• Olivier5
    6.2k
    To know whether a ball will roll downhill or uphill,Kenosha Kid

    Indeterminism says that some things are predetermined to a degree, but not necessarily everything and not necessarily to a perfect degree. We can make predictions and observations within a non-deterministic framework. QM scientists and biologists and sociologists and scores of other disciplines do it all the time.
  • Kenosha Kid
    3.2k
    Indeterminism says that some things are predetermined to a degree, but not necessarily everything and not necessarily to a perfect degree.Olivier5

    Yes, this is indeterminism-of-the-gaps. As our technology improves, error reduces, and this alleged non-determinism of nature is obliged to retreat. It is not a compelling or useful story.
  • Olivier5
    6.2k
    What is not compelling to me is the story that, if the universe was to magically rewind at the time of the Big Bang and unfold again, every single thing will happen exactly the same as it did the first time around, like when you play the same movie over again, including Tim's bumblebee flying on exactly the same trajectory through his garden, on the exact same day and time, and pollinating the exact same flowers...

    And QM is not a gap. Randomness is systemic in it, and it applies supposedly to the entire universe.
  • Kenosha Kid
    3.2k
    What is not compelling to me is the story that, if the universe was to magically rewind at the time of the Big Bang and unfold again, every single thing will happen exactly the same as it did the first time around, like when you play the same movie over againOlivier5

    And yet when you rewind a VHS and play it again, you do expect exactly the same movie, not a random one. ??? That's real. Magically rewinding the universe is not.

    What this comes down to, then, is taste. Irrespective of how much experience you have that doing the same thing in the same way produces the same result, you don't like the idea of predetermination so say the universe is random. Fine. But the universe isn't obliged to cater for your taste.

    And QM is not a gap. Randomness is systemic in it, and it applies supposedly to the entire universe.Olivier5

    Yes, it is. We don't know whether the universal wavefunction is Copenhagen-like or MWI-like or something else. It remains to be seen.
  • Echarmion
    2.5k
    What I mean is that as we measure, say, the spin of a neutron to ever greater precision, the degree of freedom of non-determinism to show its face gets ever smaller.Kenosha Kid

    That's not where the uncertainty comes from, the way I understand it. The uncertainty is fundamental. Not all values of the system can be known at a time, and the values that are not known can only be expressed as probabilities.

    Where a photon strikes the screen in a double slit experiment is not, in principle, predictable with certainty. It can only be measured, but this merely moves the uncertainty to it's speed.

    Ah, but that doesn't mean they weren't selected for. We have an appendix that is useless to us, but we are descended from grass eaters.Kenosha Kid

    Sure, we can create plausible theories to explain how certain vestigial or otherwise weird anatomies came about. But that doesn't establish that the end result was selected for. Only that there wasn't sufficient pressure to select for a different result. Meanwhile, your argument, if applied to e.g. the appendix, would lead one to look for the benefits the appendix provides to modern humans to explain its existence.

    It can't be proven. My point was just that you have an extremely simple explanation for consensus -- determinism -- or a really complicated and dubious one.Kenosha Kid

    Why do we need an explanation in the first place? Explanations are tools for specific ends, not an inherent necessity.
  • Olivier5
    6.2k
    Magically rewinding the universe is not.Kenosha Kid
    Exactly, and hence determinism is a rather esoteric idea.

    you don't like the idea of predetermination so say the universe is random. Fine. But the universe isn't obliged to cater for your taste.Kenosha Kid
    And likewise, you don't like the idea of randomness and you try to erase it from your POV, when I see it everywhere around me. To each his own metaphysics...
  • Heiko
    519
    QM is not a gap. Randomness is systemic in it, and it applies supposedly to the entire universe.Olivier5

    Isn't this a misconception? Not being able to measure position and speed of a particle does not necessarily mean it ain't at an exact position and speed at a given time. It is trivial that one cannot measure the speed of a car non-intrusively by crashing another car into it.
    This is the point where empirical science is bound by it's metaphysical starting point, i.e. that the observable universe is the universe. You will never observe ideal concepts like free will.
  • Olivier5
    6.2k
    Maybe there's a QM specialist on this site who could clear that up?
  • Kenosha Kid
    3.2k
    Exactly, and hence determinism is a rather esoteric idea.Olivier5

    Determinism is not dependent on being able to rewind the universe.

