Is the universe bounded or unbounded?

[otseng]

In the Light, stars, and creationism thread, I proposed a theory to reconcile a young earth with being able to see stars that are billions of light years away. The theory assumes that the Big Bang is true, however, it also assumes that the universe is bounded. In typical cosmology, it is assumed that the universe is unbounded.

Bounded means that the universe has a boundary to it. There exists an "edge" to the universe in which beyond this boundary, our universe does not exist.

In an unbounded universe, there is no "edge". The universe "wraps" around itself. So, if you are to go in any direction in a straight line, you will eventually come back to the starting point.

This is hard to conceptualize, but can be explained like a surface of a sphere. On the surface of a sphere, if you start at any point and then go in a straight line, you will eventually come back to the starting point. Now, instead a 2-D surface on a sphere, the universe is a 3-D topology that curves in on itself.

The ramifications of either of these two assumptions make for drastically different cosmological conclusions.

So, the questions are:
1. Is the universe bounded or unbounded? Why?
2. What are the ramifications of whether it is bounded or unbounded?

[Cathar1950]

I guess we don't Know?
What if the universe and everything in it is shrinking except space.from our perspective it looks like it is expanding. Of course if the expansion is accelerating as recent data suggests it is just shrinking faster
We are getting smaller.(sang as jimmy has a girl friend.)
I bet when they get the universe mapped out it will look like a big dna strand a double helix. If it doesn't happen in my life time all bets are off.
Interesting isn't it? I mean the universe. I want to time travel.
I remember this episode of the Simpson where Homer made a time machine out of his toaster and he kept killing bugs and and sneezed and kept changing things. After many atempts at fixing things he finally got to what he thought was right and ever one had lizard tounges. He said "close enough" because they had donuts.

[Ian Parker]

I guess we don't Know?
What if the universe and everything in it is shrinking except space.from our perspective it looks like it is expanding.

You cannot tell the difference Science is logical Positivist in that regard. However there is no theoretical mechanism through wich this could happen. It is as if you ignored the theory of gravity and said that Tyhco Brahe's theory of the planets going round the Sun and the Sun going round the Earth was equivalent to Copernicus.

[quoteI bet when they get the universe mapped out it will look like a big dna strand a double helix. If it doesn't happen in my life time all bets are off.[/quote]

Are you alluding to some versions of String Theory where one Universe can impart a flavor and beget another Universe?

Interesting isn't it? I mean the universe. I want to time travel.
I remember this episode of the Simpson where Homer made a time machine out of his toaster and he kept killing bugs and and sneezed and kept changing things. After many atempts at fixing things he finally got to what he thought was right and ever one had lizard tounges. He said "close enough" because they had donuts.

You cannot kill your Grandmother, so you cannot travel in a time machine and have complete freedom of action. Particles may be able to travel back governed by Feynmann diagrams. In as discussion on FTL in sci.relativity I wrote.

I have read this and I would like to link up tachyons with some of the basic principles of Particle Physics. I don't think this FAQ has done this completely. If we take for example a Proton. It consists of 3 quarks and a mass of interactions. The three quarks by the way are all of them more massive than the Proton! Interactions between elementary particles are governed by the Feynmann diagram which is basically a list of all the interactions that can occur.

Tachyons, if they exist, are governed by Feynmann diagrams. A Feynmann diagram guarantees the CONSISTENCY PRINCIPLE. Feynmann diagram will never allow you to kill your grandmother. Because of FDs tachyons can never exist in any sort of free state any more than quarks can. Each quark as I have said is more massive than a Proton and so a free quark will immediately create other particles.

A Tachyon will have an infinite world line and will create a timeline. As with most of physics the tachyon will go into its lowest energy state. This means, in effect, that a timeline is established in which communication between past and future is difficult.

What does this mean. Is Randi's $million safe? Yes it is. If there are no tachyons then no one can detect the future. If there are it will be detected very sporadically when chaos threatens to move us from an established timeline. Remember tachyons will be in some kind of thermodynamic equilibrium. People will have insights from time to time but no one can have $1e6 consistency. It rather looks as if the Police should look to their own officers and not employ psychics.

