Middle of the universe

[BJC]

Sorry for the misunderstanding. I did not intend my "tub of soap bubbles" as a model. I only vaguely remember something like that on an episode of THC's "The Universe". I suppose for someone to explain how the entire universe is supposed to be expanding at an accelerating rate, because the observable universe is doing that, is quite beyond my understanding.

The term "expanding" is as misleading, a better term would be "stretching" - but both terms must be used in the context of General Relativity. In GR space-time is defined as the structure (or geometry) of the gravitational field and the geometry is determined by the energy, mass, pressure etc.

 

When close to a gravitating body or energy source the gravitational field shrinks - or space-time shrinks. When far removed from a gravitating body the negative pressure of dark energy (or vacuum energy, or cosmological constant) causes the gravitational field to stretch - or space-time expands. (n.b.:. negative pressure is simply pressure acting in the opposite direction to gravity)

 

Isotropy of the universe implies no preferred location, no center. No center implies no edge. No edge implies space is infinite. (or topologically joined). The universe is assumed to be infinite in space, finite in time.

 

Obviously, "expanding space" makes little physical sense in an infinite space. However, stretching simply means the "tick marks" become further apart - the proper distance is increasing.

 

--- rats --- this makes no sense. Just look at the FLWR metric, pretty simple.

[Airbrush]

It is all based on the, reasonable, assumption that the universe is pretty much the same everywhere. That assumption is quite reasonable, but it is indeed an assumption.

 

Until I hear a convincing explanation that how the observable universe looks tells us how the entire universe behaves, I will wonder.

 

Flat Earth is the assumption that since this area looks faily flat, the world is flat.

[DrRocket]

Until I hear a convincing explanation that how the observable universe looks tells us how the entire universe behaves, I will wonder.

 

Flat Earth is the assumption that since this area looks faily flat, the world is flat.

 

There is nothing wrong with wondering. Wondering is the starting point for good research.

 

Just don't confuse wondering with the more rigorous process of theorizing on the basis of real observation and real mathematics.

 

The cosmological principle could be wrong. But since the observable universe is immense and expansion seems to be accelerating, any counter evidence will have to come from a profound revision in fundamental physics, since otherwise anything beyond the observable universe will forever be causally disconnected from us and our theories cannot address it. There are attempts to develop theories that could do just that, but I am personally skeptical that they will ever reach the necessary level of completion an rigor. I could be wrong too.

[between3and26characterslon]

You lack understanding of the burden of proof. You have made an unqualified assertion. The burden of proof is on you.

 

Just to be picky, isn't one of the tenets of science that you can not prove anything, you can only fail to disprove it. So it's not for anyone to prove a theory but rather to provide a thorough arguement supported with testable evidence so that others can try to disprove it.

 

My own inaginations have led me to wonder if the Universe is more like a rainbow rather than a tub of soap bubbles. The rainbow analogy seems to work on all levels, and passes the time musing over it, but it is just a musing and not a developed theory.

[Airbrush]

The universe is assumed to be infinite in space, finite in time.

 

Since the universe is assumed finite in time, about 13.7 Billion years old, then it was caused by some undeterminable conditions that resulted in a Big Bang. Since those conditions pre-existed the universe, would it be correct to say that is proof for something older than the universe? If the universe popped out of nothing, that "nothing" had some kind of profound potential energy which is older than 13.7 BY.

Edited June 14, 2011 by Airbrush

[MigL]

When most people talk of an expanding universe they imagine the whole and think of the edges moving apart. They should instead consider the expansion as the constituents of the universe moving apart from each other. Whether it is infinite or finite is not important, the galaxies are still moving apart, so it is expanding.

 

But to get back to a previous point, My understanding of Airbrush's 'coconut shell model ' may have been incorrect, but I still think simple connectivity is essential to a model of the universe. I assumed the 'coconut shell model' had a hole in the middle. A torus certainly does and is not simply connected. Other than the loop test failiure, a torus, or any other manifold which is not simply connected, also has preferred directions. In effect movement along the 'orbit' of the donut id different from radial movement. Now of course I cannot provide rigorous proof ( I'll leave the heavy lifting to DrR who has an understanding of differential geometry ). Now, I may be wrong, but preferred directions imply a violation of longitudinal symmetry, which would then imply a violation of the momentum conservation law. This would then mean quantum theory as well as Newtonian laws of motion ( and gravity ) become obsolete ( not sue abour GR ).

