[HN Gopher] Chaos theory eliminates quantum uncertainty
___________________________________________________________________
Chaos theory eliminates quantum uncertainty
Author : bookofjoe
Score : 55 points
Date : 2022-10-16 13:18 UTC (9 hours ago)
(HTM) web link (iai.tv)
(TXT) w3m dump (iai.tv)
| mg wrote:
| The article seems to distill the concept of quantum uncertainty
| into this statement: there is an inherent
| uncertainty about what happens to a quantum
| system when we attempt to observe it
|
| Is this a good way to put it?
|
| I'm not sure if with "quantum uncertainty", they refer to the
| same thing as Wikipedias "uncertainty principle" page:
|
| https://en.wikipedia.org/wiki/Uncertainty_principle
|
| The Wikipedia page sounds somewhat different (and harder to
| grasp) to me. It talks about predicting future states of pairs of
| physical quantities after knowing the initial conditions.
| Filligree wrote:
| Not at all. There's no uncertainty, even.
|
| Unless we're talking subjective uncertainty, in which case
| yeah, not literally everyone has landed on many-worlds yet.
| bookofjoe wrote:
| One word: 'Devs'
| Comevius wrote:
| This argument by Tim Palmer is in line with our intuitions, and
| his expertise while we are at it, but I'm pretty sure it's wrong.
| Quantum uncertainty is due to how quantum reality works, we just
| don't know exactly how quantum effects result in our classic
| reality, namely general relativity. I'm pretty sure the answer to
| that is something way less intuitive than chaos theory. I think
| Tim Palmer have spent his life chasing determinism in dynamical
| systems, and now everything is a nail to his hammer.
| mistermann wrote:
| It also overlooks that humans exists in reality, and humans run
| on consciousness (so they say), and consciousness (and the
| motion and causality that _emerges_ from it) remains somewhat
| of a black /invisible box to scientists.
| Comevius wrote:
| That doesn't have anything to do with it, classical physics
| (for example gravity) exists independently from us.
| mistermann wrote:
| If scientists were to explicitly state that they are only
| describing _a subset of reality_ (the physical /material
| realm), I would be more forgiving.
|
| But rather, they typically speak like this (from the
| article):
|
| "Quantum mechanics is usually described as a theory of
| atoms and sub-atomic particles, but in truth it is believed
| to be a theory that underpins everything in the world,
| including the weather and the galaxies - all of reality."
|
| Based on my observations, there seems to be a set of topics
| whereby most instances of human mind lose their ability to
| desire to know what is true. It if often easy to see this
| flaw in others (for example: non-theists observing
| theists), but seeing similar flaws in oneself is far
| trickier (say: materialists contemplating metaphysical
| ideas).
|
| (Note: this phenomenon applies to me as well, although I
| suspect not to the same degree as most.)
| 6gvONxR4sf7o wrote:
| I like the idea of digging deeper into counterfactuals at
| foundational levels. Science that has any use needs valid
| counterfactuals. It tells us that if we arrange stuff just like
| so, we can engineer things. Or that no matter what action we
| take, the heat death of the universe will happen.
|
| But counterfactuals and foundations don't mix easily, especially
| in QM where "what if I had measured X" isn't a really valid
| question in the standard view (the quantum zeno effect is an
| example of how hypothetical measurements and actual measurements
| _aren 't_ the same in QM).
| dvt wrote:
| In one of his papers ( _Undecidability, Fractal Geometry and the
| Unity of Physics_ , 2020), he dismisses Schrodinger's equation as
| being problematic for his theory (because it's linear so I guess
| "easy" to work with). And I'm no physicist, but I don't really
| get it: isn't the equation essentially the culmination of the
| physical _reality_ of particles having complementary properties?
|
| So in that sense, isn't uncertainty baked into our reality (and
| thus still ontological)? Even ignoring all the weird stuff that
| happens with entangled particles, spooky action at a distance,
| and all that. I literally _cannot_ measure both the momentum and
| the position of a particle to an arbitrary position
| simultaneously.
| ogogmad wrote:
| Is it possible to have a quantum theory where there is no
| "measurement"? The universe simply evolves according to the Dirac
| or Shroedinger equations, and the phenomenon that we call
| measurement is an emergent, statistical property?
|
| The motivation for the question is that in quantum physics there
| are two phases:
|
| 1. The phase where everything is quantum, and things evolve
| according to Dirac or Schroedinger. The state of a system at any
| given time then determines its state at all times in the future
| _and_ in the past. Everything is in all possible classical states
| at once.
|
| 2. Some measurement happens that is irreversible. The quantum
| state collapses, and information about the quantum state before
| the collapse is lost. The result is a single classical state.
|
| I haven't read TFA, but having something like phase 2 be emergent
| from phase 1 seems like a major breakthrough. Phase 2 is then an
| illusion. This seems better than the status quo. (I am not a
| physicist).
| gus_massa wrote:
| Yes.
|
| My preferred version is something-something-decoherence
| https://en.wikipedia.org/wiki/Quantum_decoherence The people
| that work in that are call it "Decoherence", but it's not
| finished, there are still a lot of details to fix, and perhaps
| it will need still like 50 or 100 years of hard work before
| it's completed. So it's too green and I prefer a funny name
| like "something-something-decoherence" to avoid confusion. And
| perhaps it's the wrong explanation.
| sampo wrote:
| > Is it possible to have a quantum theory where there is no
| "measurement"? The universe simply evolves according to the
| Dirac or Shroedinger equations, and the phenomenon that we call
| measurement is an emergent, statistical property?
|
| Doesn't the many-worlds interpretation fit your description? It
| of course has it's own weirdness.