    And likewise, you don't like the idea of randomness and you try to erase it from your POV, when I see it everywhere around me. To each his own metaphysics...Olivier5

    As I said, you don't know my position. It would probably surprise you.

    Isn't this a misconception? Not being able to measure position and speed of a particle does not necessarily mean it ain't at an exact position and speed at a given time.Heiko

    It's not a misconception that you cannot. There is a version of QM called Bohmian mechanics in which particles do have exact position and momentum simultaneously. It is not well liked for other reasons.
  • Kenosha Kid
    3.2k
    That's not where the uncertainty comes from, the way I understand it. The uncertainty is fundamental. Not all values of the system can be known at a time, and the values that are not known can only be expressed as probabilities.Echarmion

    I think we're speaking at cross purposes; possibly I misunderstood your earlier point. Reading back, what I think you were referring to was random fluctuations in fields, i.e. creation and annihilation of particles whose lifetimes are consistent with the uncertainty principle. At any given time during an electron's trajectory, for instance, there is a finite probability that a virtual photon will be created by some distant charge that will scatter the electron. Since this is always true, the probability of it happening approaches 1. This is the gist of the quantum field theory of the electric force.

    Sure, we can create plausible theories to explain how certain vestigial or otherwise weird anatomies came about. But that doesn't establish that the end result was selected for. Only that there wasn't sufficient pressure to select for a different result.Echarmion

    Yes, plausible. Compared to hypothesising that entire organs came into being for no reason, or that a magical man made it for no reason. If we go that route, it becomes a mystery why we don't all have organs that not only serve us no purpose, but served no purpose for any of our ancestors, in addition to the mystery of how. The resolution of that mystery is natural selection.

    Bear in mind the starting point for this tangent was the claim that life has evolved characteristics that could not have been selected for. That still remains unshown.

    Meanwhile, your argument, if applied to e.g. the appendix, would lead one to look for the benefits the appendix provides to modern humans to explain its existence.Echarmion

    ???? My argument is that characteristics that benefited our ancestors can be passed down to us whether they benefit us or not. Evolution would not be a deterministic process if organs disappeared the moment they became useless.

    Why do we need an explanation in the first place? Explanations are tools for specific ends, not an inherent necessity.Echarmion

    Fine, don't seek explanations then.
  • Pfhorrest
    4.6k
    If I may...

    I think Oliver’s point is that we can never be sure whether any observed failure of predictability is due to nature being non-deterministic or just because our measurements and theories etc are imperfect: the answer to whether or not everything in the universe is perfectly deterministic if forever hidden beyond the limits of our knowledge, which while ever-growing is never absolute. So we can’t answer for sure whether determinism is true or not.

    I think Kenosha’s point is that despite the above, indeterminism sorta has the burden of proof here, because so far everything that we have been able to know has turned out to behave deterministically, so we should expect that to continue to be the case as the limits of our knowledge push further and further out. If something seems unpredictable at the moment, it’s probably just because of shortcomings on our measurements or theories, not because it’s inherently random.

    I think that even more than indeterminism just having the burden of proof, we pragmatically always must assume that it is false and that we merely haven’t developed the right theories or made accurate enough measurements to make accurate predictions yet. Because to do otherwise is simply to give up on trying to figure out what the deterministic laws behind things are. It’s true that there always might be none, but we can never know for sure that there are none, only that we can’t tell what they are YET. So all we can do is just choose one way or the other: either give up hope of ever figuring it out, or at least TRY by assuming that we can.
  • Kenosha Kid
    3.2k
    I think Kenosha’s point is that despite the above, indeterminism sorta has the burden of proof here, because so far everything that we have been able to know has turned out to behave deterministically, so we should expect that to continue to be the case as the limits of our knowledge push further and further out. If something seems unpredictable at the moment, it’s probably just because of shortcomings on our measurements or theories, not because it’s inherently random.Pfhorrest

    Yes. The Universe appears to behave deterministically... We can write down formulae to predict outcomes and find them reliable: x in, y out. (With or without error bars.) If the universe were non-deterministic, it would have to seem deterministic, and thus any evidence of determinism would automatically be worthless. For that reason, this kind of constrained non-determinism is unfalsifiable: no evidence can disprove it. This is the same problem as the God-of-the-gaps argument.

