Infinate universes

[achilles12604]

I am totally helpless in this area so I'm looking for some assistance. What supports or debunks this idea? Is there enough to post this thread in science or should I have placed it in the philosophy arena?

Could there be an infinate regression of universes? What of the entropy of the universe and the laws of thermodynamics? Could anything re-organize heat energy into something usefull without losing even more energy in the process?

[Goat]

I am totally helpless in this area so I'm looking for some assistance. What supports or debunks this idea? Is there enough to post this thread in science or should I have placed it in the philosophy arena?

Could there be an infinate regression of universes? What of the entropy of the universe and the laws of thermodynamics? Could anything re-organize heat energy into something usefull without losing even more energy in the process?

One of the new models that recently came out as a variation of the cyclical model addresses this. Mind you, it currently does not have any evidence FOR it, it is an idea that comes from the observation that the speed at which the universe is expanding is accelerating. It will be a number of years before the satalites that were being constructed that can test some of the key assumptions will be complete (they were
already being made).

This model does away with the 'big bang'. It also does away with the idea that time has a begining (I think).

http://www.physorg.com/news89399974.html

[QED]

Infinite in what sense? There are many senses in which we might talk of infinite universes. Our own observable universe may be infinite in extent while being finite in age. There is no reason to suppose that our universe is the only one to have big-banged into existence either.

Cosmologists have shown how random quantum fluctuations in a pure vacuum (absolute nothingness) would lead to a false vacuum. Such a curved region of space would need only to contain the rest energy of 20 micrograms of matter (a permissible violation of energy conservation courtesy of the Heisenberg uncertainty principle). From here inflation takes over causing an exponential expansion to what we see today (see Victor J. Stenger, "The Universe: The Ultimate Free Lunch," European Journal of Physics 11 (1990): 236-243.).

Furthermore, the "chaotic inflationary process" described fro us by Andre linde gives rise to the constant production of new universes from within the expansion of each "parent" region. No limits are envisaged to this web of spacetime creation which might be visualized as a foam of different bubble universes fractally tiling an infinite map.

[achilles12604]

I am totally helpless in this area so I'm looking for some assistance. What supports or debunks this idea? Is there enough to post this thread in science or should I have placed it in the philosophy arena?

Could there be an infinate regression of universes? What of the entropy of the universe and the laws of thermodynamics? Could anything re-organize heat energy into something usefull without losing even more energy in the process?

One of the new models that recently came out as a variation of the cyclical model addresses this. Mind you, it currently does not have any evidence FOR it, it is an idea that comes from the observation that the speed at which the universe is expanding is accelerating. It will be a number of years before the satalites that were being constructed that can test some of the key assumptions will be complete (they were
already being made).

This model does away with the 'big bang'. It also does away with the idea that time has a begining (I think).

http://www.physorg.com/news89399974.html

Yea I read through this when you posted it on the other thread. I found it very interesting but I couldn't help wondering about certain things.

1) These individuals agree that given current specs, their model would inevitably lead back to a big bang.

The second law says entropy (a measure of disorder) can't be destroyed. But if entropy increases from one oscillation to the next, the universe becomes larger with each cycle. "The universe would grow like a runaway snowball," Frampton said. Each oscillation will also become successively longer. "Extrapolating backwards in time, this implies that the oscillations before our present one were shorter and shorter. This leads inevitably to a Big Bang," he said.

This is their solution to this problem.

Frampton and Baum circumvent the Big Bang by postulating that, at the turnaround, any remaining entropy is in patches too remote for interaction. Having each "causal patch" become a separate universe allows each universe to contract essentially empty of matter and entropy. "The presence of any matter creates insuperable difficulties with contraction," Frampton said. "The idea of coming back empty is the most important ingredient of this new cyclic model."

So let me translate how I understood this.

The universe expands due to forces of dark matter. Once the universe "stretches" out far enough, pockets which are totally void of ANYTHING at all become new universes after they contract.

Questions I would have for these students.

1) If the "casual patches" are totally devoid of anything at all, does this include dark matter? If so, how does dark matter affect their calculations since as they wrote "The presence of ANY matter creates insuperable difficulties with the contradiction". If not, then what causes this new universe to expand?

2) How would the expansion of the new universe be different from a "big bang" starting the expansion of this universe?

3) How would they explain the background radiation found in this universe?

