This would be more fun in a blog post. Twitter is a fucking horrible format for a complex analysis of special relativity.
That aside, my favourite quirk from relativity is this:
"The more you move in space, the less you move in time."
Like relativity in general, it sounds simple enough, but it's consequences are profoundly shocking. (That is, if you take the time to understand it, and don't leap to the conclusion that you know relativity better than Einstein or Penrose ;)
Take the case of two people on Earth, one stationary and one travelling past in a car. They each have a different reference frame, and a different set events which make up their present. Now imagine that there is an alien government in Andromeda debating a possible invasion of Earth. In the reference frame of the person on Earth who is moving, the debate is still going on. But, in the reference frame of the stationary person, it is a day or so later in Andromeda, and the invasion fleet is already on it's way! In nature there is no absolute reference frame we can call base reality, and both observers reference frames are equally valid. Then the outcome of the invasion debate is a foregone conclusion. How can there be any room for free will in the deliberations of the alien government? This is the crux of the Andromeda Paradox and the Reitdijk-Putnam-Penrose argument.
BTW:
"Notice that neither observer can actually "see" what is happening in Andromeda, because light from Andromeda (and the hypothetical alien fleet) will take 2.5 million years to reach Earth. The argument is not about what can be "seen"; it is purely about what events different observers consider to occur in the present moment."
Edit: If you know of any serious alternatives to the 4D spacetime/ block universe theory then I would love to read it. Rescuing free-will from the jaws of spacetime would be cool!
Rescuing free-will from the jaws of spacetime would be cool!
Free will does not exist. It is logically inconsistent. Either your choice is some function of your current state and the environment you are in, then the choice is not free, or it is independent of your current state and the environment you are in, then it is not your choice in any meaningful way, it is just the result of a coin flip.
You can do some mental gymnastics, define free will as being able to do what you want, define it as being free of various kinds of constraints, call it free if the choice is not computable in advance, if you can not measure all necessary variables, in practice or in theory, ... If you are happy with any of those definitions, fine, then you might have this kind of free will, but I would not consider any of those particularly interesting.
You’re trying to apply logic to an untestable philosophical debate. If you believe free will doesn’t exist, you can’t design an experiment that would invalidate that belief. And if your theory is untestable and unfalsifiable, then what good is it other than a creative exercise?
However, we do know from Quantum Mechanics that the universe is probabilistic and not deterministic:
So, we do know that the universe is not pre-determined and cannot be calculated in advance, but if you want to believe in humans as fully deterministic (or some other definition of no free will) inside of a non-deterministic environment, I haven’t heard anyone propose an experiment that could test that, at which point the debate of “free will” is relegated to the realm of thought experiments rather than science.
So, perhaps the better question is: Does it serve you better to believe there is free will or no free will? And leave it at that.
> You’re trying to apply logic to an untestable philosophical debate. If you believe free will doesn’t exist, you can’t design an experiment that would invalidate that belief. And if your theory is untestable and unfalsifiable, then what good is it other than a creative exercise?
This is reversing the burden of proof. The issue with "free will" is getting those who think there is a meaningful "free will" concept to actually define what they mean.
Look through this discussion and see the comments trying to justify the existence of free will, and look for definitions of what they actually mean by that.
> However, we do know from Quantum Mechanics that the universe is probabilistic and not deterministic:
That's a meaningless distinction in this context. The point is that nobody has presented a mechanism whereby you can inject any form of agency that fits a definition of "free" (see your own point: define "free") that doesn't devolve to smoke and mirrors that way.
In order to do so, there'd need to be something that would lead to measurable biases in outcomes that can not be explained by the probabilities.
The rest of your argument devolves to Russel's teapot: As long as nobody has posited a reasonable definition that'd give rise to a theory of what free will might mean, the notion is so absurd that it is entirely reasonable to say that free will makes no sense.
If you can present a definition that can't easily be shown to be just smoke and mirrors and which somehow makes sense to people, even without coming up with ways of actually testing it, I might be tempted to moderate that claim, but I've had these discussions with people for decades, and in none of them have anyone ever managed to come up with a cohesive definition of what free will would even mean that doesn't very easily start looking distinctly "unfree".
There are clearly definitions of free will that would allow something you label with that term to exist. But I challenge you to come up with one that people would agree is both "free" and "will".
No, in response to someone vaguely mentioning the words “free will”, you made the claim: “Free will does not exist.”
The burden of proof is now on you to provide evidence of your claim as well as on you to define the terms contained within your claim.
I am not arguing the “free will” debate either way for the reasons mentioned previously and do not care to define the terms as the entire debate is nothing more than a creative thought experiment as far as I can tell.
If I claim Russel's teapot doesn't exist, the burden of proof is on you to prove it exists if you disagree with me, not me, because the set of claims that are so poorly defined and unlikely as to make it an unjustified burden to expect anyone to caveat the claims to make them technically correct is infinite - someone who makes an extraordinary claim without being able to provide a justification therefore needs to be prepared to take on the burden of proof.
I equally claim that santa doesn't exist, and yet will insist the burden of anyone disagreeing with my claim lies on them, not on me, even if I make the initial claim, for exactly that reason.
In this case the claim that free will does not exists puts the burden on those who disagree *because nobody here or otherwise* have presented a definition of free will that most people would agree to, not least because without narrowing the scope with a definition I have the freedom to apply whichever definition I prefer, and I have several places in this thread.
E.g. I'd argue that "free will" would require an entity to be able to do something which cannot be explained by the combination of determinism and randomness. Given we're unaware of any kind of processes that can produce outputs that are not either deterministic or random modulated by some sort of probabilistic distribution, to claim that a process that can produce such an output exist is an extraordinary claim that would give you a Nobel in physics if you could demonstrate it.
As such: Russel's teapot.
I'd love to be wrong. I'd love for someone here to come up with a definition of free will that overcomes that problem, as if so I'd be witnessing a revolution in philosophy surpassing anything we've seen in centuries.
Just like I'd be delighted to be wrong when I say that santa doesn't exist, but I do believe I'm far more likely to be proven wrong about santa than free will, given that people can at least come up with definitions of santa that are somewhat coherent if unlikely.
The difference between free will and Russell’s teapot IMO is that free will to many is an internal, subjective, untestable experience whereas Russell’s teapot is an external object that is theoretically existent or non-existent for everyone regardless of their internal experience.
If someone says they experienced free will today when they chose to stand up, it’s on you to disprove that it couldn’t possibly happen to anyone ever, or come up with a definition of free will that means they couldn’t possibly experience what they claim to be experiencing. To them their experience is real. You’re claiming it’s not, so I don’t think Russell’s teapot applies here. I think you have set forth a bold claim that someone is not experiencing what they report they are experiencing.
> I'd argue that "free will" would require an entity to be able to do something which cannot be explained by the combination of determinism and randomness
What is your benchmark for determinism? No technology we have can predict or determine a human action. While it’s reasonable to assume that humans are deterministic, it’s still just a theory at this point. If I put the onus on you to prove determinisms in humans, you’d certainly win the Nobel as well.
That’s kind of my point is that both sides of the free will debate are a far cry from having enough evidence or the ability to conduct an experiment to settle the issue. Yet many believe they experience free will everyday and many don’t, because it’s a subjective experience.
If someone says they experienced free will today, the claim is ludicrous without a definition.
As such it's on them to first state a complete hypothesis of what happened to them, because absent that it is not even possible to start disproving it, and so rejecting it out of hand is perfectly justified just as much as it's justified rejecting Russel's teapot.
> What is your benchmark for determinism?
That everything we have so far observed with any kind of precision has turned out to be predictable to our level of precision or to show no sign of deviating from randomness.
Determinism is also a falsifiable theory: All you need to disprove it is to show the existence of a type of events which are biased in ways which can't be explained in a mechanistic or by randomness.
The total lack of such examples, despite a very substantial amounts of claims, which always collapses under scrutiny, gives me as much confidence in determinism as in gravity.
Our understanding of gravity could be massively off too - I'd consider it far more likely that we'll need to revise our understanding of gravity than determinism, because a non-deterministic model would require a fundamental change in logic to accommodate another category of causality which can not be modelled as a computation over a combination of mechanistic determinism and randomness and without just introducing regress (the last part there is essential to rule out "God did it" or "we're in a simulation" answers, both of which just lifts the question one level up).
The first step in falsifying determinism is to actually find a way of determining whether or not an event fits that criteria to show that it's even logically possible for such events to exist. Just that would get your name in the history books. Of philosophy anyway. And if anyone could present a logically sound argument for how such events could exist, it would seriously shatter my world view. I'd love that anyway because it'd force us to rethink a whole lot of things about the world from scratch. Unfortunately I think I'm more likely to meet santa.
> Yet many believe they experience free will everyday and many don’t, because it’s a subjective experience.
People's subjective experience is not in question. I feel like I make free choices every day as well. I feel like I'm exercising one right now in choosing to answer you. That does not give me any reason to presume that feeling reflects the underlying processes. That subjective experience have no bearing on the issue.
In science, when testing the existence of something, the burden of proof is generally on the one hypothesizing the existence. The existence is generally accepted if experiments fail to reject the hypothesis.
But free will is a concept, a way of viewing the world. It’s not a physical object or mechanical process that can be tested. It’s why trying to prove it scientifically or through logic is just as impossible as trying to disprove it.
It’s a philosophical debate, not a science experiment. In philosophy, a declarative statement asserting the affirmative is always true is just as big a fallacy as saying the negative is always true.
That's quite literally the opposite of how Russel's teapot works. Russel originally thought up that scenario to show how silly it is to put an unprovable idea forward (specifically the existence of god, which Russel absolutely did not believe in) and expect another party to disprove it when doing so is impossible. Here in this thread you've put forward an unprovable idea and now expect others to disprove it, which is the exact scenario Russel criticizes. How on earth did you interpret it so wrongly that you came out with the exact opposite of the message that Russel intended?
However, we do know from Quantum Mechanics that the universe is probabilistic and not deterministic
That is not true, quantum mechanics - more specifically the Schrödinger equation - is deterministic. What is not deterministic is the wave function collapse but that is also incompatible with the Schrödinger equation because it implies non-unitary evolution of the wave function. And we have - as far as I know - no really good ideas how to resolve this. In consequence I think it would be premature to declare that the universe is definitively non-deterministic.
The article you linked to seems to say the universe is indeterministic:
> Indeterminism in Quantum Mechanics is given by another "evolution" that the wavefunction may experience: wavefunction collapse.
I’ll give you that it’s not a fully settled issue though:
> According to the Copenhagen interpretation of QM, it does mean the universe is non-deterministic. There are other interpretations of QM which allow for determinism though. Which is the correct interpretation (if any)? Currently, no one knows.
> However, we do know from Quantum Mechanics that the universe is probabilistic and not deterministic:
This is not true, and there are consistent interpretations of QM that are fully deterministic (many worlds, superdeterminism, pilot wave).
Still, probabilistic vs deterministic makes no difference. There is no free will in a throw of the dice, and no free will in the wave function collapse.
On the other hand, the main philosophical position on this is compatibilism: free will in a fully deterministic universe (or probabilistic one). If you think of yourself as the sum total of all your experiences and genetics, your next action is of course determined by these; but, another agent in your shoes, one with different experiences and genetics, would make a different choice. So in this framework, your choice, even though uniquely determined by everything that happened before, and theoretically predictable 1000 years in advance, is still meaningfully "your choice".
In fact, random chance hurts this definition, and weakens the case for compatibilism; if your next action is entirely dependent on some random quantum fluctuation, and running the experiment with your exact same experience and genetics but a different random quantum event at this exact time would produce 1000 entirely different actions on your part, then it is very hard to imagine any kind of free will. So, free will actually depends on some amount of determinism. Even the type of determinism in Many Worlds would not solve this - since in that interpretation, all possible outcomes of the quantum event actually happen, so all your "choices" that depend on the random event are fully real. So, if each of the fully real copies of you, with the exact same experiences and genetics, does a wildly different thing, then it's pretty clear there is no meaningful free will in any possible sense.
I find the most satisfying version of compatibilism one where an agent is mostly determined by 'state' (genes/experiences etc), but the subjective experience of expending mental effort (e.g. when overcoming an addiction) is the agent nudging the wave function collapse this way or that. Add in the ability to influence future 'states' and one has a model much more consistent with the subjective experience of making difficult choices.
That's not compatibilism - as long as "will" can influence the physical world, you have a non-materialist philosophy. Nothing wrong with that, but it's very strange to call it compatibilism.
For what it's worth, I don't see any reason to imagine that hard decisions are of any other quality than easy decisions. It's part of my history and experience just as much that I prefer to eat salty foods than sweet ones as it is that I sometimes abstain from eating that pizza to try to manage my waistline, or refuse that job offer because I don't want to work for a company I don't find ethical.
Good to know - from the context I thought compatibilism simply meant that 'will' could influence the physical world and the physical world got to have a say as well.
But I'm not sure what to make of your second paragraph - doesn't saying there are hard and easy decisions require there be a difference of quality between the categories?
Compatibilism refers to the position that "free will" can be meaningfully accepted to exist in a purely deterministic world. It is the position that even if we accept that your actions 10 years from now could have been predicted with 100% accuracy the very second the Big Bang happened, we can still hold that you have free will in a meaningful sense. The name refers to the idea that free will is compatible with a perfectly determined future.
> doesn't saying there are hard and easy decisions require there be a difference of quality between the categories?
Not necessarily. There is a difference of "quantity" if you want, but not quality. It's like the following model: it's easy to compute 1+1, and it's hard to compute 19312123+123468. But they are not qualitatively different, they don't need different explanations: they both have the same nature, they use the same algorithm, one is just a bigger amount of state than the other.
Does your non-materialist theory involve true randomness (which is not really making a decision), or is it just more mind-stuff behaving deterministically in another dimension (which is not really free will)?
I think the standard position of free will non-compatibilists is that there is some dimension of mind whose future at any time T is not uniquely determined by its state at time T-1 (but it is influenced by that state, it's also not purely random). In this model, each agent possessing free will has a series of possible choices with "weights" for each choice pre-determined by the prior state of the agent (their history, their racial instincts etc). Which choice the agent will select cannot be known in advance. Usually it is implied that the agent has a resource of "will" that they must expend more of to select one of the choices with higher "weight". After the agent selects one particular choice, the universe proceeds deterministically (or probabilistically) until the next moment when an agent must make a choice. Whether this phenomenon is happening directly in material reality (the agent can influence wave function collapse or some other such idea) or it is happening in a separate world of mind/spirit and then there is some miraculous reconciliation of the two worlds is somewhat irrelevant.
Well, I model cognition and decision as energy in architecture. The Architecture dictates what adjacent states are available and what the default likelihood is of each. The more the energy expands itself because of its preferences, the more it can nudge the outcome towards one of the less likely adjacent states. Any outcome changes the state of the architecture and the architecture changes the state of the energy, so the two engage in a kind of coevolution.
Here's why I believe in free will: The preferences of the energy are subjective, not objective[1]. Its inputs are dictated by the architecture it resides in, but the meaning it attaches to them are determined internally and infinitely[2] more complex. So for example, someone who loves exercising gets very much the same nerve signals as someone who hates it. The difference is in the meaning each attaches to the experience, and meaning is not objective.
[1] AKA 'the hard problem of consciousness'
[2] Insofar as internal communication happens across a higher-dimensional manifold than its communication with the architecture. For ease of visualization I imagine a three-dimensional gas interacting with the two-dimensional surface of a building, but I am working on a model that properly accounts for time.
If only any other system of thought could make any kind of verifiable prediction, it would be wise to reject materialism. As it is though, you either have magical systems of thought, that reject the very framework of science; or ones which amount to materialism plus some handwaving.
Oh I accept that, but I'm also wary of theories that seem to handwave material reality. I've found Dione Fortune's writings the most useful in that regard, though she can be... obscure. Quite influential all the same.
"Free will" is a gesture at the experience we have of deliberating upon and deciding our own actions, I don't think determinism really matters, as long as we're the ones doing the deterministic calculations by which we choose what to do.
But it's okay, I understand if you have no choice but to argue with that.
>So, perhaps the better question is: Does it serve you better to believe there is free will or no free will? And leave it at that.
From a pragmatic analysis the answer is pretty straightforward[1] (Spoiler, believing in free will is better if you value moral behaviour). Glad I chose to believe in free will!
I don't think that would be the best option. There is nothing wrong with figuring out that we don't have true free will - however you want to define it - and still behave in everyday life as if we have it. It might just be a useful abstraction.
The study I linked indicates that people who don't believe in free will act as if they don't, granted, they weren't warned of the dangers of believing they don't so there might be more to explore.
But the question seems to me more about pragmatism vs realism than pragmatism vs. realism with 'some beliefs-as-if'. I find realism unsatisfying philosophically because we can see historical beliefs being so off the mark that we'd have to live in a pretty special time to have anything close to a realistic model of the universe, I think making good predictions is simply the best tool that we have. If that comes at the cost of having a single internally-consistent model of the universe, that's unfortunate, but at least I'm not attached to the wrong one. So if my belief in free will and my belief in Newtonian Mechanics are incompatible, that's not such a big deal to me as a pragmatist. In fact it's a useful feature of the metaphysics, since the places they come into conflict give an idea of where they're incomplete.
It doesn't seem worth spending much time here, lest the entire argument becomes nothing more than a semantic one. If your definition of "free will" is "this thing that I undeniably feel" then sure, you've made it undeniable by definition.
>> However, we do know from Quantum Mechanics that the universe is probabilistic and not deterministic
Do we? Quantum mechanics looks like there is genuine randomness, but one interpretation of experiments testing the Bell inequalities is non-locality. It could be completely deterministic, we just don't know what determines it.
Or maybe it is. Didn't some big name physicists "prove" that if humans have free will then so do electrons? Not sure why it has to be an inherent property rather than an emergent property, but I just read the summary.
You can dismiss them as “mental gymnastics” but defining the term is the heart of the discussion. Philosophers argued about gravity and heat a lot too before we settled on rigorous physical definitions that could be expressed mathematically.
At a first approximation there are obviously limits to our “free” will as no one has yet been able to will themselves to float through the air without support, go without food or water indefinitely, pop a pet dragon into existence, survive the physical destruction of their brain, etc.
So it’s hard to start from a position that anyone ever seriously thought “free will” meant no limits or dependencies.
Mental gymnastics was probably not the best choice for the wording. What I really meant is defining free will as something that is in a certain sense trivial. If you want to call making choices according to your personal preferences free will, fine, but this is a triviality and we don't need to debate over this for centuries. And the next guy looks into the predictability of decisions and assigns free will to an entity if its future behavior can not be determined with certain resource constraints. Fine except that the term is now overloaded, you might have the first but not the second kind of free will and both properties are not well described by the term free will.
You've put the dilemma nicely - it can't be both 'free' and 'your will' by your definitions (well, without admitting supernatural beings that can affect and be affected by the natural world, but are not part of it).
Personally I'm happy with other definitions, not because I feel I'm doing mental gymnastics, but because the version you give is clearly not what normal people mean by it when they refer to it. It might well be related to what philosophers argue about, but normal people who offer you a 'free choice' or who say that you did something 'of your own free will' do not mean anything like 'your choice was not a function of the state of the universe'.
Despite being happy with those other definitions that you aren't, I'm equally skeptical of the idea that free will has to be rescued just because different points in time can be observed simultaneously. What does someone even mean by free will if it can't cope with that?
> Personally I'm happy with other definitions, not because I feel I'm doing mental gymnastics, but because the version you give is clearly not what normal people mean by it when they refer to it. It might well be related to what philosophers argue about, but normal people who offer you a 'free choice' or who say that you did something 'of your own free will' do not mean anything like 'your choice was not a function of the state of the universe'.
There's certainly a duality here where it's fine to talk about people having choices even if one strictly believe they don't, but my experience is that if anything people tend to often get exasperated or outright agitated if you try to question to what extent their decisions are free. A whole lot of human society is organised around the idea that we have agency and that we're the product of choices we've made of our own volition.
E.g. if you genuinely believe the notion that we have free will is nonsense (and I do), then the logical extension is to be very uncomfortable with the notion of e.g. prison used for vengeance or anything at all other than to the bare minimal extent required to protect others, because the logical conclusion of thinking people don't have agency is that there was no way other than other external stimuli in their lives that they could have come out making other decisions.
It's a very uncomfortable thing to view society through a lens of seeing free will as an illusion. But it's also very hard to unsee the lack of any kind of coherent theory of free will that could justify anything else.
The reality is that if you actually talk to people about this, you'll quickly find that most people go through life with a very strong belief that they have agency and that people around them have agency, but the moment you start to question what that belief is based on, the basis for it tends to start to crumble very, very quickly. As I've said elsewhere, in decades of discussing this subject I've never seen someone come up with a definition of "free will" that still looks either "free" or like "will" under scrutiny. Usually you end up with people trying variations of arguments that just leads to infinite regress (e.g. arguing our soul gives us free will, at which point the question just shifts to a definition soul that would give it agency).
> if you genuinely believe the notion that we have free will is nonsense (and I do), then the logical extension is to be very uncomfortable with the notion of e.g. prison used for vengeance or anything at all other than to the bare minimal extent required to protect others
Not really. You can view it as a game theoretic situation. Will the use of prison likely produce a good outcome or a bad outcome? Whether or not the criminal was deterministically required to commit the crime, the structure of punishments will (perhaps deterministically) affect the incidents and severity of future crimes.
Just because the creature in Black and White may have made decisions deterministically doesn't mean I won't punish it if it behaves in an inappropriate way. If anything, believing the agents are deterministic would make me even more keen to punish in situations where it will change behaviour usefully.
You are just agreeing with the OP here. The point is that prison is useful for some things, eg protecting others, changing behavior etc. But if there is no free will, then it makes no sense to say prison is for vengeance.
These discussions are always interestingly recursive, since if I do not believe in free will then my own view on free will is itself not a free choice. And yet I still feel strongly that my not believing in free will appears to be my free choice.
This is what I mean by setting vengeance up vs. "the bare mininal extent required to protect others".
I agree that there are still people who needs to be locked up, including under possibly brutal sentencing terms. E.g. Anders Behring Breivik who carried out the 2011 terrorist attacks in Norway is up on a parole hearing today - if he gets out (it'd take a miracle) it doesn't matter if it's free will (in any sense of the term) or purely deterministic processes that leads him to act if he is still probabilistically likely to carry out another attack - it's still more important to keep the public safe from him than to worry about whether or not he had a genuine choice.
To the extent there's a measurable effect of seeing the punishment of others, that too might be a justification, though I find that dicier. But if that is done based on a cold calculation of how it affects offending rates that to me is still very different from vengeance.
So to be clear I'm not arguing it removes the justifications for punishments, and I agree with your mention of seeing it as a game theoretic situation - even really harsh punishments might be the best choice in some circumstances. But it removes "they chose this themselves" or "they deserve it" as a justification (the feeling is still valid; acting on it becomes cruel), and that makes for a very different legal system. It also shifts a focus towards considering that if it's not about vengeance, then you should look at how to actually optimise the balance between the public good and treating the prisoners as humanely as you can without reducing the public benefit of the punishment too much.
Norway is far from achieving that, but if you look at e.g. Bastøy fengsel [1] ([2] has links to assorted longer articles), you can get one idea of what de-emphasising vengeance and taking rehabilitation and trying to address reoffending rates might start to look like (though Norway has by no means solved that, Bastøy also certainly haven't made it worse, but it also is not the norm in Norway either - yet anyway). For some people, it might well be that harsher prisons works better, or are necessary (I doubt Breivik will ever get the chance to serve his time somewhere like Bastøy for example). (Bastøy is the - so far - culmination of a process of reform that started in the 1960's, at a point where Norwegian prisons were quite brutal and the brutality of it eventually triggered a strong counter-reaction.)
