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Various Pre Big Bang Scenarios Discussed By Pros


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#35 exchemist

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Posted 07 February 2019 - 05:54 AM

I had an interesting email from a Buddhist living in Ireland :) on the subject of matter creation and space time and the unruh effect. 

 

"

 there is not as of yet any consensus about what a complete model of the fundamental structure of spacetime will look like. Personally, if I was to hazard a guess, and based on all the various models that have been proposed, I’d say that particles are not fundamental entities with independent existence at all, but rather observer-dependent artefacts. At the most immediate level, they are probably best understood as representing the relationship between an observer, and a region of spacetime. If that relationship changes, so do notions of “number of particles” - hence we get phenomena such as the Unruh effect, Hawking radiation, etc. Also, properties of these particles themselves largely depend on considerations of symmetry, so depend on the structure of spacetime and other fields, both large scale and small scale. It may simply not be meaningful to speak of a “particle” as something that exists independently of an observer and his relative orientation in spacetime, with spacetime itself of course also being a dynamic entity. So it’s really more of a vast, intricate, interdependent network of relationships, than merely a collection of separate entities.

"

Markus, I presume. 

 

I certainly came out of my quantum chemistry course feeling that the electron is more of a wavelike thing than a Newtonian "particle" and I've been a bit suspicious of the idea of a "particle" ever since, the usefulness of the concept notwithstanding. When you think about it, a "particle" is a fairly improbable thing, with its notional mass, charge and "spin" but lack of physical extension. It looks a lot like a physicist's approximation to make the maths tractable.  So it is not too surprising that, as with all approximations, it breaks down under certain circumstances.  



#36 Flummoxed

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Posted 07 February 2019 - 06:15 AM

Markus, I presume. 

 

I certainly came out of my quantum chemistry course feeling that the electron is more of a wavelike thing than a Newtonian "particle" and I've been a bit suspicious of the idea of a "particle" ever since, the usefulness of the concept notwithstanding. When you think about it, a "particle" is a fairly improbable thing, with its notional mass, charge and "spin" but lack of physical extension. It looks a lot like a physicist's approximation to make the maths tractable.  So it is not too surprising that, as with all approximations, it breaks down under certain circumstances.  

 

Yes

 

and

 

Yes. Speculative plausible mathematical approximations, based on what we observe, giving testable conclusions that agree with observations with a good degree of accuracy, might not give the full picture.

 

I do not think the many worlds theory is very plausible but the concept of many Aeons I find plausible. I might be wrong, if so why? 

 

Would any one like to comment on the above theories put forward in the OP or any other theory re pre big bang scenarios originated from paid professionals. ?



#37 exchemist

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Posted 07 February 2019 - 06:34 AM

Yes

 

and

 

Yes. Speculative plausible mathematical approximations, based on what we observe, giving testable conclusions that agree with observations with a good degree of accuracy, might not give the full picture.

 

I do not think the many worlds theory is very plausible but the concept of many Aeons I find plausible. I might be wrong, if so why? 

 

Would any one like to comment on the above theories put forward in the OP or any other theory re pre big bang scenarios originated from paid professionals. ?

Not me, I'm afraid. I find all this stuff a bit too speculative and remote from observational testing to spend the time on it. 

 

But the particle business struck a chord with me, as it I have my own reservations about that, for quite different reasons from those of Markus. I find it easiest sometimes to think of the electron as a wavelike thing, but which can only be detected in units of whole particles, rather as many people think of the quantisation of light. That seems to make sense of things like the double slit experiment, as well as the shapes and behaviour  of atomic and molecular orbitals (including phase, with its symmetry consequences).

 

Particles are a good model for many purposes but, as in a lot of physical science, especially chemistry, you need to change models according to the phenomenon under consideration.  

 

But I won't go on, as this is off-topic for this thread.



#38 Flummoxed

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Posted 07 February 2019 - 11:32 AM

Not me, I'm afraid. I find all this stuff a bit too speculative and remote from observational testing to spend the time on it. 

 

But the particle business struck a chord with me, as it I have my own reservations about that, for quite different reasons from those of Markus. I find it easiest sometimes to think of the electron as a wavelike thing, but which can only be detected in units of whole particles, rather as many people think of the quantisation of light. That seems to make sense of things like the double slit experiment, as well as the shapes and behaviour  of atomic and molecular orbitals (including phase, with its symmetry consequences).

 

Particles are a good model for many purposes but, as in a lot of physical science, especially chemistry, you need to change models according to the phenomenon under consideration.  

 

But I won't go on, as this is off-topic for this thread.

