Are congenial constants also "holey"? Crowell pointed to two very interesting papers by Jaffe et al and by Jenkins (MIT) This is the long one, with a lot of interesting detail: http://arxiv.org/abs/0809.1647 Quark Masses: an Environmental Impact Statement This other one is more of a quick summary: http://arxiv.org/abs/0906.0029 (A workshop paper Jenkins gave at Zakopane, Poland about the results.) The general impression one gets is that Standard Model parameters are not, after all, very fine-tuned for conscious life to exist. A lot of variation (at least in quark masses, for instance) would still allow "us". The question remains, are the parameters tuned to produce a lot of astrophysical black holes? Around 1993 Smolin pointed out that IF tracts of spacetime reproduce by black hole bounce during which slight variations in the SM constants can occur, THEN the population of tracts would be dominated by those whose SM constants are "holey" or conducive to reproduction. The typical array of SM constants would be at or near a local maximum for reproductive success. So that one would predict that no "small" change in the parameters would result in more abundance of holes. But this is the sort of detailed analysis that Jaffe and Jenkins do in the 2008 paper! They study the effect of slight variations in SM parameters (namely quark masses.) However the criterion they watch is whether the parameters are "congenial". They use "congenial" to mean conducive to complex life. They find that the quark masses we have are not especially congenial. A fine-tuner would have been able to play around quite a bit. I wonder how the Jaffe Jenkins analysis would have gone if the criterion they were varying for had been "holey"---apparently so far Smolin's hypothesis has not been disproven. No one has yet been able to exhibit a small change in any SM parameter which would have resulted in more astrophysical black holes. So the conjecture stands. The most recent status report on this is here: http://arxiv.org/abs/hep-th/0612185 The status of cosmological natural selection It seems to me that with a little work someone might be able to falsify (disprove the CNS hypothesis). One of the main predictions derived from it so far is about the strange quark mass as reflected in the maximum mass a neutron star can have without collapsing to hole. The prediction is that one will never find a neutron star of mass > 1.6 solar, because that would mean the top quark mass was not finetuned to promote collapse. The whole thing is a bit IFFY, and it seems in need of some solid analytical work. (Stable elements like C, N, O help gas clouds radiate heat and thus facilitate collapse to form stars---many things we think of as anthrogenic are also simply star-genic or hole-genic. We aren't the only things that benefit from supernova explosions. Star-formation in general benefits. And so on. You can see that issues here need to be sorted out.