[Falleen Prince Xizor]

For years it had been accepted mostly that the unvierse was a flat static plane of infinite size. Which was still expnading...somehow.
Thanks to Quantum Mehanics and relativity, the structure of the universe has come under more scrutiny that ever.

The curvature of space time, as provided for by Special Relativity has laid weight to the claims that the universe in spherical, finite , and expnading like a balloon.

This theory opens many questions... such as:

Where on the bubble are we? Inside it? on the Surface?

we don't know, the finite nature of the universe would also mean something would have to exist outside our universe

From this, the multiverse, or "beer keg" theory came into being. This see's many, if not an infinite number of universes floating in the 11th dimension, much like bubbles in the beer keg.

This has provided an explanation for the big bang. two bubbles collided, and exploded, creating a new bubble: our universe.

This has ominous connotations, what if our bubble hits another one?

"Dark Energy" appears to be the key to any new universe hypothesis, dark energy being a seeming anti-gravity emanating from star-nurseries, which is accelerating the universe's expansion.

It's sourse, and actual structure remain a mystery.

An explanation is provided by the "Brane Theory".

That our universe is a flexible sheet of space time, a brane (membrane), which is curved, like a saddle, by einsteins relativity.

These "saddles" are stacked on top of each other, and they affect each other. Explaining particle interference and dark energy.(gravity from other dimensions/universes/branes)

There are many other theories, the String theory and Supersymmetry being among them, explanation of the above welcomed!

what do you believe?


FPX

[Comrade Ogilvy]

That is amazing but I wonder what is outside of the so called beer keg!

[Classical Liberal]

The curvature of space time, as provided for by Special Relativity has laid weight to the claims that the universe in spherical, finite , and expnading like a balloon.

By looking at background radiation, scientists mostly belive it is flat and infinite, or so I belive. The spherical universe creates problems because of the weird singularities at the "poles."

we don't know, the finite nature of the universe would also mean something would have to exist outside our universe

Assuming the universe is finite both in in a cocnept of space and time. Some theories support the idea of a pre-big bang universe.

From this, the multiverse, or "beer keg" theory came into being. This see's many, if not an infinite number of universes floating in the 11th dimension, much like bubbles in the beer keg.

This has provided an explanation for the big bang. two bubbles collided, and exploded, creating a new bubble: our universe.

This has ominous connotations, what if our bubble hits another one?

This reminds me of ekpyrotic theory (colliding branes).

[Falleen Prince Xizor]

That is amazing but I wonder what is outside of the so called beer keg!

The 11th dimension is a mystery, it is believed that the bubbles/unvierses bear many similarites, some almost perfect replicas

The romantic notion is that there are a million elvises who still live, and a million who never made it, and a million of you, as professionalt elvis impersonators, all in different universes.

It is believed that the laws of physics break down, basically an open singularity, and if you enter it, you cease to exist.

I agree, it is amazing!

By looking at background radiation, scientists mostly belive it is flat and infinite, or so I belive. The spherical universe creates problems because of the weird singularities at the "poles."

Not necessarily, all the background radiation proves is that the universe is the same in all directions, adding weigh to a spherical hypothesis, plus, a perfect sphere doesn't poles.

Assuming the universe is finite both in in a cocnept of space and time. Some theories support the idea of a pre-big bang universe.

It's easier to say the laws of physics didn;t exist in the pre big bang singularity. the pre big bang universe, if anything, would have been other bubbles.

[Classical Liberal]

Not necessarily, all the background radiation proves is that the universe is the same in all directions, adding weigh to a spherical hypothesis, plus, a perfect sphere doesn't poles.

They looked at it and determined the universe is not positively or negatively curved. It is "flat."

It's easier to say the laws of physics didn;t exist in the pre big bang singularity. the pre big bang universe, if anything, would have been other bubbles.

It is mostly a mystery, it is belived the universe had weak forces and was dark, then it began to heat up and the forces became stronger and it reached a point, the big bang, and is moving back in the direction of being cold.

[SueDeNîmes.]