|
| https://en.wikipedia.org/wiki/Many-worlds_interpretation
| ogogmad wrote:
| Is MWI (which appears to only assert that there is a
| wavefunction for the whole universe) a form of
| superdeterminism?
| nathias wrote:
| if this is true and the experiment can be explained away, this
| would not tell us anything about the world, but shift the
| question about ontological determinism back to metaphysics and
| outside of the reach of empirical knowledge
| motohagiography wrote:
| I had the impression it was set up mainly to assert a
| metaphysical position by inventing uncertainty about quantum
| physics' certain-uncertainty. I like outsider ideas more than
| most people, but this one seemed like a pitch for something
| self-centering. A lot of ideas about uncertainty are mainly
| rhetorical devices for neutralizing concrete arguments and
| opposition to the speakers underlying ideology, so personally I
| read the article as a kind of propaganda.
| [deleted]
| naasking wrote:
| > if this is true and the experiment can be explained away,
| this would not tell us anything about the world
|
| Actually, it would tell us something very important, namely
| that at the quantum level measurements are not statistically
| independent.
|
| > shift the question about ontological determinism back to
| metaphysics and outside of the reach of empirical knowledge
|
| Assuming by "ontological determinism", you mean to what extent
| we can truly discover natural laws, I don't know why anyone
| thinks this is a problem. Turing machines are simple and
| deterministic and yet have undecidable problems; and yet we can
| create a Turing machine that can enumerate the space of all
| possible programs. It trivially follows that humans obviously
| have enough degrees of freedom to enumerate all possible
| theories that can explain some set of observations, so this
| objection is a total nothingburger.
| photochemsyn wrote:
| I don't think Palmer has ever published anything on quantum
| mechanical systems, so this claim seems questionable and might be
| some kind of ideological viewpoint. Seems to wander well beyond
| the author's sphere of expertise.
|
| Palmer has nevertheless done a lot of interesting work in
| atmospheric and oceanic systems. Here's one, which also explains
| why current warming trends would persist for decades even if we
| halted all fossil fuel use tomorrow, something many seem to not
| have grasped:
|
| "Uncertainty in Weather and Climate Prediction", Slingo & Palmer
| (2011)
|
| > "In terms of seasonal to decadal prediction, the predictability
| of the system resides primarily in the oceans, where the greater
| thermal capacity and the much longer dynamical time scales for
| adjustment impart a memory to the coupled ocean-atmosphere
| system, which exceeds that for the atmosphere alone by several
| orders of magnitude. Nevertheless, the ocean, like the
| atmosphere, is a chaotic, nonlinear system, and so an ensemble
| approach to seasonal to decadal prediction is fundamental to
| forecasting on these time scales also."
|
| https://royalsocietypublishing.org/doi/full/10.1098/rsta.201...
|
| Anyone wanting a solid introduction to the notion of chaos in
| fluid dynamics should look at work of the original researcher who
| discovered the phenomenon, Ed Lorenz (1995) The Essence of Chaos.
|
| https://www.goodreads.com/book/show/154291.The_Essence_of_Ch...
| naasking wrote:
| > I don't think Palmer has ever published anything on quantum
| mechanical systems, so this claim seems questionable and might
| be some kind of ideological viewpoint.
|
| People are so quick to dismiss without any evidence. Why not
| look at his actual publications:
|
| https://www.physics.ox.ac.uk/our-people/palmer/publications
|
| Some choice excerpts:
|
| * Bell's theorem, non-computability and conformal cyclic
| cosmology: A top-down approach to quantum gravity,
| https://avs.scitation.org/doi/10.1116/5.0060680
|
| * Supermeasured: Violating Bell-Statistical Independence
| Without Violating Physical Statistical Independence,
| https://link.springer.com/article/10.1007/s10701-022-00602-9
|
| * Discretization of the Bloch sphere, fractal invariant sets
| and Bell's theorem,
| https://royalsocietypublishing.org/doi/10.1098/rspa.2019.035...
|
| * The Invariant Set Postulate: a new geometric framework for
| the foundations of quantum theory and the role played by
| gravity,
| https://royalsocietypublishing.org/doi/10.1098/rspa.2009.008...
|
| The last is when he first started publishing about quantum
| mechanics back in 2009, in which he described "invariant set
| theory" as a new approach to quantum foundations that was well
| received. He actually worked with Stephen Hawking on developing
| supergravity before he switched to climate modelling.
| photochemsyn wrote:
| I guess that's what I get for only looking at the top page of
| Google Scholar results for 'Palmer quantum chaos climate'.
| However, Palmer's view on quantum systems does seem to be
| pretty set and fairly ideological in nature (i.e.
| experimental verification doesn't seem to be much of a
| concern). For example:
|
| (2005) "Quantum Reality, Complex Numbers, and the
| Meteorological Butterfly Effect "
|
| https://journals.ametsoc.org/view/journals/bams/86/4/bams-86.
| ..
|
| > "By considering an idealization of the upscale cascade
| (which provides a novel representation of complex numbers and
| quaternions), a case is made for reinterpreting the quantum
| wave function as a set of intricately encoded binary
| sequences. In this reinterpretation, it is argued that the
| quantum world has no need for dice-playing deities, undead
| cats, multiple universes, or "spooky action at a distance.""
|
| At this point, I think anyone pushing this view of how QM
| works without experimental results to back it up is just
| tilting at windmills.
| naasking wrote:
| > However, Palmer's view on quantum systems does seem to be
| pretty set and fairly ideological in nature (i.e.
| experimental verification doesn't seem to be much of a
| concern).
