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John Conway: Discovering free will (2011)

82 points| monort | 7 years ago |plus.maths.org | reply

134 comments

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[+] dekhn|7 years ago|reply
If you're an armchair quantum theorist, I have a suggestion. Rather than sitting around positing how the world works, build an actual quantum experiment, and spend some time just thinking about what's going on with your intuitive brain and comparing it to what you observe.

It's a bit pricey, but https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=69... is a full quantum erase experiment with a straightforward, visible path for the photons.

I personally found that arguing with people with pop-sci level of understanding of quantum to be pretty exhausting. If you can setup an experiment like this and understand it, it goes a long way to reconfiguring your brain to accept the counterintuitive implications of QM.

That said I still hold out an irrational hope for superdeterminism.

[+] theoh|7 years ago|reply
This is a teaching problem, because (like most things that are taught) there's no way for most students to verify it.

People who seek out areas of ambiguity or contested models in later life, after formal or professional education: good luck to them. They would surely benefit from your suggestion. But the rest of us are going to have to just believe what we are told, having applied certain personal heuristic filters to the info we are getting...

[+] montenegrohugo|7 years ago|reply
So it seems that quantum particles do not "choose" their state until observed. I've heard this multiple times now, including in this article (demonstrated by the 33 sticks analogy).

I'm curious, has any research been done on HOW they "choose" their state when observed? I imagine it is pretty difficult (if not impossible) to analyze this, but is there any insight of the factors that make a quantum particle choose its state? Or is the prevalent theory that it is completely random?

PD: I find this topic fascinating.

[+] n4r9|7 years ago|reply
This is basically where interpretations of quantum mechanics come into play. The maths/experiments alone don't tell you much. There are only a few things we can be sure of, e.g. the particle is not choosing a locally determined, pre-existing value as in classical mechanics. What you believe after that comes down to which "comforting illusion" you are most willing to ditch.
[+] sleepyams|7 years ago|reply
I think the insight is that there isn't really a built-in mechanism in particles for making choices, it's more that through experimentation we are _imposing_ a structure that forces a choice in an attempt to extract information. But we find that even when we force the system to make a choice, we get effectively no information and this appears to us to be a sort of complete randomness.

I interpret Conway's idea (in part III) to be that this is not a structural randomness, but rather randomness only in response to structure that _we_ impose during an experiment (e.g. determining spin), and that this is similar to our free will which is not structured (if you subscribe that that theory).

EDIT: I feel like I should clarify: at play here is the question of how mechanistic the universe is. If we accept that the universe is mechanistic, then we are forced into a position where we have to say (if we wish to avoid determinism) that there is such a thing as a "completely random" mechanism, and furthermore we have to effectively absolve free will of any structural restrictions by requiring that it is somehow part of our vitality as humans (call this mind-body dualism or whatever -- there is a long history of this debate). Obviously this is all beyond physics, but it is important to realize what assumptions we are implicitly requiring in order to discuss randomness and free will in this case.

[+] joe_the_user|7 years ago|reply
So it seems that quantum particles do not "choose" their state until observed. I've heard this multiple times now, including in this article (demonstrated by the 33 sticks analogy).

As I understand it (and correct me if I'm wrong), the particles give different distributions depending on how they are observed and these distributions vary in fashion distinction from how they would vary if there were underlying classical distribution involved - this gives "quantum logic".

[+] Viliam1234|7 years ago|reply
> I'm curious, has any research been done on HOW they "choose" their state when observed?

They do not. There is no "particle choosing", ever.

What happens instead is that you (the observer) are also composed of particles. This is something that people are kinda willing to admit, but afterwards they deny the logical consequence... that the particles that create you can also be in more than one state at the same time.

What happens instead is "entanglement", which means that certain options of one particle become connected to certain options of another particle. All options continue to exist, but only some of the relations between different particles exist. Specifically, when observe the particle, the option "particle going left" becomes entangled with the option (remember, you are also a system of particles) "you see the particle going left"; and analogically, the option "particle going right" becomes entangled with the option "you see the particle going right".

Now each version of you observe one specific outcome... and can ask themselves 'what made the particle choose this specific outcome?' But there was no choice; it's just that the other movement of the particle is entangled with a different version of you.

