Gerard ’t Hooft, The Cellular Automaton Interpretation of Quantum Mechanics

[Genady]

I've just started reading this book (2016). Feels very refreshing and promising. Are you familiar with it? What do you think?

[Genady]

't Hooft insists that this work is not a follow-up on the Wolfram's one:

An extensive study of the role of cellular automata as models for addressing scientific questions was made by Stephen Wolfram in his book A New Kind of Science. He attached a special philosophy to his approach. Since cellular automata have complexity and computational universality in common with many models of physical systems, Wolfram suggests that experiments with cellular automata themselves can reveal many special features of such physical systems. The reader might have the impression that our book is a follow-up on Wolfram’s pioneering work, but we do not have such ambitions as yet. The classes of models considered by Wolfram may well be too restrictive for our purposes, and furthermore, our basic question very specifically pertains to the origin of quantum mechanical phenomena.

Both Zuse and Wolfram already speculated that quantum mechanical behaviour should be explained in terms of cellular automata, but did not really attempt to get to the bottom of this—how exactly do we explain quantum mechanics in terms of a cellular automaton? Do we need a very special automaton or does every automaton sooner or later produce quantum mechanical behaviour?

Computational scientists have studied many features of cellular automata that will not be used in this work; this is because these issues involve quite special initial states, while quantum mechanics will force us to consider primarily generic states.

[joigus]

I'm aware of it. What Gerard 't Hooft is doing is trying to gradually build up towards models of deterministic variables that produce quantum mechanical dynamics in a simple way. More in particular the "logic of superpositions," but in such a way that there's a more satisfactory "ontological basis."

But, he --and others-- declare that it's nowhere near quantum mechanics as to predictive and explanatory power. It's no substitute for quantum mechanics, let me tell you that.

Here's a sample of some of his disclaimers, qualifications, and answers to criticism:

https://physics.stackexchange.com/questions/600367/measurement-in-t-hooft-cellular-automation-interpretation-cai/601452#601452

https://physics.stackexchange.com/questions/32502/can-quantum-mechanics-really-be-the-same-as-underlying-deterministic-theory/34160#34160

https://physics.stackexchange.com/questions/30065/why-do-people-rule-out-local-hidden-variables/34073#34073

But this is not one of the topics I've studied more in detail, to tell you the truth. I don't think there's a significant number of experts, saying, "yeah, that's the ticket! How didn't we think of that before?"

 

[Genady]

32 minutes ago, joigus said:

I'm aware of it. What Gerard 't Hooft is doing is trying to gradually build up towards models of deterministic variables that produce quantum mechanical dynamics in a simple way. More in particular the "logic of superpositions," but in such a way that there's a more satisfactory "ontological basis."

But, he --and others-- declare that it's nowhere near quantum mechanics as to predictive and explanatory power. It's no substitute for quantum mechanics, let me tell you that.

Here's a sample of some of his disclaimers, qualifications, and answers to criticism:

https://physics.stackexchange.com/questions/600367/measurement-in-t-hooft-cellular-automation-interpretation-cai/601452#601452

https://physics.stackexchange.com/questions/32502/can-quantum-mechanics-really-be-the-same-as-underlying-deterministic-theory/34160#34160

https://physics.stackexchange.com/questions/30065/why-do-people-rule-out-local-hidden-variables/34073#34073

But this is not one of the topics I've studied more in detail, to tell you the truth. I don't think there's a significant number of experts, saying, "yeah, that's the ticket! How didn't we think of that before?"

 

Oh yes, he makes it very clear from the beginning that (a) there still is MUCH work to do, and (b) it is NOT to replace or modify QM, but to give it a deterministic interpretation. The goal is to define a way how to think about QM and, maybe, about "quantum gravity", rather than change a way of doing QM.

[Genady]

P.34: "When we talk of an interpretation, this means that, even if we find it hard or impossible to identify the ontological basis, the mere assumption that one might exist suffices to help us understand what the quantum mechanical expressions normally employed in physics, are actually standing for, and how a physical reality underlying them can be imagined."

[Genady]

p.49: "Deterministic quantum mechanics is neither a modification of standard quantum mechanics, nor a modification of classical theory. It is a cross section of the two."

[Genady]

About 1/3 into the book. Interesting read, but many strange assumptions have to be accepted for the thing to work. Makes me appreciate Copenhagen even more.