|
| I don't understand this objection. Palmer's theory would
| have to be consistent with all existing evidence for
| quantum mechanics. There's a rich unexplored area in
| quantum foundations (superdeterminism), and he's found a
| novel, plausible model for how it could work, so why
| wouldn't he explore it fully until it's been contradicted?
|
| A different interpretation on QM might also imply some
| _new_ experiments that orthodox QM wouldn 't consider
| interesting. For instance, Hossenfelder has suggested that
| there might be some unusual regularities in repeated low
| temperature experiments if superdeterminism is true,
| regularities that would be implausible if reality is
| actually indeterministic. Palmer's theory has testable
| predictions for large-scale cosmology, so it's not like his
| ideas are unfalsifiable in principle.
|
| Furthermore, Palmer is a theoretician not an
| experimentalist. Bell created his theorem but
| experimentalists designed and ran the actual experiment.
| lisper wrote:
| >I don't think Palmer has ever published anything on quantum
| mechanical systems, so this claim seems questionable and might
| be some kind of ideological viewpoint. Seems to wander well
| beyond the author's sphere of expertise.
|
| Indeed.
|
| The question of whether quantum uncertainty is epistemological
| or ontological is formally undecidable (on the assumption that
| quantum mechanics is actually true). For starters, there
| already exists a quantum interpretation where uncertainty is
| ontological: Bohmian mechanics. But you don't even need that.
| All you need is to hypothesize a "cosmic Turing machine"
| computing the digits of pi or some other normal number and the
| stipulation that every time you do a quantum experiment the
| result is the next digit that the TM writes to its tape. That
| is an ontologicical interpretation of QM that is every bit as
| valid as Bohmian mechanics, and every bit as useless.
|
| It doesn't _matter_ whether quantum uncertainty is ontological
| or epistemological. What matters is that the outcomes of
| quantum measurements are fundamentally unpredictable _for the
| entity conducting the experiment_. It doesn 't matter whether
| the information generated by the experiment was pre-existing or
| somehow magically came into existence by wave function collapse
| or whatever, what matters is that the outcome is _not
| predictable even in principle_. And so it doesn 't matter what
| mathematical model you put underneath this unpredictability. It
| can be axiomatic, it can be chaotic, or it can be a cosmic
| Turing machine computing the digits of pi. It doesn't matter
| because one of the things we cannot know, even in principle, is
| which of these hypotheses are correct. It's a non-scientific
| question.
|
| [UPDATE] The general principle is that quantum experiments
| produce an unbounded amount of information which cannot be
| predicted from the finite information available to any observer
| before those observations are made, so there has to be an
| unbounded amount of "hidden" information "out there" somewhere
| that in inaccessible except by performing quantum experiments.
| Different interpretations hide this inaccessible information in
| different places. Copenhagen hides it in wave function
| collapse. Bohm hides it in the particle positions, which are
| posited to be real numbers, every one of which contains an
| infinite amount of information. Chaotic dynamics hides it in
| the initial conditions which, like Bohmian positions, are real
| numbers which contain an infinite amount of information. If you
| look at how the math plays out, they are _literally_ reading
| out digits of real numbers as if they were written on a TM
| tape.
|
| I think physics would benefit from the study of information
| theory.
| guerrilla wrote:
| > It doesn't matter whether quantum uncertainty is
| ontological or epistemological. What matters is that the
| outcomes of quantum measurements are fundamentally
| unpredictable for the entity conducting the experiment. It
| doesn't matter whether the information generated by the
| experiment was pre-existing or somehow magically came into
| existence by wave function collapse or whatever, what matters
| is that the outcome is not predictable even in principle. And
| so it doesn't matter what mathematical model you put
| underneath this unpredictability. It can be axiomatic, it can
| be chaotic, or it can be a cosmic Turing machine computing
| the digits of pi. It doesn't matter because one of the things
| we cannot know, even in principle, is which of these
| hypotheses are correct. It's a non-scientific question.
|
| Thanks. That was actually really insightful. I never thought
| about it like that. It's beyond the scope of science and what
| models are _for_. We 'd be switching purposes at that point.
| The tools only do what they are meant to: predict; it doesn't
| make sense to them for to do something else (unless we
| specify that new purpose), especially when we do so as if
| we're not.
| hackandthink wrote:
| "It doesn't matter whether quantum uncertainty is ontological
| or epistemological"
|
| It matters for a lot of people, they want to know und
| understand. And maybe somebody comes up with an experiment.
|
| "What Bell's Theorem really shows us is that the foundations
| of quantum theory is a bona fide field of physics, in which
| questions are to be resolved by rigor- ous argument and
| experiment, rather than remaining the subject of open-ended
| debate.
|
| In other words, it is a mistake to crudely divide quantum
| theory into its practical part and its interpretation, and to
| think of the latter as metaphysics, experimental or
| otherwise."
|
| Matt Leifer: "Is the Quantum State Real?..."
|
| https://arxiv.org/pdf/1409.1570.pdf
| lisper wrote:
| > maybe somebody comes up with an experiment.
|
| Yes, it all turns on that. But the point is that coming up
| with an experiment would in and of itself falsify QM. To
| call that a major breakthrough would be quite the
| understatement, and so I predict with great confidence that
| it is not going to happen any time soon.
|
| > it is a mistake to crudely divide quantum theory into its
| practical part and its interpretation
|
| That's true, but I am not dividing it crudely. I am simply
| pointing out things that are logically implied by the
| mathematical structure of the theory, and one of those
| things is that quantum measurements bring new information
| into the world. If anyone figures out a way to access the
| source of that information, that information would no
| longer be new, and that would falsify the theory. That is,
| of course, possible. But again, I'll give long odds
| against.
