Black holes in cosmological natural selection

The natural-selection scenario that Lee Smolin describes for universes selects for ones most likely to produce black holes. That is not the same thing as selecting for a universe that has the same characteristics as ours or for a universe that has characteristics conducive to biological life. It’s easy to imagine a universe more likely than ours to produce black holes but less likely to produce biological life. For example, gravity in our universe is much weaker than the other forces. It’s reasonable to suggest that probably in most universes, there is less of a disparity between gravity and the other forces. If gravity was much stronger, all matter would quickly collapse into black holes before the first stars had a chance to form. Such a universe would be full of black holes and have no life.

In a universe that has gravity the same strength as in ours but has orders of magnitude more baryonic matter, the matter would collapse into black holes. Or consider a universe in which the strength of gravity and the amount of baryonic material are the same as in ours, but the Schwarzschild radius is larger. If less mass in a given volume would form a black hole, then it would be easier to form black holes.

Speculation about a hypothetical universe with different characteristics or laws of physics isn’t even necessary. If in our universe stellar black holes were a small percentage of all black holes, then maximizing the number of black holes would not require maximizing the number of stars. It was hypothesized that black holes could have been created at the Large Hadron Collider at CERN. In that scenario, primordial black holes would have been copiously produced during the Big Bang and would greatly outnumber stellar black holes.

Also, it’s possible that micro black holes could appear in the internal loops of all Feynman diagrams. If that’s the case, the black holes in the internal loops of Feynman diagrams would far outnumber primordial black holes produced in the Big Bang, which in turn would far outnumber stellar black holes. Selecting for a universe that produces black holes does not require selecting for a universe that maximizes the number of stars.