Where is the center of the universe?

[SHISHKABOB]

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?

 

[rglong]

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.

 

[rglong]

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.

 

[rglong]

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.

 

[Tanelorn]

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.

 

[DaveC426913]

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.

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?

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.

And the center of the Earth's surface could be said to have infinite centers

Then none are unique. Thus, they cannot be centre.

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"?

 

[DaveC426913]

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.

 

[Tanelorn]

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.

 

[DaveC426913]

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.

 

[salvestrom]

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.

 

[Chronos]

There is nothing imaginary about the math. Get used to it.

 

[salvestrom]

There is nothing imaginary about the math. Get used to it.

Imaginary numbers? Virtual particles? Besides, imagination and imaginary are not the same thing.

 

[Chronos]

Blue moon and bleu cheese? Blue and bleu are not the same thing. Your point escapes me.

 

[salvestrom]

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.

 

[Tanelorn]

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.

 

[DaveC426913]

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.

 

[Tanelorn]

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.

 

[salvestrom]

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

 

[SHISHKABOB]

can you imagine something that is entirely unrelated to something that you have once experienced? It's like trying to imagine another color.

 

[ynot1]

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.

 

[Cosmo Novice]

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...

 

[salvestrom]

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.

 

[DaveC426913]

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

Apologies.

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.

 

[salvestrom]

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

 

[Tanelorn]

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.

 

[ynot1]

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.

 

[Tanelorn]

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

 

[ynot1]

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.

 

[Tanelorn]

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!

 

[ynot1]

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.

 

[Tanelorn]

Well I thought you or the others were having a dig at me for using the term imagination in a science related discussion.

I don't think I would want to manage a Hilbert's grand hotel, it would mean an infinitely bad headache every time a new guest walks in. Is the Universe actually a Hilbert Hotel? Its giving me a headache :)

 

[ynot1]

Well I thought you or the others were having a dig at me for using the term imagination in a science related discussion.

I don't think I would want to manage a Hilbert's grand hotel, it would mean an infinitely bad headache every time a new guest walks in. Is the Universe actually a Hilbert Hotel? Its giving me a headache :)

I'll admit it would have to have a rather large parking lot. But I don't think the universe is really infinite like a Hilbert hotel. More like finite unbounded. Maybe a regular hotel with no borders around it? <[:>)]

 

[Tanelorn]

Its all good.

This JWST should help answer a few questions and maybe raise a few more.
I discovered this FAQ which shows how well it is expected to perform. Just have to still be around in 5-10 years to see the results:

http://www.jwst.nasa.gov/faq.html#howlong


I wonder if a future successor to the JWST might benefit from being beyond the solar system completely?

 

[ynot1]

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!

Terms like imaginary, as in imaginary numbers, do seem to get into the lexicon.

 

[Drakkith]

I wonder if a future successor to the JWST might benefit from being beyond the solar system completely?

Other than reduced heating by the sun, which is worked around by cooling the telescope, I don't really see any benefit. It would be far more expensive to send it beyond the solar system than to just load it up with coolant. Plus once it's beyond about Mars or Jupiter solar panels are no longer an effective means to provide power, meaning you need an Radioisotope Thermoelectric Generator. Also you would have to increase the size and power requirements of the antennas in order for the signals to be sent and received between Earth and the telescope.

 

[phinds]

So the more telescopes or other space probes we build the larger the universe becomes.

So you think if we build more and bigger and better telescopes, the observable universe will become bigger? Or is it that the entire universe will become bigger? I don't get how our building telescopes has any effect on either.

 

[Drakkith]

So you think if we build more and bigger and better telescopes, the observable universe will become bigger? Or is it that the entire universe will become bigger? I don't get how our building telescopes has any effect on either.

I think he means that in the view of whatever philosophers he was referring to, the more we see the more exists. Not in the sense that the diameter of the observable universe becomes larger, just in that the more we look at the more exists and the more detailed it becomes. But this would raise a million more questions in my mind, so I don't agree with it.

 

[Genx63]

first you say the universe spread out from a single point and then you say that point don't exist. I don't buy the balloon analogy. That would indicate that all matter is spreading out on a 2 dimensional plane. When a star goes supernova does the star all of a sudden not exist? Why is everyone so dead set against a point of origin for the universe? Maybe it's because it would punch too many holes in your theories. I'm no genius I'm not even very smart but even your balloon theory has a center.

 

[minio]

Balloon analogy is called analogy because it is not exact description. For start try to imagine that balloon has 3D surface and its expadnig in 4D space.

 

[Spourk]

first you say the universe spread out from a single point and then you say that point don't exist. I don't buy the balloon analogy. That would indicate that all matter is spreading out on a 2 dimensional plane. When a star goes supernova does the star all of a sudden not exist? Why is everyone so dead set against a point of origin for the universe? Maybe it's because it would punch too many holes in your theories. I'm no genius I'm not even very smart but even your balloon theory has a center.

Do a google search for Hypersphere. You're not quite grasping the balloon analogy the way it's meant to be presented, if you are still trying to say there is a center of the balloon. A hypersphere is a little easier to look at and see how you can actually travel and never reach a center, or an edge, it just keeps looping back on itself in higher dimensions.