Yes, parallel worlds -- the true shocking discovery of the quantum physics. Actually, all physicists admit that parallel worlds exist on the microscopic scale, the only controversy is that half of them say "and it's the same on the macroscopic scale, too", while the other half goes "I can't believe in macroscopic parallel worlds, therefore there must be a magical thing called 'quantum collapse' which makes this madness stop before it gets too large". (The belief in quantum collapse in unfalsifiable, because no matter how large system of particles existing in parallel configuration you build, the possible counter-argument goes "but if you make it even larger, then it will finally collapse". And this goalpost can be pushed indefinitely.)

Unlike in science fiction, the parallel worlds of quantum physics have the property that the more they differ, the less they can interact. If they only differ in position of one particle (one world where the particle goes left, another where it goes right, but everything else is exactly the same), there is a lot of interaction. But if they differ in hundreds of particles, the interaction is almost zero. The disappointing part is that you can never observe the parallel universe directly, because - again - you are composed of particles; even your very act of thinking means moving millions of particles in your brain around... so just the fact that you noticed a particle moving left has put millions of particles in your brain in a different position than if you would have noticed the particle moving right.

The problems with thinking about quantum physics arise when we imagine that the microscopic scale is just like the macroscopic scale, only smaller. ("Particles are like oranges, only smaller, duh. Actually, they are more like waves on the lake. Anyway, must be the former or the latter, because those are the only options I am familiar with.") When instead, the macro scale is a statistical aggregate of the micro scale, so we can't observe e.g. things that get cancelled out by other things. Instead of trying to fit the micro scale into our everyday experience, the proper way is to study the micro scale by its own laws, such as probabilities being expressed by complex numbers, and then think how could our everyday experience arise from this, i.e. again, what laws would then govern huge systems of particles, such as ourselves.

[+] dingo_bat|7 years ago|reply
> "You mustn’t misread it, we’re not asserting these particles make decisions, we’re not saying they have any consciousness. What happens is they act, they indubitably act, and which action the particle does is free in this sense, it is not a predetermined function of the past. And that’s not the same as randomness, oh dear me no!"

Why not? Couldn't seem to find a reason for this assertion. If the behavior of a particle is not predetermined, how is it not random?

[+] popnroll|7 years ago|reply
I don't know if this adds anything to your comment; The input of a program is neither predetermined nor random.

If there is an input "out of our reality", then our reality would not be predetermined nor would it be random. (Which makes sense for the simulation hypothesis, which I enjoy having that conversation with my colleagues)

[+] dplavery92|7 years ago|reply
Conway talks a little about this distinction in his talk at Google, at around 40 minutes: https://youtu.be/r1bDSlt1n9M?t=2401

The crux is that randomness is indistinguishable from a large collection of pre-determined hidden variables (imagine rolling all the dice for all of the outcomes of Physics ahead of time), but not all of the behaviors of quantum mechanics can be accounted for by (local) hidden variables (Bell's theorem.)

[+] finmin|7 years ago|reply
Conway proves the existence of free will not by nebulous philosophical arguments but by a combination of quantum mechanics and relativity.

Note the definition of 'free will' here is specific: fundamental particles future states cannot be purely a function of the information in their past light cones and so only 'they' can fully determine their future state, and this is not the same thing as them having random number generators; they truly are free

[+] Rounin|7 years ago|reply
As far a I can tell from the article, Conway doesn't prove the existence of free will at all, not even attempt to do so. Instead he explores what the implications of free will would be if it exists.

And despite the claim to the contrary, his definition of "free will" isn't appreciably different from randomness, only he uses the word "randomness" to mean pseudorandomness, so he sticks the term "free will" on true randomness.

An interesting contribution to quantum physics, presumably, but not a proof of free will.

[+] atemerev|7 years ago|reply
For me, this is a bad name for the theorem. Free will is not just indeterminism, it also includes agency.

If I understood the argument correctly, there is still one possibility of global determinism: imagine a "God function", a random oracle that gives all results to all measurements, unpredictable but fully deterministic. Even if it can't be predicted from previous states of the world, it can still maintain some sort of "determinism". It can even be tractable: imagine a pseudo-random generator with some seed and "external" state as this God function. It should all work.

[+] nabla9|7 years ago|reply
The free will as it defined in this context means the ability of an entity to do truly __random__ choices not dependent on the surrounding environment or their causal history.

It does not mean that they can intelligently freely choose between the options. Any cognitive mechanism that does reasoned decisions is not free. It can just have a random or arbitrary[1] element in it.