    However we should, in this non-deterministic universe, expect some behaviour that cannot be generalised well. There should be mysteries as to why we cannot predict outcomes. These could falsify determinism, and the measurement problem may well be a good example. But since unfortunately we have equally good/bad deterministic and non-deterministic theories for this, neither backed by knowability or tractability, the jury is out for now.
  • Echarmion
    2.5k
    I think we're speaking at cross purposes;Kenosha Kid

    Probably. We seem to be misunderstanding each other pretty much across the board.

    I am really just talking about the probabilistic quality of QM, the fact that e.g. at what exact time an atom of a radioactive element decays appears random.

    Bear in mind the starting point for this tangent was the claim that life has evolved characteristics that could not have been selected for. That still remains unshown.Kenosha Kid

    I never made that claim though. All I said is that not all properties of an organism are necessarily selected for.

    ???? My argument is that characteristics that benefited our ancestors can be passed down to us whether they benefit us or not. Evolution would not be a deterministic process if organs disappeared the moment they became useless.Kenosha Kid

    I was referring to your argument before that argument, but since you're talking to multiple people I should have reiterated.

    What you wrote was that since we evolved to see deterministic patterns, it stands to reason this conferred a survival advantage, and is hence evidence that the universe is really deterministic.

    This is presupposing that every attribute we have right now confers a survival advantage. But that's not the case.

    Fine, don't seek explanations then.Kenosha Kid

    I just think it's important to recognise that some things cannot be explained in a meaningful way. Seeking explanations for everything sends you down metaphysical rabbit holes that people tend to eventually fill up with gods.

    QM is a good example, because I don't see a reason to suspect that whatever the fundamental forces of the observed universe are can then be further explained or interpreted. If such forces exist, and it's not turtles all the way down.

    However we should, in this non-deterministic universe, expect some behaviour that cannot be generalised well. There should be mysteries as to why we cannot predict outcomes.Kenosha Kid

    I think this is a misunderstanding of how we construct our reality. There'd be nothing mysterious about the unpredictable outcomes. They'd just be things that the natural laws make difficult to predict. Like weather patterns. We'd still get quite good at it if it was probabilistic instead of deterministic.
  • Olivier5
    6.2k
    Determinism is not dependent on being able to rewind the universe.Kenosha Kid

    But it's dependent on knowing the laws of the universe, which is equally esoteric.

    you don't know my positionKenosha Kid
    Now I'm curious, do expound.

    There is a version of QM called Bohmian mechanics in which particles do have exact position and momentum simultaneously. It is not well liked for other reasons.Kenosha Kid
    It's non local, in particular. Which means you can never isolate any sub-set of events from the rest of the universe in any calculation. This is the Eye Of God hypothesis: One Logos Tying The Whole World In One Very Long And Convoluted, Yet Eternally Predetermined Sentence Which Will Never End Contrary To This One.
  • Kenosha Kid
    3.2k
    I am really just talking about the probabilistic quality of QM, the fact that e.g. at what exact time an atom of a radioactive element decays appears random.Echarmion

    So, yes, radioactive decay is an example of a quantum field theory, the electroweak theory. But it isn't characterised by atoms or hadrons either spitting out or not spitting out components at random. The system evolves deterministically through both paths simultaneously, both decaying and not decaying, until the wavefunction collapses/universe branches/superposition decoheres/whatever else happens to yield singular observables.

    This is presupposing that every attribute we have right now confers a survival advantage.Echarmion

    That doesn't follow. It just needs to have conferred a survival advantage to our ancestors.