For others even less prison (Norway as it is have sentences that would look comically short for e.g. Americans or British people). But evaluating it as a "game theoretic situation" as you say would in any case very likely lead to very major change to how the legal system would work most places in the world (including Norway)
It seems that we agree that taking a game theoretic view can justify more than just 'the bare minimal extent required to protect others' as it can also include questions of setting examples and letting justice be seen to be done that can form part of the decisions of other future potential criminals, or victims who might feel like taking the law into their own hands.
So, as to 'they chose this themselves', that's begging the question a little - as we've already seen I think that believing in determinism doesn't stop you from believing that people can choose things. As to 'they deserve it', questions of what people deserve is a huge other topic, and I think it's most likely possible to define desert in terms that fit within a deterministic viewpoint.
However, perhaps you're right about its effect since I do in fact think that vengeance is a thoroughly dumb rationale for treating people badly. This is to such an extent that I'd feel surprised to find anyone seriously try to justify it, which is why I didn't really engage with your apparent suggestion that it was an important justification. There are lots of ways you can try to justify criminal punishment in my view but 'vengeance' doesn't fit into any moral system I consider valuable unless it's actually being used as a code for game theoretic concerns or rehabilitation.
But I don't feel so strange thinking this, since most people I know think the same, even those who don't share my views on free will and I'm pretty sure I believed it before I came to that conclusion on free will.
> This is to such an extent that I'd feel surprised to find anyone seriously try to justify it, which is why I didn't really engage with your apparent suggestion that it was an important justification.
I mean, a key example of how vengeance still plays into punishment is the level of support for capital punishment.
I'm glad we find it equally unjustified.
Also, I agree that you certainly can dismiss vengeance as a valid argument without dismissing free will, btw. - a lot of people who do believe in some variant of free will absolutely do reject vengeance. My point was more to offer up an example of something that is very hard to reconcile with rejecting free will.
> E.g. if you genuinely believe the notion that we have free will is nonsense (and I do), then the logical extension is to be very uncomfortable with the notion of e.g. prison used for vengeance or anything at all other than to the bare minimal extent required to protect others, because the logical conclusion of thinking people don't have agency is that there was no way other than other external stimuli in their lives that they could have come out making other decisions.
I think this lacks imagination for human cruelty. If they had no free choice but to steal my things, then I guess I don't have any free choice but to torture them in revenge. Hard determinism does not erase the possibility of punishment.
It doesn't erase the possibility, of course. It doesn't even erase the possible moral justifications for punishment. I was very specific with my wording there for a reason: It does erase the main moral justifications used for vengeance.
With respect to using hard determinism as an excuse for vengeance, keep in mind that even a society that buys into the lack of moral justification for vengeance on a hard determinist basis will still have every reason to punish you for it purely based on the expected effect on future offending (by you or others).
This is one of the things that often cause people to react to a determinist view: They tend to think that it either makes it pointless to make choices because they have no control, or that it makes everything a free for all because you have no responsibility.
But the problem with that line of thinking is that we don't get to "step out of the illusion". We live within a world where irrespective of whether your choices are free, you do make them - choosing to do nothing (or anything) because your choices are not free is in itself a choice, and has consequences that may be good or bad for you. Making choices because you think you can use lack of free will as an excuse may or may not end well for you even if your choice to do so was not free.
> I was very specific with my wording there for a reason: It does erase the main moral justifications used for vengeance.
It seems to do so either by erasing justification entirely (thus permitting anything), or by making it impossible to justify reforming any one person (by removing moral responsibility).
That is, under hard determinism, either society does not have to bother justifying anything it would like to do in response to what it considers a crime, or if you think moral justifications for actions are still required, it makes it impossible to actually say "person X requires rehabilitation", because placing such blame requires free will from which moral responsibility follows.
> E.g. if you genuinely believe the notion that we have free will is nonsense (and I do), then the logical extension is to be very uncomfortable with the notion of e.g. prison used for vengeance or anything at all other than to the bare minimal extent required to protect others, because the logical conclusion of thinking people don't have agency is that there was no way other than other external stimuli in their lives that they could have come out making other decisions.
There's this dialog from some centuries ago (I guess it's from some Enlightenment philosopher?) that goes like this
- Guards, please, set this murderer free: he has no free will, so he can't be held responsible for his actions.
And the guard replies
- Uhm.. no. But if I'm making a mistake, don't worry: per your own explanation, I can't be held responsible for it either.
First is that while an argument is being made, absent subjective agency on his part he is no more than a candle flame illuminating the room. The candle once lit must illuminate - it cannot do anything else. And so I grant in the sense of a flame burns, he makes an argument - but without subjective agency, while an argument us being made I’m not sure what precisely we mean by he.
Second absent free will, truth seeking has no more transcendent meaning or inherent value than a fly’s turd seeking. Love, wisdom, justice simply are, and are no better or worse than hate, ignorance or cruelty.
The validity of an argument does not rest on the agency of the entity who made it. An argument put forward by a computer can be judged by its content just as much as an argument by some hypothetical entity with free will.
Your rejection on the basis of my claim that none of us have free will is logically unsound whether we have free will or not.
> Second absent free will, truth seeking has no more transcendent meaning or inherent value than a fly’s turd seeking. Love, wisdom, justice simply are, and are no better or worse than hate, ignorance or cruelty.
I agree with that. Nothing has any inherent meaning or value. The meaning or value in everything is merely the value we subjectively assign to it. That does not remove that value. The subjective experience is just as good or bad whether or not it's based on values we've merely assigned to it without any choice in the matter.
To me this notion that we need free will to value the feeling of freedom or the beauty of love, wisdom and justice is bizarre. The experience is the same whether or not the underlying choices are free or purely deterministic.
I'm a hard determinist, materialist, atheist, yet I spent a large portion of my youth writing goofy sentimental romantic poetry - the two are not in conflict; I can recognise love is a biochemical reaction following a chain of deterministic events and still feel it.
There is no denial that the subjective experience of free will is real, even to a free will denier. That is, we're not talking about qualia. See the distinction of 'hard' free will.
So in fact there was no absence of subjective agency. But I get your point. You hold the belief that free will deniers are themselves automatons. A strange but expected reversal of conclusions--understandable, as yet it's more of that reflexive defensiveness on display.
And to your second point, for your statement to follow, you'll first have to show that truth seeking has transcendent meaning or inherent value in the first place. That sounds as tough to solve as the free will debate ;).
> There is no denial that the subjective experience of free will is real
I guess I am loathe to throw something so essential and universal to the human experience out the window.
I think many people get into verbal and philosophic contortions because like me they find it difficult to accept something which goes against their fundamental experience, and yet unlike me they're unable to let go of a materialist reductionist view of the universe.
> reflexive defensiveness
Reflexive - that is to say not controlled by me. ;-)
As to my second point, I cannot show that. I believe without proof that existence has meaning, justice, truth, wisdom are good and to be sought, and ignorance, slavery, cruelty are bad and to be rejected.
But we're not throwing anything out the window. We agree the experience of free will is real.
I just don't agree that the underlying reality of it is that there's anything "free" about it any more than e.g. a movie character has free will.
Yet that movie character will still make choices within their movie world that matters to the character, even though the choices are all illusory, and even the characters existence is illusory.
(I'd go much further and argue that we can't tell if space or time has any existence independent of a single instant of sentience, but it doesn't matter - the only thing that matters is that we experience it as if it has; the fundamental defence of philosophical materialism against philosophical idealism is exactly that: it doesn't matter; we have to act as if reality is as we sense it, whatever we know or believe we know about it)
I don't see the contradiction. I don't go around living my life thinking that what I do don't matter because the choices aren't free. They feel real and feel free, and the consequences are real whether or not the choice was truly free.
The only thing it changes is perhaps how I look back at things, and some views on morality:
I try not to have regrets (I do sometimes, because whatever my views I can not override all feelings, and would not wish to anyway), because while I may wish I had acted differently, I am pretty good at accepting that I couldn't have. I can try to act differently in the future, and hope I actually will, but what happened in the past, happened.
At the same time I can feel angry about how someone else acts but recognise that while that may inform how I act around them in the future because it may say something about how they will act in the future, it feels immoral to me to seek vengeance (that doesn't mean I can't feel a strong urge to, because the feelings are still real).
> As to my second point, I cannot show that. I believe without proof that existence has meaning, justice, truth, wisdom are good and to be sought, and ignorance, slavery, cruelty are bad and to be rejected.
And that's entirely fine, and I would largely agree because it's almost entirely orthogonal to the question of whether free will is real or just an illusion.
You could of course try to actually put forward a definition of free will that is possible to defend which is not based on smoke and mirrors.
But you don't, cause you can't ;)
(and as the other response pointed out: this is exactly the kind of response I expect when I ask for definitions of free will, because the notion of it collapses rapidly when people try to define it)
Our “soul” is that being which “ can affect and be affected by the natural world, but are not part of it”. You can feel it as you are one of these “supernatural being”. Case closed.
This is conflating causation and determination. It is true that one's choice must have a cause, and this can either be internal or external to oneself. But it is not true that the choice must be _determined_ by the cause. The Agent Causation [0] view denies the notion that only states or events can serve as causal priors, and instead asserts that substances themselves may be the terminal "cause"
That just introduces infinite regress [1] into the mix. In order to justify why that would introduce free will you now need to justify why the substance itself has free will. It's not a solution.
What is a substance? Does it have a definition in any testable theory?
You claim that causation and determination were conflated, but if the distinction between them depends on terms that can't be defined scientifically, then you haven't shown that they are different in what they refer to in the universe. It's conceivable that on a physical level causality is just a word for a property of a deterministic system.
Regarding your either/or line of reasoning in your first paragraph. Are you sure these are the only two possibilities? Could there be partial dependence on the current state of one’s mind and environment? Does the same exact state always lead to the same exact decision? That is, if a universe began exactly as ours did and everything was the same up until time t when a decision is made by someone is that decision always the same? It seems to be to yes and that would support your view but does it have to be yes.
Also, I wonder if your either/or line of reasoning depends on the Law of the Excluded middle. What happens to your reasoning if that law is not true?
One can certainly also imagine a mix of both option, for example your preferences deterministically determine which options you consider but a random event determines the choice you make. But that doesn't make a big difference, it's still a mix of predetermined and random things.
A third option would have to be a wild thing - a choice would have to neither depend on the state of the universe, i.e. be determined, nor be independent of the state of the universe, i.e. be random. I personally don't see any room for a third option but there are probably a lot of things you could try to poke holes into. Is the state of the universe a meaningful concept? How does it relate to time? Does true randomness exist?
I was thinking of the third option. I don’t have anything intelligent to say about that option but posed it as a possibility. I imagine that believing in the third option would roughly be equivalent to a religious belief. That is, one believes that option because the alternative is unpalatable.
"Unpredictable" is imprecise to the point of being meaningless.
If a black box is fully deterministic to the point that you can construct a model that is entirely accurate, then there's nothing "free" about it. What you're modelling has no agency. For the notion of "free will" to have any meaning at all, it doesn't need to be "unpredictable" in the sense that it keeps confounding someone trying to predict it all the time, but it does need to deviate from predictions sometimes or you have just an automaton, and it needs to do so in a way that is fundamentally impossible to model, and it needs to do so without just injecting randomness.
I've yet to see anyone present a definition of "free will" that doesn't reduce to smoke and mirrors, because that would mean coming up with some fourth category in a venn diagram of determinism, randomness and the combination of the two where they intersect, that is non-deterministic in a way that can't be explained by layering a deterministic model and randomness.
I see no reason to think that just because something is predictable it is not free. That seems like such a strange constraint to me that I can only assume that we have different understandings of what it means to be free.
