RE: Big Bounce vs Big Bang
July 14, 2016 at 9:28 pm
(This post was last modified: July 14, 2016 at 9:38 pm by Alex K.)
The articles you have posted fall a bit in the common science journalism trap of taking one paper from the body of literature of many 100s and running with it, downplaying the context and speculative nature.
The consensus does not point towards big rip and I don't think there is a very compelling underlying physics model that would yield such a divergent expansion.
As to the big bounce, that stuff is really interesting, but Gielen and Turoks paper is not the last word nor provides decisive scientific evidence in favor (In a recent review of bouncing cosmologies, it is one of 150 or so references, and even there more or less a footnote, to give you some context) it may well be one of the more important references because they try to tackle a difficult theoretical problem, the complete quantum physics of the earliest stages of cosmic evolution - they have shown in a speculative simplified scenario that they can handle the quantum physics involved. This approach is still somewhat removed from a realistic picture and involves many unknowns concerning how this conformal model might arise from the physics we know. The "classical" inflation paradigm is still simpler and more well defined and explains the observations, but since it suffers from two conceptual problems (trans planckian effects and past singularities), the big bounce stuff might one day provide a fully developed alternative.
As to the 750 GeV diphoton resonance at the LHC, that would be epic, but the latest rumours dampen the hopes a bit. The ICHEP conference is approaching, and if there is a discovery in the 2016 data, we should be hearing some more concrete rumours. So far all we got was inofficial claims that the signal is not there any more.
The consensus does not point towards big rip and I don't think there is a very compelling underlying physics model that would yield such a divergent expansion.
As to the big bounce, that stuff is really interesting, but Gielen and Turoks paper is not the last word nor provides decisive scientific evidence in favor (In a recent review of bouncing cosmologies, it is one of 150 or so references, and even there more or less a footnote, to give you some context) it may well be one of the more important references because they try to tackle a difficult theoretical problem, the complete quantum physics of the earliest stages of cosmic evolution - they have shown in a speculative simplified scenario that they can handle the quantum physics involved. This approach is still somewhat removed from a realistic picture and involves many unknowns concerning how this conformal model might arise from the physics we know. The "classical" inflation paradigm is still simpler and more well defined and explains the observations, but since it suffers from two conceptual problems (trans planckian effects and past singularities), the big bounce stuff might one day provide a fully developed alternative.
As to the 750 GeV diphoton resonance at the LHC, that would be epic, but the latest rumours dampen the hopes a bit. The ICHEP conference is approaching, and if there is a discovery in the 2016 data, we should be hearing some more concrete rumours. So far all we got was inofficial claims that the signal is not there any more.
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition
