Saturday, April 30, 2022

Many Worlds is like Superdeterminism

I posted this provocative comment on Scott Aaronson's blog:
MWI fails to resolve the measurement problem, as Fred #14 explains, but the problems are much worse. Scott has explained that superdeterminism is contrary to scientific thinking, and so is MWI, for somewhat different reasons.

Superdeterminism makes randomized controlled experiments impossible, because hidden dependencies control the outputs. MWI also rules out free will, and then makes it impossible to interpret outcomes. If you do an experiment with ten possible outcomes, and see one, you learn nothing because all of the other possibilities occur in parallel universes. MWI might be of some use if it were able to say that some universes were more probable than others, but it cannot do that. So MWI also makes experiments impossible.

MWI does not make any successful predictions, unless you add the Born rule and do Copenhagen in disguise. Just like the superdeterminists, the MWI advocates seems to be willful contrarians who do not actually have a quantitative theory to back up their ideas.

Aaronson says that he is mostly on board with the Many Worlds Interpretation. He says:
I already teach MWI in my undergrad quantum information class, in such a way that according to the poll we give at final exam time, roughly half the students end up as MWI proponents (with the others split among Bohm, Quantum Bayesianism, Penrose-style dynamical collapse theories, agnosticism, and rejection of the whole question as meaningless).
Deutsch is a big believer in quantum computing, and says it would prove many-worlds, as the extra worlds could explain where the magic computation takes place. My view is the contrapositive. I think many-worlds is nonsense, and that makes me skeptical about quantum computing.

I will be interested to see what pushback I get. Surely the MWI believers will say that I am wrong.

Update: Not much response so far. One guy has a link to a paper arguing for the Born rule, but that's all.

A video interview of Deutsch on many-worlds, which he prefers to call the multiverse, was just posted. He claims great importance to the concept, but when asked to quantify the universes, he cannot give a good answer.

Update: Still no serious defense of MWI. Weird. Maybe they only believe in it to the extent that they do not have to defend its inadequacies. Finally, the thread is being hijacked by "Feminist Bitch" who complains that "we get a pseudo-intellectual rationalist-tier rant about whatever’s bumping around Scott’s mind right now." Not enough about her favorite leftist feminist causes. Sigh.

Update: And now Aaronson has been shamed into donating to feminist causes:

I stayed up hours last night reading Alito’s leaked decision in a state of abject terror. I saw how the logic of the decision, consistent and impeccable on its own terms, is one by which the Supreme Court’s five theocrats could now proceed to unravel the whole of modernity.
So the whole of modernity depends on imposing illogical rulings on the people?

Update: Aaronson has closed the thread after detailing how he was bullied as a child. He is annoyed that feminists and others demand special oppression status, while no one has any sympathy for nerds like him.


  1. Teacher: Now Timmy, what is 7 + 3?

    Timmy: It's 11.

    Teacher: Incorrect Timmy, It's 10.

    Timmy: But Teacher, in some other universe it could actually be 11.

    Teacher: Perhaps Timmy, but we aren't in that universe doing bad arithmatic. In this universe it is still 10 and you are still incorrect.

    I get the disturbing realization that if the MWI crowd had just had better teachers with enough gumption to say "NO. That is not correct" we would not be in this mess right now where mathematical prodigies feel comfortable enough to literally invoke imaginary universes in order to claim they got the correct answer.

  2. Good point. I get the impression that the quantum professors are teaching that MWI is just an interpretation, and they never explain that MWI does not allow computing anything.