| naasking wrote:
| > And so it doesn't matter what mathematical model you put
| underneath this unpredictability. It can be axiomatic, it can
| be chaotic, or it can be a cosmic Turing machine computing
| the digits of pi.
|
| I don't think this is correct. Each formal model will allow
| you degrees of freedom that are ruled out by other models
| because the axioms differ. This is why a quantum field theory
| for Bohmian mechanics has been much harder to formulate than
| it was for Copenhagen, for example.
|
| Unifying quantum mechanics with general relativity could
| actually be easier under a "fractal model" of quantum
| mechanics than it is with Copenhagen.
|
| Edit on your [update]:
|
| > [UPDATE] The general principle is that quantum experiments
| produce an unbounded amount of information
|
| That doesn't sound correct either. No experiment can produce
| an unbounded amount of information. I'm not sure where you're
| getting this idea.
| lisper wrote:
| > Each formal model will allow you degrees of freedom that
| are ruled out by other models because the axioms differ.
|
| Nope. All QM interpretations produce the same predictions.
| They are formally equivalent in the same sense that lambda
| calculus and TMs are equivalent.
|
| The reason it is hard to unify Bohm and relativity to
| produce a Bohmian quantum field theory is that Bohm is
| committed to an intuitionistic metaphysics that requires
| there to be an answer to which measurement of an entangled
| system was performed first, and so it requires the
| imposition of an arbitrary foliation of space-time. This is
| a _metaphysical_ requirement, not a physical one. That is
| what makes it hard to extend Bohm to a field theory.
|
| > No experiment can produce an unbounded amount of
| information.
|
| No _single_ experiment can, but over time you can do an
| unbounded number of experiments. Note that I am
| deliberately using the term "unbounded" rather than
| "infinite". These are not the same. An unbounded quantity
| is finite at any given time, but it can keep growing
| without an upper bound.
|
| (In actual fact all of these numbers are probably finite
| and bounded because the observable universe is finite and
| the second law of thermodynamics puts a limit on how many
| experiments you can do.)
| naasking wrote:
| > Nope. All QM interpretations produce the same
| predictions.
|
| Correction: the same _observable_ predictions in the
| domains we 've tested. They all have different
| metaphysical implications which impact the plausibility.
|
| > They are formally equivalent in the same sense that
| lambda calculus and TMs are equivalent.
|
| No, that's not strictly correct. Bohmian mechanics allows
| the existence of quantum non-equilibrium, as but one
| example. Isomorphism is fine as an informal analogy, but
| it's not strictly true.
|
| > This is a metaphysical requirement, not a physical one.
| That is what makes it hard to extend Bohm to a field
| theory.
|
| The axioms of _every_ interpretation are metaphysical.
| The axioms are what let you make certain steps in one
| interpretation that cannot be done in another. This is
| why unifying GR with Bohmian mechanics is hard but isn 't
| with Copenhagen, which is exactly what I said.
| lisper wrote:
| > Correction: the same observable predictions
|
| "Observable" is redundant. A prediction in science is
| understood to mean a prediction about the outcome of an
| experiment, i.e. a prediction about an observation.
|
| > in the domains we've tested.
|
| No. The predictions of all QM interpretations are the
| same, full stop. If this were not the case we would not
| be having this conversation at all, we could determine
| which interpretation was correct by doing an experiment.
|
| (There is one exception to this, and that is GRW
| collapse, which predicts that there is some macroscopic
| scale at which systems stop exhibiting quantum behavior
| because of internal spontaneous collapse. But so far all
| experiments have falsified this.)
|
| > The axioms of every interpretation are metaphysical.
|
| No, that's not true. Bohmian positions are physical.
| Collapse is physical. Multiple worlds are physical.
|
| The thing that makes Bohmian foliations metaphysical is
| not that they are unmeasurable, it is that they are
| _arbitrary_. You cannot tell which foliation is correct
| _even in principle_.
| naasking wrote:
| > If this were not the case we would not be having this
| conversation at all, we could determine which
| interpretation was correct by doing an experiment.
|
| No, that's not correct. Again, Bohmian mechanics allows
| for quantum non-equilibrium, but we're not yet sure how
| to create such a state. So it is does make observably
| different prediction, in principle. This prediction is
| just not within experimental reach at the moment.
|
| Most interpretations make equivalent predictions, but not
| all. Those predictions that differ are outside of domains
| we've tested.
|
| > No, that's not true. Bohmian positions are physical.
| Collapse is physical. Multiple worlds are physical.
|
| They are physical by virtue of metaphysical assertions
| about what does and does not exist, ie. the axioms.
|
| > The thing that makes Bohmian foliations metaphysical is
| not that they are unmeasurable, it is that they are
| arbitrary. You cannot tell which foliation is correct
| even in principle.
|
| A preferred foliation can be derived from the wave
| function in Bohmian mechanics. You can arguably do
| without one. Both references are cited here:
|
| https://link.springer.com/article/10.1007/s10955-015-1369
| -8
| lisper wrote:
| > Bohmian mechanics allows for quantum non-equilibrium,
|
| Yes, of course. In Bohmian mechanics, particles have
| actual locations, and so _of course_ those locations
| cannot be required to obey the Born rule except by
| hypothesis. But it does not follow that...
|
| > it ... does make observably different prediction, in
| principle
|
| > but we're not yet sure how to create such a state
|
| > This prediction is just not within experimental reach
| at the moment
|
| It is not just that we "don't know" how to create these
| non-Born states, it is that creating such a state would
| _falsify quantum mechanics_. Creating such a state would
| necessarily involve some physical process that violates
| the Schroedinger equation. No such process has ever been
| observed. It is possible that this could change, but it
| 's extremely unlikely. And there is absolutely no reason
| to believe that such a new process, were it to ever be
| discovered, would have anything to do with Bohmian
| mechanics. It is as likely that we will discover a
| violation of conservation of energy or the second law of
| thermodynamics as we are to discover a violation of QM.