 

I don't think we're ready to, or can, take that step.

[michel123456]

When most people talk of an expanding universe they imagine the whole and think of the edges moving apart. They should instead consider the expansion as the constituents of the universe moving apart from each other. Whether it is infinite or finite is not important, the galaxies are still moving apart, so it is expanding.

 

But to get back to a previous point, My understanding of Airbrush's 'coconut shell model ' may have been incorrect, but I still think simple connectivity is essential to a model of the universe. I assumed the 'coconut shell model' had a hole in the middle. A torus certainly does and is not simply connected. Other than the loop test failiure, a torus, or any other manifold which is not simply connected, also has preferred directions. In effect movement along the 'orbit' of the donut id different from radial movement. Now of course I cannot provide rigorous proof ( I'll leave the heavy lifting to DrR who has an understanding of differential geometry ). Now, I may be wrong, but preferred directions imply a violation of longitudinal symmetry, which would then imply a violation of the momentum conservation law. This would then mean quantum theory as well as Newtonian laws of motion ( and gravity ) become obsolete ( not sue abour GR ).

 

I don't think we're ready to, or can, take that step.

 

IIRC there are indications of a prefered direction (see Dark Flow) that do not seem to violate QT or Newton's Laws of Motion.

[csmyth3025]

Since the universe is assumed finite in time, about 13.7 Billion years old, then it was caused by some undeterminable conditions that resulted in a Big Bang. Since those conditions pre-existed the universe, would it be correct to say that is proof for something older than the universe? If the universe popped out of nothing, that "nothing" had some kind of profound potential energy which is older than 13.7 BY.

There actually is a hypothesis that the universe did, indeed, "pop out of nothing":

 

The idea that the Universe may have appeared out of nothing at all, and contains zero energy overall, was developed by Edward Tryon, of the City University in New York, who suggested in the 1970s, that it might have appeared out of nothing as a so-called vacuum fluctuation, allowed by quantum theory. Quantum uncertainty allows the temporary creation of bubbles of energy, or pairs of particles (such as electron-positron pairs) out of nothing, provided that they disappear in a short time. The less energy is involved, the longer the bubble can exist. Curiously, the energy in a gravitational field is negative, while the energy locked up in matter is positive. If the Universe is exactly flat , then as Tryon pointed out the two numbers cancel out, and the overall energy of the Universe is precisely zero. In that case, the quantum rules allow it to last forever.

(ref. http://www.lifesci.s...ibbin/cosmo.htm )

 

I'm not sure how this works if there is truly "nothing" - that is, are there quantum fluctuations when there is "nothing" (no universe or "singularity" or anything at all)?

 

Chris

[MigL]

Sorry I was in a rush when I wrote the previous post.

 

What I meant to say was that since motion along the bigger circumference of a torus or donut is different from motion along the smaller circumference, then translational symmetry invariance is violated and so is the law of conservation of momentum ( there is also a difference in curvature which may mean a different gravitational constant in different directions as well as posiibly differing vacuum energy states in said directions ).

For that matter, if you draw triangles on the inside curve of a torus the added angles will be less than 180Deg while on the outer curve the triangles added angles will be greater than 180Deg. since curvature is positive on the outside and negative on the inside, saddle shaped, curve. This means rotational symmetry invariance is also violated and the basis for conservation of angular momentum is invalidated. The only one of the 'simple' symmetries that is conserved is time symmetry invariance so conservation of energy would still be valid.

 

Base on this and, assuming my logic is correct ( I'm no expert on differential geometry ), I don't see a torus as a valid model for our universe.

[DrRocket]

Just to be picky, isn't one of the tenets of science that you can not prove anything, you can only fail to disprove it. So it's not for anyone to prove a theory but rather to provide a thorough arguement supported with testable evidence so that others can try to disprove it.

 

"Burden of proof" is a common expression meant to imply which party has the onus. Science is based on evidence, as you describe, not proof. You are correct, that a theory can be falsified, in fact by a single valid empirical observation, or equivalently by disagreement with a body of theory that has been substantiated by empirical data, within its known domain of validity (in essence what is contradicted is the empirical data that supports the theory).

 

That said, the burden to provide evidence lies with anyone advocating a radically new theory. That includes the requirement to clearly and quantitavely define what that theory is. This tends to weed out the wackos and avoid wasting large blocks of time.

