Caption: A cartoon
of a possible multiverse.
Articles of interest:
- Zhi-Wei Wang, Samuel L. Braunstein, 2021,
Life, the universe and the hidden meaning of everything:
W&B
- Fred C. Adams, 2016,
Constraints on Alternate Universes: Stars and habitable planets with
different fundamental constants:
FA.
Let:
- M be the multiverse.
- B be all the fundamental parameters
of physics and
cosmology.
- 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:
- 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.
- 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?
- 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.
- 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.
- 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).
- 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.
Credit/Permission: ©
David Jeffery,
2015 / Own work.
Image link: Itself.
Local file: local link: multiverse_bayesian.html.
File: Cosmology file:
multiverse_bayesian.html.