Look for FTL keyword in Google Groups to get the exact context of these remarks and get a presentation of the Theory of Relativity.

In the same vein Jack Scarfetti wrote.

The father of one of the Ohio marines killed in Iraq woke up with a
start 5:45 AM knowing something happened to his son several hours before
Marine Corps informed him of his son's death. On PBS News this AM on my
drive to SLAC. Secretary of DOE here at 10AM.

I agree with Henry Stapp that conscious mind is not classical mechanical
or classical electromagnetism. However, it cannot be ordinary quantum
theory either because of signal locality, i.e., you cannot clone a
photon for example. This means you cannot use nonlocal quantum
entanglements as a direct C^3 channel. You need an auxillary classical
signal as in quantum cryptography and teleportation as examples. Brian
and Penrose have suggested different ways to extend quantum theory. The
key is "signal nonlocality", which is necessary not only for telepathy,
for psychokinessis, for battle-tested (literally) CIA remote-viewing,
but also for our own ordinary consciousness as evidenced by Dick
Bierman's replication of Radin's "presponse" data in the live human
brain. Antony Valentini has clarified this issue.

Macro-quantum theory ODLRO spontaneous symmetry breakdown in open
systems pumped out of Valentini's "sub-quantal heat death" describe all
living matter. Signal nonlocality happens there because

1. Born probability interpretation breaks down for the phase-rigid
LOCAL macro-quantum order parameter.

2. The projective ray postulate | > ---> z|z> is violated (arbitrary
normalization)

3. The Landau-Ginzburg equation replaces the Schrodinger equation. The
former is local, nonlinear and more importantly NON-UNITARY.

i.e. arbitrary normalization is not possible. |<x|Order Parameter>|^2
has an absolute scale ~ macroscopic eigenvalue i.e. MEAN number of
bosons occupying the same single-boson state.

On Aug 4, 2005, at 7:24 AM, caryn anscomb wrote:

Dear Brian et al,

Brian Josephson ‘Pathological Disbelief’:
This is CSICOP representative Randi in full swing:
“There is no firm evidence for the existence of
telepathy, ESP or whatever we wish to call it, and I
think it is the refuge of scoundrels in many aspects for
them to turn to something like quantum physics, which
uses a totally different language from the regular
English that we are accustomed to using from day to
day, to merely say, oh that's where the answer lies,
because that's all very fuzzy anyway'. No it's not very
fuzzy, and I think that his opinion will be differed with
by the scientific body in general ...”
One wonders ... can Randi seriously be suggesting that
explanations based on quantum mechanics are, on that
account alone, automatically inadmissible?....................

CSICON: Committee for Surrealist Investigation of Claims of the Normal.
http://www.rawilson.com/csicon .shtml
“Patapsychology begins from Murphy's Law, as Finnegan called the First
Axiom, adopted from Sean Murphy. This says, and I quote,” The normal
does not exist. The average does not exist. We know only a very large
but probably finite phalanx of discrete space-time events encountered
and endured." In less technical language, the Board of the College of
Patapsychology offers one million Irish punds [around $700,000 American]
to any "normalist" who can exhibit "a normal sunset, an average
Beethoven sonata, an ordinary Playmate of the Month, or any thing or
event in space-time that qualifies as normal, average or ordinary."
I assume the Amazing Randi has yet to take up the challenge
Caryn.