 

My own inaginations have led me to wonder if the Universe is more like a rainbow rather than a tub of soap bubbles. The rainbow analogy seems to work on all levels, and passes the time musing over it, but it is just a musing and not a developed theory.

 

What in the world is this supposed to mean ?

 

See previous paragraph.

 

Since the universe is assumed finite in time, about 13.7 Billion years old, then it was caused by some undeterminable conditions that resulted in a Big Bang. Since those conditions pre-existed the universe, would it be correct to say that is proof for something older than the universe? If the universe popped out of nothing, that "nothing" had some kind of profound potential energy which is older than 13.7 BY.

 

The "finiteness in time" that you describe is not really an assumption. It results from an analysis, by Steven Hawking (link to original papers in my post in Cosmo Basics) based on general relativity. The much quoted, and misunderstood singularity of the big bang is a failure to be able to extend timelike geodesics indefinitely into the past. One result is the finite age of the universe.

 

This could be wrong: the hypotheses in Hawking's analysis could be violated, or general relativity could break down in unexpected ways as quantum effects become important. But as it stands there is no meaning to "before" the big bang and no meaning to any causitive factor for the big bang.

[J.C.MacSwell]

"Burden of proof" is a common expression meant to imply which party has the onus. Science is based on evidence, as you describe, not proof. You are correct, that a theory can be falsified, in fact by a single valid empirical observation, or equivalently by disagreement with a body of theory that has been substantiated by empirical data, within its known domain of validity (in essence what is contradicted is the empirical data that supports the theory).

 

That said, the burden to provide evidence lies with anyone advocating a radically new theory. That includes the requirement to clearly and quantitavely define what that theory is. This tends to weed out the wackos and avoid wasting large blocks of time.

 

 

What in the world is this supposed to mean ?

 

See previous paragraph.

 

I think it means he has a burden that he knows he cannot prove.

Edited June 15, 2011 by J.C.MacSwell

[DrRocket]

When most people talk of an expanding universe they imagine the whole and think of the edges moving apart. They should instead consider the expansion as the constituents of the universe moving apart from each other. Whether it is infinite or finite is not important, the galaxies are still moving apart, so it is expanding.

 

But to get back to a previous point, My understanding of Airbrush's 'coconut shell model ' may have been incorrect, but I still think simple connectivity is essential to a model of the universe. I assumed the 'coconut shell model' had a hole in the middle. A torus certainly does and is not simply connected. Other than the loop test failiure, a torus, or any other manifold which is not simply connected, also has preferred directions. In effect movement along the 'orbit' of the donut id different from radial movement. Now of course I cannot provide rigorous proof ( I'll leave the heavy lifting to DrR who has an understanding of differential geometry ). Now, I may be wrong, but preferred directions imply a violation of longitudinal symmetry, which would then imply a violation of the momentum conservation law. This would then mean quantum theory as well as Newtonian laws of motion ( and gravity ) become obsolete ( not sue abour GR ).

 

I don't think we're ready to, or can, take that step.

 

I have no idea why you think that curvature of spacetime, as with your torus, would necessitate a violation of conservation of momentum.

 

A torus is not necessarily curved. There is such a thing as a flat torus, and it is seriously being considered as a cosmological model.

 

Take a rectangle. Identify two edges together. That is a cylinder and it is flat, just as flat as the rectangle.

 

Now identify the two ends of the cylinder together. That is a flat 2-torus. You cannot embed it in 3-space. If you identify the ends "with a twist" you get the Klein bottle.

 

You can get a flat 3-torus by starting with a cube and playing a similar game.

[Airbrush]

The "finiteness in time" that you describe is not really an assumption. It results from an analysis, by Steven Hawking (link to original papers in my post in Cosmo Basics) based on general relativity. The much quoted, and misunderstood singularity of the big bang is a failure to be able to extend timelike geodesics indefinitely into the past. One result is the finite age of the universe.

 

This could be wrong: the hypotheses in Hawking's analysis could be violated, or general relativity could break down in unexpected ways as quantum effects become important. But as it stands there is no meaning to "before" the big bang and no meaning to any causitive factor for the big bang.

 

I like your scientific precision in terms. Certainly the finiteness of time is calculated, not merely "assumed".

 

There may be no mathematical or scientific meaning to "before the big bang", nor for any causitive factors for it, but common sense tells us there had to be something before the big bang, or the big bang could not happen. That something may well be what we call "nothing" but nothing is not as simple as the word implies, i.e. the absence of everything.