If I know someone well, I might predict that when offered a free choice between an ice cream and a brussels sprout they will choose the ice cream. The fact that I was able to predict that with an incredibly high degree of certainty didn't stop them from being free.
I understand why you would call your offer a free choice, the are no constraints attached to the options that could obviously influence the decision, for example picking the ice cream also requires paying a million. Different people with different preferences would make different choices.
But pick one specific person, why would you call their pick a free choice? There choice might not be influenced by your offer but it will be by their preferences. Let them choose, rewind the universe a minute or two, let them choose again. They will make the same choice over and over and over again.
Maybe not if there is true randomness in the universe and this choice happens to be influenced by some random event.
Given the same starting state, either you get the same outcome every time, or there's randomness involved, that is the point.
I challenge you to describe a selection process that is not fully deterministic but where the lack of determinism is caused by something other than randomness.
That is what you need to be able to come up with to define free will in a way that isn't smoke and mirrors.
Only if you define 'agency' as requiring magic. If you think that there's no conflict (as I do) between being an automaton and having agency, then there's no problem here.
Yes, if I argue that "free" means "not free" there's no problem there, I agree. Which is why I keep asking those who believe in free will here to actually define it. People almost never even try, because once you do it very quickly becomes clear that it's incredibly hard to the point that you'd have a theory named after you and get taught in university philosophy courses if you managed to come up with something that isn't obviously broken.
The point being that if you start asking questions to determine what people think free will means, you'll find most will argue an automaton can not have free will. In which case to "rescue" free will you need to come up with a way in which entities with supposed free will are not automatons.
So, sure, it is possible to posit an infinite set of theories of "free will" that are true. But I'd claim that nobody has so far managed to come up with one that is both true and that most people will agree fits the woolly concept of "free will" the way most people use it.
The concept is almost religious in the sense that most proponents of it are unwilling to try to nail down specific definitions that might give rise to testable hypotheses, and those who do tend to come up with definitions that are so far from the common understanding as to be meaningless.
I think free will is the feeling of being a choice making agent in the absence of unreasonable external constraints. This isn't original or unique with me, and I've held this view for quite a large number of years (e.g. this comment from 6 years ago: https://news.ycombinator.com/item?id=11740316). It fits pretty well with what people mean when they say 'free will' or 'free choice' in normal every day life (i.e. if you have a gun to your head, you don't have free will, but in lots of other cases you do).
Your definition of it being entirely nonsensical is clearly even worse than this definition for being accepted the way most people use it, since your view implies that there is nothing people mean when then say 'free will', while the fact that almost everyone can tell the difference between someone robbing a bank of their own free will and someone robbing a bank because their loved one is being held hostage tells you that it really does have meaning.
Try probing what people think having free will actually means, and you'll quickly see that people tend to react very strongly if you suggest that they don't have some vague undefined ability to take actions that are not defined merely by the state of their brains and inputs.
To me what you describe does not at all match what I've observed people try to defend as free will whenever you peer beneath the vague veneer of external coercion.
> Your definition of it being entirely nonsensical is clearly even worse than this definition for being accepted the way most people use it, since your view implies that there is nothing people mean when then say 'free will', when there clearly is something that is meant.
That is not at all what I meant by calling it nonsensical. I am very sure that people do mean "something" and my experience is that this "something" includes a very strongly held belief that peoples actions can't be predicted based purely on the state of their brains and inputs. Try to suggest to people that maybe they're effectively just machines, and you'll find a lot of people balking at it, because it e.g. would imply no soul or anything to set us apart.
What I meant by calling it nonsensical is that when you start probing into why people hold beliefs like that, you'll find it evaporate as you probe. You'll find people can't put up arguments for, but more critically few can even describe a version of free will that fits their beliefs.
You've given a definition, and that's great, but it's a definition that defines away the problem under discussion - nobody who argues against free will would disagree with you that there exists a feeling of being a choice making agent. We disagree with those who claim that we are choice making agents other than in the same way that an automaton can be.
So you are right in the sense that free will by the definition you have given exists. But that's not the kind of free will most people here who are denying free will are debating.
If anything, the definition you have given tends to be an important answer to those who believe in "hard free will" to disambiguate them for why you should keep making choices if you don't have free will: Because whether or not it is an illusion, we do have that feeling, and whether or not we have control over the choices made, if we don't make any choices we still suffer the consequences. So the only logical choice, illusory or not, is to still make choices as if you have free will whether or not you think we have "hard free will".
That said, once one decides that "hard free will" doesn't exist, it tends to have a significant effect on personal beliefs. E.g. punishment (as opposed to rehabilitation, or incarceration for protection) becomes cruel if you accept that "hard free will" is an illusion - a person may believe they have free will, but if it's an illusion we're punishing people for things they didn't have an actual choice in. (Note that this does not really affect the issue of coercion - a person threatened with a gun to take your example might still be due different treatement than one who did something bad without being threatened, because the latter is still more likely to be a risk to others; but there's a difference between risk mitigation/protection/rehabilitation and vengeance - if it was a truly free choice based on "hard free will" vengeance might well be morally justified, while without "hard free will" vengeance is morally horrendous)
You've got some interesting points there, but I think that the reaction some people have to the idea that they might be deterministic is actually to do with dualism and not free will. People try to pull free will into the dualism debate because they are desperately looking for reasons to back up their feeling that they are essentially more than pure material. I don't think that these two topics really have much to do with each other, which I think can be seen by looking at what people really mean when they actually talk about free choice and free will in everyday life rather than in philosophical conversations where they're already trying to justify a position.
I agree that is probably part of it. In terms of "hard free will" that debate is of course entirely orthogonal - a soul would just be another part of the combined system under consideration, but I can very well see people seeing the two as combined.
> I don't think that these two topics really have much to do with each other, which I think can be seen by looking at what people really mean when they actually talk about free choice and free will in everyday life rather than in philosophical conversations where they're already trying to justify a position.
I certainly agree that people often conflate these two separate subjects. This is also part of why I push so much on definitions, because so much of the time we speak past each other when discussing these subjects.
> ability to take actions that are not defined merely by the state of their brains and inputs.
How would one prove/falsify that one's actions are merely a function of their brain state and inputs?
Even assuming we have a perfect mapping of the brain and perfect measurement of all neural action, experiments still happen over time and the act of observing changes the observed, so you'd never have repeatability.
It seems to me that determinism is as unscientific as the soul hypothesis.
You can reduce that problem arbitrarily: To falsify determinism all you need to show is any instance, however small, of a non-random source of events without a measurable source.
To raise serious questions, you don't even need to prove the existence of such an effect - just finding even individual particles reacting in ways that seems to show structure (so e.g. ruling out randomness) without a reasonable idea as to cause would justify substantial effort in identifying the cause, and each failure to identify any would successively and significantly weaken the justification for determinism.
In other words: Same as with any other hypothesis for which no experimental data in history indicates otherwise.
Given that most of our reality involves trusting cause and effect, and to an extensive amount measuring it, and no such origination has ever been shown, it is justified to consider determinism to be true until there's data to show otherwise.
What is a "non-random source of events"? Did you mean sequence of events?
Picture a band playing live on stage. Is the music produced random? Is it measurable by brain state/inputs? What if one of the musicians is slightly off tempo? What if one of them plays a wrong note? Is that sequence of events random enough? And is it still all measurable?
> each failure to identify any would successively and significantly weaken the justification for determinism
Failure to justify could also be explained by determinism. As could every other outcome from every experiment, since determinism is, by definition, the meta cause of cause and effect itself.
What is free will but an experience? I think it is completely plausible that organisms that exist in a fully deterministic physical reality still have the experience of free will. Or vice versa for that matter.
Why do "I" have this experience of having a viewpoint and making decisions? That is a mystery that I am not close to solving. However why would any of that define how the universe must work?
Much like a finite being can hold thoughts of Cantor's classes of infinities in her finite brain. The domains in question are unrelated.
This comes to the definition of terms that much of the free will debate wastes cycles on.
Those that deny the concept of free will do not deny the subjective experience of free will. The subjective experience of free will was never under question.
The debate has always been about 'hard' free will, i.e., if the universe is fully deterministic, if 'choice' is an illusion.
Forget people. Let's suppose we're all robots. Free will means our actions depend at least partially on our internal state; that is, our internal state can somehow influence our actions (the opposite is terrifying: being able to watch your actions but having no meaningful input on them). With this definition, free will is perfectly compatible with determinism (this is called compatibilism [0]). It's also compatible with probabilistic theories like quantum mechanics or every other branch of physics.
It's like in chess. If you are running an algorithm that plays chess, you will just play the moves mindlessly, so no free will right? Except that per my definition your internal state is influencing your moves, so, you are free (in this sense).
But there are situations where you're forced into a move. For example, the king is in check, there is only one move possible, then this move is forced. It's precisely in this forced case where there is no free will: you are being compelled to move by forces beyond your internal state.
"Forced" moves can have some shades of gray in chess as well. For example, you may be forced to sacrifice a piece to defend the Queen, because sometimes the game is just lost if you don't do so. So.. the rules of the games allow you do to something else, but you can't meaningfully choose if we suppose you're playing for winning. And, of course, you can only play legal moves: some board states have few legal moves left so you're comparatively less free. In those cases, you have your free will partially constrained.
Well free does not exist only if logic is bound by what the human mind can conceive. It may be possible for something not be random, and to have no antecedent at the same time.
Also, the concept of free will is bound up with the concept of consciousness. What is the entity that may or may not have free will? Until we define and understand that, free will will be an ill-defined concept not amenable to proper analysis
Amazing that all this conflab about free will and you seem to be the first to bring up consciousness. "Free Will" is a construct of consciousness don't you think?
With varying degrees of conscious capability comes increasing amounts of free will. But absolute free will? For example, I choose to end my life, because I choose too is going to be a very hard push. It is only going to happen if I really want it, and will only want it if I am in a situation that calls for such drastic action. Those situations, we can see, are generally on the peripherals (although way too common these days).
So our free will is a function of the Human Condition, which is relative to our levels of consciousness.
You are free to call this free will, I would not. For a good hash function there is no way of predicting the output for a given input besides executing the hash function. But I don't see why I would call the output free. If there is no better way to figure out what you will do than letting your brain go through its internal calculations, fine, your behavior is unpredictable, but how is it free?
Your points are well stated and succinctly out. They’ve made me think about this issue more than I ever have. It’s not a question I’ve ever been interested in but I like the reasoning you are giving.
The first sentence above though helps to illustrate a problem when thinking about this stuff. You wrote, You are free to…. From your perspective no one has that freedom but our everyday experience is such that it’s hard to really follow through with this belief. Perhaps consciousness and self awareness comes at a cost of not being able to fully embrace the notion that we don’t have free will. It certainly feels like I have exercised free will but that is likely just an illusion.
I also behave and talk all day long as if we have free will, it's just a useful abstraction. But my world view will not shatter if someone puts me into an MRI machine and tells me what I will choose for dinner later that day.
> You can do some mental gymnastics, define free will as being able to do what you want, define it as being free of various kinds of constraints, call it free if the choice is not computable in advance, if you can not measure all necessary variables, in practice or in theory, ... If you are happy with any of those definitions, fine, then you might have this kind of free will, but I would not consider any of those particularly interesting.
It is quite interesting in fact, as it lets you sensibly assign moral responsibility to those who were acting of their own free will, even if the world is deterministic. Arguably that's the only kind of free will worth having, and what people mean when they talk about free will (not what people say they mean).
> Free will does not exist. It is logically inconsistent...
That line of argument makes no difference between the free will of humans and that of animals, insects, bacteria or rocks. But that can't possibly be true: we humans invented free will after all.
That's the mental gymnastics that keeps me mentally strong. No beast, nor angel. "Freedom evolves" (DD).
I prefer to think that it's a soulspace dynamically mapped onto a physical space at stochastic points designated by a wave function density distribution. So that at any point in time we have zero, one or more random souls influencing our behavior. So it wasn't particularly me, your honor.
This argument has always sounded like a strange bit of gerrymandering of identity. I suppose for some definitions of the terms you used that 'your current state' could be different from the 'you' that is deciding, but I wouldn't call any of those distinctions intuitive.
I think your argument against free will can be boiled down to the question of if true RNGs exist. Even leaving out quantum probability, we can easily consider systems of such high entropy that a computer the size of the universe would be unable to deterministically calculate the results.
Free will isn't a theory before someone comes up with an actual definition. That is the problem. I keep asking people for a definition, and the outcomes are generally either "smoke and mirrors" (complexity hiding something not at all "free"), appeal to a "soul" which just leads to infinite regress, or failure to even try.
Without someone willing to actually define what they mean, the discussion is moot - it makes no sense to claim that an undefined concept exists.
That statement at all doesn't say anything, because what does "choose unimpeded" mean?
That is at the core of this discussion, and why what then follows is a wall of text to set up compatibilism vs. incompatibilism and determinism vs indeterminism, including addressing the issue that many of the proponents of various variants would interpret "choose unimpeded" in entirely different ways.
You'll see that the page itself introduces a number of different interpretations, and you'd struggle to get most people to agree with those definitions.
E.g. many compatibilist views "work around" the determinism issue by separating our internal view of our ability to choose with the physical reality of the choices. In that case I'd agree that that kind of "soft" free will is possible, but it's also meaningless. E.g. a murderer may have exercised such "soft" free will, but that does not create any moral responsibility for their action if determinism meant they had no actual control anyway.
As such, while that kind of "free will" is reasonable to say it exists, it is not the kind of free will usually debated, because it doesn't actually address the important question of whether or not we actually have the ability to make a genuinely free choice. E.g. if we were to rewind time, could we choose differently? On the basis of what?
With the added caveat that merely another outcome in line with e.g. probabilistic effects from quantum effects are not a choice - so let's say we repeat the experiment many times: can you introduce a bias that is inconsistent with randomness; when you start diving into this you start quickly seeing that even trying to define a way of determining if something meaningfully is a "choice" gets at the core of the issue.
So let's restate it:
If we can agree that a an "unimpeded choice" is a decision that is something other than a pure deterministic or probabilistic effect caused by the preceding physical state, then how can you restate that in a way that makes its existence or nonexistence testable?
Determinism for human action is very popular among science enthusiasts because we've decided that determinism elsewhere in science is true, and since our brains is part of the universe then it must also be deterministic.
But we only perceive determinism insofar as we only measure what we're able to measure. Then you arrive at quantum probabilities, and it seems to me the multiverse theory is as scientific as believing quantum particles have free will.
Free will just cannot be described by physics. This is very similar to the perception of the time flow. Time in physics is static. There is no now. Surely one can plug any time value into physical equations, but that will not explain, for example, why when we look at a thrown ball, we perceive a movement, and not, say the whole trajectory of the ball at the same time.
And given that the free will and now are connected it is easy to see why we cannot describe the free will using physical equations. Well, at least until we will manage to describe now.
Pardon, but your argument does not appear to be coherent. Your example in particular does not seem connected to your thesis in any way. I would suggest reformulating an argument that does not depend on a hazy refutation of physics.
Time in physics is similar to the number of a frame in video. For example, from two frames of a video of a thrown ball one can deduce the its whole trajectory. But it does now explain why when we see the video we see ball's movement. In a sense from a physical point of view the whole trajectory exists at once, there is nothing special about a particular point of a trajectory. There is no now.
Now back to the freedom of will. Its feeling originates in now as if it exists, it is about changing the future following the now. But since the notion of now is not reflected in physical equations, those cannot describe the freedom of will. In physics the whole timeline exists at the same time. In other words time is static and future has already happen. Thus there is literally no choice in physics.
>>Time in physics is similar to the number of a frame in video. For example, from two frames of a video of a thrown ball one can deduce the its whole trajectory. But it does now explain why when we see the video we see ball's movement. In a sense from a physical point of view the whole trajectory exists at once, there is nothing special about a particular point of a trajectory. There is no now.
Here you are conflating a perceptual task with a kinematic equation. What makes you think that these two concepts make sense to tie together so intimately?
This is as free as you can get and I don't think anyone ever posited "free will" as something other than this.
I would not call this free, it's a choice completely determined by you and the environment. Same situation, same resulting choice. Every single time. And people have certainly used free will to mean many different things.
People mean that if you go back to the past knowing something you didn't know the first time around you would have the ability to make the "better" choice the second time around because of the new information.
First, even constrained choices can be meaningful. Just because I can't choose to fly by flapping my arms, wouldn't mean I don't have free will. If free will exists, I can still choose among the options available to me. I don't think anyone operates by the definition of "free will" that you seem to be proposing. Free will is the ability to select from among the options you are given. The opposite of that would be that you'd always make the same pick every time, because your decisions are actually the results of forces acting upon you. If you had the choice between red, green, and blue; you'd choose red every time if we could rerun your life up to that moment in time.
Which is what makes the question kind of unknowable. Because we can't rerun our lives to see if we could make different decisions with all of the exact same conditions as before. Even running the choice twice isn't the same. Because the second time you do it, you're now a person who has previously made this choice. And that makes the scenario different, because you are different. We have no real way of testing free will.
But better still: the question does not matter at all.
Either free will exists or it doesn't. There's no spectrum of "50% will" or whatever. You can either make choices or you're essentially the result of all the forces acting upon you.
So, what are the consequences of both scenarios?
If free will exists, then fine, we can make choices. We can choose to do whatever. There's nothing really interesting to be said about this branch.
However. If free will does not exist, then there's something weird going on. Because if free will does not exist, I don't have any choice in whether or not to post this message. I post this message because your post elicits that response in me. Just like you made your post for the same reason. And we just keep pulling this thread all the way back to the big bang.
But we also don't have the choice in how we feel about this discussion either. You will either accept this or not based on the various physical, biological, and chemical processes going on inside of and around you. So you will either agree or disagree and that decision itself is preordained. Regardless if it is true or not. You're either the type to believe in free will or not and you can't choose that. Because if you could choose that, you'd have free will.
Even if you believe you are making a change, you're not. Because you were going to make that change due to the forces at work on you. Forces that were eventually going to interact with you because those forces themselves are the products of other forces, etc. So if you hear all this, take it to heart, and decide to live a life of apathy because you have no free will and nothing matters. Then that's what was going to happen at this point and time regardless.
Free will implies agency, and isn't disproved by predictability. I love pizza and hamburgers, and just because you can predict that I will eat either pizza or hamburgers with 95+% likelihood, that does not imply that I did not actively choose one of the two. I had the freedom to choose tofu, I just decided not to because I hate it.
> Take the case of two people on Earth, one stationary and one travelling past in a car. They each have a different reference frame, and a different set events which make up their present. Now imagine that there is an alien government in Andromeda debating a possible invasion of Earth. In the reference frame of the person on Earth who is moving, the debate is still going on. But, in the reference frame of the stationary person, it is a day or so later in Andromeda, and the invasion fleet is already on it's way!
I’m pretty sure this is wrong (or misleading) on multiple levels:
1) An event in Andromeda occurs at single moment, it’s our observation of the event that is warped. So there aren’t two realities, one where they’re still debating and one where they aren’t. In both realities the debate has concluded, it’s just our observation of the event takes place at different reference times.
2) The car would need to be moving at a non-insignificant fraction of the speed of light to have an observation dilution of a day or more. It’s physically impossible for humans to move that fast with our current technology.
When you undergo an acceleration, it corresponds to a hyperbolic rotation of the spacetime around you (from your frame of reference). When the acceleration is small, the rotation is also very, very small; however at very large distances, even a small rotation can have a large effect.
In the example, that "large effect" is the alien debate moving in time forward or backwards a day (again, from the accelerated reference frame).
This has nothing to do with the observation delay, it's just an artefact of what it means for two far apart events to happen "simultaneously": simultaneity is a relative property, so two things that happen simultaneously in one reference frame might not happen simultaneously in another.
The reason this doesn't introduce a paradox is because without a specific reference frame, events only have a partial order: when you compare two events, there are three possible results:
1) Event A is in the past light-cone of event B.
2) Event B is in the past light-cone of event A.
3) Neither event is in the past light-cone of the other.
For 1+2 this means that the time between the events is greater than the distance between the events, whereas for 3 it means the reverse. For 1+2, the ordering of the events is the same for any reference frame. For 3, there will always be some frame of reference where both events appear to happen at exactly the same time, so nothing can be said about their order without choosing a reference frame.
That it has critics does not imply it's not widely held.
Regardless, that's just a dispute about terminology: sure we could say that we should only talk about events being "simultaneous" if they happen in exactly the same place - but in that case it's not a particularly useful term anymore. It's just an argument about how we apply words derived from newtonian intuitions to a relativistic context.
Mathematically, for a given reference frame we can draw a space-time diagram, and certain events will be above the horizontal line. We can draw the same space-time diagram for a different reference frame and have those same events be below the horizontal line.
Whether that horizontal line has any actual physical relevance doesn't really matter IMO, the maths says that events move in relation to the line when the frame of reference accelerates, and that's what the "paradox" is illustrating.
Having said that, if the "one way speed of light" exists (https://en.wikipedia.org/wiki/One-way_speed_of_light) and even if it's not the same in all directions, then this "plane of simultaneity" is definitely a physical thing, since you can send a beam of light to a target, measure how long it takes to return, and using the speed of light in that direction you can work out exactly when that beam hit the target in your local time - ie. you've found two events to be simultaneous from your frame of reference, that are not in the same location.
The reason the scenario posits an invasion from so far away is that that's about how much distance it takes for a small speed difference here to translate into a day long time difference there.
You could imagine an event happening a day later from a traveling car, but that’s about it. Two people can’t actually observe an event a day later from the same reference point (Earth), and naturally the event occurs at a singular time at Andromeda’s reference point. Same with any point between Earth and Andromeda. So, if you can’t observe it at different times from the same reference point did it actually happen at different times?
From the Wikipedia page on the thought experiment, check out Criticisms:
> The interpretations of relativity used in the Rietdijk–Putnam argument and the Andromeda paradox are not universally accepted.
> Howard Stein[5] and Steven F. Savitt[6] note that in relativity the present is a local concept that cannot be extended to global hyperplanes.
> Furthermore, N. David Mermin[7] states: That no inherent meaning can be assigned to the simultaneity of distant events is the single most important lesson to be learned from relativity. — David Mermin, It’s About Time
A philosophical idea may not have meaningful implications within the scope of physics, but that doesn’t make it useless.
Rietdijk–Putnam argument, for example, appears to sort of elevate the idea of differing planes of simultaneity, taken from special relativity, to an idea of a four-dimensional universe. It’s a curious thought experiment and I wonder how it reconciles with a model where the universe is considered to be 4D with the fourth dimension being time. My intuition doesn’t work all that well beyond three dimension so I can’t tell if those are essentially the same or not.
It’s not falsifiable, but neither is string theory.
So as I'm driving, the debate is going on, but as soon as I slam on my brakes, it's already happened! They're already on their way! Oh but now the squirrel is out of the road and I'm late so I speed way back up and the debate hasn't even started yet now.
No. The only thing that is "happening right now" on Andromeda from my point of view is the causality wave (light) that is hitting me right now. It's nonsense to talk about anything happening "right now" if its causality wave hasn't reached me yet.
But even beyond that you have the math wrong. Andromeda galaxy is only 2.5 million light-years from Earth. To get a 1 day difference in time dilation across 2.5 million years would take 1 in 913 million difference which someone traveling at even 100MPH (45m/s) isn’t going to see. (1 - (45^2/((3x10^8)^2))^0.5 simply isn’t enough.
I did the calculations from
https://en.wikipedia.org/wiki/Special_relativity#Lorentz_tra... and it comes to ~0.25 years if the person in the car is moving towards Andromeda at 30m/s.