    There'd be nothing mysterious about the unpredictable outcomes. They'd just be things that the natural laws make difficult to predictEcharmion

    What do you mean, difficult to predict? For instance, would it make the vertical component of motion of a ball on an inclined plane difficult to predict?
  • Olivier5
    6.2k
    so far everything that we have been able to know has turned out to behave deterministicallyPfhorrest

    I think this is demonstrably not true, but if you can prove that the lottery is behaving deterministically, you could earn millions...
  • Kenosha Kid
    3.2k
    But it's dependent on knowing the laws of the universe, which is equally esoteric.Olivier5

    No, it's not. Being able to approximate the laws of the universe well is dependent on the universe -- or at least the part of it being modelled -- behaving deterministically. The universe can behave deterministically without intelligent life modelling it. Intelligent life cannot model it scientifically if it isn't there.

    Now I'm curious, do expound.Olivier5

    Perhaps in another thread, but it's basically a mish-mash of transactional quantum mechanics and many-worlds interpretation: determinism forwards and backwards in time.

    It's non local, in particular. Which means you can never isolate any sub-set of events from the rest of the universe in any calculation.Olivier5

    That's true more generally, e.g. the EPR paradox is an example of ultra-nonlocal behaviour. Ultra-nonlocal behaviour was actually the subject of my PhD. That sort of behaviour is not problematic in transactional QM.

    Interestingly, I've just found this paper: https://www.nature.com/articles/s41598-019-56357-3#ref-CR29

    This argues that nature is fundamentally stochastic. This is not necessarily random, though. Stochastic modelling is suitable for the sorts of unknowable or intractable deterministic processes previously discussed.
  • Echarmion
    2.5k
    So, yes, radioactive decay is an example of a quantum field theory, the electroweak theory. But it isn't characterised by atoms or hadrons either spitting out or not spitting out components at random. The system evolves deterministically through both paths simultaneously, both decaying and not decaying, until the wavefunction collapses/universe branches/superposition decoheres/whatever else happens to yield singular observables.Kenosha Kid

    And the result of all this is that we cannot predict the exact time an individual atom will decay. We can only give probabilities for timeframes, correct?

    That doesn't follow. It just needs to have conferred a survival advantage to our ancestors.Kenosha Kid

    Right. Of course when talking about evolution, only the ancestors matter, since individuals don't evolve. But I think that my point still holds if we clarify "survival advantage to some ancestor". For example, it might be caused by a random (in an evolutionary sense) mutation that just happened to occur this generation. Traits might also genetically linked, so that a trait that actually does nothing to improve inclusive genetic fitness becomes dominant because it's linked to other traits that do.

    What do you mean, difficult to predict? For instance, would it make the vertical component of motion of a ball on an inclined plane difficult to predict?Kenosha Kid

    We could imagine that the motion is probabilistic, but with such a narrow Amplitude (is that the right word) that the inaccuracies wouldn't matter for everyday purposes.
  • Olivier5
    6.2k
    This argues that nature is fundamentally stochastic.Kenosha Kid

    Stochastic
    Having a random probability distribution or pattern that may be analysed statistically but may not be predicted precisely.

    Well, that's what I'm saying. Nature behaves as if there was some randomness in there...
  • Kenosha Kid
    3.2k
    Stochastic
    Having a random probability distribution or pattern that may be analysed statistically but may not be predicted precisely.

    Well, that's what I'm saying. Nature behaves as if there was some randomness in there...
    Olivier5

    Stochastic methods are used for all sorts of intractable deterministic, statistical applications.
  • Olivier5
    6.2k
    And they are also used for all sorts of calculations about random events.

    determinism forwards and backwards in time.Kenosha Kid
    Double whammy. It wasn't enough one way?
  • Kenosha Kid
    3.2k
    And the result of all this is that we cannot predict the exact time an individual atom will decay. We can only give probabilities for timeframes, correct?Echarmion

    Yes, that is the measurement problem. At a given time, we know how much of the wavefunction should be |decayed> and how much |undecayed> but we don't know which we'll see when we measure.

    Traits might also genetically linked, so that a trait that actually does nothing to improve inclusive genetic fitness becomes dominant because it's linked to other traits that do.Echarmion

    That would still be selected for. Sickle cell disease is an example. It confers a survival disadvantage in and of itself, but ends up making the odds of survival greater. If sickle cell disease conferred no survival benefit due to immunity from malaria, it would have been eliminated from the genome due to its survival disadvantage.

