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Could I ask you for the relation between Wheeler's ideas and the multiverse? Do you know if these are related?

I ask you this because I found this very interesting article written by Kip Thorne with Wojciech Zurek and Charles W Misner (https://www.its.caltech.edu/~kip/PubScans/VI-50.pdf) where they seem to indicate that Wheeler was a multiverse proponent

For example, at some part of the article they wrote:

"Wheeler described to his two former students his idea that the laws of physics are mutable: Those laws must have come into being in our universe’s Big Bang birth, and surely there are other universes, each with its own set of laws. “What principles determine which laws emerge in our universe and which in another?” he asked"

and also, at the end of it, they wrote

"Wheeler speculated that universes governed by sensible laws could come to be inhabited by observer–participators."

But then I contacted a biographer and analyzer of Wheeler's works and he told me that Wheeler's ideas are completely different to any kind of multiverse and that Wheeler was not happy with the idea of a multiverse.

He said:

"There are a few hundred essays that Wheeler wrote from the 70s to the 90s where he built up his ideas. If you can find something in his essays about how his approach to quantum theory is the same as the multiverse approach, I will stand corrected. But I have looked over these for years, and have not seen anything other than his complicated relationship with Hugh Everett's Many Worlds. I have seen many physicists just guess what Wheeler was talking about, without citing anything that he actually wrote When you ask them their source it is usually "Well that is what my colleagues think" and when you ask their colleagues, they were just giving an interpretation of the phrase "it from bit" without reading any of the essays."

Also he cited Wheeler

"Its [MWI/Everett] infinitely many unobservable worlds makes a heavy load of metaphysical baggage."

(He said that His approach (It from Bit) was meant to alleviate this philosophical issue, i.e to eliminate the multiverse in Everett's Interpretation)

So, are Wheeler's ideas and the multiverse compatible or not? Is the biographer that I contacted right? Is Wheeler's "It from Bit"/"Participatory Universe"/"Pregeometry and Law without Law" and the Multiverse related? Apart from this, do you know of any quote of Wheeler that indicates that his ideas are compatible with the idea of a multiverse?

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The dissonance comes from using the term "multiverse" too loosely. As far as Everett's many worlds and its derivatives, Wheeler supported Everett as his student, but distanced himself from his interpretations. He was committed to Bohr's Copenhagen interpretation with its role of the observers in "shaping" reality. In a letter to Stern he even coopted Everett to the Copenhagen interpretation against his own explicit words, see The Many Worlds of Hugh Everett in Scientific American.

Moreover, Wheeler drew a stark contrast between his "participatory universe" proposal and popular multiverse ("ensemble of universes") conceptions in World as system self-synthesized by quantum networking (1988). The subsection is characteristically titled: No ensemble, no factory for making universes. Observer participancy the whole source of the "out there" plus life, mind, communication:

"Those constants must have nearly the values they do, Robert H. Dicke, Brandon Carter, and others point out, if life is ever to be possible—not merely life as we know it, but life of almost any conceivable form. This observation has led some investigators to the idea of an ensemble of universes, one differing from another in the values of the dimensionless constants... There operates on such an ensemble of universes, Charles Pantin argued in 1951, something "analogous to the principle of Natural Selection, that only in certain Universes, which happen to include ours, are the conditions suitable for the existence of life, and unless that condition is fulfilled there will be no observers to note the fact"...

The contrast between the two views could hardly be greater: selection-from-an-ensemble and observer participancy. The one not only adopts the concept of universe, and this universe as machine, it also has to postulate, explicitly or implicitly, a supermachine, a scheme, a device, a miracle, which will turn out universes in infinite variety and infinite number. The other takes as foundation notion a higgledy-piggledy multitude of existences, each characterized, directly or indirectly, by the soliciting and receiving of answers to yes-no questions, and linked by exchange of information."

Does this mean that Wheeler's self-synthesized worlds can not be subsumed under some sort of "multiverse" in a vague sense? He does not use the language but emphasizes and repeats constantly that the synthesis depends on multiple choices made by the "multitude of existences", the observers. These choices determine not just the present but even the past, since it only exists to the extent that there is information about it in the present. And that information depends on the choice of questions to be asked.

Moreover, Wheeler's "law without law" slogan means that not just the past (initial conditions) but even the physical laws themselves are ultimately the result of those choices. Different choices, different answers, different worlds. This idea was later termed "It from Bit" (1989). The first OP quote refers to this picture, not to (what Wheeler called) "ensemble of universes". But one is free to call it the "multiverse" of observer created worlds if one so wishes. In Bohr’s “Phenomenon” and “Law Without Law” (1985) we read:

"So far as we can see today, the laws of physics cannot have existed from everlasting to everlasting. They must have come into being at the big bang. There were no gears and pinions,no Swiss watchmakers to put things together, not even a pre-existing plan. If this assessment is correct, every law of physics must be at bottom like the second law of thermodynamics, higgledy-piggledy in character, based on blind chance, insofar as it is not mere mathematical identity.

[...] The elementary quantum phenomenon has much of the character of an elementary act of creation. The phenomenon that we call "a photon from a distant quasar" reaches into the present from billions of years in the past. It is wrong to think of that past as "already existing" in all detail. The "past" is theory. The past has no existence except as it is recorded in the present. By deciding what questions our quantum registering equipment shall put in the present, we have an undeniable choice in what we have the right to say about the past."

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