Monday, September 29, 2008

Like clouds in our coffee ... all these other universes ...

In Darwinian Universes And Colliding Branes: Eschewing A Cosmic Singularity, Access Research Network correspondent Robert Deyes comments on cosmologist Lee Smolin's "Darwinian universe" theory:
Cosmologist Lee Smolin has developed his own Multiverse theory conjecturing that within the confines of black holes, there might be other universes forming and expanding just like our own that would never be visible to us because of the limited horizon of black holes (their gravitational pull is so strong that even visible light cannot escape) (Ref 4). Smolin's ideas would certainly make good science fiction. Universes that originate from explosions that are hidden from sight in black holes make a backdrop for a great story in which intelligent beings such as us are oblivious to the origin of their cosmos, believing it to be in some way unique (Ref 4, p.89). With so many universes spawning from black holes, Smolin argues, it becomes more probable that at least one of them will have laws of physics that are fine-tuned for the formation of stars, planetary systems and eventually life. Or does it?

Smolin's idea of universe progeny spawning from black holes within parent universes bears striking similarities to the evolutionary tree of common descent that Darwin provided as the sole picture in 'The Origin Of Species'. According to Smolin, as universes 'improve' their ability to generate more stars and thereby produce more black holes, 'fitter' universes will swamp out those that are less finely tuned, have fewer stars and therefore produce less progeny (Ref 4, p.90-100). Given time, enough universes will have produced enough stars to generate enough black holes to produce more progeny universes with life-supporting, physical parameters such as our own.

But what is to say that fine-tuning will necessarily improve to the phenomenal level that we find in the laws of physics that under gird our own cosmos? Smolin's theory relies on the early parent universe going through expansion-collapse cycles before it becomes 'fit' enough to produce stars and consequently black holes for its progeny to form (Ref 4, p.97). For such a cosmos, the mechanical energy needed for expansion-collapse would eventually decay just as a ball bouncing on a living room floor would eventually stop bouncing. Such observations are consistent with the second law of thermodynamics. So for Smolin's parent universes to generate progeny, they would have to get fit before the bouncing energy ran out.

Oddly enough Smolin's theory also suffers from a lack of testability and falsifiability. We have no way of testing whether or not a host of universes and other worlds actually exist behind black holes.

About all that, I said, in By Design or by Chance?:
All these universes popping up in the clouds in our coffee, in the torment of a black hole, in the futility of an escaped balloon—their existence guarantees that our universe is a product of chance. If only they would exist . . . if only they would exist . . .

See also: Major media, imagining themselves sober, think there are many universes, not just double vision.

The Big Bang exploded; seriously, is there room for reasonable skepticism about the Big Bang?

Could God live in an infinite sea of universes? It depends.

Will thecosmic multiverse landscape ensure the triumph of intelligent design?

Now, remind me again why we need multiverse theory in the first place?

Multiverse theory: Replacing the big fix with the sure thing?