separate to our own or perhaps something in which our Universe is contained in some way.
 
  • #156
SHISHKABOB said:
would it be that there is no center or that every point is the center? Or is there a difference between those two?
The centre point of a surface is a special, privileged point that no other point on the surface has. There is no point on the surface of a sphere that is privileged, therefore, no point is the centre.

rglong said:
The center of the Earth's surface is not the center of the Earth as a whole.
Do you grant that the surface of the Earth is finite in extent, yet has no centre?

rglong said:
A solid 3-d shape like the Universe does have a center.
What makes you say that?

Some 3D shapes have centres. That does not mean all do.

rglong said:
And the center of the Earth's surface could be said to have infinite centers
Then none are unique. Thus, they cannot be centre.

rglong said:
If you laid the Earth out flat, then it would have a defined center since you would have to chose a latitude or longitude to define as the edge, no matter where you cut a globe and lay it out, you will end up with a center.
That is correct. The moment you artificially divide it up, providing artificial boundaries, you make artificially privileged points. You would no longer have a surface of a sphere.

If you go nuts with your scissors and cut the Earth's flattened shape into confetti, then your shape will have straight edges and acute vertexes. Does that say anything at all about the original shape of the Earth's surface before you mangled it? Does it mean "the surface of the Earth has straight edges and vertices"?
 
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  • #157
Tanelorn said:
If the Universe is not truly infinite would this suggest that there is something else besides the Universe?
It does not suggest it, no.

Nor does it in-and-of-itself rule out there being something else - but not being infinite does not suggest there is anything else.
 
  • #158
Well it is hard to imagine that everything that is or ever can be is finite. There again it is difficult to imagine infinite as well.
It is also hard to imagine that there is any final level of reality or structure, since everything we know of in our everyday life is contained inside or is a part of something else; sub atomic particles, atoms, molecules, planets, solar systems, galaxies, clusters etc.
 
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  • #159
Tanelorn said:
Well it is hard to imagine that everything that is or ever can be is finite. There again it is difficult to imagine infinite as well.

We don't have to imagine it. Imagination is flawed by definition, since it depends on things we've experienced before.

The mathematics shows us. It is the only accurate model.
 
  • #160
DaveC426913 said:
We don't have to imagine it. Imagination is flawed by definition, since it depends on things we've experienced before.

The mathematics shows us. It is the only accurate model.

What a bizarre thing to say. I'm pretty sure I've never experienced a thousand mauruading snargle-bangs from Ceti-Prime Zeta demanding my left shoe and some yo-yos. (I may have experienced Douglas Adams at some point).

And an infinite universe is not the only model, you say this yourself. It's also possible that the universe is finite and unbounded. It's also possible there is an outside to what we currently consider the universe, regardless of whether the model requires it.

The moment you consider anything you cannot currently see, you are imagining.
 
  • #161
There is nothing imaginary about the math. Get used to it.
 
  • #162
Chronos said:
There is nothing imaginary about the math. Get used to it.

Imaginary numbers? Virtual particles? Besides, imagination and imaginary are not the same thing.
 
  • #163
Blue moon and bleu cheese? Blue and bleu are not the same thing. Your point escapes me.
 
  • #164
Chronos said:
Blue moon and bleu cheese? Blue and bleu are not the same thing. Your point escapes me.

Nobody said anything about math being imaginary, only you brought it up.
 
  • #165
I strongly believe it is not just about the math! The Universe is Physical and not just a computer running a bunch of equations.


Consider x = y * z, it is meaningless and tells us nothing.

However when we add the Physics we get Ohm's law. The Physics allows us to understand what is really going on and the equation allows us to calculate specific numbers.



Back to the earlier discussion; nothing beyond the Observable Universe can be proven to exist.
So we have to extrapolate from the conditions inside our own Universe and assume that homogeneity and isotropy apply beyond it.
For any kind of presumed reality beyond that, we have to list all possible possbilties, or just give up and say we can't do this.
I very much doubt that the rest of reality is blue cheese, but it ok to write it down in a brainstorming session, we can add the odds later.
 