|
| > They are physical by virtue of metaphysical assertions
| about what does and does not exist, ie. the axioms.
|
| Well, yeah. The whole _idea_ of "physical" is itself a
| metaphysical assertion. We could be living in a
| simulation.
|
| > A preferred foliation can be derived from the wave
| function in Bohmian mechanics. You can arguably do
| without one.
|
| OK, that's news to me, but I don't have time to read that
| paper right now. I'll put it on my reading list.
|
| [UPDATE] They want $40 to access that paper. If you want
| to send me a copy I'll read it, but I won't pay that much
| for access to one paper. Sorry.
| mistermann wrote:
| > and there is absolutely no reason to believe
|
| Logic and epistemology seem to often take a backseat when
| the mind comes in close contact with the unknown.
|
| > Well, yeah. The whole idea of "physical" is itself a
| metaphysical assertion. We could be living in a
| simulation.
|
| Similarly, when it finds itself in these circumstances,
| it can often be observed flipping between 100% certainty
| and 100% uncertainty (the middle ground, _the unknown_ ,
| seems a "highly undesirable" place to be). On one hand,
| you might say this is "just people being people", but I
| am suspicious whether it is actually that simple.
|
| It's called the _Hard_ Problem of Consciousness for good
| reason, I think.
| sampo wrote:
| > I don't think Palmer has ever published anything on quantum
| mechanical systems, so this claim seems questionable and might
| be some kind of ideological viewpoint. Seems to wander well
| beyond the author's sphere of expertise.
|
| I don't think anyone can be an that much of an expert in
| quantum foundations. It's a research topic full of questions
| and not much answers, so you don't need deep expertise to grasp
| the current situation and the limits of current knowledge. In
| that sense, it should be a free game for almost anyone with a
| PhD in physics.
|
| https://en.wikipedia.org/wiki/Quantum_foundations
| MontyCarloHall wrote:
| Chaotic systems are deterministic, but so sensitive to initial
| conditions that even slight perturbations will lead to wildly
| different, seemingly random outcomes. But if you could prepare
| two chaotic systems with _exactly_ the same initial conditions,
| they would both follow the same trajectory. In practice, this is
| often impossible to do, since it requires drawing two real
| numbers within some absurdly small epsilon of each other (for the
| trajectories to be equivalent within some delta of each other, on
| some finite timescale Delta t. epsilon - > 0 as delta -> 0, Delta
| t -> infinity).
|
| We think of quantum randomness as truly random because the states
| are quantized, so it's easy to initialize a system with the exact
| same starting conditions and watch it follow unpredictable
| trajectories.
|
| Is this basically arguing that if we treat the entire universe as
| some macroscopic quantum state, comprising all the individual
| states of each discrete quantum, it would evolve
| deterministically? However, since we are only powered to observe
| a few quanta at a time, they appear to evolve completely
| randomly, but only because we are not privy to the states of
| every other quantum state in the universe?
| defrost wrote:
| The Lorenz Attractor pictured is a trajectory through pase
| space for a single initial condition; the key result from
| Lorenz (and from Smale with his Horseshoe maps) is that for ANY
| absurdly small epsilon you can find two initial positions
| within that epsilon that end up seperated down the track in
| time ...
|
| ergo, your: > since it requires drawing two real numbers within
| some absurdly small epsilon of each other.
|
| just won't do.
| MontyCarloHall wrote:
| Yup, I was sloppy with my writing. I just clarified it.
| wodenokoto wrote:
| Sixty symbols did a video on spooky actions at a distance
| coinciding with the Nobel prize this year for the same thing.
|
| It explains why we can show that it cannot be hidden variable /
| immeasurable initial state that causes the randomness.
|
| Basically we can change the probabilities of experiment B, made
| on particle B, by changing the experiment we do on particle A.
|
| I suppose that entanglement could still live in a deterministic
| world. E.g, given initial state/variable and interaction with
| entangled particle A, B will behave so and so. I'm sure you
| could work out a number of initial states for A and B and how
| each set of states react to each other, that could give the
| same proportions as the probabilities mentioned in the video.
|
| But given that initial states cannot be measured, is it really
| a better explanation?
|
| https://youtu.be/0RiAxvb_qI4
| zmgsabst wrote:
| I'm curious why non-local hidden variables aren't a bigger
| topic, given that we know there's non-local quantum numbers,
| eg those carried by anyons.
|
| If we believe reality is non-local, then why would we also
| believe it's non-determinate?
| deng wrote:
| > Is this basically arguing that if we treat the entire
| universe as some macroscopic quantum state, comprising all the
| individual states of each discrete quantum, it would evolve
| deterministically?
|
| Yes, I think in the end he is arguing for Superdeterminism,
| although for some reason he does not mention that concept in
| his article.
| mistermann wrote:
| > Chaotic systems are deterministic
|
| _By definition_ , chaotic systems "are" deterministic, but it
| does not necessarily follow that all systems that have had a
| label of "chaotic" attached to them are necessarily
| deterministic. It can certainly cause them to take on that
| appearance from certain frames of reference though.
| [deleted]
| layer8 wrote:
| > the states are quantized, so it's easy to initialize a system
| with the exact same starting conditions
|
| That doesn't seem right. Position, velocity and momentum etc.
| are not discrete values in quantum mechanics. It is not
| practically possible to repeatedly put particles into the same
| exact state.