    We could imagine that the motion is probabilistic, but with such a narrow Amplitude (is that the right word) that the inaccuracies wouldn't matter for everyday purposes.Echarmion

    Which is back to the non-determinism of the gaps: anywhere where it might show its face it is obliged to hide in tiny error bars.
  • Kenosha Kid
    3.2k
    And they are also used for all sorts of calculations about random events.Olivier5

    Indeed. Point being you can't read 'stochastic' and infer 'non-deterministic'. For instance, Brownian motion is modelled stochastically. That is not to say that collision events are random, simply that the particles involved have unknown initial states that, were they known, could not be feasibly tracked over time, but nonetheless are statistically predictable.
  • Olivier5
    6.2k
    Point being you can't read 'stochastic' and infer 'non-deterministic'.Kenosha Kid

    I can do so very easily. If it looks like a duck, walks like a duck and quacks like a duck.... Why would I not infer that it's a duck?
  • Kenosha Kid
    3.2k
    I can do so very easily. If it looks like a duck, walks like a duck and quacks like a duck.... Why would I not infer that it's a duck?Olivier5

    As you will, but if you are aware that stochastic methods are used to model deterministic processes and yet insist that anything modelled stochastically is random, you do give up the right to be taken seriously.
  • Olivier5
    6.2k
    I'm not really insisting that, if it looks like a duck, walks like a duck and quacks like a duck, it must be a duck. I'm just saying that this is the conclusion I will draw, personally, because I see no good reason to assume it's an elephant instead. You on the other hand, when you see that it looks like a duck, walks like a duck and quacks like a duck, you conclude that it ought to be an elephant... That is your call, not mine. That sounds pretty odd to me from an empirical epistemologic perspective but you are entitled to your opinion...
  • Pfhorrest
    4.6k
    If it is known that there are some elephants that look, walk, and quack like ducks...
  • Kenosha Kid
    3.2k
    I'm not really insisting that, if it looks like a duck, walks like a duck and quacks like a duck, it must be a duck. I'm just saying that this is the conclusion I will draw, personally, because I see no good reason to assume it's an elephant instead. You on the other hand, when you see that it looks like a duck, walks like a duck and quacks like a duck, you conclude that it ought to be an elephant... That is your call, not mine. That sounds pretty odd to me from an empirical epistemologic perspective but you are entitled to your opinion...Olivier5

    So, let me get this straight... You are aware that stochastic methods are employed to model both random and intractable, statistical systems. And you're not insisting that something modelled stochastically is automatically therefore random. So presumably you're telling me that the above paper is using stochastic methods to model something that looks random, i.e. walks like a duck. Walk us through that.
  • Olivier5
    6.2k
    The article is beyond my pay grade. You keep misunderstanding extremely simple points. Let me rephrase one more time:

    When I see a phenomenon that displays a behavior resembling randomness (eg the Galton box and its results plotted against a Gauss curve), I say it looks like randomness, and I'm going to treat it as such. Maybe that's what it is ontologically. Or maybe not, but ontology is for metaphysicians. As far as science is concerned, the theories and tools that can successful model such a phenomenon are probabilistic. If one wants to study such stochastic phenomena, even for the purpose of finding some determinism in them, one will have to use probabilities, which are the best way to think of such phenomena that we have found so far.

    When you see a stochastic pattern, you immediately conclude that no randomness could possibly be at play, because you don't like the idea.

    So if it looks like a duck, walks like a duck and quacks like a duck, you conclude that it cannot be a duck because ducks don't exist. Hence it must be an elephant.
  • Kenosha Kid
    3.2k
    When I see a phenomenon that displays a behavior resembling randomness (eg the Galton box and its results plotted against a Gauss curve), I say it looks like randomnessOlivier5

    No, I understand that, that is, as you say, very simple. Simplistic, even.

    You said the above paper 'looks like a duck', i.e. "displays a behaviour resembling randomness". Can you walk us through that reasoning please?
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