Brian Josephson <b...@cam.ac.uk> wrote:

--On Thursday, August 4, 2005 12:28 am +0100 Colin Bennett
wrote:

> Like everyone else in the world, I recognise your own achievements,
> but if you don’t mind me saying so, like others of your stature, you
> have a somewhat innocent Victorian view of innocent science ? you see
> it as a respectable gentleman of the 19th century would see it, that
> is something which is the best for the best in the best of all
> possible worlds

Hmmm! Sounds like you've not come across my Pathological Disbelief
lecture at

=b=

* * * * * * * Prof. Brian D. Josephson :::::::: b...@cam.ac.uk
* Mind-Matter * Cavendish Lab., Madingley Rd, Cambridge CB3 0HE, U.K.
* Unification * voice: +44(0)1223 337260 fax: +44(0)1223 337356
* Project * WWW: http://www.tcm.phy.cam.ac.uk/~ bdj10
* * * * * * *

This is a question which is rather different than the infinity (or otherwise) of the Universe. If we have time travel governed by Feynmann diagrams then such things as Evolution are not going to obey the assumption of pure randomness. Evolution will be on a timeline.

The same thing will be true incidentally of the origin of the Universe and tachyons, predicted by some theories may mean that we have to think again about the need for supersymmetry to stabilise Inflation.

[Cathar1950]

I like fred allen wolf's books but I wonder how much the weirdness of quantum Physics works in the Macro level. It seems things by that level are pretty much determined. I still think time travel is fun.
Maybe it is a given that everything is related and connected and we effect the universe thru observation which is a form of participation.
But so is everything and anything and everyone. Maybe reality is just an averaging out.
If I went back in time and killed my grandmother so that I prevented my birth then I couldn't go back and prevent my birth so I would still be born.
I just think it has to happen first befor we could go back. and forward would just be speeding up the processes until we arived.

[Curious]

There's something called Oblers' Paradox, which asks the question: if the universe is infinite, why are there not an infinite number of stars visible in the night sky? In fact why is there even night? An infinite number of stars would take up every single spot of space in every direction and glow as brigthly as daylight.

Really, where do they dig up these theories? Such a statement is absurd. If I was to say that in the universe there were an infinite number of hands would this mean that each hand had an infinite number of fingers ? Of course not, similarly, there is no reason to assume that given an infinite amount of space there would be any necessity for each volume of space to have more than a few stars present within it (or for any particular volume to contain any at all). If there was infinite space there is nothing to say that an infinite number of stars must be close to each other.
Regarding the light from an infinite number of stars being as bright as daylight, this also is ridiculous and really shows that the formulation of such an absurd theory was based on very little common sense.

To make it easier to understand let us assume space as 2 dimensional for this example and that the point O is the centre of a series of concentric circles and the stars could be plotted on the different circumferences and assume point O to be a line parallel to the light emitting surface.

Star A1 is distance d from point O.
Point O receives L amount of light from star A1.
Star A2 is distance 2d from point O.
Point O receives L/2 light from star A2.
Star A3 is distance 4d from point O.
Point O receives L/4 light from star A3.

Ok, lets assume I do this an infinite number of times. The light from this infinite number of stars reaching point O would still be less than 2L.

Complicating this is the fact that light does not travel infinitely fast, so when we look up at the stars, we are actually seeing them as they existed in the past. What this means is that in a finite, unbounded universe, if we looked hard enough, we would be able to see the point in space that we now occupy as it existed billions and billions of years ago (or a figure equal to that of the warp of space).

But this also means that a finite, unbounded universe violates Oblers' paradox. Not only would we be seeing the light from our neighbor stars, we would be able to see the light from the distant past with equal magnitude, and the light that wrapped around the universe could theoretically create a feedback loop that would burn up the sky like a Bude light.

If not for the fact that light from farther galaxies is dispersed throughout a greater area (imagine shining a torch at a wall and moving it forwards and backwards). Such diminishment would mean that, as above, the light might only approach 2L but never actually equal or exceed it. Of course, an infinite number of stars in a finite universe would cause another greater problem unless successive generations of stars were similarly diminished in size so that the mass might never exceed, for example 2M.(Obviously this is ludicrous as stars require sufficient mass to exist as stars)

[Ian Parker]

I like fred allen wolf's books but I wonder how much the weirdness of quantum Physics works in the Macro level. It seems things by that level are pretty much determined. I still think time travel is fun.
Maybe it is a given that everything is related and connected and we effect the universe thru observation which is a form of participation.
But so is everything and anything and everyone. Maybe reality is just an averaging out.
If I went back in time and killed my grandmother so that I prevented my birth then I couldn't go back and prevent my birth so I would still be born.
I just think it has to happen first befor we could go back. and forward would just be speeding up the processes until we arived.