| thrown_22 wrote:
| >since it requires drawing two real numbers within some
| absurdly small epsilon of each other.
|
| Not small, zero.
| MontyCarloHall wrote:
| Definitely, if we care about the outcome of the trajectories
| as t\to\infty.
|
| For certain systems, at smaller timescales, merely an absurd
| amount of precision will suffice [0,1].
|
| [0] https://en.m.wikipedia.org/wiki/Lyapunov_exponent
|
| [1] https://en.m.wikipedia.org/wiki/Lyapunov_time
| zmgsabst wrote:
| I think that last paragraph is right.
|
| If everything shares some weak correlation with the stuff
| around it, then it might experience 10^-6 or whatever
| perturbation experiment to experiment, and accordingly the runs
| deviate according to some statistics about the system. Or the
| state of the early universe. Or something we don't understand.
| nobodyandproud wrote:
| > We think of quantum randomness as truly random because the
| states are quantized, so it's easy to initialize a system with
| the exact same starting conditions and watch it follow
| unpredictable trajectories.
|
| With hidden variables--which by all accounts haven't been ruled
| out--it means we cannot do this.
|
| That is to say, there's no way you can tell you've set the same
| initial conditions.
| guerrilla wrote:
| > With hidden variables--which by all accounts haven't been
| ruled out--it means we cannot do this.
|
| Local hidden variables have been ruled out. So it's not
| really like chaotic systems at all, whose development is
| internal.
| shadowgovt wrote:
| The development of a fractal isn't internal. Its shape is
| completely predetermined by its mathematical description.
|
| I think what the author is trying to say is that we could
| imagine the universe is a massively hyper-dimensional
| fractal that we are utterly hopeless to determine the
| initial starting point on. I can't immediately see a reason
| that model wouldn't work, but its descriptive power
| (relative to QM) is basically nil... To be consistent with
| the observations that demanded a quantum mechanical
| understanding of the universe, we have to introduce the
| idea that we can't know where we are on the fractal, so
| this is more a philosophical pondering than a physical one.
| nobodyandproud wrote:
| Non-local hidden variables have not.
| guerrilla wrote:
| So it's not really like chaotic systems at all, whose
| development is internal.
| nobodyandproud wrote:
| Can you explain why non-locality means non internal?
| sampo wrote:
| > Local hidden variables have been ruled out.
|
| Superdeterminism is a local hidden variable theory, that
| has not been ruled out. Superdeterminism circumvents the
| Bell's theorem, by extending determinism not only to the
| things being measured, but also to the entities doing the
| measurements.
| texaslonghorn5 wrote:
| For the last part, I think so. You could imagine the universe
| as being operated on by some giant Hamiltonian operator with a
| basis of eigenstates, and then the amplitudes will just
| deterministically evolve according to the Schrodinger equation.
| superb-owl wrote:
| I can't get past the paywall, but I'd be curious to know what his
| solution to the violation of the Bell inequality is.
| bookofjoe wrote:
| https://archive.ph/6kaJc
| lupire wrote:
| "Counterfactual Fractal Geometry" , so Bell's inequality only
| applies in a reality that is different from our true reality.
|
| > We have to suppose that the whole universe, and literally
| everything there is in it, is collectively a chaotic system
| evolving precisely on some cosmic fractal geometry. "
|
| I guess one way of trying to make it make sense is that he
| believes in global hidden variables (non-locality), which
| reduces physics to "things are exactly this kind of weird
| because all the complexity of the universe is encoded in one
| giant number present at the big bang that is available to every
| particle forever.
| EGreg wrote:
| He explains it in the article. Questioning one of the
| assumptions in the Bell theorems
| naasking wrote:
| Indeed, he's on the superdeterminism train with Sabine
| Hossenfelder:
|
| https://www.frontiersin.org/articles/10.3389/fphy.2020.00139.
| ..
| fsh wrote:
| I am not aware of any superdeterministic theory that can
| explain the violation of Bell's inequality. They only argue
| that a violation of Bell's inequality is _not impossible_
| in a superdeterministic local hidden variable theory (but
| no such theory has been formulated). I suspect this is why
| Hossenfelder just knocks down a few strawmen in her video
| on superdeterminism [1], instead of addressing the elephant
| in the room (experimental violations of Bell 's
| inequality).
|
| [1] https://www.youtube.com/watch?v=ytyjgIyegDI
| rafaelero wrote:
| Accepting the very simple assertion that the thing being
| measured is not independent from the act of measurement
| already renders the bell inequality invalid.
| naasking wrote:
| Of course there are:
|
| * Hossenfelder's own toy model,
| https://arxiv.org/abs/2010.01327v5
|
| * Gerard 't Hooft's cellular automata model: https://webs
| pace.science.uu.nl/~hooft101/gthpub/FFP11_2010.p...
|
| * https://www.journals.uchicago.edu/doi/10.1086/714819
|
| Models that violate Bell's theorem are in fact simple to
| construct. Everyone agrees that superdeterminism can
| evade Bell's theorem, the key is making this evasion as
| plausible or more plausible than accepting many worlds or
| the absence of counterfactual definiteness.
|
| Given so little effort has been expended in this
| direction because of incorrect assumptions of
| superdeterminism, it's not surprising that these models
| are still rudimentary proofs of concept, but the notion
| that Bells' theorem is some insurmountable obstacle is
| just incorrect.