4) Since energy/matter/entropy can not be created or destroyed, once this universe began to expand without any cause since dark matter can not be present and there was no big bang, what would fill this universe of nothingness? It would be totally void of anything at all. It had to be or else their model wouldn't work.


Numbers 1 and 4 are by far the biggest issues with their theory in my mind. For thir idea to work no energy or matter could be present, yet the new universe would expand without any cause and without the big bang, and be full of energy and matter after it existed. This theory has logical holes all over the place.


PS - Also crucial to their theory is thir own calculations about dark matter, which are in direct contradiction with previous calculations.

Also key to Frampton and Baum's model is an assumption about dark energy's equation of state -- the mathematical description of its pressure and density. Frampton and Baum assume dark energy's equation of state is always less than -1. This distinguishes their work from a similar cyclic model proposed in 2002 by physicists Paul Steinhardt and Neil Turok, who assumed the equation of state is never less than -1.

A negative equation of state gives Frampton and Baum a way to stop the universe from blowing itself apart irreversibly, an end physicists call the "Big Rip." The pair found that in their model, the density of dark energy becomes equal to the density of the universe and expansion stops just before the Big Rip.

[Confused]

I like the concept of pocket universes in the landscape. But what QED states is true. Though I think you would be better off starting with Brian Greenes books to get you started. That is what I did. It is actually where I learned what QED stood for.

Susskind introduced the term Landscape in 2003 to denote a mathematical space representing all of the possible environments that theory allows. Each has its own Laws of Physics, it own elementary particles, and its own constants of nature. Not even the 3-D concept of space are sacred. Inflationary cosmology is leading us to the megaverse which has innumerable pocket universes (Alan Guth). Some are microscopically small and some are big but empty. But somewhere in the megaverse, the constants are this number, while in others they are this number, etc....

Theoretical physics has an outgrowth of Eternal Inflation for a megaverse full of pockets that have bubbled up out of inflating space.

Astronomical discoveries provide confirmation that the size and shape of the universe exponentially "inflated" to a size much bigger than the 10-15 billion light years. Add this to the fact that we now know the cosmological constant (extra gravitational repulsion, sort of like antigravity that was believed to be completely absent to the real world) isn't quite zero as was initially thought to be, means that antigravity isn't absent from the world, as was assumed. This further adds weight to a megaverse (mulitverse).

[Confused]

I like the concept of pocket universes in the landscape. But what QED states is true. Though I think you would be better off starting with Brian Greenes books to get you started. That is what I did. It is actually where I learned what QED stood for.

Susskind introduced the term Landscape in 2003 to denote a mathematical space representing all of the possible environments that theory allows. Each has its own Laws of Physics, it own elementary particles, and its own constants of nature. Not even the 3-D concept of space are sacred. Inflationary cosmology is leading us to the megaverse which has innumerable pocket universes (Alan Guth). Some are microscopically small and some are big but empty. But somewhere in the megaverse, the constants are this number, while in others they are this number, etc....

Theoretical physics has an outgrowth of Eternal Inflation for a megaverse full of pockets that have bubbled up out of inflating space.

Astronomical discoveries provide confirmation that the size and shape of the universe exponentially "inflated" to a size much bigger than the 10-15 billion light years. Add this to the fact that we now know the cosmological constant (extra gravitational repulsion, sort of like antigravity that was believed to be completely absent to the real world) isn't quite zero as was initially thought to be, means that antigravity isn't absent from the world, as was assumed. This further adds weight to a megaverse (mulitverse).

[achilles12604]

I like the concept of pocket universes in the landscape. But what QED states is true. Though I think you would be better off starting with Brian Greenes books to get you started. That is what I did. It is actually where I learned what QED stood for.

Susskind introduced the term Landscape in 2003 to denote a mathematical space representing all of the possible environments that theory allows. Each has its own Laws of Physics, it own elementary particles, and its own constants of nature. Not even the 3-D concept of space are sacred. Inflationary cosmology is leading us to the megaverse which has innumerable pocket universes (Alan Guth). Some are microscopically small and some are big but empty. But somewhere in the megaverse, the constants are this number, while in others they are this number, etc....

I understand you are a big proponent of the string theory. However, it is listed as a theory for a reason. The concepts may work in theory, but then again so do multiple other theories.

Theoretical physics has an outgrowth of Eternal Inflation for a megaverse full of pockets that have bubbled up out of inflating space.