 

The following is very interesting. "Vacuum fluctuation" or "Quantum fluctuation". Is it true that quantum rules allow the universe to last forever?

 

"The idea that the Universe may have appeared out of nothing at all, and contains zero energy overall, was developed by Edward Tryon, of the City University in New York, who suggested in the 1970s, that it might have appeared out of nothing as a so-called vacuum fluctuation, allowed by quantum theory. Quantum uncertainty allows the temporary creation of bubbles of energy, or pairs of particles (such as electron-positron pairs) out of nothing, provided that they disappear in a short time. The less energy is involved, the longer the bubble can exist. Curiously, the energy in a gravitational field is negative, while the energy locked up in matter is positive. If the Universe is exactly flat , then as Tryon pointed out the two numbers cancel out, and the overall energy of the Universe is precisely zero. In that case, the quantum rules allow it to last forever."

 

I'm not sure how this works if there is truly "nothing" - that is, are there quantum fluctuations when there is "nothing" (no universe or "singularity" or anything at all)?

 

Chris

 

I think you mean: "How long does it take for a quantum fluctuation to create a universe?" With eternity to work on that, eventually a quantum fluctuation CAN create a universe, but that is a lot of quantum fluctuations over unimaginably long periods of time, before the big bang.

Edited June 15, 2011 by Airbrush

[DrRocket]

I like your scientific precision in terms. Certainly the finiteness of time is calculated, not merely "assumed".

 

There may be no mathematical or scientific meaning to "before the big bang", nor for any causitive factors for it, but common sense tells us there had to be something before the big bang, or the big bang could not happen. That something may well be what we call "nothing" but nothing is not as simple as the word implies, i.e. the absence of everything.

 

The following is very interesting. "Vacuum fluctuation" or "Quantum fluctuation". Is it true that quantum rules allow the universe to last forever?

 

"The idea that the Universe may have appeared out of nothing at all, and contains zero energy overall, was developed by Edward Tryon, of the City University in New York, who suggested in the 1970s, that it might have appeared out of nothing as a so-called vacuum fluctuation, allowed by quantum theory. Quantum uncertainty allows the temporary creation of bubbles of energy, or pairs of particles (such as electron-positron pairs) out of nothing, provided that they disappear in a short time. The less energy is involved, the longer the bubble can exist. Curiously, the energy in a gravitational field is negative, while the energy locked up in matter is positive. If the Universe is exactly flat , then as Tryon pointed out the two numbers cancel out, and the overall energy of the Universe is precisely zero. In that case, the quantum rules allow it to last forever."

 

Common sense is not a good guide. When black holes were first predicted, "common sense" told many people, including Einstein, that they were not physical. Unfortunately there is no substitute for solid theories, backed by empirical evidence, and rigorous deductions from those theories.

 

Nobody knows what the net energy content of the universe is, or if the concept is actually meaningful since there is no universal time in general relativity.

 

The best available theory for cosmology is general relativity (GR), which is a theory of gravity. The other foundations of modern physics, the quantum field theories that comprise the Standard Model of particle physics specifically exclude gravity. GR is a completely deterministic theory. Quantum theories are stochastic. The two are not compatible. GR probably breaks down when quantum effects are important, and the singular nature of spacetime that is predicted in connection with the big bang may not be (I suspect is not) physical.

 

There is a lot of speculation, even informed speculation, put forth in cosmology. but no one really knows what happened prior to about 10^-33 seconds. . Perhaps if and when there is a successful melding of GR and quantum theory more will be understood.

 

Beware of popularizations. They are interesting and entertaining, but not definitive and sometimes inaccurate.

[between3and26characterslon]

 

What in the world is this supposed to mean ?

 

 

 

What I mean is, in my limited experience, the answers to science or something analogous to an answer is quite often staring us in the face. I'm sure people used to wonder at rainbows and when Newton used a prism to make his own rainbow and prove light was made of many colours people would have realised that the knowledge that light was made of many colours was staring them in the face all along i.e. rainbows.