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  • #166
salvestrom said:
What a bizarre thing to say. I'm pretty sure I've never experienced a thousand mauruading snargle-bangs from Ceti-Prime Zeta demanding my left shoe and some yo-yos. (I may have experienced Douglas Adams at some point).

And an infinite universe is not the only model, you say this yourself. It's also possible that the universe is finite and unbounded. It's also possible there is an outside to what we currently consider the universe, regardless of whether the model requires it.

The moment you consider anything you cannot currently see, you are imagining.

I didn't say you can't imagine things, I simply said it depends on things you're already experienced. This is why when you said "...it is hard to imagine that everything that is or ever can be is finite. There again it is difficult to imagine infinite as well..." I pointed out that our imaginations are flawed. Perhaps a better word would have been 'limited'.

You're having difficulty, because it is totally outside your realm of experience. The universe is not obliged to make sense to you.
 
  • #167
The human mind is pretty good at brainstorming and perhaps one of these extra-universe solutions is close to correct, which is why I like to read them all. I have a variation of the colliding branes involving two particles in an infinite space which eventually collide and BB. The problem is this is a localised explosion type BB, whereas we need the BB to occur everywhere in space simultaneously and I believe this requires extra dimensions like the branes hypothesis - unless I am misunderstanding the idea.
 
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  • #168
DaveC426913 said:
I didn't say you can't imagine things, I simply said it depends on things you're already experienced. This is why when you said "...it is hard to imagine that everything that is or ever can be is finite. There again it is difficult to imagine infinite as well..." I pointed out that our imaginations are flawed. Perhaps a better word would have been 'limited'.

You're having difficulty, because it is totally outside your realm of experience. The universe is not obliged to make sense to you.

Well, for one, I'm not the poster who you are quoting in brackets. :P

I'm not having difficulty. I favour one over the other at present because neither makes a tremendous difference to the model and I prefer finite and unbound. I also never said the universe was oblidged to do anything for me.

I think the statement of imagination being flawed is erroneous. Limited is even worse. I apply the word imagination the moment we consider anything that isn't present, particularly the future.

Is imagination rooted in past experience? Not entirely. Is it able to produce something "unreal". Definitely. But so can mathematics. Dragons versus 11-dimensions. Ooh. 11-dimensional space dragons. I have to go write that down. /hug
 
  • #169
can you imagine something that is entirely unrelated to something that you have once experienced? It's like trying to imagine another color.
 
  • #170
SHISHKABOB said:
can you imagine something that is entirely unrelated to something that you have once experienced? It's like trying to imagine another color.
No. You must have experienced the ingredients going into images before you can form an image. The re-configuration of these ingredients is where creativity comes into play.
 
  • #171
I think say we are limited by a combination of our sensory experiences and our own cognition and consciousness, which is the essentially same for all animals just at varying levels of awareness and intelligence.

My arguing point would be this, we can imagine things inside our experience; like seeing in 8vision like a spider, but then try to imagine what it would be like to fly by echo location like a bat without relating it to little images on a screen and a sweeping light...

What I guess I am saying is that we can imagine any random configuration of events - as long as they are descriptive in a way that confirms with our sensory understanding and/or our cognition and consciousness. Sight, touch, smell, sound, taste, thoughts and emotions are the things we understand, we cannot imagine anything that is not one of those without using an analogy.

I think this applies to when we think about anything prior to the Universe, or prior to the original cause, even if its turtles all the way down...
 
  • #172
Cosmo Novice said:
I think say we are limited by a combination of our sensory experiences and our own cognition and consciousness, which is the essentially same for all animals just at varying levels of awareness and intelligence.

My arguing point would be this, we can imagine things inside our experience; like seeing in 8vision like a spider, but then try to imagine what it would be like to fly by echo location like a bat without relating it to little images on a screen and a sweeping light...