γ is indeed very close to 1, so the humans' watches would still agree closely after 2.5 million years, but the humans would be a quarter of a light year apart at that point, so they need to disagree about something to get the same observed speed of light from Andromeda.
Direction of travel was undefined in the example, just a car on the earth. Suppose they where traveling 30m/s away from andromeda vs towards it suddenly the timing switches.
Chose a specific vector and both observers exactly agree with the events timing. Essentially the only thing they disagree about is what Andromeda’s location and velocity is. (Edited this several times, but it all simplified to choice of vectors.)
But even that’s assuming spaceships rather than “one stationary and one travelling past in a car” the guy in a car is never going to end up light years distant from the stationary person.
> I’m pretty sure this is wrong (or misleading) on multiple levels:
> 1) An event in Andromeda occurs at single moment, it’s our observation of the event that is warped. So there aren’t two realities, one where they’re still debating and one where they aren’t. In both realities the debate has concluded, it’s just our observation of the event takes place at different reference times.
Yeah, they're making the mistake of assuming a minute is a minute.
It's closer to the difference in angular motion vs linear motion. If you are closer to the center, you move very little linearly. If you are closer to the outer edge, you move very little angularly.
Now you look at the linear distance as time passed for the object and the angular distance as the amount of "space-time" an object has gone. The amount of "space-time" is constant. It's a bit of a wonky model, but it's probably the simplest one that encapsulates the concept.
So just because they spent 3 days debating, you spent 5 days watching, and Bob only spent 1 day watching; that doesn't mean Bob is 2 days ahead of Andromeda and 4 days ahead of you. Since we are all also traveling through space at different speeds, we've all traveled the same amount of space-time, so we're all seeing the same things.
As for our perception, that more depends on our relative positions from each other rather than speed. Because nothing is faster than light, we can never experience an event before we see it.
I once read a physicist on this, in a newspaper, who said "if I didn't believe in free-will, then I wouldn't bother getting up in the morning." I thought that was cute.
I think the term free-will has clouded the issue a bit. Forget about free-will. Scientists, instead, normally talk about Determinism vs indeterminism, or nondeterminism in CS. These have a more precise definition than that other thing. The universe is deterministic if the outcome of events are completely determined by previous events. Or the universe is nondeterministic if the outcome of events are not certain, but follow a random distribution.
As to the precise details of the speeds and distances etc, it is a thought experiment, swap the car for a rocket traveling past at 0.86c, if you like. Or instead of aliens deliberating all day, maybe they are more efficient than we are, and they make their decision instantly by flipping a digital coin powered by the perfectly nondeterministic quantum fluctuations of the vacuum.[0]
For earth rocket man, there is a moment before the quantum dice roll when the decision is indeterminable, it's completely random. But at the same moment in the stationary frame, the fleet is already on it's way. Unless you wish to argue that a stationary reference frame is somehow more valid than a moving one, you have to accept that in the moving frame, the event of the dice roll has still not occurred and should be random, but how can it be random, if it has already happened in the stationary frame. Hence the paradox.
I hope that cleared things up some?
[0] The vacuum has an api: https://qrng.anu.edu.au/
> For earth rocket man, there is a moment before the quantum dice roll when the decision is indeterminable
Assuming earth rocket man's speed does not change, if he quickly alternates between 0c and 0.99c he could flip flop between "determinate" and "indeterminate".
Anyway for all system on earth the decision event would be in the relativistic present with no causality order
Well, another way of looking at it is that the observer is not the same as the decider.
So ultimately your reference frame is only current within the locus of your own mind and any decisions you make get broadcasted out to observers in the universe. They make their own decisions about where to be, how fast to be, and so on, and from their perspective it could be yesterday from when the decider decided, but its irrelevant just as much as being farther away in 3d space gives a longer delay in ping time.
Whether or not the decider has free will or not I don't think can be argued by this specific example.
FWIW, I feel this is the right way to look at it. Furthermore (or perhaps I should say equivalently) the "observers" on Earth have not observed the decision, and thinking of them as such seems to be a Galilean fallacy.
> Twitter is a fucking horrible format for a complex analysis of special relativity.
Keep in mind that regular people can and have simply replied to the theoretical physicist who posted it and received replies helping them understand better. In this sense it’s a fantastic medium. The same magic that keeps reliably producing spectacular “ah, actually I have a phd in the thing you’re arguing with me about” moments is at play here lowering the barrier to talk to really smart people.
"Rescuing free-will" would depend on there being something to rescue in the first place. I've yet to see a definition of free will that a casual observer would agree is "free" once you strip it of the smoke and mirrors.
To me the Andromeda Paradox isn't very interesting, because the question is only problematic if you consider time as a process that events happen within simultaneously in a way that you can precisely globally order by positing some way of counting objective units of time backwards from the point the two people on earth both see the invasion force.
If you instead look at the passage of time as simply the propagation of cause and effect where the propagation rate may differ depending on features of the events being propagated, then you get a dependency graph where when you interact different cause-effect chains meet. Only the nodes (events happening) matters, not the edges (the unobservable-because-nothing-interacted other than propagation).
The notion of something happening simultaneously then becomes abstract - you have no objective matter of measuring something being simultaneous except by whether or not they directly interact in a given moment. You're relying on your universe behaving in a way that means you can count events to try to maintain a chronology on the basis you know how they're spaced apart. But the best we can do is count the number of such events that happens in different frames under different conditions between causal chains merging.
Once you ditch the idea of "global ordering time" the "paradox" is nothing of the sort.
Because in that respect talking about "when" the event in Andromeda happened is meaningless, because it is a conversation based on projecting a model of the world as it appears from one local part of that cause-effect graph to another on the basis that there's an objective global ordering outside of what we can impose by counting chronology comparing clock time when we directly interact. It may make your mental model of what happened when messy, but that is because thinking of what happened when instead of what interacted with what in which order is messy.
(if there's any way of achieving faster than light travel, my totally-usupported-by-any-theory bet is that it would show our notion of time to be too static, and that it'd "bypass" the cause-and-effect paradoxes by affecting the laws of physics at the points of FTL interactions)
> "The more you move in space, the less you move in time."
Even better IMO: everything is moving at the max speed (c) through spacetime, and accelerating along one dimension means decelerating along other dimensions; for example, stationary objects have 0 speed in spatial dimensions but move at c through time, and photons move at c through space but are stationary along the time dimension.
I think this conveys the right intuition but it's a bit finicky and artificial to make that concept precise so I think it's better to say that the concept of moving through spacetime at a given speed is not well-defined.
Particles have a trajectory through spacetime. They don't move along the trajectory because the time dimension is already part of the trajectory. So the speed at which they move along their spacetime trajectory seems to be a meaningless concept.
What is true however is that if the particle takes a clock with it, and you mark a tick every second the clock ticks, then the ticks will be equally spaced along the trajectory (where distance is measured using the Minkowski metric).
This makes a bit more precise what it means for photons to be stationary along the time dimension. It does not mean that they move horizontally in a space-time diagram. They move diagonally at speed c, as you expect, so for an outside observer they do move through time.
However, the Minkowski distance between any two points on photon trajectories is zero.
So if you wanted to annotate their trajectory with the clock tickmarks you could start somewhere and put your first tick there, but then your second tickmark would be infinitely far away on their trajectory.
Thus, for an outside observer, a clock approaching the trajectory of a photon would appear not to tick.
From a different point of view, we can reason by analogy to Euclidean geometry. When we have a curve through space we can talk about the tangent vector at any point. But the length of the tangent vector is not a well-defined concept. Only its direction is. You can define the length of the tangent vector for a particular parameterisation p(t) but for the curve itself, i.e. the set {p(t) : t in R}, the length of the tangent vector is not defined.
It is similar for a curve through spacetime. We can parameterise a curve with some variable x and write the curve as {p(x) : x in R} but this is just a set and the length of the tangent vector of p(x) depends on which parameterisation you chose for the curve. But the data of how a particle moves through spacetime is only the curve {p(x) : x in R} itself, not the function p(x): different parameterisations describe the same physical situation as long as the set {p(x) : x in R} is the same.
Isn't the whole point that talking about "the present moment" about something very far away isn't particularly meaningful when simultaneity for spatially separated events depends on the observer?
Wouldn't all that matters here be their relative velocities to Andromeda, and not to each other? And relative to Andromeda, the person in the car might actually be going slower.
Separately, I don't think chronology is broken. It's ok that there is predestination because there is no way for actions taken here to propagate back there in time to change things. If a change does somehow propagate back through a wormhole or something, it's all good, just spinning up another dimension probably...
"...it always goes by one second per second. That’s the only speed at which time can possibly go by, and that’s true whether you’re speeding or staying still or in a gravitational field or not. There’s no such thing as the speed with which we move through space-time, the idea of a speed is the amount of distance we travel as a function of time, that’s what speed is. So it just doesn’t apply to going through space-time, it’s a different kind of thing."
Disclaimer: I’m interested in relativity and have been reading about it lately but I’m no authority.
> We all move through time at one second per second, don’t we?
You need to define “move through time”. The only way to measure time is with a clock, and the clock’s motion relative to you affects the measurement.
If you let everyone define “time” as the thing measured by the watch on their wrist, then everyone moves through time at one second per second, but since people are in motion relative to each other and therefore have different frames of reference, their clocks will measure different times.
Since no frame of reference is privileged, there is no “absolute time”. Of course you could pick one and measure every event against that one, but that would be an arbitrary choice.
This is my understanding. If I’m wrong, I’d be happy to be corrected.
That's my understanding too but I am also saying that "less you move in time" needs to be more rigorously defined. As it stands above I'm not sure it makes sense, even though it might be a useful fiction to get a handle on the weirdness of it all.
At least when you think of objects moving slower than light there can't be reversing of casuality. But relativity allows for that, we just drop the faster than light solutions usually as non-physical.
Recently there's been an interesting paper about what happens when we don't drop these solutions: https://arxiv.org/abs/1910.02780
Imagine the Andromeda fleet can move faster than light. When you look at it from Earth POV suddenly it manifests near Earth out of nothing. Looks very similar to quantum mechanics indeterminism - if alien general decided to send the fleet it's there, if he didn't - it's not there, and there's no local cause for it appearing suddenly.
What the paper above explores is - starting from relativity including faster-than-light objects and trying to prevent paradoxes they derive quantum mechanics.
"This would be more fun in a blog post. Twitter is a fucking horrible format for a complex analysis of special relativity."
My very first sentiment, having read the whole thing.
Both observers are just seeing what already happened millions of miles away. Though they see the alien fleet arriving at different times, it's not possible that the aliens are doing different things in different reference frames. They made one decision and then the two people see the results of that decision at different times
I was thinking the same thing about this working better as a blog post. It's so frustrating for each sentence to be it's own line and to be interrupted every moment. The content itself is excellent, but I really wish there was a better platform for it than Twitter.
Two alternatives for 4D spacetime:
- Julian Barbour argues for timeless physics in his book...Timeless Physics. No spacetime but you don't get back free will.
- David Deutsch will get you free will back, if you are willing to go along with the many-worlds interpretation.
A real paradox is if you can reach two mutually-exclusive conclusions. In the special relativity theory, the order of events depends on the frame of reference. It is not much unlike 2D space if something is left or right to each other depending on a rotation.
"I don't like how does the special relativity/quantum physics works" is not a paradox on its own. In this case, it just challenges our pedestrian view of time.
It's a paradox in the same sense that Zeno's paradox is. As in "if we assume the world is how we intuit it to be without thinking it through and having the proper understanding, this problem seems self-contradictory" rather than in the sense of something actually self-contradictory.
