It is a sign of the much greater maturity of the physical collapse models that their parameters can be constrained by experiment. The ability to be constrained is a good sign, not a bad one.

I love John Preskill’s standard nod to superdeterminism in his writings: without mentioning it by name he says “I leave it up to the reader to decide how seriously to take this possibility”

https://news.ycombinator.com/item?id=33223391

The idea is that the natural laws are fractal, which when mapped out trace many state space configurations. But with a fractal there are always gaps in state space that remain no matter how much you zoom in or out; fractals preserve certain structural invariants at all scales.

So the idea is that counterfactual reasoning sometimes fails in a fractal universe, because statistical independence no longer works as a general rule (your counterfactual could lie in one of those gaps). He first published this idea in 2009 under the name "invariant set postulate":

https://en.wikipedia.org/wiki/Invariant_set_postulate

His paper with Hossenfelder is also a good overview:

https://www.frontiersin.org/articles/10.3389/fphy.2020.00139...

Superdeterminism gets an unnecessarily bad rap.

If determinism is true, don't you mean "necessarily"? :)

Yes. That is a big reason why most physicists do not favor superdeterminism.

The game of life is perhaps a nice analogy here. On the 2d grid of the game of life, a glider seems moving in a certain direction when time moves forward. But in the 3d grid, where time is the third dimension, a glider is just a static volume of space.

The reason we experience time is that the evolution of the block universe does depend on the dimension you look at (e.g entropy generally increases in the positive time dimension), and because our consciousness is an emergent property of a self-sustaining structure within the block universe, it's plausible at least that we perceive movement in time different from movement in space. I realize this is very sloppy wording but I'm having trouble finding better words to describe my intuition here.

That's one way of interpreting it, but superdeterminism does not entail or require this. Superdeterminism can be formulated just fine for a universe that evolves in time from some initial state according to causal processes.

It’s not violated - it simply doesn’t apply because its predetermined that the measurements that are done work well together. The experimenters follow the script.

If you could refine what these words all mean, I guess we could understand it as something more than "Deutsch seems to think that yes", which can replace your sentence entirely, "yes" describing it all as precisely.

I am myself, in some ways, a general intelligence running on a quantum computer but I dont feel like I can observe myself existing in a novel special way. Let alone being able to then express it for you in a way that is novel as well.

And while you are indeed a general intelligence, I don’t think you’re running on a quantum computer.

If many-worlds is true, we are already observing ourselves in each of those universes in which we can observe, we just don't communicate with our replicas. And if the AGI can communicate with its other instances, the exponential replicas will quickly overload their channel.

I request further elaboration here, please. Examples would be great.

> than the fact that logic is not falsifiable

What?

Also, many worlds interpretation as it currently exists is already falsified by its incompatibility with gravitational nonlinearity.

"True" free will is ruled out by all existing physical theories, so that's not why it's controversial. The bigger problem with superdeterminism is that it wants to explain physics without assuming statistical independence, even for far away events.

“Proposed” - but as something that avoids the issue but it’s not worthy of much consideration.

  - I was going to ask whether it is still possible to maintain, in the light of experimental experience, the idea of a deterministic universe?

  You know, one of the ways of understanding this business is to say that the world is super-deterministic. That not only is inanimate nature deterministic, but we, the experimenters who imagine we can choose to do one experiment rather than another, are also determined. If so, the difficulty which this experimental result creates disappears.

  - Free will is an illusion - that gets us out of the crisis, does it?

  That's correct. In the analysis it is assumed that free will is genuine, and as a result of that one finds that the intervention of the experimenter at one point has to have consequences at a remote point, in a way that influences restricted by the finite velocity of light would not permit. If the experimenter is not free to make this intervention, if that also is determined in advance, the difficulty disappears.

Uhh, no. Essentially all existing physical theories are devastating for any non-compatabilist account of free will.

The point, that many ignore, however is that, free will does not matter. It is irrelevant. Regardless of whether one has free will or not, one still has to make choices and support the consequences of said choices. Lack of free will was never the get out of jail free card some fear it to be.

If you bring in to the discussion sociology and psychology, free will makes even less sense.

That being said, in her latest book she has a pretty strong argument against free will that does not require superdeterminisim so if that sounds interesting check it out.

E.g., I am in some universe taking every possible action right now, but I'm only experiencing the actions which I "chose" to take.

Furthermore it still removes any actual willed choice of path within the context of our existence. I am not some meta-entity seeing all possible paths and choosing one for some unknown reason. That would be an existential alien "haunting" me and not "free will".

(Of course, you could also just say the feeling is an illusion.)

I don't know if you can ever answer it one way or the other, because while consciousness certainly exists (again a fact I believe just because I feel it), it can't in any way influence the universe, at least per current theories of physics.

On the other hand, if you're right that many-worlds is real and our consciousness persists in all of them, then we will, individually, come to realize that is the case, as find ourselves still alive, forever, ever more improbably (since, I think, the odds of dying would never be 1, so you'll always be alive in some lucky world).

I believe someone called that idea "quantum immortality" and I find it conceptually interesting if not somewhat terrifying. However it does seem like the inevitable conclusion of these ideas.

I'm not sure I'm following the argument. Let me phrase it this way: can you devise an experiment which will determine if a given entity is conscious?

> I believe someone called that idea "quantum immortality"

(Thanks for the term; I'd heared the idea expressed before, but not that phrase.)

Skimming the wikipedia page, I didn't find any of the counter-arguments to be particularly compelling.

So, while I'm not sure how deeply I believe it (simply because it feels very unintuitive -- and I'm definitely not about to try to kill myself to test it!†), I agree with you: it really does seem like the inevitable conclusion of these ideas; I also agree it's somewhat terrifying!

Especially when you consider that as time goes on, probably in the majority of the universes where you are alive, you are just barely alive, clinging onto life by a thread, in great pain. The only consolation is that, perhaps, you'll still have enough awareness to think to yourself, "incredible that I haven't died yet -- I guess many-worlds really is true!"

(† Even if you are knock-down 100% convinced in quantum immortality, you probably still don't want to engage in wildly risky behavior or try to kill yourself -- because you will be killing yourself off in a large number of universes, and causing a lot of pain to your loved ones in those universe. A similar argument could be applied to engaging in any sneaky behavior which would cause significant pain if discovered.)

No, without being able to define what consciousness is we can't make an experiment to test for it. The simplest explanation in my view is that qualia are a base "element" of the universe and information systems and our consciousness is a loosely drawn subset of qualia associated with our brain/body's information system. To be clear this is not dualism, the qualia are not some magical thing riding on top of physics and cannot change the path of particles from their physically determined routes.

Regarding quantum immortality I don't know if it necessarily demands a universe in which some form of every person lives forever by some unexpected chance of quantum improbability. At least in terms of a continuity of normal life it may be that the probability of a person living longer than a human body physically can is zero. However some have argued there is a non-zero chance that random quantum fluctuations could lead to brief instances of a person arising from "nothingness" anywhere and anytime in the universe, and some of those persons could by pure luck happen to match the mind of a person elsewhere. However this does start getting into the realm of silliness and quantum randomness and infinite universes allowing for literally every possible combination of particles.

Yeah, intuitively somehow it seems absurd to think that "everything possible is happening", somewhere, in some dimension. It almost feels like a modern version of Zenos paradox. Like, in the limit, there are no universes in which you're alive...