Universe cyclic model and energy loss

[mtanti]

I'm "aware" of current theories about the cyclic model but what's wrong with this hypothesis?

The universe starts crunching forming a big black hole
All the energy is sucked back into this big black hole
The big bang starts again with all the matter and energy as the previous big bang

Assuming this is possible, there would be no difference in each cycle and would not be getting longer and larger.

Feel free to destroy my argument (nicely)

 

[marcus]

I'm "aware" of current theories about the cyclic model but what's wrong with this hypothesis?

The universe starts crunching forming a big black hole
All the energy is sucked back into this big black hole
The big bang starts again with all the matter and energy as the previous big bang

Assuming this is possible, there would be no difference in each cycle and would not be getting longer and larger.

Feel free to destroy my argument (nicely)

I think you want some criticism of this crunch --> bang (also called "bounce") scenario. You say "what's wrong with this hypothesis?" and
"feel free to destroy...(nicely)"

Hopefully you will get some feedback of the kind you want. Personally I think you are right to call it an HYPOTHESIS----that is, something that needs testing. A scheme or model which we don't know if it is right and has to be developed to where it makes observable predictions.

Basically I think it is a good hypothesis. So I'm not one of those people who will criticize it for you.

It is currently the leading concept in Quantum Cosmology (research area devoted to understanding the big bang using quantized versions of general relativity rather than the classical version). Leading in the sense of more scholarly research publication and more citations than the alternatives (such Steinhardt's cyclic, or ekpyrotic, or clashing branes hypothesis).

If you do a keyword literature search, ranked by citations, like this
http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=DK+quantum+cosmology+and+date+%3E+2005&FORMAT=WWW&SEQUENCE=citecount%28d%29
what comes up is mostly bounce approach papers, investigating the crunch-->bang idea you are asking about
that is, sticking with recent papers (since 2005) and ranking by how often the papers have been cited in other research, to get a rough idea of relative importance

Some of the authors involved with this are Ashtekar, Bojowald, Param Singh, Corichi, Vandersloot,...there are about twenty names I think of, won't list them all.

You mentioned energy loss, in your title. It don't think that is a problem. These people run computer models of lots of different cases and the bounce result is pretty robust. It tends to happen in whatever case. Quantizing the theory of gravity leads to quantum correction terms that these people have found make gravity repellent at very high density. There is no dissiption of energy. The problem is finding some obscure observable effect of the bounce which one could use to TEST the idea----which, for example, would prove that it didn't happen if you didn't see the effect. Some feature of the Cosmic Microwave Background perhaps. that is the kicker. A theory that you can't test remains half-baked.

Somebody named Zygmunt Lalak in Warsaw Poland just posted a paper with an idea for testing. Param Singh has presented some ideas. there's hope, but it's tough.

the same would apply to any ideas you might have about a bounce cosmology scenario. there has to be something that makes it testable
==================

the Steinhardt cyclic, or ekpyrotic scenario had gotten quite a bit of publicity and a lot of people have heard about it--for whatever that's worth. There is not as much current professional research about it and it seems even farther from being testable---but that could change

nobody can say what the quantum cosmology research picture is going to look like even two years out (in my humble view)

 

[Chronos]

I second marcus's position. No definitive test for a bouncing model yet exists. It remains speculative until then.

 

[Onsan]

Zombie thread warning!

ok, so I had this whacky idea that the galaxies are one day going to be swallowed up by their ever-gorging black holes, which also given enough time coalesce into one incomprehensibly massive black hole/singularity, beginning a new cycle of the universe.
Trying to find answers I came across this thread. It was comforting to learn that I'm not the only loon out there (sorry OP )

my problem resolving this concept though is what happens to the radiation leaked from the poles of the black holes?
If space doesn't exist prior to the big bang, then where would this energy be emitted to?
If energy can be lost like this, would a universe governed by a cyclic model move to a lower entropy with each cycle until it fizzles out to nothingness?

 

[bill alsept]

Speculating I would say there is a difference between black holes as we think we know them and the final black hole made from all the other black holes. The difference being that the final black hole/singularity (maybe it should be called "The Singularity") would not have anymore matter to accumilate. At that point everything in the universe will have already been pushed into the singularity. There would not be excessive amounts of matter bottle necking at the event horizon and shooting out the polls anymore. The finale singularity should be quite calm.

In a cyclical universe space did exist before the bounce but it too would have completely condensed along with everything else back into The Singularity.

I can imagine The Singularity made of every single quanta in the universe packed so dense that it becomes basicly one particle with no moving parts and cold.
The entropy at the singularity would be back to almost zero and ready for its next round of inflation.

 

[Onsan]

i think i can accept that The Singularity could be that immense that it would alter the fabric of space and time, or even maybe that the emissions from the poles reaches a point that it is contained by this warping/contraction of space to the point that it creates a feedback loop that possibly even triggers the next cycle.

but why cold though? i would think that it needs to be incredibly hot for something to trigger the next cycle. if it's cold it lacks all energy and is unlikely to change from that state.
or am i misinterpreting what you mean by cold?

 

[bill alsept]

i think i can accept that The Singularity could be that immense that it would alter the fabric of space and time, or even maybe that the emissions from the poles reaches a point that it is contained by this warping/contraction of space to the point that it creates a feedback loop that possibly even triggers the next cycle.

At the end there would be little to no space left as well as no emissions from the poles.





but why cold though? i would think that it needs to be incredibly hot for something to trigger the next cycle. if it's cold it lacks all energy and is unlikely to change from that state.
or am i misinterpreting what you mean by cold?

If nothing could move inside the singularity where would the heat come from other than on the surface were the last remnants of quanta were still acumilating. Why would the cycle need heat to trigger it?