Try this thought experiment: If you were 1 dimensional, and lived on the outside of a circumfrence of a circle, where would the center be? As a 1 dimensional being, you can only traverse the line on the outside of the circle, you'd never be able to reach the "Center" because that is in the 2nd dimension. You could go forward, or back, nothing else. Where is the center?

That being said, how well did the "Earth is the center of the universe" theory work out for Cosmology?

(Forgive me if this has all been presented to the OP already)

 

[Drakkith]

first you say the universe spread out from a single point and then you say that point don't exist. I don't buy the balloon analogy. That would indicate that all matter is spreading out on a 2 dimensional plane.

Of course. That's why it's and analogy. Extrapolating the same principles into 3 dimensions instead of two would give us a hypersphere. Currently the standard model doesn't care whether we are on an actual hypershpere or not, it simply says the universe is expanding.

When a star goes supernova does the star all of a sudden not exist?

The material that made up the star still exists. Whether you could call it a star or not is debateable.

Why is everyone so dead set against a point of origin for the universe? Maybe it's because it would punch too many holes in your theories.

You are correct. A point of origin for the universe would be a big glaring hole in our current model of the universe. A model which is the best fit to observations and theoretical work by far. Punching holes in the theory is akin to not believing gravity exists and saying that fairies hold everything together. You would have to make up stuff that isn't even observable in both cases.

I'm no genius I'm not even very smart but even your balloon theory has a center.

It isn't a theory, it's an analogy. A way to visualize and a tool to help people understand the basic concepts. Don't take it for more than it is. Arguing against it is like arguing that students shouldn't start learning physics with blocks sliding on frictionless surfaces because they don't exist. They do that because it's easier to learn the basics that way.

 

[ynot1]

So you think if we build more and bigger and better telescopes, the observable universe will become bigger? Or is it that the entire universe will become bigger? I don't get how our building telescopes has any effect on either.

Yes the observable universe becomes bigger. Point being you can observe more with better telescopes. Why would the universe get bigger, except for expansion?

 

[Drakkith]

Yes the observable universe becomes bigger. Point being you can observe more with better telescopes. Why would the universe get bigger, except for expansion?

The observable universe wouldn't increase in diameter no matter how many telescopes we built or how big we built them. We simply can't see past a certain point because there isn't anything to see.

 

[ynot1]

The observable universe wouldn't increase in diameter no matter how many telescopes we built or how big we built them. We simply can't see past a certain point because there isn't anything to see.

Certainly. I should have said the observed universe. Maybe a distinction without a difference?

 

[ynot1]

would it be that there is no center or that every point is the center? Or is there a difference between those two?

I can define the center of a circle - every point on the circle is equidistant from the center - pick the closest one. I presume such can be said of a sphere except you only have one choice. But there is no point equidistant from every point on the surface of the earth, as well as the universe, ergo the Earth and the universe technically have no center according to my understanding of the definition of center. This assumes the universe has a surface, but that is debatable.

 

[Drakkith]

Certainly. I should have said the observed universe. Maybe a distinction without a difference?

Certainly as we get more telescopes and they get bigger and better we will be able to see dimmer objects or get better resolution, but I wouldn't say the observed universe becomes "bigger". But I'm not one of those philosophers you were talking about either.

 

[ynot1]

Certainly as we get more telescopes and they get bigger and better we will be able to see dimmer objects or get better resolution, but I wouldn't say the observed universe becomes "bigger". But I'm not one of those philosophers you were talking about either.

I meant the telescopes get bigger, not the universe.

 

[phinds]

Yes the observable universe becomes bigger. Point being you can observe more with better telescopes. Why would the universe get bigger, except for expansion?

So, you figure that when folks learned how to sail around the world, and could therefore see more of it, it got bigger?

I think you misunderstand the term "observable universe". It is NOT based on what we CAN see, it is based on what we COULD see, and it is at present 13.72billion light years in radius and if we had the most amazingly wonderful telescopes that could possibly be built, and that could see throughout the electormagnitic spectrum, it would STILL be 13.72 light years in radius.

 

[Fredrik]

So, you figure that when folks learned how to sail around the world, and could therefore see more of it, it got bigger?

I think you misunderstand the term "observable universe". It is NOT based on what we CAN see, it is based on what we COULD see, and it is at present 13.72billion light years in radius and if we had the most amazingly wonderful telescopes that could possibly be built, and that could see throughout the electormagnitic spectrum, it would STILL be 13.72 light years in radius.

That's the number of years that the oldest light has been traveling towards us, but due to the expansion of the universe, the actual radius in significantly larger. I don't remember exactly, but I think it's about 45 billion light-years.

 

[phinds]

That's the number of years that the oldest light has been traveling towards us, but due to the expansion of the universe, the actual radius in significantly larger. I don't remember exactly, but I think it's about 45 billion light-years.

Yes, I agree, and I knew that but got sidetracked by the silliness of the concept of the OU getting bigger because of telescopes so I fixated on the photon age, not the current diameter (which of course IS getting bigger, but not because we have better telescopes)