 

Yes the thread is speculative, but the theories discussed are plausible, and it might have brought a touch of reality :)  

 

Some of the stuff coming out of string theory like Multiple universes I find a little too speculative, but the concept of higher dimensions, might not be completely wrong and are in line with some mathematical models, including E8.

 

Why particles have particular stable characteristics is very interesting. The life time of muons is very short depending on relativistic effects. They decay to electrons and appear to lose mass/energy in the form of photons. This is off topic, other than what ever caused particles to come into existence from a cold/hot :)  dense state at the beginning of this universe/Aeon inflationary period does not preclude particles bigger than muons for example that might not be stable and might decay to stable particles like electrons etc giving off lots of light in the process at different frequencies. 

 

If a particle comes into existence in a cold space from nothing, why should it not be hot and unstable, lose a photon or two of energy and become stable. ? 

 

Sanity restored I hope.



#39 hazelm

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Posted 07 February 2019 - 12:23 PM

Yes the thread is speculative, but the theories discussed are plausible, and it might have brought a touch of reality :)  

 

Some of the stuff coming out of string theory like Multiple universes I find a little too speculative, but the concept of higher dimensions, might not be completely wrong and are in line with some mathematical models, including E8.

 

Why particles have particular stable characteristics is very interesting. The life time of muons is very short depending on relativistic effects. They decay to electrons and appear to lose mass/energy in the form of photons. This is off topic, other than what ever caused particles to come into existence from a cold/hot :)  dense state at the beginning of this universe/Aeon inflationary period does not preclude particles bigger than muons for example that might not be stable and might decay to stable particles like electrons etc giving off lots of light in the process at different frequencies. 

 

If a particle comes into existence in a cold space from nothing, why should it not be hot and unstable, lose a photon or two of energy and become stable. ? 

 

Sanity restored I hope.

Q:  What was in that cold/hot space before particles?  Muons, etc.?  And you know the next question.  I think the whole problem is that humans crave a beginning and an end.  We think we have found the end - although E A Poe would disagree.  Beginning is more difficult because we have to keep "finding/creating" new ????  out of nothing.    Maybe we should work on "why do humans crave a beginning".



#40 exchemist

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Posted 07 February 2019 - 12:35 PM

Yes the thread is speculative, but the theories discussed are plausible, and it might have brought a touch of reality :)  

 

Some of the stuff coming out of string theory like Multiple universes I find a little too speculative, but the concept of higher dimensions, might not be completely wrong and are in line with some mathematical models, including E8.

 

Why particles have particular stable characteristics is very interesting. The life time of muons is very short depending on relativistic effects. They decay to electrons and appear to lose mass/energy in the form of photons. This is off topic, other than what ever caused particles to come into existence from a cold/hot :)  dense state at the beginning of this universe/Aeon inflationary period does not preclude particles bigger than muons for example that might not be stable and might decay to stable particles like electrons etc giving off lots of light in the process at different frequencies. 

 

If a particle comes into existence in a cold space from nothing, why should it not be hot and unstable, lose a photon or two of energy and become stable. ? 

 

Sanity restored I hope.

I have a real problem understanding what can possibly be meant by assigning a temperature to space.

 

Temperature is a property of matter in a state of thermal equilibrium. It can also be associated with a black body distribution of radiation, but only because that corresponds to the emission from matter in thermal equilibrium at a certain temperature. 


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#41 Flummoxed

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Posted 08 February 2019 - 04:43 AM

Q:  What was in that cold/hot space before particles?  Muons, etc.?  And you know the next question.  I think the whole problem is that humans crave a beginning and an end.  We think we have found the end - although E A Poe would disagree.  Beginning is more difficult because we have to keep "finding/creating" new ????  out of nothing.    Maybe we should work on "why do humans crave a beginning".

 

That is the big question, and pure speculation.

 

Quick and Easy Speculation (with in a speculation)

The time line appears to be as follows > there is no gravity (which emerges from the existence of matter)> space expands (due to dark energy), the rapid expansion allows particles to appear from the vacuum. These particles slow the expansion and prevent further particles appearing from the vacuum. According to Penrose this might happen over and over again as gravitational entropy > 0 as galaxies get further and further apart. The expansion of the universe is currently accelerating, which might lead to another Bang. 

 

 

I have a real problem understanding what can possibly be meant by assigning a temperature to space.

 

Temperature is a property of matter in a state of thermal equilibrium. It can also be associated with a black body distribution of radiation, but only because that corresponds to the emission from matter in thermal equilibrium at a certain temperature. 