 

So now take a body of rainfall 1km³ and shine some Sun at it. You will see a rainbow and so will I but we will not see the same rainbow. If you were to define the ends of the rainbow as a and b in relation to yourself c then mine would be defined as a', b' and c'. So the rainbow exists everwhere within this haze of rain but you can not be certain where exactly it is (or at least we can not agree where it is), and it is only there when you look at it (observe it). This is analogous to the quantum world (more precisely is a good analogy to my limitted knowledge and understnding of the quantum world) and it is relative to every observer which is a good analogy to the macro world.

 

If the Universe is granular, which is a developing theory (and I guess that could mean either descrete untits of spacetime or a continuum which is mixed up at a quantum level), it makes the rainbow analogy even more appealing.

 

You could then think that ou universe is a 'rainbow' in a haze of a much bigger Universe. We all think we see the same Universe because it's soo big but if we could instantly travel millions of lightyears we might be able to see parts of the Universe we can't see from here. Every observer sees a different Universe. So the analogy works from the micro to the macro Universe (for me anyway).

 

But like I said it is not a theory, I have no thorough arguement or real evidence, so really it's more of a musing.

[MigL]

Sure DrR, I understand your point, but there has been a lot of talk about a donut shaped universe and that's what I have a problem with. But using your same example of the rectangle rolled over into a tube and identifying the two ends together, would motion along the 'tube' length ( ie from one end to the other ) be the same as motion along the circumference of the tube ( Its very hard to describe directions on a donut shape, sorry if I'm not very clear )?

I can easily 'see' that motion in any direction on a spherical surface ( and by extension on a 3-sphere ) is equivalent with no preferred direction. Even rotation of a given angle is equivalent.

But I cannot 'see' the same for a donut shape, or a flat torus. That is why I say ( rather believe ) that there is preferential direction and inequivalent rotations, implying violation of momentum and angular momentum conservation laws.

[granpa]

the idea of a torus universe is simple.

its just a cube and as you leave one face you reappear on the opposite face.

 

its best not to think of it as embedded in any higher dimensional space.

[MigL]

Yeah, I see what you mean. A flat torus preserves angles and distances. That was my mistake , thinking it had to curve to join one end to the other, which is , in effect, embedding it in higher dimensional space. All it means is one end continues into the other end. So I guess my attempt at using conservation laws to determine the shape of the universe fails.

 

However I still believe that a simply connected space makes more sense, and wasn't it Poincaire 's conjecture which Pearleman won the Field's prize for proving ( and refused the million dollars ) that a 3-sphere is the only simply connected finite ( compact ) manifold ?

 

But as to size, ie finite but unbounded or infinite, let's try a variation of my previous argument. If the universe is infinite, does that imply an infinite amount of energy. And, if so, does the law of energy conservation make sense ?

The law basically tries to 'balance the books', but any finite amount taken from infinity still leaves an infinite amount. It would seem that only afinite amount of energy allows the conservation law to work, implying a finite but unboundes universe. Or am I again missing something ?

[Dekan]

A "Conservation of Energy" Law, if true, implies the Universe only has a limited amount of energy - which has to be "conserved".

 

However, is there really such a Law? Who says there is one? We humans do - because we observe things locally on Earth which seem to support it. But looking outside the Earth, we see galaxies flying apart at an accelerating rate. This puzzles us, because we can't account for where the energy comes from, to make them accelerate.

 

So we invent concepts like "Dark Energy". Which is a kind of 21st Century equivalent of the 18th Century "Caloric Fluid", or "Phlogiston".

 

Why can't there just be an endless supply of energy, which doesn't have to be conserved?

Edited June 20, 2011 by Dekan

[csmyth3025]

 

...So we invent concepts like "Dark Energy". Which is a kind of 21st Century equivalent of the 18th Century "Caloric Fluid", or "Phlogiston".

 

Why can't there just be an endless supply of energy, which doesn't have to be conserved?

 

In general dark energy is a catch-all term for any hypothesised field with negative pressure, usually with a density that changes as the universe expands.

(ref. http://en.wikipedia....Repulsive_force )

 

Dark energy is just a shorthand way of saying "We don't know what it is, but it's causing the expansion of the universe to accelerate".

 

Since we don't know what dark energy is, we also don't know if there's an endless supply of it or not.

 

Chris

[owl]

I've only read through page three, but here are my two cents so far:

 

DrRocket:

Remember that the big bang was not an explosion in space but an explosion of space.

 

Remember? Says who? Define “space.” What is exploding?... and still expanding? How is space different from empty volume?

 

csmyth3025:

In the ill-used ballon analogy people have a hard time understanding that the 2-D balloon surface represents the 3-D universe in which we live.