I like how Einstein never mixed free will with true randomness. Used the better metaphor: throwing the dice.

---

[1]: What I mean with arbitrary is something that derives choices that are not relevant to the decision decision. For example pseudorandomness.

[+] dziungles|7 years ago|reply
I find the topic of the free will to be the most fascinating.

The abscence of the free will ('free will' as it is defined by the pop culture) is a revolutionary idea because the current world structures and narratives are based on the notion that free will exists.

It is a much more revolutionary idea than Copernicus' round Earth discovery, because the illusion of the free will influences our lives more and in multiple ways.

I'm also a strong believer that the society without the idea of the free will would be a much more compassionate, healthier and happy.

[+] coldtea|7 years ago|reply
There's an endless loop in this argument.

Per definition, if free will doesn't exist, then you can't say that "the illusion of the free will influences our lives more and in multiple ways."

If free will doesn't exist, then our lives, thoughts and choices are predetermined, and thus they can't be "influenced" by our belief in free will (or lack thereof).

In fact if we are in such a world, the we can't even opt to believe in free will or not -- since in such a world, our beliefs are also predetermined themselves.

The society wont be any more "compassionate, healthier and happy" in such a world based on any of its beliefs. It would only be compassionated, healthier and happy if its predetermined to be so.

The only option for your argument to work, would be for free will to exist while the society doesn't believe it does. Such a society, indeed, could be more compassionated, healthier and happy (it remains to be proven, but it's a possibility that non-belief in free will could change things positively, as long as free will exists for this non-belief to make a difference).

[+] glitchc|7 years ago|reply
It's been tried. Many times over. The type of society you advocate is a religious one. One would argue this is still the dominant model. In America, more than 50% believe in some form of God. Some nations are outright religious. Poland and Italy are ~85% accepted Catholic and over 95% if you include lapsed Catholics.

Most religions believe in predestination, in that God's Will supersedes man's will, everything happens for a reason, and our fate is decided the day we are born. Individual religious folk are more compassionate on average, take care of the needy, poor and downtrodden. Religious societies however, have led to intolerance, persecution and rigid class systems.

[+] imglorp|7 years ago|reply
> society without the idea of the free will would be a much more compassionate, healthier and happy.

I'm less optimistic.

What will keep people--resigned to their fate--from plopping on the couch to wait it out, as opposed to attempting something more ambitious? As someone famous said, if the outcome was certain, it wouldn't be a game; so if humans don't have some risk, some excitement, there will be no motivation.

[+] akavel|7 years ago|reply
I'm not really sure I understand what you're arguing for or observing, but notably, the article actually argues for free will existing (thus I assume not being an illusion), if you read it to the end:

> Although the Free Will Theorem can't prove if we have free will, it does have a fundamental consequence: if the Universe is deterministic, and a particles behaviour is always described by a function of the past, then we can’t have free will. And Conway is convinced that we do: "I can’t prove we have free will but I still believe that we do."

> While this and other repercussions are still being discussed by the mathematics, physics and philosophical communities, the theorem has had a profound impact on Conway himself. "It’s really affected how I look at the world. I believe that the glimmerings of freedom are in every particle – in the clouds, in everything – the particles are all taking free decisions."

> [...]

> And he immediately emphasises he’s not attributing some sort of consciousness to the particles. "You mustn’t misread it, we’re not asserting these particles make decisions, we’re not saying they have any consciousness. What happens is they act, they indubitably act, and which action the particle does is free in this sense, it is not a predetermined function of the past. And that’s not the same as randomness, oh dear me no!"

Though I'm still not sure to what extent this whole argument hangs on the third axiom dubbed "MIN", which according to the article, "isn’t experimentally testable" per Conway. Given it's also the one I don't-understand-the-most, I'm not sure how to look at the whole thing at face value. That said, the way they constructed the analogy, and how the article's author managed to approach it with an attempt at simplifying, are totally super interesting. I mean, that just the possibility of even constructing an analogy here (between something so vague and problematic to measure as free will, and something so material and experimental as behaviours of particles) is certainly stimulating for thoughts and some philosophical pondering.

[+] tmoravec|7 years ago|reply
> I'm also a strong believer that the society without the idea of the free will would be a much more compassionate, healthier and happy.

There's a major religion where one of the main theses is that everything is predestined. I haven't noticed those societies to be significantly more compassionate, healthier, or happy.

