Exploring the Origins of the Universe

[RAD4921]

Is the observable universe an exploded singularity or maybe even an exploded black hole?

 

[marcus]

Is the ... universe ... an exploded black hole?

that is one comparatively well-articulated theory of how the universe came into being

see for example a recent paper by Smolin
Scientific Alternatives to the Anthropic Principle
http://arxiv.org/hep-th/0407213

 

[marcus]

Quantum Gravity provides a picture of the inside of a black hole where there is no actual singularity but rather a continuation which
may develop into an expanding phase, undergoing inflation and resulting in a new universe.

When QG is used to study the big bang singularity and a generic black hole singularity they are found to be rather similar----both are quantum bounces in which a contracting phase reaches a maximum density and changes over into expansion. Because the two ex-singularities are similar, Smolin describes putting them together to construct a theory in which the black holes in one universe in effect bud off and produce a new generation of universes, with possibly slight variations in the basic constants of the Standard Models of physics and cosmology----so that each child universe is not identical but slightly different from the parent.

Smolin's article is due to be published by Oxford Univ. Press in a book called
Universe or Multiverse

The good thing about this particular theory is that it is testable. It makes predictions about the parameters of the Standard Model and about outcomes of future observations. It can be checked by astronomers and refuted by the evidence if it is wrong. So it is not just some daydream Multiverse but a theory with some predictive and explanatory power.
Worthwhile checking out, if yr intrstd.

 

[RAD4921]

To Marcus

Marcus, Thanks for the PDF link. I first I couldn't understand about the subject of the anthropics principal (philosophy) with big bang physics but as the paper evolves they go into inflation and contracting universe. This is a piece of information is just what I am looking for. Thanks. RAD

 

[marcus]

Details:

Leonardo Modesto
Disappearance of the Black Hole Singularity in Quantum Gravity
http://arxiv.org/gr-qc/0407097

Date and Hossain
Genericity of Big Bounce in isotropic Loop Quantum Cosmology
http://arxiv.org/gr-qc/0407074

if there is a quantum bounce-type continuation at the bottom/center of any black hole and if our universe begins with a similar quantum bounce (under generic or broadly general assumptions) then why not join the two?
our universe resulted from a black hole in a prior universe.

if that is how universes arise, with slight variations of the physical constants from generation to generation (analogous to genes) then universes will evolve a set of physical constants which is compatible with star formation and the production of abundant black holes. Universes with "good" genes will have reproductive success. With bad genes, or physical constants, stars and galaxies will never coalesce, stars atoms will decay radioactively before they manage to have normal lives, supernovas will blow too much of the star away so the remnant will not be massive enough to collapse into a black hole, neutron matter will be too strong and never get compressed enough to collapse into a black hole, and so on. Various things can go wrong and prevent a Universe from having children.
So it is the "good" physical constants, like good genes, which get passed on.

therefore Smolin's CNS (cosmic natural selection) model predicts that the parameters of our universe are optimized for producing lots of black holes and, among other things, one will never discover a neutron star above a certain top mass (IIRC around 3 solar masses). for instance. If one finds an unexpectedly massive neutron star then it shoots down the theory. No one has found such a thing so far but they could find one tomorrow. So it is falsifable. that is the point----construct a theory which can be refuted by experiment: which bets its life on some predictions about future observation. If a theory does not do this, then it is vacuous.