Dark energy, 11 dimension multiverse, colliding branes ..I'm afraid I don't like any of it - not that I have a clue whether or not any of it's true. None of it explains observation - instead it explains why other theory doesn't fit observation. None of it is falsifiable.

I liked our universe better 10 years ago when it promised to be self-explanatory, before it slipped into part of something unknowable and ineffable.

[Classical Liberal]

None of it explains observation

They attempt to explain known facts. If they could not, they would be discarded.

None of it is falsifiable.

Science advances by falsification, mostly.

[enLight]

Well, before we go around deciding which theory is right or wrong, we have to keep in mind that they are just theories and ussually cannot be proven at this point in time. In fact, any of them could easily be reversed, discarded or replaced tomorrow.

However, with that in mind, the notion of the universe being spherical makes sense. A bang begins it in the center and then everything else expands outward - being blown in that direction.

With the universe beinging finite - which seems to be the case, noting the birth/death cycle that everything in the universe is subject to - that would mean some force or entity would have to have created the universe. This obviously points us in a logical argument for the existence of a creator God outside of our universe.

The real question is: What is outside of the so-called bubble? Are we the only universe. After all, just because there is an "ouside" doesn't mean there has to be other universes on the outside.

The truth of the matter is this: We, as humans, can only observe things through the filter of the natural laws of our universe. In fact, we can only comprehend things through these laws.

Thus, I think it is quite foolish to make speculations as to what is outside of the universe because it is very probable that we will never be able to observe it or understand it. The "outside" exists beyond our methods of comprehension.

[Classical Liberal]

Well, before we go around deciding which theory is right or wrong, we have to keep in mind that they are just theories and ussually cannot be proven at this point in time. In fact, any of them could easily be reversed, discarded or replaced tomorrow.

Theories are (well-tested) hypotheses that explain observed phenomena. They are discarded if something along the way contradicts them. It's not really about how to prove a theory because if someone had observed only one thing, and the theory explains it, then it is "proven."

However, with that in mind, the notion of the universe being spherical makes sense. A bang begins it in the centre and then everything else expands outward - being blown in that direction.

This is a misconception. The big bang did not start at some central point, it would have happened at all points in space. Technically, the big bang happened everywhere.

With the universe beinging finite - which seems to be the case, noting the birth/death cycle that everything in the universe is subject to - that would mean some force or entity would have to have created the universe. This obviously points us in a logical argument for the existence of a creator God outside of our universe.

Your assumption of the universe being finite for the above reasons is flawed. You are philosophizing, but this is a science forum, and we would need scientific evidence and theories for your claim to be more respected. However, I think what you said here would be more than welcome in the Agora.

The universe is currently thought to cover an infinite amount of space.

I googled in a phrase, and I immediately found something cool, although kind of kiddy, that fixes the misconception you have (had) about the big bang.

http://www.astro.ucla.edu/~wright/infpoint.html

The real question is: What is outside of the so-called bubble? Are we the only universe. After all, just because there is an "ouside" doesn't mean there has to be other universes on the outside.

That would depend on what theory or theories you thought could accurately explain the universe.

The truth of the matter is this: We, as humans, can only observe things through the filter of the natural laws of our universe. In fact, we can only comprehend things through these laws.

Yes...

Thus, I think it is quite foolish to make speculations as to what is outside of the universe because it is very probable that we will never be able to observe it or understand it. The "outside" exists beyond our methods of comprehension.

Well, this isn't a place for speculation. This is for science.

[enLight]

Your assumption of the universe being finite for the above reasons is flawed.

Well, first off, my claim is not just something I pulled out of my ass. The simplest argument for a finite universe (that is, one following the birth/death cycle) is found in the Second Law of Thermodynamics - also known as the Law of Increased Entropy. Entropy, if you are unfamiliar with the term, is defined as a measure of unusable energy within a closed or isolated system (the universe for example). As usable energy decreases and unusable energy increases, "entropy" increases. Entropy is also a gauge of randomness or chaos within a closed system. As usable energy is irretrievably lost, disorganization, randomness and chaos increase.