[+] zaarn|7 years ago|reply
If we discovered free will doesn't exist, provably, which is my current position, I don't think anything would change.

The illusion that we have free will was strong enough that we used law to keep everything in line, make people responsible for their actions, etc.

I see no reason why either side of the coin would or should stop that behaviour.

If our actions are a result of our environment, shouldn't the environment to the best of our ability be changed such that negative actions have a lower probability of occuring?

With free will you punish people for a crime because it's their fault. Without you punish people to create an environment in which crime is not desirable. (Though resocialization / rehabilitation is probably a better option)

[+] 8bitsrule|7 years ago|reply
Absence... is a revolutionary idea

Indeed. For one thing, if it were true, then everyone who's ever been convicted of a crime and punished has been the victim of a complete fantasy ... imposed on them and us by fate.

Stereotypes, biases, hate crimes, going to war or not, building the pyramids or not, painting the Mona Lisa, creating a symphony ... picking this flower or not, falling in love or not, discarding a cigarette butt on the beach ... all equally driven by immutable, unstoppable fate?

That's not happy.

[+] posterboy|7 years ago|reply
You are free to do so, but talking in absolutes won't get you anywhere. There's the will to be free and the will to be content, not to say contained. These are two extremes and the target is in the middle, if and only if this is really just a two dimensional thing ... If you wonder how two dimensions can have a middle, think of negative and positive parts of the number line as individual axis ... I havent' figured out the maths, it's not a normed vector space, though.

Either way, people strive for consistency, but will is a highly inconsistent notion. So there must be more angles to the equation.

Free will is an oxymoron, or the homogenous solution ignoring higher orders at best, because will immediately constrains freedom.

[+] austinjp|7 years ago|reply
Well that's a cliffhanger. How would that society be all those things?
[+] flabbergast|7 years ago|reply
Free will does exist, only we don't have it. We live in our own little world of illusions, thinking and dreaming. In reality every random influence can change our path.

Reality only exists in the present moment; just try to "be" there for a few minutes (without thinking) and you realize you don't have "free will". These are qualities that come with a huge price that almost none of us can or want to pay for, mainly because we love to dream we already have it.

Examples of people with free will are: Jesus Christ, Buddha, etc..

[+] montenegrohugo|7 years ago|reply
I'm curious as to what your theological beliefs are? How come you list Jesus (which I would understand if you are christian) but also, in the same breath, Buddha?
[+] thefranke|7 years ago|reply
The whole free will debate always falls flat on its face because the distinction between free will and free choice is never made. You may not have free will, but you have natural tendencies that you gravitate towards. However, these can only be expressed if you have the choice to do so.

There is a joke that I think captures this philosophy of Compatibalism quite well: A reporter asks a citizen in Pyongyang to comment about life in North Korea. The citizen answers "Well, I can't complain".

[+] posterboy|7 years ago|reply
Ensembles can disentangle, right? Then, if measuring only one side, how do you know the other side is entangled? How did experiments establish entanglement anyway? If you measure hundred runs and all correlate, sure you can say the next one will too, but that's literally a predetermined outcome.
[+] stultifying|7 years ago|reply
Okay, but it still doesn't mean the particle passes through both slits.
[+] bloak|7 years ago|reply
"Conway thinks the free decisions of the particles inside us might account for our own free will."

Another mathematician, Roger Penrose, made a similar claim, but with "consciousness" instead of "free will".

I find this very implausible. So does Douglas Hofstadter, probably, though I've not yet read his main book on the subject.

Thought experiment: You make a mathematical model of how neurons work, you cut up a human's brain, and you build a machine that simulates it. Wherever the model required randomness, you use pseudorandom numbers, generated cryptographically, so the entire system is deterministic. You connect it up to some kind of humanoid robot. Does the resulting system behave roughly like a human, and, if so, does it have free will, and is it conscious?

People who believe that consciousness or free will depends on fundamental physics have to believe:

* Either that the simulated human won't work like a human: it will mysteriously fail to function, but how exactly?

* Or that the simulated human will seem to work like a real human, but nevertheless it won't be conscious; it will be a mere "zombie".

The first option seems intuitively implausible to me, and the second option sounds like silly sophistry.

[+] wool_gather|7 years ago|reply
> I find this very implausible. So does Douglas Hofstadter

Dennett does a good refutation of Penrose. There's some in Darwin's Dangerous Idea (I think; might be confusing it with Consciousness Explained), but he finishes the job in Freedom Evolves

Long story short, his assertion is that the contradiction between determinism in physics and free will in humans is a category mix-up, not a true contradiction. There are so many layers between the two levels, so many interactions, that when you get to the top level at which we consider an coherent blob of "matter" called an "organism" -- with a "brain" even -- there really are things called "thinking" and "free will". But way down at the level of molecules, those concepts aren't even nonsensical; they're just meaningless. To talk about free will, you have to have a very high vantage point. And that's why it gets confusing when you go back down to the building blocks.

This is similar to the systems argument against Searle's Chinese Room: the phenomenon we find so interesting disappears when the system is broken down, exactly because it's an emergent product of the system.

There are analogies I could make, but I'd probably miss something, so I'll leave it to Dennett (he actually uses the Game of Life to make his point). I highly recommend reading Freedom Evolves if you're into these ideas. Very thought-provoking, especially for its compact length.

[+] foldr|7 years ago|reply
In the case of free will I don't see any intuitive implausibility. It's intuitively plausible that someone/something could exhibit human-like behavior without actually having free will. After all, some people think that regular humans fall into this category!
[+] goldenkey|7 years ago|reply
They probably would be conscious too if QM randomness is psuedorandomness. It is not known whether Quantum Randomness is special. It could be the result of deterministic pseudorandomness. All randomness might be either complex scenarios with insufficient information or algorithmically random sequences..

Here is a good in depth article by Scott Aaronson on this: https://www.americanscientist.org/article/quantum-randomness

[+] finmin|7 years ago|reply
a) Penrose' claim is about something completely different, namely the non-algorithmic computational abilities of the brain by quantum-gravity effects

b) intuition is irrelevant - this is a proof of the physics of free-will, it doesn't matter how 'plausible' it sounds. Quantum mechanics isn't intuitive either - why should it be ?

[+] DesiLurker|7 years ago|reply
It seems to me your assertions assumes that the randomness you get out of a quantum mechanical system is essentially same as psuedo-random sequences in quality. which may very well be true functionally (as in being able to simulate specific behaviors) but it is still completely deterministic (unless you use a true random event like decay of a nuclei etc). Until then your option-2 fall into the phys-zombie mode.

If I peer deeper into that line of thought I'd say it assumes that consciousness is simulate-able by physical deterministic processes and then goes onto say Ah look the behavior is indistinguishable so we have simulated the consciousness. BTW you can tell I am not a believer in turing tests like setup for 'measuring consciousness'. IMO its of a completely different nature.

here is my take: Could it be that consciousness needs quantum mechanics to actually 'express' itself in human brain? this is borrowed from Penrose's Orchestrated-Objective-Reduction thesis. if so we could have either of those outcomes depending on the sophistication of your simulation and handling of various perturbations in human brain architecture. personally I lean more towards this option, especially after learning that QM processes play more central role in biology than we thought originally despite 'it' being too warm, wet & noisy. In short, if there is any evolutionary advantage to be had from QM effects, biology will adapt to exploit it.

I'd argue Option 2 is not silly sophistry if you consider following scenario:

1) Lets say we create a planet sized computer with enough capacity to simulate every human being in the way you described. then we decide Ah we dont need to be in meatspace anymore because what difference it makes anyways.. so we simulate all human minds and 'upload' each human into this computer. now if we are wrong about consciousness then essentially we would have willfully committed genocide on our own race (& every other living thing).

2) suppose we develop a Opt-2 based super-intelligent AI which is way better then us at everything. now why should it keep such resource hogs as humans around? IMO precise definition of consciousness matters quite a bit here as it creates a quality worth preserving/exploring further.

[+] popnroll|7 years ago|reply
Oh boy, I know this is arrogant; It's pretty easy to show evidence of determinism. 1) Read my brain, check if in ten seconds I will say yes or nothing. 2) Don't tell me. 3) Wait ten seconds. 4) Compare results. I'm aware of the experiments of reading brain decisions faster than our consiousness (machines telling which button we will play "before we realized"). No, no psychomotor tricks. Just read my brain, don't tell me until I made my choice. If you get 100% I believe you, meanwhile, no evidence.
[+] ppod|7 years ago|reply
>no evidence

Why do you assume that the null hypothesis is free will?