Astronomical discoveries provide confirmation that the size and shape of the universe exponentially "inflated" to a size much bigger than the 10-15 billion light years. Add this to the fact that we now know the cosmological constant (extra gravitational repulsion, sort of like antigravity that was believed to be completely absent to the real world) isn't quite zero as was initially thought to be, means that antigravity isn't absent from the world, as was assumed. This further adds weight to a megaverse (mulitverse).

This section includes a good example of what I inferred above. You mention extra gravitational repulsion.

Well having had almost no experience with this term I tried to look it up. I could not find much on it at all and what I did listed it as a theoretical component of a theoretical model of the origin of the universe.

You state this component was discovered not to be zero and it isn't absent from the world. Ok- where was this discovery made and by whom? Where can I get more information concerning this theory? What experiments were conducted to determine its plausibility?

I'm not denying it (yet). I am simply asking for a source which lists some proponents of this idea, and their writings and most importantly their experiments. Because as you have pointed out to me, without experiments to back things up, it can all be lumped into the same "special pleading" basket to which God has been assigned.

Here is a brief list of some of the "problems" with the string theory. Included is the aforementioned lack of testing (it is not falsifyable), troubles with regards to temporal matter, and others.

However since I am far from an expert in this arena, I will simply let the experts battle out their opinions and go with what has been tested and proven and extrapolate from there.

Problems and controversy

String theory remains to be confirmed. No version of string theory has yet made an experimentally verified prediction that differs from those made by other theories. In this sense, string theory is still in a "larval stage": it is not a proper physical theory. It possesses many features of mathematical interest and may yet become important in our understanding of the universe, but it requires further developments before it is accepted or discarded. Since string theory may not be tested in the foreseeable future, some scientists[7] have asked if it even deserves to be called a scientific theory; it is not falsifiable in the sense of Popper.

For example, while supersymmetry is now seen as a vital ingredient of string theory, supersymmetric models with no obvious connection to string theory are also studied. Therefore, if supersymmetry were detected at the Large Hadron Collider it would not be seen as a direct confirmation of the theory. More importantly, if supersymmetry were not detected, there are vacua in string theory in which supersymmetry would only be seen at much higher energies, so its absence would not falsify string theory. By contrast, if observing the Sun during a solar eclipse had not shown that the Sun's gravity deflected light by the predicted amount, Einstein's general relativity theory would have been proven wrong.

On a more mathematical level, another problem is that, like many quantum field theories, much of string theory is still only formulated perturbatively (i.e., as a series of approximations rather than as an exact solution). Although nonperturbative techniques have progressed considerably – including conjectured complete definitions in space-times satisfying certain asymptotics – a full non-perturbative definition of the theory is still lacking.

Philosophically, string theory cannot be truly fundamental in its present formulation because it is background-dependent: each string theory is built on a fixed spacetime background. Since a dynamic spacetime is the central tenet of general relativity, the hope is that M-theory will turn out to be background-independent, giving as solutions the many different versions of string theories, but no one yet knows how such a fundamental theory can be constructed. A related problem is that the best understood backgrounds of string theory preserve much of the supersymmetry of the underlying theory, and thus are time-invariant: string theory cannot yet deal well with time-dependent, cosmological backgrounds.

Another problem is that the vacuum structure of the theory, called the string theory landscape, is not well understood. As string theory is presently understood, it appears to contain a large number of distinct vacua, perhaps 10500 or more. Each of these corresponds to a different universe, with a different collection of particles and forces. What principle, if any, can be used to select among these vacua is an open issue. While there are no known continuous parameters in the theory, there is a very large discretuum (coined in contradistinction to continuum) of possible universes, which may be radically different from each other. Some physicists believe this is a benefit of the theory, as it may allow a natural anthropic explanation of the observed values of physical constants, in particular the small value of the cosmological constant. However, such explanations are not usually regarded as scientific in the Popperian sense.

The strongest scientific argument in favor of string theory is that it appears to contain a theory of gravity embedded within it and thus may provide a solution to the thorny problem of reconciling Einstein's general relativity with quantum mechanics and the rest of particle physics. There are, however, two fundamental problems, which are hard to get around.

First, string theory predicts that the world has 10 space-time dimensions, in serious disagreement with all the evidence of one's senses. Matching string theory with reality requires that one postulate six unobserved spatial dimensions of very small size wrapped up in one way or another. All the predictions of the theory depend on how you do this, but there are an infinite number of possible choices, and no one has any idea how to determine which is correct.