This is in fact where Feynman diagrams come in. This introduces consistency. The macroscopic world does indeed observe micro events. There is indeed an averaging which is why if your son is killed in Iraq you might feel something, but you can't produce anything for James Randi.

Another area which might be looked at is the relationship between tachyons and the initial expansion of the Universe.

As far as Olbers paradox is concerned, this is resolved by the Universe expanding. The infinite Universe is infinitely red shifted.

[Alien]

As far as Olbers paradox is concerned, this is resolved by the Universe expanding. The infinite Universe is infinitely red shifted.

Not only. The red shift is never infinite (I mean its frequency is never zero). Look at the foxile radiation of the Big Bang: it has still a temperature slightly higher than zero Kelvin and therefore a frequency different from zero.

I think an easier explanation is that there is a limit beyond which no photon has already reached us.

This is because the travelled distance of the photon is still lower than the distance created by the recession of the galaxy in the total time of the universe.

Everything beyond this limit is therefore black.

[Curious]

As far as Olbers paradox is concerned, this is resolved by the Universe expanding. The infinite Universe is infinitely red shifted.

Not only. The red shift is never infinite (I mean its frequency is never zero). Look at the foxile radiation of the Big Bang: it has still a temperature slightly higher than zero Kelvin and therefore a frequency different from zero.

I think an easier explanation is that there is a limit beyond which no photon has already reached us.

This is because the travelled distance of the photon is still lower than the distance created by the recession of the galaxy in the total time of the universe.

Everything beyond this limit is therefore black.

I think Ian Parker means an infinite shifting towards zero which itself cannot become zero because this would end the shift. There is a problem though of how an infinite universe could expand beyond its own boundary as an expansion would mean that there was previously a finite universe which was able to expand. For an infinite redshift to exist it would be necessary for the universe to exist forever more and/or to have already existed forever. In this way the shift could shift infinitely towards zero frequency (or infinite wavelength).

[Ian Parker]

I think Ian Parker means an infinite shifting towards zero which itself cannot become zero because this would end the shift. There is a problem though of how an infinite universe could expand beyond its own boundary as an expansion would mean that there was previously a finite universe which was able to expand. For an infinite redshift to exist it would be necessary for the universe to exist forever more and/or to have already existed forever. In this way the shift could shift infinitely towards zero frequency (or infinite wavelength).

In my first posting I quoted the Cosmological Principle which said that no matter how far we travelled the Universe would always look the same. This means that the Universe is unbounded, this is not quite the same thing as infinite as the Universe could be a hypersphere of finite dimension. We are the distant Universe! Both models are consistent with General Relativity.

The temperature of the Universe,at the moment, is 2.7K. This represent the recombination of ionised gas. About 300,000 AUC (Ab Universum Condita). Inflationary models propose recession speeds faster than that of light. As I think I mentioned gravitational waves can penetrate ionised gas, so LISA (when launched) will see down to 10-1000 AUC.

[harvey1]

The temperature of the Universe,at the moment, is 2.7K.

Since WMAP measured it at 2.725K does this mean the universe is running a bit of a fever?

[Curious]

In my first posting I quoted the Cosmological Principle which said that no matter how far we travelled the Universe would always look the same. This means that the Universe is unbounded, this is not quite the same thing as infinite as the Universe could be a hypersphere of finite dimension. We are the distant Universe! Both models are consistent with General Relativity.

I see your point. Then we should also consider the possibility of a 3rd choice of a universe that is unbounded but does not wrap around on itself but spreads out forever. This could be described as the infinite universe. The universe that is unbounded but wraps around on itself should be considered finite as countless particles set on a course in all directions from a particular point would eventually arrive back at their point of origin, leaving no area of the universe unexplored.