 

Me too.

 

The 2-D surface of a balloon is imbedded in a 3-D world (the one in which we live).

 

A curved surface (of a balloon) occupies 3-D space.

 

The space manifold in which we live isn't imbedded in any sort of higher dimension as far as we know. It may have positive curvature (like a sphere), negative curvature (like a saddle) or just be flat (like a sheet of paper laying on a desk). As DrR points out, this manifold we live in is the whole enchilada. There are no outside dimensions (that we know about) and there is nothing outside of it.

 

All this assumes that space is something that has the property of shape.

 

DrRocket:

1) in the case of positive curvature itis a 3-sphere 2) in the case of zero curvature it is Euclidean 3-space and 3) in the case of negative curvature it is hyperbolic 3-space. If the assumption of isotropy is relaxed then other possibilities,

 

If we allow, just for a thought-experiment-moment, that space is just empty volume (contrary to all of the above,) then “it” has no shape, even though all the cosmic stuff *in space* is distributed in various possible ways.

Then, without any assumptions about intrinsic vs extrinsic curvature, and without the leap into non-Euclidean geometry/cosmology, we can speak of #2 above as good ol’ Euclidean 3-D space with no “shape." How all cosmic “stuff” (in space) is distributed is another *matter.*

 

insane_alien:

...an inability to imagine a lack of an outside does not mean that there must be an outside.

 

We have been here before in the “Is the universe infinite?” thread.

If space is not a thing but rather just empty volume, then beyond all the “stuff”, seen and beyond, is... more empty space... no “wall” or boundary... which simply begs the question, ... and what beyond that? If “nothing” that means more empty space... whether or not there is any “stuff” out there.

[csmyth3025]

...If we allow, just for a thought-experiment-moment, that space is just empty volume (contrary to all of the above,) then "it" has no shape, even though all the cosmic stuff *in space* is distributed in various possible ways.

Then, without any assumptions about intrinsic vs extrinsic curvature, and without the leap into non-Euclidean geometry/cosmology, we can speak of #2 above as good ol' Euclidean 3-D space with no "shape." How all cosmic "stuff" (in space) is distributed is another *matter*.

 

We have been here before in the "Is the universe infinite?" thread.

If space is not a thing but rather just empty volume, then beyond all the "stuff", seen and beyond, is... more empty space... no "wall" or boundary... which simply begs the question, ... and what beyond that? If "nothing" that means more empty space... whether or not there is any "stuff" out there.

The prolem, of course, is that we have nasty old gravity to deal with. If there is enough of it, it might just force all the stuff in the universe (including photons) to follow giant geodesics that will eventually lead it back to where it started (if the universe is closed).

 

The "shape" of empty space is dictated by the fields that are contained in it. These fields tell all the stuff in the universe how to move. We don't know yet whether all that stuff will go flying off farther and farther forever or whether it will eventually come back around "full circle". As I understand it, our observations so far are leaning more towards the former rather than the latter.

 

Chris

[owl]

A lot of the dialogue in this thread has already been covered in my old thread, "Another Far Out Cosmology" in the Speculations section, pg 3. So, rather than repeating a lot of what I have already said, I hope it is OK to quote from selected relevant posts there.

But I will start with csmyth's reply to me in this thread:

csmyth3025:

The problem, of course, is that we have nasty old gravity to deal with. If there is enough of it, it might just force all the stuff in the universe (including photons) to follow giant geodesics that will eventually lead it back to where it started (if the universe is closed).

 

The "shape" of empty space is dictated by the fields that are contained in it. These fields tell all the stuff in the universe how to move. We don't know yet whether all that stuff will go flying off farther and farther forever or whether it will eventually come back around "full circle". As I understand it,our observations so far are leaning more towards the former rather than the latter.

 

True, we don't know, but more matter is being discovered all the time, not even counting whatever "dark matter" is supposed to be. So the jury is out on whether it is an oscillating, Bang/Crunch cycle or bang to entropy, and it all just finally dissipates.

 

(Again, if the following transcription is out of line, please advise. Just trying to avoid endless repetition.)

 

From "another far out cosmology' (all below);

4/16, my post 19:

One would be a stupid fool to believe the earth to be the center of the universe, as I explained in detail in the cosmology discussion as it was still in the old thread about the end of space. ... I had earth and our visible cosmos deep in the membrane thickness of a way larger scale "balloon" model in that context.