What I guess I am saying is that we can imagine any random configuration of events - as long as they are descriptive in a way that confirms with our sensory understanding and/or our cognition and consciousness. Sight, touch, smell, sound, taste, thoughts and emotions are the things we understand, we cannot imagine anything that is not one of those without using an analogy.

I think this applies to when we think about anything prior to the Universe, or prior to the original cause, even if its turtles all the way down...

I'd argue that science is no better position than imagination regardless of how either are compiled.

Infinity is, itself, a millenia old imagined concept.
 
  • #173
salvestrom said:
Well, for one, I'm not the poster who you are quoting in brackets. :P

Apologies.
salvestrom said:
I think the statement of imagination being flawed is erroneous. Limited is even worse. I apply the word imagination the moment we consider anything that isn't present, particularly the future.
Please, don't take my statement out of context. You're responses sound as if you think I said we don't have an imagination.

I am simply saying that not being able to imagine something (such as an infinite universe) is a terrible reason for doubting its existence.
 
  • #174
DaveC426913 said:
I am simply saying that not being able to imagine something (such as an infinite universe) is a terrible reason for doubting its existence.

Totally. <3

I wasn't taking it that you had suggested we don't have one - that'd be just plain weird - only taking exception to what seemed like a sidelining, or put down. But I think we are on the same page now. =D
 
  • #175
DaveC426913 said:
Apologies.
I am simply saying that not being able to imagine something (such as an infinite universe) is a terrible reason for doubting its existence.



Dave, I say that things are difficult to imagine, but I never intended to be understood that I doubt its existence. For me the two are separate. I just can't imagine anything infinite.

Actually the biggest reason I have for suspecting the Universe is spatially finite is that it is temporally finite. Again no proof just a hunch.
 
  • #176
Tanelorn said:
Dave, I say that things are difficult to imagine, but I never intended to be understood that I doubt its existence. For me the two are separate. I just can't imagine anything infinite.

Actually the biggest reason I have for suspecting the Universe is spatially finite is that it is temporally finite. Again no proof just a hunch.
Good hunch I believe. As I recall Einstein the finite unbounded universe is fundamental to relativity.
 
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  • #177
When I try to visualize what a finite Universe would look like I see something like this except 10^30 times the size of our observable universe.
The vast voids between clusters of galaxies are somewhat represented as well as a spatial void beyond.
I think many cosmoligists also visualize a finite Universe as one in which the large spatial dimensions curve back around on themselves


http://www.wikinfo.org/upload/0/0a/Crab.nebula.arp.750pix.jpg
 
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  • #178
salvestrom said:
I'd argue that science is no better position than imagination regardless of how either are compiled.

Infinity is, itself, a millenia old imagined concept.
Humbling. Certainly science, particularly cosmology, is an aid to our imagination, as well as our earthly endeavors. That is we can use it to test our ideas. Some philosophers, maybe what they call relativists, argue that the universe exists only in our perception of it. So the more telescopes or other space probes we build the larger the universe becomes.
 
  • #179
OK I would like to remove all instances of imagine from my posts on this thread and instead use terms like visualize.
I agree that infinity cannot be visualized - except by a mind of infinite size taking an infinite time! Other good words are thought experiment, postulate, speculate, premise, conjecture etc.
Terms like imagination are not very acceptable even if you are using a little!
 
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  • #180
Tanelorn said:
OK I would like to remove all instances of imagine from my posts on this thread and instead use terms like visualize.
I agree that infinity cannot be visualized - ecept by a mind of infinite size taking an infinite time! Other good words are thought experiment, postulate, speculate, premise, conjecture etc.
Terms like imagination are not very acceptable even if you are using a little!
There's a strange story about this. Imaginative mathematicians actually deal with infinities as at http://en.wikipedia.org/wiki/Hilbert's_paradox_of_the_Grand_Hotel. Now actually there's a gentleman named Hilbert who owned a huge mansion bought by the Lucas Oil Stadium family. Complete with a replicated IU gymnasium. It was on the market for years until Lucas picked it up for a song - about $3.5 million.
 

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