 

This is the crux of the problem, I suspect the annswer lies in a type of Hawking radiation, the Unruh effect and Black body, and the speed of expansion of the universe.



#42 hazelm

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Posted 08 February 2019 - 05:01 AM

That is the big question, and pure speculation.

 

Quick and Easy Speculation (with in a speculation)

The time line appears to be as follows > there is no gravity (which emerges from the existence of matter)> space expands (due to dark energy), the rapid expansion allows particles to appear from the vacuum. These particles slow the expansion and prevent further particles appearing from the vacuum. According to Penrose this might happen over and over again as gravitational entropy > 0 as galaxies get further and further apart. The expansion of the universe is currently accelerating, which might lead to another Bang. 

 

 

 

This is the crux of the problem, I suspect the annswer lies in a type of Hawking radiation, the Unruh effect and Black body, and the speed of expansion of the universe.

Thanks, Flummoxed



#43 Flummoxed

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Posted 12 February 2019 - 05:24 AM

I have been looking for a plausible method for particle creation, I suspected a kind of Hawking Radiation might be behind it, but could not find any good links, until I stumbled across Friedman, Robertson and Walker FRW.

 

There all sorts of interesting links based around Hawking and Friedman, Robertson and Walker file:///C:/Users/andyl/Downloads/IJMPD-2012-Hawking-Inflation.pdf  https://mpra.ub.uni-...paper_52402.pdf After ploughing through these and looking at some others that caused me to glaze over, I think my speculation based on the pros speculations is correct. Particles did come into existence during the inflationary stage of the universe. The attached files explain the mechanism. 

 

Penrose might be right as g>0 the inflation could start again. :) with another aeon. 

 

I looked for a pop science explanation or utube but couldnt find anything simpler Sorry


Edited by Flummoxed, 12 February 2019 - 05:25 AM.


#44 exchemist

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Posted 13 February 2019 - 06:21 AM

The link above is way over my head, i think I need to go back to schooI. Did anyone else read it or understand it. :)

Nope. And that's why. I find I have a limited appetite for talking out of my arse, and if I were to read it and pass comments, that is what I would be doing. :) 



#45 Flummoxed

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Posted 13 February 2019 - 07:09 AM

Nope. And that's why. I find I have a limited appetite for talking out of my arse, and if I were to read it and pass comments, that is what I would be doing. :)

 

I was guessing looking at the other threads on the forum, there is likely no one capable of commenting sensibly. My mathematical ability is well above many others on this forum, and the paper lost me very quickly. I am not even sure it was related to the thread in the end.

 

I tend to disagree with you ref not speculating, it is only by raising questions/speculations, that people learn. Problems only happen when people cant accept they are wrong or learn from their mistakes. 

 

Would you agree the idea of the universe appearing out of a singularity appears to be a complete load of bollocks promoted by those without even a lay mans understanding of the inflationary stage of the visible universe. ?  

 

I hope you accept I have kept the speculations here to that coming from plausible professionals, and that the theories presented have been interesting. Is there anything I have wrote on the thread you disagree with. 

 

Unless anyone else has anything plausible, interesting or amusing to contribute, I am finished with this subject.

 

 

 

I tend to disagree with you ref not speculating, it is only by raising questions/speculations, that people learn. Problems only happen when people cant accept they are wrong or learn. 



#46 exchemist

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Posted 13 February 2019 - 10:15 AM

I was guessing looking at the other threads on the forum, there is likely no one capable of commenting sensibly. My mathematical ability is well above many others on this forum, and the paper lost me very quickly. I am not even sure it was related to the thread in the end.

 

I tend to disagree with you ref not speculating, it is only by raising questions/speculations, that people learn. Problems only happen when people cant accept they are wrong or learn from their mistakes. 

 

Would you agree the idea of the universe appearing out of a singularity appears to be a complete load of bollocks promoted by those without even a lay mans understanding of the inflationary stage of the visible universe. ?  

 

I hope you accept I have kept the speculations here to that coming from plausible professionals, and that the theories presented have been interesting. Is there anything I have wrote on the thread you disagree with. 

 

Unless anyone else has anything plausible, interesting or amusing to contribute, I am finished with this subject.

 

 

 

I tend to disagree with you ref not speculating, it is only by raising questions/speculations, that people learn. Problems only happen when people cant accept they are wrong or learn. 

Ah I had not realised you were British. Bollocks (or "ballocks" as I prefer it, according to the Kingsley Amis spelling) is a dead giveaway. :)

 

But I'm going to decline even your invitation to comment on the singularity question, unless you can point to some potential observation that could discriminate between that concept and any rival.  