The implications of the Second Law of Thermodynamics are considerable. The universe is constantly losing usable energy and never gaining. We logically conclude the universe is not eternal. The universe had a finite beginning -- the moment at which it was at "zero entropy" (its most ordered possible state). Like a wind-up clock, the universe is winding down, as if at one point it was fully wound up and has been winding down ever since.

However, that is just a simple deduction. More specific evidence hints at a "Hall of Mirriors" theory.

http://www.newscientist.com/news/news.jsp?id=ns99994250

To sum up the important parts...

Scientists have announced tantalising hints that the Universe is actually relatively small, with a hall-of-mirrors illusion tricking us into thinking that space stretches on forever.

...

At the centre of the debate are observations by NASA's Wilkinson Microwave Anisotropy Probe (WMAP), which was launched in 2001. The probe measures temperature ripples in the "cosmic microwave background", the afterglow radiation from the big bang fireball.

Astronomers are interested in how strong different sizes of ripples are, as this reveals vital information about the early Universe, and might tell us how big the Universe is today. Many astronomers suspect that the Universe is infinite.

In that case, the microwave background ripples should have an unlimited range of sizes. But while WMAP's observations of small-scale ripples have matched predictions for an infinite Universe almost perfectly, the large-scale measurements have not. On the largest scales, WMAP has shown that the ripples almost disappear.

...

Computer simulations that model the birth of the microwave background create this pattern once every few hundred runs. But it could mean that space itself is not big enough to support the broadest ripples...

"Just as the vibrations of a bell cannot be larger than the bell itself, any fluctuations in space cannot be larger than space itself," [Jeffrey Weeks] says.

Weeks and his colleagues, a team of astrophysicists in France, say the WMAP results suggest that the Universe is not only small, but that space wraps back on itself in a bizarre way (Nature, vol 425, p 593).

Despite being finite, the Universe would not have any kind of edge. If a spacecraft blasted off in what we'd perceive to be a straight line - the line a beam of light would follow - it would eventually end up back where it started.

Because of this odd wraparound effect, the light from one galaxy could follow two different routes to the Earth, so the same galaxy would appear in two different parts of the sky. Effectively, the Universe would be like a hall of mirrors, with the wraparound effect producing multiple images of everything inside.

...

According to Weeks, the WMAP results point to a very specific illusion - that our Universe seems like an endlessly repeating set of dodecahedrons, football-like shapes with a surface of 12 identical pentagons. If you exit the football through one pentagon, you re-enter the same region through the opposite face and you keep meeting the same galaxies over and over again (see graphic, bottom).

Weeks says the match between the predictions of his repeating-football model and the WMAP observations is striking: "I was just blown away, the results are far better than I could have imagined."

If confirmed, they would indeed be stunning. They would mean that the Universe is relatively small, something like 70 billion light years across. What's more, we could in theory see the entire cosmos and check that there are no hidden corners where the laws of physics are different.

Other sites related to this topic are here:

http://luth2.obspm.fr/Compress/oct03_lum.en.html

http://www.space.com/scienceastronomy/universe_soccer_031008.html


I could probably find some more stuff suggesting a finite universe, but I don't have the time right now. If I find more sites in the near future, I will post it here.

[Classical Liberal]

Now I will consider this. You were vague on your reasons for believing the universe is finite, and you seemed to be speculating in your earlier post.

[Falleen Prince Xizor]

I have no doubt we reside i a finite universe.

I also categorically reject that tehre was any-sort of preconcieved power at work in willfully creating this finite universe.

I just don't like the idea of the big bang.

It still is, however, the only real plausible ecplanation.

I don;'t like it purely because of teh... requirement.. of a trigger..

That said, hawking's "no Boundary" principle doen't make sense, so it is the only real action.

I like the idea of living in a giant, unstable beer keg.

Are you all familiar with interference?

[Classical Liberal]

That said, hawking's "no Boundary" principle doen't make sense, so it is the only real action.

What about the No-Boundary Proposal?

Are you all familiar with interference?

What kind of interference?

[Falleen Prince Xizor]

As an alternative to the big bang, hawking proposed a universe like a ballon attached to a pump, getting bigger and smaller, but without ever reaching a singularity.

Particle interference?

the photon experiment.

[STA]

Are there any books on this?

Damn, high school, wont teach us this in grade 9.

[Looter]

Entropy is q rev/ T. The expanding Universe is an optical Illusion. The Big Bang is repackaged Creationism. The Universe is finite, goes in circles, and ends at Black Holes.

[democrat-hippie]

this is a really amazing topic, and it is one topic that the human brain can almost not comprehend.....

[Hamilcar]

The curvature of the universe is almost certainly exactly zero. Observational evidence (in particular from the CMB) for this is strong.

The big question right now is whether the universe is about to enter another era of inflation, as the vacuum energy takes over and the scale factor begins to follow an exponential.

Are there any books on this?

There are plenty of popular science books on these issues. I particularly recommend Brian Greene (who also did a great PBS series) and the (now somewhat outdated) "Black Holes and Time Warps" by Kip Thorne.


If anyone has any questions about cosmology, ask away. I'm about top graduate with a degree in maths and physics (focusing on astrophysics) and will start my D.phil in astrophysics this fall. If I can't answer your questions well enough, I will try and point you to literary references.

[Comrade Ogilvy]

For years it had been accepted mostly that the unvierse was a flat static plane of infinite size. Which was still expnading...somehow.
Thanks to Quantum Mehanics and relativity, the structure of the universe has come under more scrutiny that ever.

The curvature of space time, as provided for by Special Relativity has laid weight to the claims that the universe in spherical, finite , and expnading like a balloon.

This theory opens many questions... such as:

Where on the bubble are we? Inside it? on the Surface?

we don't know, the finite nature of the universe would also mean something would have to exist outside our universe

From this, the multiverse, or "beer keg" theory came into being. This see's many, if not an infinite number of universes floating in the 11th dimension, much like bubbles in the beer keg.

I think first of all that the perception of the "curvature of space time, as provided for by Special Relativity has laid weight to the claims that the universe in spherical, finite , and expnading like a balloon." is false at its roots just because of the mere fact that the "curvature" perception is only peculiar to humans looking at space (universe) through telescope while the earth is rotating constantly, thus I think it might have been an unconcious accident that whoever thought of the curvature of space time, regardless of them being scientists or not, made a mistake most likely out of trying to go ahead of themselves without trying to maintain a firm foundation of facts and variables, thus I think it is just a matter of lack of remembering the bigger picture that is proven as a basis to make theories such as about "the curvature of space time".

And Special Relativity is a theory that stems from the Relativity theory of Albert Einstein, correct me if I am wrong, and I have read on this theory and it is simply based on mere reasoning rather than logic and integrating reason with logic, which is important to reach any definite basis for anything.

Please respond to my post with intellect rather than emotion.
Thank you.

[Hamilcar]

Some points:

Special relativity does not deal with curvature.
General relativity does - in GR, curvature *is* gravity.

The curvature of spacetime can be thought about in various ways. The easiest way to visualize it is to consider two-dimensional beings living on a three-dimensional surface.
Imagine that this surface isn't flat, but curved. Then the beings moving around on this surface would be subject to forces as they move over the curved parts that they cannot explain easily. They cannot "see" the three-dimensional curvature of their world.

Similarly, our spacetime is four-dimensional and it is curved near massive objects. We experience this curvature as the force of gravity.

One could say that in both cases, the world is curved in a "higher dimension" (for the 2D beings, in the 3rd dimension), but that doesn't mean that the world is actually *in* such a higher dimension. The curvature is an intrinsic property of the surface. Using the higher dimension is merely a crutch to illustrate curvature.

And Special Relativity is a theory that stems from the Relativity theory of Albert Einstein, correct me if I am wrong, and I have read on this theory and it is simply based on mere reasoning rather than logic and integrating reason with logic, which is important to reach any definite basis for anything.

Both SR and GR are based on a set of simple postulates that are not at all obvious. Einstein made some thought experiments and transcribed the consequences into mathematics - first SR then GR.