I Possible universes as in Modal Logics

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MathematicalPhysicist
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It seems to me quite plausible to find some similarities between the number of possible modal logics and the number of possible universes.
For every possible universe you can find a suitable modal logic that describes it.

But is it also true that for any modal logic there exists a universe that is described by it?

I mean think of infinitude of universes, the place where metaphysics meets physics.
Are physicists interested in these sort of logics?
Is there a bridge between logicians and physicists?

Well as Michio Kaku once said:"can a theory of everything be proven by experiment?".

I guess that the answer to this is "No", you cannot make endless experiments to probe every possible universe, but you cannot also find such a theory of everything, cause there are an infinite number of models and modalities.
The search for a theory of everything is futile...
 
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Perhaps seeking knowledge is futile. Have not studied semantics, epistemology nor existentialism in many years, the former somewhat subsumed in semiotics, but can comment that these modes of thinking remain useful tools, not descriptions of reality. Physics strives to describe what actually exists within the limits of our instruments despite epistemic flaws.

I am serene knowing I must continuously study, learn, reevaluate knowledge without arriving at an ultimate destination.
 
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MathematicalPhysicist said:
But is it also true that for any modal logic there exists a universe that is described by it?
Not necessarily. We only have evidence for one universe. And, some modal logics might not be generalizable in that fashion. We've pretty much moved beyond Plato's idea that everything we can imagine exists.
MathematicalPhysicist said:
Are physicists interested in these sort of logics?
Perhaps a few, but not many. Maybe a few hundred or less.
MathematicalPhysicist said:
Is there a bridge between logicians and physicists?
Yes. The logicians usually call themselves mathematicians or theoretical physicists when engaged in this activity, however. Almost nobody in academia or science identifies professional as a logician anymore. Very few have since the 1700s or so (coinciding with the replacement of "natural philosophy" with "science" as the dominant discipline studying the physical world), and since the 1970s that number is dwindled further. Plenty of philosophers and mathematicians still use formal logic, but they just don't identify that way. "Category theorist" is a popular description that overlaps heavily with "logicians" using "modal logics" in the sense that you are using it, although they aren't identical. Abstract algebra also heavily overlaps with it.
MathematicalPhysicist said:
Well as Michio Kaku once said:"can a theory of everything be proven by experiment?".
Depends upon what you mean by proven. It could certainly predict everything in the Standard Model and GR and additional things specific to the TOE and if it did that would probably be considered proof of the TOE even though the TOE wasn't necessarily a unique way to produce those results.
 
https://arxiv.org/pdf/2503.09804 From the abstract: ... Our derivation uses both EE and the Newtonian approximation of EE in Part I, to describe semi-classically in Part II the advection of DM, created at the level of the universe, into galaxies and clusters thereof. This advection happens proportional with their own classically generated gravitational field g, due to self-interaction of the gravitational field. It is based on the universal formula ρD =λgg′2 for the densityρ D of DM...
Many of us have heard of "twistors", arguably Roger Penrose's biggest contribution to theoretical physics. Twistor space is a space which maps nonlocally onto physical space-time; in particular, lightlike structures in space-time, like null lines and light cones, become much more "local" in twistor space. For various reasons, Penrose thought that twistor space was possibly a more fundamental arena for theoretical physics than space-time, and for many years he and a hardy band of mostly...

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