#47 Flummoxed

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Posted 14 February 2019 - 05:37 AM

Ah I had not realised you were British. Bollocks (or "ballocks" as I prefer it, according to the Kingsley Amis spelling) is a dead giveaway. :)

 

But I'm going to decline even your invitation to comment on the singularity question, unless you can point to some potential observation that could discriminate between that concept and any rival.  

 

Expat Brit I think covers me.

 

Singularities are what you get when the mathematics of a theory break down ie fails to give meaningful answers. This is why we have speculation as to what is inside a Black hole, because no one sensible believes singularities exist except. The concept of singularity is bollocks or as wiki puts it https://en.wikipedia...y_(mathematics)

 

Singularities are highly improbable in nature, and most likely do not exist, except as a mathematical convenience. Inflationary theory combined with Aeons neatly steps around any singularity or multiverse. :) 



#48 Dubbelosix

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Posted 14 February 2019 - 06:30 AM

I said I would pop in from time to time, and I was coming here at night reading the posts here. I am glad Flummox has brought up the issue of the singularity as being bollocks.

 

There are problems with inflation however, that are not just a matter of it leading to multiple universes (or even in Hawkings attempt to reduce those down to some kind of finite landscape), there is the issue of a fine tuning problem. You need special conditions to even have an inflation stage and this is a wild fine tuning, on the odds of the cosmological constant. Penrose is the main scientist I know of that has brought up this tuning issue.



#49 hazelm

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Posted 14 February 2019 - 07:02 AM

Shall I explain it to you all?  <G>

 

No, seriously, if you don't understand it,  I'll skip it entirely.  I'll be back when you all work it out.   Which I know you will do.  :-)



#50 Flummoxed

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Posted 14 February 2019 - 10:55 AM

Shall I explain it to you all?  <G>

 

 

Please do :)

 

A Paper on Penroses Aeons or CCC Cosmic Cyclic Cosmology https://arxiv.org/pd...1808.01740.pdf 

 

"This paper presents strong observational evidence (99.98% confidence) of anomalous individual points in the very early universe that appear to be sources of vast amounts of energy, revealed as specific previously unobserved signals found in the CMB sky. Though seemingly problematic for cosmic inflation, the existence of such anomalous points is an implication of conformal cyclic cosmology (CCC), as what could be the Hawking points of the theory, these being the effects of the final Hawking evaporation of supermassive black holes in the aeon prior to ours. Although of extremely low temperature at emission, in CCC this radiation is enormously concentrated by the conformal compression of the entire future of the black hole, resulting in a single point at the crossover into our current aeon, with the emission of vast numbers of (mainly) photons, whose effects we appear to be seeing as the observed anomalous points. Remarkably, the B-mode location found by BICEP 2 is at one of these anomalous points (an additional expectation of CCC).

"


Edited by Flummoxed, 18 February 2019 - 08:28 AM.

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#51 Dubbelosix

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Posted 14 February 2019 - 03:20 PM


People guessed you might be back,  :shocked: 

 

It's a bit of a well-known secret I would be coming back from time to time, since I already said I would, what I won't be doing is making threads because I won't be able to commit to them for the time being.

 

You are quite impressed with inflation that you speak of it like it should be truth, the fact is it was nothing more than a ''smudge-idea'' to fit experimental data. When you have a large enough universe, and the time it takes for light to reach all parts of the universe, requires a lot of fine tuning. The quickest, probably least imaginative idea was that some symmetry broken in the early universe leading to an inflation (in which we would be expected to believe) underwent a superluminal expansion phase for a very short moment - and so they dabbled more and showed how you could synthesize the main particles of the standard model from the phase itself. It all sounds nice, but it is probably one of the most wildest idea's we have simply come to accept.

 

I made points in the past that inflation can happen ''without inflation.'' If you respect the laws of nature, then a rotating universe is actually not so strange... and if it rotates fast enough, it will expand and even in a way that mimics inflation. This way, we don't need any fine tuning, but the inflationary phase arises as a natural part of the Poincare symmetries of spacetime. We need to look for more natural answers, than being obsessed with inflationary phases of mysterious origins and idea's of cyclic universes.

 

Why cyclic universes? Well I see a big problem in Penroses model, that is, it is not true to the situation of the distant past of this universe. There is no escaping the fact the universe had to be very dense during the earliest stages... and while Penrose argues that a scale invariance ensures that the universe ''forgets what size it is, and a big bang happens all over again,'' there are asymmetries in his theory, which is a BIG problem, since this ''late scale invariance'' has different densities and that is a problem for a uniform cyclic process.