| gus_massa wrote:
| > _Of course, this is such a startling conclusion that physicists
| have looked for other ways to explain Bell's theorem. There is
| indeed an alternative interpretation, but it is too weird to be
| plausible. It assumes that the settings for the apparatus that
| measures the spin of one of the entangled particles somehow
| influence the measurement outcome for the other particle. It is a
| weird explanation because it implies what Einstein called "spooky
| action at a distance" - the idea that what happens to one
| particle can instantaneously influence another, distant particle.
| Einstein didn't like spooky action at a distance, and neither do
| I, nor indeed most physicists I know._
|
| I agree, nobody likes any of the current explanations.
|
| > _But to understand this, we have to think big, very big indeed.
| We have to suppose that the whole universe, and literally
| everything there is in it, is collectively a chaotic system
| evolving precisely on some cosmic fractal geometry. In this
| picture, there is no guarantee that hypothetical counterfactual
| worlds that you simply cooked up in your head, will lie on this
| fractal geometry. If they don't, then these counterfactual worlds
| will be inconsistent with the assumed geometric laws of physics._
|
| So the proposal is even worse. There are some universes that are
| possible and some universes that are impossible in spite they
| locally look good and you changed just a tiny thing from a
| possible universe. It's even more unintuitive and horrible that
| all the current proposals. It looks like a hidden global variable
| theory, but I'm, not sure.
|
| I don't understand all the digression about chaos and fractals.
| If you assume that the possible universes is a dense subset of
| the imaginable universes (like the rational numbers in the real
| numbers), it will make the trick. Also any manifold would be
| probably fine.
| texaslonghorn5 wrote:
| If you have a red ball and a green ball, and you put each in a
| box, and you randomly pick one of the boxes and give the other
| to your friend, and you travel a trillion miles away and open
| the box, you instantly know what color ball your friend has.
| This is just classical correlation.
|
| Or a more entanglement-like example, you randomly pick a pair
| of red socks or green socks from your drawer but don't know
| what you picked. Then put the socks you picked into two boxes
| and give one box to your friend. If you go a trillion miles
| away and look at your sock then your friend is guaranteed to
| have the same color. This isn't quite entanglement or the Bell
| pair since it's a mixed state, but the same idea of classical
| correlation holds and so these kinds of "action at a distance"
| scenarios aren't impossible from a classical perspective.
| gus_massa wrote:
| What you are describing is a "hidden variable" theory. They
| are disproved by the experiments of the Bell's inequality.
| It's more weird, much more weird.
|
| Let's continue with your experiment about the pair of red or
| green socks. If you and your friend measure if they are red-
| or-green, both will get the same results. This can be
| explained with a classical theory. Nobody disagree with that.
|
| The weird part is that you can measure if they are 50%red and
| 50%green! Can I call it yellow? This makes no sense with
| classical socks and colors, but it makes sense for quantum
| particles and other properties.
|
| But there are two ways to combine 50%red and 50%green, the
| technical notation is (R+G)/sqrt(2) and (R-G)/sqrt(2), one
| with a plus and one with a minus. Can I call them good-yellow
| and bad-yellow? Or you prefer yellow and blue? In one of the
| experiments, red means vertical and green horizontal, so one
| of the combinations is a 45deg diagonal like this / and the
| other is a 45deg diagonal like this \\. You don't need fancy
| equipment to measure the combinations, it's just a polarizer
| rotated 45deg. Can I call them yellow and backyelow? I prefer
| good-yellow and bad-yellow because it's more clear that
| something weird is happening.
|
| If you measure red-or-green and your friends measures good-
| yellow-or-bad-yellow, then the results will not be
| correlated. If you got "red", your friend has a 50%
| probability of getting good-yellow and a 50% probability of
| getting bad-yellow. There is nothing to explain here.
|
| If you and your friend measure if they are good-yello or bad-
| yellow, both will get again the same results. This can be
| again explained with a hidden variable theory. Both socks
| "know" what to say if they are asked if they are red-or-green
| and what to say if they are asked if the are good-yellow-or-
| bad-yellow.
|
| It get's more interesting when you pick more combinations,
| like 90%red and 10%green. Can I all it orange? And you can
| pick 10%red and 90%green. Can I call it lemon? If you measure
| red-or-green and your friends measures orange-or-lemon, then
| if you got red, your friend will get orange 90% of the time.
|
| And there are good-orange, bad-orange, good-lemmon and bad-
| lemmon. And there are many more shades of orange-yellow-
| lemon. But this is getting too long.
|
| You can have very smart socks that know what to answer for
| every possible combination of colors. So if you and your
| friend ask for the same color, whatever it is, both get the
| same result.
|
| The problem is when you and your friend measure many times
| using the correct shades of orange and lemon. So the results
| don't agree 0% neither 100%. You can count how many times you
| get each combination of results, like (red-vs-dark-orange, or
| green-vs-bright-yellow), and then add and subtract some of
| them.
|
| If you assume the socks can's communicate with the other
| socks before answering, then the result of the calculation is
| smaller then some number. But in the experiments disagree.
|
| There are some videos with all of this, with a better and
| longer explanation by MinutePhysics and 3Blue1Brown
| https://www.youtube.com/watch?v=zcqZHYo7ONs and
| https://www.youtube.com/watch?v=MzRCDLre1b4&t=0s
| chatterhead wrote:
| Quantum parallax with observer based views creates an infinite
| series of state changes.
| lupire wrote:
| This is a climate scientist saying (without justification) that a
| century of physicists missed the obvious trivial explanation. A
| little humility is in order.
|
| The whole crux of QM, as shown by actual experiments in lab, is
| that it really is different from just really complicated
| classical mechanics.
| sampo wrote:
| > This is a climate scientist saying (without justification)
| that a century of physicists missed the obvious trivial
| explanation.
|
| As far as I understand, and even though the article doesn't
| call it by name, he is making a case for superdeterminism.