If you think about this in the quantum-mechanical framework, it appears to contradict this free-will problem. In relativity, reality is a solid block, and future events are as immutable as past (no free-will). But in QM this statement would be expressing a level of certainty which violates the measurement problem and Heisenberg's Uncertainty principle. In Penrose's recent book he posits an interesting hypothesis on the Big Bang based on this. Roughly... stuff in the observable universe appears to be slowing down, getting colder, and further away from each other. Things start hot and energetic, and slowly lose energy, slow down and disperse. So, taking this model of the universe and winding it back, you get to the Big Bang, when the universe was infinitely hot and dense. Winding the model forward, you eventually reach a state when the universe is infinitely cold and empty. This is the heat death of the universe, a state of oblivion where there is absolutely no interaction, and no stuff.
This violates Heisenberg, but QM is the map, not the territory, right? So maybe, in practice, reality has a way of beating Heisenberg? Thanks to technology, we have been able to probe this question quite recently. Scientist tried to create a near-perfect vacuum, with all the energy and stuff removed, and isolated from the rest of the universe. Inside the vacuum they created an electrical circuit fed to a computer. The circuit was broken by two floating polished plates, separated by an incredibly small gap, roughly the size of a short wavelength of light. So in this test chamber photons of all sizes could exist around the two plates, but between the plates only the smallest photons could fit. If any large photons enter the chamber they would create positive pressure around the plates, pushing them together, closing the circuit and registering a result. As the scientists pushed the vacuum closer and closer to a perfect vacuum, would Heisenberg get in the way? Maybe the experiment is not powerful enough to push the vacuum close enough to really challenge him?
The experiment was a success. As the vacuum increased, eventually large photons showed up outside of the plates and pushed them together. Photons where appearing out of thin air to ensure that no perfect vacuum could be attained. We call these Virtual Particles. They usually annihilate themselves before becoming "real" and observable, but if local conditions are just right, like near a black-hole, some virtual particles are lucky enough to get pulled and stretched, and this process lends them enough energy to materialize. The virtual particles are of course random, and this apparatus is actually used now to generate proper random values. You can actually tap in to the vacuum energy with an API to get your source of entropy!
https://en.wikipedia.org/wiki/Casimir_effect
Vacuum energy quantum RNG: https://qrng.anu.edu.au/
Back to Penrose... when the universe approaches this infinitely cold empty state, it turns out to be the same, mathematically, as the hot dense state. With everything being so distant and disconnected, the universe sort of forgets that it is big and empty. Then all it takes is the enough quantum fluctuations and virtual particles to appear in some small region of space, that they pull on each other and become real. This might, according to Penrose, trigger another Big Bang.
What does this have to do with relativity and free will? If it is true that nature, at the smallest level, is fundamentally random, then the block universe containing a predetermined future cannot be real. So free will is safe? Not quite. If the Andromeda people are anything like us, their brains are subject to same laws. The electrical activity in the firing synapses, that we call thinking, must also be subject to the random fluctuations of quantum mechanics. How can they have free will, when the electrical impulses driving that will are fundamentally random and unpredictable?
To me the main reason quantum effects does not affect the free will argument is because one can - and probably should given that otherwise it makes QM keep coming up -, reframe it to not worry about absolute determinism and instead apply just probabilistic models.
The real question becomes one of probabilities: Unless some entity is able to introduce measurable biases that deviates from predictable probabilistic distributions relative to what could be predicted based on its complete state (including its internal physical structure) and complete inputs, it makes little sense to suggest the entity has agency.
But that leaves us with the problem of explaining how something could effectively break the laws of physics in a way that doesn't just lead to infinite regress.
The day I see someone give a definition of free will that overcomes that, I'll be in awe. Not holding my breath.
> Unless some entity is able to introduce measurable biases that deviates from predictable probabilistic distribution
This is always the problem with arguments for free will or at least the idea that one "could have done something different" that try to use physics/science.
It requires metaphysical action, literally something that cannot be understood with physics. The whole purpose of physics is to define the universe as deterministic. Quantum randomness is exactly that, random. If it was influenceable in some way, it wouldn't be random. Furthermore, the decision to influence it would still be deterministic so the metaphysics doesn't even make sense.
There is no room for free will in physics, period. All processes are completely deterministic. Even quantum processes might appear to be probabilistic if you look at individual particles, but the statistics are nevertheless completely deterministic: if you look at enough particles, a predictable shape will emerge. The future is set in stone and not only is there no way to change it, but the concept of changing the future doesn't even make sense.
Free will is not something that exists in nature, it is something that exists in the psychology of agents with limited information about the world they operate in. Attempting to find a physical basis for free will is like trying to use an optical drive to read data off a pancake.
"Free will" is a very poorly defined concept that mostly falls out of problems with theodicy in early moral philosophy. Since the idea of "free will" plays a major role in Christian ethics this notion has permeated a huge amount of the Western intellectual tradition, but only makes sense in the framework of other archaic philosophical questions around theodicy like "if god is omnipotent, omniscient, and omnibenevolent why is there evil?" This question is only remotely interesting if you have a cultural reason to need to believe that these three things must be true (or if you're curious about the development of the Western intellectual tradition, in which case it's a very important question to understand).
Free will might be hard to define but it has plenty of very well-defined corollaries. For example, if there is such a thing as free will, it would not be possible to reliably predict a human being's actions in advance.
> not be possible to reliably predict a human being's actions in advance.
That's also true for purely deterministic systems. Basically any complex deterministic system (and quite a few relatively simple ones) you very quickly get to a point where you can't predict future behavior.
On top of that, showing exactly the issues with metaphysical "free will", this corollary has a lot of constraints that are also poorly defined. For example if a person's behavior were entirely unpredictable (i.e. completely random) we would also say that they don't have free will. Therefore there is only a subset of unpredictable behaviors we would say follow from free will but that subset is just as tricky to pin down as the notion of free will itself.
"Free will" only makes sense in a particular moral world view with plenty of axioms most people would agree don't hold for them.
It's also worth clarifying that "free will" only becomes problematic to define in when it is posed as a metaphysical issue. We clearly have very useful, practical definitions of free will such as not holding people accountable for doing something when held at gun point.
The difference between quickly getting to a point where you can't forecast the weather, and the fact that you can't predict wavefunction collapse at all, is significant on a more than metaphysical level. Figuring out which bucket human beings fall in to is a legitimate question.
Which of these are commonly accepted (or even argued by a sizable minority) to have free will in a metaphysical sense?
> Figuring out which bucket human beings fall in to is a legitimate question.
That may be true, but it doesn't seem like it has anything to do with the ill-defined notion of "free will". I'm also not familiar with anyone who views human behavior to be anything like a collapsing wave form so I'm not entirely sure this is a "legitimate" question since I'm not sure there is any evidence or support for the one side of the argument (though I'm always up for pointers to arguments about this).
>Which of these are commonly accepted (or even argued by a sizable minority) to have free will in a metaphysical sense?
Of the two that would be the wave functions, some of which are people, and people are what's argued to have free will.
>That may be true, but it doesn't seem like it has anything to do with the ill-defined notion of "free will".
Nondeterminism in physics is the space that free will is allowed to fill, and if there was none, there would be no room for free will.
>I'm also not familiar with anyone who views human behavior to be anything like a collapsing wave form
Human beings are physical systems, quite chaotic at that. It is possible that deep inside your brain, decisions turn on molecular events that are uncertain due to quantum mechanics. Evidence for free will? Not really, but it's a hole in determinism that makes false the statement, "physics leaves no room for free will."
Quite the opposite: physics is predicated on the idea of free will in the experimenter. That is: their decision to use X machine to perform Y experiment at Z time is essentially an independent, or at least fully random, "choice" on their part. If the experimenter does not have free will, then you run into the possibility of their decision to run the experiment as being somehow entangled with the results. See "Superdeterminism"
But otherwise I agree that "free will" is basically just a silly argument over the definition of an undefinable term, or a way to explain away loopholes in theology.
There is no room for free will in classical mechanics. Quantum mechanics has plenty of "room for free will," because either:
1. The universe is not deterministic (if you believe that wavefunctions collapse)
2. The mysterious thing that makes conscious entities experience high-amplitude events more often than low-amplitude events is not deterministic (if you believe in MWI).
Evidence for free will, a definition of free will; those things physics cannot provide. But there's room for it.
1. Chaos theory ensures that unless we have INFINITE precision measurements, even a perfect simulation of our universe will diverge based on even the smallest differences. A difference of one particle's velocity in the googolth decimal place will eventually cause wildly different simulation outcomes. So, in practice, it's impossible to know what's going to happen given a long enough time frame, unless we can get advanced enough to have literally infinite precision measurements.
2. Given objection 1, using the law of large numbers to explain away quantum processes' non-determinism from initial conditions seems like a cop-out to me. Yes, given enough particles, they converge around some predictable value. But given the need to have exactness in measurements to predict chaotic processes, if a SMALL number of individual particles interact with other matter, and they sometimes do, how could the probabilistic nature of those individual particles be neglected?
Let me sum it up this way. If I take a quantum random number generator and use it to generate lat-long coordinates, and visit that place, could anyone or anything predict what happens given initial conditions before I do that? No, it is not bound by initial conditions.
> quantum processes [...] are nevertheless completely deterministic
It's like you're trying to avoid mentioning hidden variables or bell's theorem directly. That is, you're probably not correct when you say something like that.
Am I crazy, in that I actually like Twitter threads for this sort of thing--at least in the hands of a capable author? When threaded correctly (as this one is), its easy to follow. And the requirement to condense and split thoughts into tweet-sized chunks creates natural breaks to pause and consider the content before continuing. I find the cadence of "each thought is a tweet" provides a nice rhythm.
Sure, you can do this with paragraphs in a blog post. But Twitter works equally well in my mind!
I agree with you. I can understand why a theoretical physicist would find this format frustrating to read. For a layman, the forced tempo of threads helps me understand each point before I move on.
You may actually have something there. The average word length in English is approximately 5 letters, which gives you an average of about 56 words per tweet. That's roughly 5-6 solid sentences, which is... one good paragraph. It probably didn't work as well before they raised the character limit from 140 to 280.
Note that Thread Reader loses the images attached to some of the tweets (at least for me).
Edit: strike that, it was Firefox's social tracker protection blocking them. Just need to click the shield icon left of the address bar and temporarily disable it.
In the topic of special relativity, I wholeheartedly recommend recently published "Unusually Special Relativity| by Andrzej Dragan (https://www.amazon.com/Unusually-Special-Relativity-Andrzej-...). It starts from basic high-school mathematics but covers many paradoxes and puzzles. Some might challenge ordinary students, who know the formula but didn't stretch their minds on "what if" questions. It includes cases where velocity is higher than the speed of light - as there are a few caveats on "nothing can travel faster than light".
Also, this "velocity addition for v<<c" is covered in the first chapter.
I read its draft almost 20 years ago (back then, it was a collection of notes in Polish) and didn't find anything remotely close to it in English. Later, I had the pleasure of attending his course.
Also, Andrzej Dragan is a notorious individual, primarily known in photography (https://andrzejdragan.com/). To the point that there are posts on "how to Draganize a picture".
I love the name of the scientist Al Unapietra. The thing is very well explained, but it's very sad to see it as a twitter thread, which is a mostly unreadable format.
Twitter threads don’t bother me. The brain quickly adapts to skipping the irrelevant parts (username, like buttons, etc) and to expecting the cadency of tweets.
I believe it is harder to write (due to the character limit of each text block), but, far from “unreadable”, I can read it fairly easily.
Oh, I don't bother by the stupidly repeated usernames and dates. I just want to read the damn thing.
But it is literally unreadable to me. I couldn't finish reading the thread and had to find an alternative way out of twitter.
Fist trial, using my android phone with fennec fox. There is a modal that hides the content asking me to "log in"; if I close the modal I go back to the twitter homepage. Thus unreadable because I don't have a twitter account. Sometimes I have managed to read a few tweets by a "smart" combination of closing the successive modals and reloading the page, but not this time.
Second trial, using my laptop with firefox browser and heavy adblocking. I can read only the first three tweets, the rest do not load due to some third-party javascript.
