Caption: A cartoon of a possible multiverse.

Articles of interest:

1. Zhi-Wei Wang, Samuel L. Braunstein, 2021, Life, the universe and the hidden meaning of everything: W&B
2. Fred C. Adams, 2016, Constraints on Alternate Universes: Stars and habitable planets with different fundamental constants: FA.

Let:

1. M be the multiverse.
2. B be all the fundamental parameters of physics and cosmology.
3. L be life as we know it: To be definite let us say life as we know it must be based on carbon and liquid water. Carbon is the only atom that forms complex molecules and liquid water is hard to dispense with as the medium of biological chemical reactions.

Conditional probabilities:

1. P(M|B as fixed by the logic of reality) = 0 since there are NO degrees of freedom. Also B = B-observed since we know they exist. This case would be a successful falsification test in the in the sense used by philosopher of science Karl Popper (1902--1994). But then we'd wonder why the logic of reality dictated life as we know it.

2. P(M|B): People argue that if B looked special and so as if fixed by the logic of reality then low. But since B-observed do NOT look special then P(M|B) must be bigger than low, and so the multiverse has passed a significant falsification test. Martin Rees (1942--) has made this argument. Can it put in a Bayesian analysis form?

3. P(L|B inconsistent with L) = 0 which implies B must be restricted somehow and there some restrictions though perhaps NOT so tight: see FA. This the anthropic principle in some version in action.

4. P(L|B-biophilic observed) > 0: Note P(L|B inconsistent with L)=P(L|B-biophilic=0)=0. As B-biophilic↑, P(L|B-biophilic)↑ with maximum 1.

5. P(L|region(B-biophilic) ∪ M with Sciama probability distribution with all existing parameters known to exist): Note 0 if in region(B-biophilic=0) and low if region(B-biophilic high) since there is so much more volume for region(B-biophilic low) in a high dimensional parameter space. Most life will be on the shoreline of the island of habibility in Dennis Sciama's (1926--1999) theory---which if true may Fermi paradox---aphorized in one person's recollection as "Where are they?" by Enrico Fermi (1901--1954): see Wikipedia: Fermi paradox: The original conversation(s).

6. P(L|region(B-biophilic) ∪ M with Sciama probability distribution with many existing parameters unknown to exist): Note 0 if region(B-biophilic=0) and can be high region(B-biophilic high) as argued by W&B. If you knew all the parameters that existed, you'd be back to the previous case.