| Which hasn't been missed, but has it's own Wikipedia article.
|
| https://en.wikipedia.org/wiki/Superdeterminism
|
| In fact, Bell (of Bell's theorem fame) himself discussed
| (super)determinism as a way to escape Bell's theorem.
| naasking wrote:
| > This is a climate scientist saying (without justification)
| that a century of physicists missed the obvious trivial
| explanation. A little humility is in order.
|
| He's a mathematical physicist [1] that happens to work on non-
| linear dynamical systems that apply to climate models. You
| know, like the non-linear dynamics seen in a quantum
| measurement. Maybe don't be so dismissive. He won the Dirac
| gold medal for theoretical physics in 2014, for instance.
|
| [1] https://en.wikipedia.org/wiki/Tim_Palmer_(physicist)
| kcexn wrote:
| This is a wild over simplification of what 'chaos' theory is
| actually studying and the statements it makes.
|
| Chaos theory in general states that for some deterministic
| systems, small changes in the initial conditions can lead to a
| wildly different deterministic outcome.
|
| A closer metaphor than the butterfly metaphor is a car on a wet
| road.
|
| Think of driving your car on a wet road. This is a completely
| deterministic system, there is nothing we don't know about how
| cars handle on wet roads. When you take that one corner too fast
| however, your car loses traction on the road, whether your car
| spins out or just fish tails for a bit before straightening out
| depends a great deal on the speed and angle that you entered the
| corner at. If you don't know the speed or angle that you entered
| the corner accurately, you don't know if you can bring the car
| back under control again or not.
|
| I don't think anybody in the field of Quantum Mechanics doubts
| that it is possible for Quantum effects to be entirely
| deterministic. But it may be so sensitive to small changes in
| initial conditions (which may be as far back as the birth of the
| universe), that even if we knew the exact deterministic equations
| to solve for Quantum Mechanical systems, they would never make an
| accurate prediction.
| stephc_int13 wrote:
| What seems clear, so far, is that our models are still not
| perfect and can't describe all of our observations or
| experiments.
|
| We're talking about the map, not reality.
|
| Given that after quite a bit of time we have almost reached
| scientific consensus, but not quite, I think humility is
| required.
|
| There are a few hints showing that QM is not the end game.
| FridayoLeary wrote:
| Science was pretty much agreed upon in the Middle Ages. Most
| philosophers agreed that Aristotle and the Greeks had pretty
| much worked everything out. Point is a consensus can be very
| far from the truth. As it stands the Standard Model is, to
| quote somebody 'a hideous cludge'. It relies on many invisible,
| undetectable entities such as 'dark matter', 'dark energy' all
| kinds of subatomic particles, yet it cannot explain gravity. It
| also introduces concepts such as inflation. Worse still, it is
| contradicted by qm!
|
| I think it's still possible that the entire standard model
| might still be uprooted in favour of something simpler.
| vecter wrote:
| Curious, what are those hints?
| sampo wrote:
| Do the double slit experiment in a non-uniform gravitational
| field. Nobody knows how to calculate that.
|
| We have two perfectly good and internally consistent
| theories: Quantum mechanics and general relativity. But they
| are inconsistent with each other.
| vecter wrote:
| Ah yes. My understanding is more that we have to make
| gravity fit within QM as opposed to the other way around,
| but perhaps a unified theory would require changes to QM
| also?
| senko wrote:
| Gravity
| scythe wrote:
| >In a series of technical papers I have developed a mathematical
| model where the counterfactual worlds which arise when you try to
| prove Bell's theorem do not lie on the assumed fractal geometry
| of the universe.
|
| If I'm reading this correctly, the author is describing a model
| of superdeterminism -- although it's not clear where fractal
| geometry comes into play.
| drdec wrote:
| > If I'm reading this correctly, the author is describing a
| model of superdeterminism -- although it's not clear where
| fractal geometry comes into play.
|
| My (limited) understanding was that the fractal geometry was
| part of the hidden variable system which is limiting the
| possible universes. The idea being that if a potential universe
| needs to correspond to a point in a fractal, then making a
| small change (via a counterfactual) could easily result in a
| universe which is not a point in the fractal.
| roywiggins wrote:
| It kind of smells like superdeterminism? In which the universe is
| conspiring to make you choose the correct measurements during
| Bell tests to result in the observed correlations.
|
| https://en.wikipedia.org/wiki/Superdeterminism
| rafaelero wrote:
| Or the observed correlations are caused by the measurement?
| naasking wrote:
| It is superdeterminism. "Conspiracy" is a feature of some
| superdeterministic theories, but not all.
| n4r9 wrote:
| Do you mean "theories" or "models"? If the former, please
| could you provide an example of a superdeterministic theory?
| naasking wrote:
| https://news.ycombinator.com/item?id=33224172
| sampo wrote:
| > It kinds of smells like superdeterminism?
|
| Yes. From your link: _Physicists Sabine Hossenfelder and Tim
| Palmer have argued that superdeterminism "is a promising
| approach not only to solve the measurement problem, but also to
| understand the apparent non-locality of quantum physics"._
|
| (Tim Palmer is the author of the posted article.)
| nyc111 wrote:
| "Philosophers call this "epistemological" uncertainty -
| uncertainty to do with lack of knowledge."
|
| Nature is self-similar. If we observe epistemological uncertainty
| in the macro world, the same will be true for the micro world.
|
| This is an example of physicists appropriating a philosophical
| question and trying to solve it by data analysis.
| Robotbeat wrote:
| Physics is just "natural philosophy."
___________________________________________________________________
(page generated 2022-10-16 23:00 UTC)