No big deal. Third trial, now I open a "clean" firefox browser session with just ublock origin, and I manage to read about 30 tweets, until it starts talking about hyperbolic rotations. The thread obviously continues, but the sole link below it "show replies" does not work. When I click on it it says "Whoops! Something went wrong. Please try again!".
Typically I wouldn't bother and stop reading. Fuck twitter. But today I really wanted to read this thread because I teach these things. Thus I learned to use nitter, which gives an interface of twitter that, even if it's equally ugly, it sort of works (in that you can actually manage to read the text).
In retrospect, this is an extremely sad state of affairs. We have an excellent article which is made of a short text, a few simple formulas, and a few simple images. This could be a static html page of a handful of Kb with img tags. But it is a slow and humongous javascript monstrosity that does not even work, and may disappear at any time if twitter "bans" this user for reasons unrelated to this text.
I got it now. Yes, Twitter is a walled garden, even if it has large windows to see most of things, there is definitely a wall there.
The tricky part is that if this was published in a static html page it would be less likely that it would reach us (even if the page was linked in the thread). Distribution is hard.
A good compromise I think is keeping the thread but having a link to a blogpost with the same content in the first (or second) tweet.
A Twitter thread formatting tool that also publishes a web version and automatically link to it in the second tweet is a good micro Saas idea if anyone is looking I think.
> The tricky part is that if this was published in a static html page it would be less likely that it would reach us
But this is an orthogonal issue. Twitter could have exactly the same terms of service, but still serve a single, static, small, html page that would load instantly on all devices. But instead, they choose to serve a bloated mess that does not work in many browsers, and is slow everywhere. Just to display a few lines of text.
For what it’s worth, I clicked on the HN link on my iPhone and it opened in the Twitter app (that I never use) and it was extremely readable. Literally no problems reading it at all.
I used my web browser and the powerful magic of...scrolling down.
I know shitting on twitter threads is a venerable HN tradition, but at this point I barely even know what people around here are complaining about anymore.
I tune out after a certain point with these types of long Twitter threads. It's like reading a magazine conveyed via telegraph.
People are correct to point out it helps material reach a wide audience, but that's not the point. The point is what could be better?
The original argument was to keep communication brief, shorter is better, etc. The fact it keeps being circumvented in this way suggests sometimes a longer format is necessary.
As a practical matter, in this case the person could have linked to a long form blog post and used Twitter as a sort of comment discussion section?
Personally i think a lot of people do threads because it's easier to write. Also you can take days or weeks of writing threads in public, updating them with new information, without appearing to do "stealth" edits, or adding "Update <date>:" to each added section.
For readers twitter threads are pretty crap tho, that's why I really like to use thread reader app.
But it isn't easier to write something like this one in the "tweet storm" format. The author has to carefully consider how to divide the explanation up into separate tweets in a way that flows naturally.
Some people prefer it, and there's tools for those that don't. Such as [0], as another user so helpfully posted, and for which I am grateful, since I fall into the latter camp with you.
Summary: For small angles, approximation makes it look like gradients (y/x) add simply (a+b). Similarly low velocity in relativity world makes it look like velocities just add as well. With some insight we discover how it really works, including how the approximation makes it look correct for small values.
But who was actually genuine surprised or flabbergasted that there was an extra factor that in macro real life becomes zero but is there in extreme speeds? The un-intuitiveness is typically more to do with understanding what that factor means and where it came from.
The insight is, in my opinion, more related to the attaching of the idea of "rotation" to space-time, and using that to explain why we can't just add velocities at high "rotations".
It is interesting that "real" observations of relativistic objects are quite different from what you expect them to be. For example, a cube passing by at relativistic speed would appear as if it is rotating towards you. This allows you to see some of its sides which you normally wouldn't [1].
An interesting quirk of this, is that the description of the path of a particle under constant proper acceleration in special relativity is mathematically very close to that of a simple harmonic oscillator.
Now, just as you can use rotation in the complex plane (i^2 = -1) to describe a simple harmonic oscillator in 2D space,
x + iy = e^(it)
It's possible to use a rotation in the split-complex plane[1] (j^2 = 1) to describe the motion of a particle undergoing constant proper acceleration,
x + jt = e^(ajτ)/a - 1 [2]
This is because multiplying by e^(jτ) preserves the split-complex modulus (|x+jt|^2 = (x + jt)(x - jt) = x^2 - t^2), which is equivalent to the Minkowski norm. Expanding the above gets you,
x = cosh(aτ)/a - 1
t = sinh(aτ)/a
which are the more traditional expressions you would typically see.
[2]: There's a line of reasoning that allows you to write this down almost immediately, or in maths-speak makes it trivial, but I can't remember it at the moment. I spent a good deal of time thinking about this for a university assignment years ago in order to avoid spending 2 minutes doing an integral.
Heh, small world. I met Markus Deserno when I was visiting MPI-P for a few weeks some, uh oh, 15(?) years ago, working on coarse grained molecular dynamics for polymer physics. Nice chap.
This is just the most basic consequence of relativity. It's not a "delightful quirk". It's literally the first thing you learn when you study the theory.
The description of relativistic movement by hyperbolic rotations is really neat. One way I like to think of it is that moving with respect to some other observer puts you into a different "world", where the x and t axes are rotated towards each other. You can see from the diagrams that for example different events happen in different orders in both "worlds". And this is not just due to signal propagation, but there really is no "true" ordering if the events are sufficiently separated.
Bit there is one thing I never understood, even though I have a PhD in physics. Why does relative movement put you into a different "world"? Or more precise, why does relative movement correspond to a lorentz boost? That is not a piori neccessary. A stupid example is a laser pointed to the moon. If you flick it quickly, the spot can move faster than light over the ground. But you can also imagine mass moving independent of boost. You have a rock at x=0, t=0. At t=1, cut it and paste it at x=1. At t=2, cut it and paste it at x=2. Now make the time steps infintely small. It is moving (in the sense of dx/dy>0) but not moving (in the sense of v or ß = 0).
My intuition is, if you look at electromagnetism, it takes some time for a changing electric field to create a magnetic field, and for the magnetic field to create an electric field. This is what Einstein meant when he said, time exists so that not everything happens at once. If you think of a relatively moving object - and I'm thinking of it completely in terms of EM for the sake of simplicity - what happens is that the fields are propagating. One field creates the next field not at the same space but slightly in front. So the whole thing is rotated towards the x axis. The "time" vector does not point completely in the time direction, but in the space direction. This gives you time dilation as well as the subjective experience of an intertial frame (because you are just moving forwards in time, but not in space from your POV). I think this microscopic perspective shows why motion must == boost. But does anybody here know if there is a canonical answer to this question?
Edit: I just realize this is basically electromagnetism of moving bodies which Einstein already solved in 1905 :-) but I still find it hard to wrap my head around
I don't know if I admire more the mastery of science of the author or the willpower necessary to write those posts on such a wrong medium for them. Worse than one twit per paragraph, only MMSes.
Some people hate tweet threads like this, but I feel like it really forces concise communication and arranging thoughts into small but complete chunks. I’ve never put my thoughts into this format, but I would guess it’s actually pretty difficult and requires some careful planning to do it well, especially for a challenging topic like this. Thanks for sharing this to hacker news, sohkamyung!
It's like Power Point presentation. Forcing everyone to read at the same pace, waiting for the point to show up, instead of skimming to the part they need to read.
The way I think of it is we're always moving at the speed of light, through the time axis. Any normal 3d motion is orthogonal to the time dimension, so the time component shrinks ever so slightly as you move faster.
Photons move only in the 3 dimensions, thus never experience time.
Now I don't know what "rotation" means. After reading that thread, the phrase
"rotating through spacetime" is still just gibberish. It sounds like he's trying to solve a physics problem backwards by making the units match: because the Lorentz transformation is a hyperbolic rotation matrix with a trig property applied, somehow it is a rotation? That just perverts the word "rotation".
I like this, but it doesn't completely remove the "unintuitivenes" of relativity.
For example, why do we measure in fractions of light speed?
What happens when we are already rotated all the way to light speed and then fire another bullet?
I guess there are other ways to reason about this, but it still doesn't feel intuitive to me.
It’s important that the “angle” isn’t directly the fraction of c, but tanh^-1(v/c). This number is also called “rapidity”, and goes to infinity as v -> c. Yes, hyperbolic angles aren’t limited to [0, 2 pi).
You can’t rotate all the way to lightspeed, that would be rotation by an infinite angle. For any finite angle (i.e. speed below c), you can always add the angle of the bullet to get a new (finite) angle.
That's amazing, and it was well explained in 1908!
Yet students today are learning a horrific bastardized version of it. Physics is absolutely terrible when courses and books try to to remove the "complicated" math, and in its place they put something more complicated and ambiguous.
Teach the math!
It's like Greenspun's Tenth Rule, but for math:
"Any sufficiently complicated scientific theory contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Complex Analysis."
This is too longwinded (and a Twitter thread ugh). I'll repeat an analogy I read somewhere else.
Everything in the universe moves at constant speed through (four-dimensional) spacetime. To simplify the analogy we'll just consider two dimensions: space (x-axis) and time (y-axis) with your spacetime vector being of constant length. At rest your spacetime vector is (0,1). You speed up to 10% of light speed and your spacetime vector is approximately (0.1, 9.99) so you're moving slightly slower through time.
What I like about this analogy is it constrains your space vector to the speed of light. Warp Bubble Andys like to pump negative values for energy and mass into equations to rationalize something they want to be true: that faster-than-light travel is possible. To me, this is just a fundamental lack of understanding about the domain of a function. Velocity is no different. I firmly believe it's bounded by [0,c). Values outside of that range just don't make sense are as such undefined. Garbage in, garbage out.
Why? Because it describes movement as rotation from the infinitely far away point (a special basis vector there). And "coordinates" there are somewhat self-normalizing, because there is a special basis vector that keeps coordinates' squares.
And, of course, it is investigated as a tool to think about relativistic coordinates, linking my comment to a tweet part that says "wrong tools can obscure things".
> Because it describes movement as rotation from the infinitely far away point
Doesn't this also work in normal geometry as the length of a translation goes to zero and the distance to the rotation's origin goes to infinity... because a big circle looks like a straight line up close?
Exactly. CGA has special point e_{inf} which is infinitely far away from any other regular point (with regular euclidian coordinates) and linear movements are rotations around that point.
I might have missed it, but is there (or do we know of) a different model for which the velocities actually add? Essentially, how do we go from slopes to angles here?
Yes, he introduced it near the bottom - instead of using speeds (which are like slopes), you use "rapidities" which are the angles of the hyperbolic rotations.
In classical Newtonian mechanics, velocities add normally a+b = c (an approximation which works near perfect for almost all velocities humans interact with). I think you might be asking a different question, though, but I'm not sure what.
That aside, my favourite quirk from relativity is this:
Like relativity in general, it sounds simple enough, but it's consequences are profoundly shocking. (That is, if you take the time to understand it, and don't leap to the conclusion that you know relativity better than Einstein or Penrose ;)Take the case of two people on Earth, one stationary and one travelling past in a car. They each have a different reference frame, and a different set events which make up their present. Now imagine that there is an alien government in Andromeda debating a possible invasion of Earth. In the reference frame of the person on Earth who is moving, the debate is still going on. But, in the reference frame of the stationary person, it is a day or so later in Andromeda, and the invasion fleet is already on it's way! In nature there is no absolute reference frame we can call base reality, and both observers reference frames are equally valid. Then the outcome of the invasion debate is a foregone conclusion. How can there be any room for free will in the deliberations of the alien government? This is the crux of the Andromeda Paradox and the Reitdijk-Putnam-Penrose argument.
BTW:
https://en.wikipedia.org/wiki/Rietdijk%E2%80%93Putnam_argume...More info https://en.m.wikipedia.org/wiki/Relativity_of_simultaneity
Edit: If you know of any serious alternatives to the 4D spacetime/ block universe theory then I would love to read it. Rescuing free-will from the jaws of spacetime would be cool!