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by lmm 2257 days ago
> Conway distinguishes Free Will from randomness by showing that randomness is just a special case of determinism. The random numbers could have been written down before the big bang and looked up when needed, which is still predetermined. What makes Free Will free is that it's the selection of some future state independently from the information in a particle's past light cone. Only the particle determines that part of its state.

That's a distinction without a difference - how would you tell whether the particle is magically looking up its results in the universe's big book of random numbers or deciding for itself? It's true that quantum-mechanical randomness is localised, in a provable sense, but there's no contradiction between that and what "randomness" is usually understood to mean.

> One implication is that our brains, being composed of particles, derive their free will from the sum of the particles' free will.

This is unfounded speculation.

2 comments

> That's a distinction without a difference - how would you tell whether the particle is magically looking up its results in the universe's big book of random numbers or deciding for itself? It's true that quantum-mechanical randomness is localised, in a provable sense, but there's no contradiction between that and what "randomness" is usually understood to mean.

one of the points the theorem makes is that you can't get the behaviour of fundamental particles by injecting randomness into an otherwise determinstic system. Free Will is different from randomness.

Have you watched the lectures ?

> one of the points the theorem makes is that you can't get the behaviour of fundamental particles by injecting randomness into an otherwise determinstic system. Free Will is different from randomness.

What is the distinction you're drawing, concretely? There simply isn't one unless you're using some very non-standard definition of randomness.

> Have you watched the lectures ?

I attended the 2005 version IRL.

> What is the distinction you're drawing, concretely? There simply isn't one unless you're using some very non-standard definition of randomness.

AFAIUI by noting that the dice could have been thrown ahead of time and then looked up, we can treat it as a function of time and then it becomes as though another part of the information in the past light cone which doesn't explain the behaviour of particles, as exemplified by FIN, MIN & TWIN

Right, so if you had a fixed dice roll in the past and translated that into the measurement results on each axis in a static way, that wouldn't work. You have to make a fresh random dice roll after the experimenter chooses which axis to measure - or you have to translate the past dice role into the result for the axis in a way that depends on which other axes the experimenter chose to measure.

I assert that this is not terribly surprising, and Conway is actually just doing a sleight of hand around the definition of "random". We would normally expect a truly random event to be (by definition) uncorrelated with anything else, in this case including counterfactual versions of itself - the random measurement you get from a given axis must not be correlated with the measurement you would have got if you'd measured a different combination of axes. That's maybe a little odd, but I don't think it contradicts people's normal notion of "randomness", particularly in a QM context. It's like how in early online poker games people would cheat by figuring out the "random seed" and know all the cards - because that's not real randomness.

and I reply that I just record the "fresh" random roll ahead of time and you look that up. Doesn't make any difference. I think you're confusing random with pseudorandom.
> and I reply that I just record the "fresh" random roll ahead of time and you look that up. Doesn't make any difference.

Well, per everything that Conway's said, it does make a difference - if the experimenter is somehow able to choose which axes to measure after all dice rolls have been fixed, and the mapping of dice roll to measurement result is fixed (and does not depend on which axes the experimenter measures), then that creates a contradiction.

To my mind that's normal quantum behaviour - we see the same thing in the double slit experiment or Bell's inequalities (which this is just a variation on). Quantum behaviour cannot be explained by rolling dice ahead of time, because random results in different possible universes/branches must be uncorrelated with each other, even though we tend to assume that only one of those branches "actually happens". And this result is a cool demonstration of that. But there's no contradiction between that and most people's normal notion of "randomness", IMO.

by "sleight of hand" of are implying Conway isn't being honest ? I think he was entirely sincere.
I hate to criticise him under these circumstances, and I'm going to leave out the more personal side of things, but: The impression I got was that he was playing up the "free will" angle to appeal to a popular audience, at the expense of the physics. Most academics with a book to sell do that to a certain extent, but I felt that he went past what's reasonable. I won't speculate as to whether that was insincerity as such or belief in his own hype.
maybe in that case you can help me see why Conway et al are wrong in this ? Because I'm only quoting here, and the paper is beyond me.
> This is unfounded speculation.

Strictly speaking, the whole discussion of determinism vs free will suffers from this defect.