The problem is the same as for solipsism, and were identified two millennia ago.
Nearly all of science works like this. Collect some data, form a hypothesis, collect more data, and construct a theory that makes predictions. The prediction is that, for a set of given conditions, a particular measurement will be observed, with some confidence. The prediction might be: The displacement will be 95% likely to be between 1.4 and 1.5 meters.
There is nearly always a probability involved, even in a supposedly deterministic field like celestial mechanics. It is hard to think of examples that do not fit this pattern. Reader Andrei suggests quantum mechanics predicting that the H2O molecule is stable. Maybe also Darwin's "survival of the fittest". But 99+% of all scientific work involves probabilities.
Many-worlds theory rejects all probabilities. They have no notion of some worlds being more likely than others. Your branch of the wave function is all that is real to you, and all possibilities happen in parallel worlds. The seemingly unlikely possibilities are just as real. Some researchers have arguments for why we might subjectively perceive probabilities, but these arguments are not widely accepted, and do not function as real probabilities anyway.
Superdeterminism also rejects probabilites, for different reasons. It denies that you can even set up a controlled experiment. You might toss a coin 100 times and get 50 heads, and that is no indication of a fair coin. The coin could be weighted to come up heads 90% of the time, but a conspiracy of forces going back to the Big Bang might have forced a misleading statistical outcome. In short, probabilities are meaningless.
Gerard ’t Hooft was one of the top geniuses being the Standard Model, and he has been sucked into superdeterminism. To show how twisted his thinking has become, his latest paper says:
A complete answer to the question ‘what happens in an EPR-Bell experiment?’, is not given here, but we do summarise what, according to this author, the principal weaknesses are in Bell’s argument, which is not the mathematical calculations but the general assumptions, in particular those connected with causality and ‘free will’. ...Really, he cannot fathom why scientists believe in free will? I don't think he is joking, as he has written papers against free will, such as this one. And sure enough, he shows no clue to understanding why anyone would believe in it.
All this implies for instance that Alice and Bob have no free will. Not in a deterministic world. For unfathomable reasons, many experienced scientists have difficulties with that.
He is so eager to abolish free will that he also abolishes probabilities.
Sean M. Carroll and Scott Aaronson back many-worlds theory, and hence also reject probabilities.
Scott Aaronson writes:
The original papers by Gerard ‘t Hooft on “superdeterminism” were shockingly blase about the absurd implications I mentioned — implications that would mean you could explain basically anything (telepathy, superluminal signaling, etc.) via similar devices, and that physics would be over — and (to their credit) were also clear enough that there was no possible other way to interpret them. None of the other papers I saw about “superdeterminism” showed any inkling of appreciating the enormity of the problem. And none of them contained what I saw as the slightest hint of a promising idea to balance the absurdity.That is all true, but the same is true about many-worlds. Because anything can happen in the parallel worlds and there is no way to say how unlikely those things are, the theory can explain basically anything. And the proponents show no inkling of appreciating that they are rejecting 99% of all modern science, and offering nothing in return.
By the usual standards I apply to anything else, this would be more than enough reason for me to ignore the topic thereafter.
And I mean literally nothing. There is no paper on many-worlds or superdeterminism that has ever contributed anything to modern science. No paper has made a successful prediction, or even explained how a prediction could be made. No paper has explained anything that we don't already know.
It is as if some smart person announced: Maybe 99% of all science is wrong, and it only seems right because God is performing miracles to trick us.
I cannot disprove such a statement, just as I cannot disprove solipsism. But what is the point? There is no evidence for such thinking. The view has no benefits. It cannot predict or explain anything. And it discards most of the best of human knowledge.
I am flabbergasted at the sloppy thinking of our intellectual leaders.
Update: Andrei writes:
Superdeterminism is a generic concept like “field theory”. Is it possible for a field theory to predict telepathy? Yes. Does it mean that all field theories are non-scientific? Not really. General relativity or electrodynamics are field theories and are universally accepted as science. ... the superdeterministic theory that reproduces QM would not predict telepathy either.His argument is that someone might construct a superdeterministic theory that reproduces known physics, and so that would be scientific.
No. He could say the same about solipsism, simulation, or anything else that denies reality. Under those theories, no one can do any experiments to test the theory, so there cannot be anything scientific about them.
Yes, I really believe that belief or disbelief in MWI should have no bearing whatsoever on what risks you’re willing to take in your life. Or to put it differently: whatever about MWI causes you to think it would bear on that, that’s precisely the part you need to discard in order to continue along the Zen path.He is also denying reality. Under MWI, he has no ability to take risks. If, say, he goes skydiving, he will crash in some branches and land safely in others. MWI has no way of saying which branches are more likely. The concept makes no sense in MWI, as the copy of him that survives will think that he is the real Scott, and nothing bad happened. He also has no free will in MWI, as every apparent choice puts him in a branch, but the opposite choice puts him in another branch and that Scott will think that he made that opposite choice.
All these forms of solipsism are unscientific, and nothing in life makes any sense if you believe in them. Andrei and Scott both pretend that you can adopt these beliefs, and go on with life just as before. You cannot.
Update: Scott responds:
My argument is simply that the superdeterministic theory that does all these wonderful things — e.g., naturally reproduce QM while not superluminal signaling or telepathy — is a nonexistent construct. I personally see no reason why anything like it should exist; at any rate it doesn’t exist at present. But it’s more than that: I don’t accept the framing that this is a “promising research program that just needs more time to succeed.” I’ve seen nothing — nothing — of the slightest scientific interest ever come out of it. I don’t see why anything would, given thatI agree with all that, but the same could be said for many-worlds and the other solipsist theories. In particular (1) MWI was motivated by people with a philosophical objection to Copenhagen QM, and searched for an exotic way to avoid measurements; and (2) the mechanism is a form of magic that defies all scientific analysis.
(1) its original motivation was a terrible one (basically, people who didn’t understand the Bell inequality, and then after it was finally explained to them, searched for some arbitrarily exotic way in which they might still be right), and
(2) the “mechanism” they decided on is effectively indistinguishable from magic — it’s just that you arbitrarily declare that this magic is only for violating the Bell inequality, and not for any of the more interesting things that magic would seem able to do once you introduce it into the universe.
Scott does not agree with that, of course, as he has joined the MWI cult. He just brushes aside the magic by calling it Zen.