The second concern is that even the part of string theory that is understood is internally inconsistent. This aspect of the theory relies on a series expansion, an infinite number of terms that one is supposed to sum together to get a result. Whereas each of the terms in the series is probably finite, their sum is almost certainly infinite. String theorists actually consider this inconsistency to be a virtue, because otherwise they would have an infinite number of consistent theories of gravity on their hands (one for each way of wrapping up six dimensions), with no principle for choosing among them.

[Confused]

Ok. Go beyond string theory to multiverse theory for landscapes. M theory makes no dimensions per se. It instead focuses on the Landscape.

I am trying to find a site online that can put your questions into laymens terms. Like I said, Brian Greene and Leonard Susskind are 2 authors with excellent laymen terms books out. But they are books.

Sites:

http://pancake.uchicago.edu/~carroll/encyc/


http://super.colorado.edu/~michaele/Lambda/phys.html

http://super.colorado.edu/~michaele/Lambda/why.html

http://dhushara.freehosting.net/book/up ... 1/cos4.htm

Hopefully these can clarify it better. I can't think of any other way to explain it. But the cosmological constant represents the extra gravitational repulsion, a kind of antigravity that would instantly destroy the universe if it was not astonishingly small. It essential counters the effect of graviational attraction.

http://relativity.livingreviews.org/ope ... ode21.html

And once again, it isn't so much the old model string theory.

But keep in mind, we are into theoretical/cosmological/quantum mechanics physics now, not the standard model physics.

[achilles12604]

Ok. Go beyond string theory to multiverse theory for landscapes. M theory makes no dimensions per se. It instead focuses on the Landscape.

I am trying to find a site online that can put your questions into laymens terms. Like I said, Brian Greene and Leonard Susskind are 2 authors with excellent laymen terms books out. But they are books.

Sites:

http://pancake.uchicago.edu/~carroll/encyc/


http://super.colorado.edu/~michaele/Lambda/phys.html

http://super.colorado.edu/~michaele/Lambda/why.html

http://dhushara.freehosting.net/book/up ... 1/cos4.htm

Hopefully these can clarify it better. I can't think of any other way to explain it. But the cosmological constant represents the extra gravitational repulsion, a kind of antigravity that would instantly destroy the universe if it was not astonishingly small. It essential counters the effect of graviational attraction.

http://relativity.livingreviews.org/ope ... ode21.html

And once again, it isn't so much the old model string theory.

But keep in mind, we are into theoretical/cosmological/quantum mechanics physics now, not the standard model physics.

Ok I think I am able to wrap my mind around the cosmological constant however the cause for this constant and the resulting physical reprocussions of it are still unclear. Perhaps I can think of it in terms of a gravitational force and its relation to masses.

I also am unclear how it relates to string theory, but I will read further when my eyes are not about to fall out of my skull.

[Confused]

Ok. Go beyond string theory to multiverse theory for landscapes. M theory makes no dimensions per se. It instead focuses on the Landscape.

I am trying to find a site online that can put your questions into laymens terms. Like I said, Brian Greene and Leonard Susskind are 2 authors with excellent laymen terms books out. But they are books.

Sites:

http://pancake.uchicago.edu/~carroll/encyc/


http://super.colorado.edu/~michaele/Lambda/phys.html

http://super.colorado.edu/~michaele/Lambda/why.html

http://dhushara.freehosting.net/book/up ... 1/cos4.htm

Hopefully these can clarify it better. I can't think of any other way to explain it. But the cosmological constant represents the extra gravitational repulsion, a kind of antigravity that would instantly destroy the universe if it was not astonishingly small. It essential counters the effect of graviational attraction.

http://relativity.livingreviews.org/ope ... ode21.html

And once again, it isn't so much the old model string theory.

But keep in mind, we are into theoretical/cosmological/quantum mechanics physics now, not the standard model physics.

Ok I think I am able to wrap my mind around the cosmological constant however the cause for this constant and the resulting physical reprocussions of it are still unclear. Perhaps I can think of it in terms of a gravitational force and its relation to masses.

I also am unclear how it relates to string theory, but I will read further when my eyes are not about to fall out of my skull.

Not string theory. Megaverse or multiverse theory.