 

... Who says that gravity is not a constant (ed:continual) force ever since the bang or bangs, just diminished in force with more distance (the square of the distance, as I understand it) ad infinitum. There is no waiting while "gravity waves" reach us... For example, the gravitational pull between earth (and other planets) and the sun is steady. No delays waiting for it to reach us just because it travels at light speed, if it does...which seems well established.

 

From 4/18, post 24:

What you never understood about that model was the scale of the whole expanding balloon with a thick skin and buried deep within that skin is the "atom" of our solar system (part of a molecule/ galaxy of "rubber".) (Edited emphasis.)

 

From my post 30:

The inflating balloon model is well worn in cosmology. My version adds some details of scale like a way more vast "balloon" than our little local environment...visibility limit... deep within the membrane. Probably never verifiable or falsifiable... but it's speculative.

and;

I do remain open to reasonable falsification of the balloon model and the present multiple bangs and crunches model...

I'll still be pursuing how batches of merged supermassive black holes beyond our cosmic horizon, scattered all around our visible cosmos, still acts like a big sphere around our smaller sphere (as far as we can see.) (Ed: See Spyman's links and comments on the shell theorem of gravity in that thread.)

 

Here is the address of the The Balloon Analogy In Cosmology I called "well worn" though I disagree with its assumptions* as evident in my presentation. http://www.astro.ucl...t/balloon0.html

 

From post 32:

I see cosmos expanding into space beyond what we can see, though not "empty" where more stuff might exist.

"...beyond the universe" is a silly phrase, since the universe must be all there is, known and unknown. (Edited emphasis.)

I see the Big Bang locus at the center of the balloon in the very large scale model and the multiple bangs and crunches as happening on the smaller scale within the "balloon membrane" as already presented in detail.

Btw, my 'model' is 3-D. A fourth spacial dimension is an abstraction with no referent in the real cosmos, in my opinion.

From post 34:

I understand gravity to be constant (ed: rather continuous, as it does fluctuate with, for instance, depleting sun mass over time or black holes gaining mass)...between all masses, since the "bang" and still (ed: pulling among all masses, and without a distance limit, as per the *universal* law of gravity.)

 

From post 45:

Here is a relevant piece from a Kelley Ross paper I've been studying in depth for the dialogue in the "Is Space Infinite" thread:

Ross quotes Scientific American, "Is Space Finite?" [Jean-Pierre Luminet, Glenn D. Starkman, & Jeffrey R. Weeks, April 1999, pp. 90-97]:

One problem with the conclusion is that the universe could be spherical yet so large that the observable part seems Euclidean, just as a small patch of the earth's surface looks flat [a common idea in "inflationary" theories]. A broader issue, however, is that relativity is a purely local theory [!]. It predicts the curvature of each small volume of space -- its geometry -- based on the matter and energy it contains. Neither relativity nor standard cosmological observations say anything about how those volumes fit together to give the universe its overall shape -- its topology. [p. 92].

 

And finally, from post 47:

And of course if many Bangs happen all over the universe, not from the same epicenter, all bets are off as to overall shape of "all there is."

Edited June 22, 2011 by owl

[pantheory]

...............So the question is, What does it mean when physicists say there is no center of the universe?

 

Thank you for your time,

caharris

(bold added)

 

The basis for saying there is no center of the universe is based on a closed universe model involving Riemann geometry that is the geometry of General Relativity. In this geometry if the universe is totally closed one can travel in a straight line and end up where one started. It is not a forth dimensional geometry but parallel lines accordingly can intersect. For a long time cosmologists asserted that there was no edge nor center to the universe for this reason since they believed in curved space concerning the universe as a whole. This is based upon a curved geometry of space. The most in-depth observations today seem to indicate that the universe is flat. If so on the largest scales, then the universe could have both edges concerning the radial extent of matter and a central area geometrically which some physicists today consider.

Edited July 5, 2011 by pantheory

[dapifo]

If we consider the Global Universe as the total Universe. (infinite or finite). and we consider Our Universe like that Universe that we know (from 10 exp -35 to 10 exp +27 meters), I propose the idea that we can divide the Global Universe in various (infinite) power of 10 levels or spectra (see attached file). Like a RAINBOW or MATRYOSHKA DOLLS.

 

deletia

Edited June 13, 2012 by swansont