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  • It is only continuous because it is random, so prior to making a measurement, you describe it in terms of a probability distribution called the state vector. The bits 0 and 1 are discrete, but if I said it was random and asked you to describe it, you would assign it a probability between 0 and 1, and thus it suddenly becomes continuous. (Although, in quantum mechanics, probability amplitudes are complex-valued.) The continuous nature of it is really something epistemic and not ontological. We only observe qubits as either 0 or 1, with discrete values, never anything in between the two.


  • bunchberry@lemmy.worldtoScience Memes@mander.xyzCrystals
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    17 days ago

    OrchOR makes way too many wild claims for there to easily be any evidence for it. Even if we discover quantum effects (in the sense of scalable interference effects which have absolutely not been demonstrated) in the brain that would just demonstrate there are quantum effects in the brain, OrchOR is filled with a lot of assumptions which go far beyond this and would not be anywhere near justified. One of them being its reliance on gravity-induced collapse, which is nonrelativistic, meaning it cannot reproduce the predictions of quantum field theory, our best theory of the natural world.

    A theory is ultimately not just a list of facts but a collection of facts under a single philosophical interpretation of how they relate to one another. This is more of a philosophical issue, but even if OrchOR proves there is gravitational induced collapse and that there is quantum effects in the brain, we would still just take these two facts separately. OrchOR tries to unify them under some bizarre philosophical interpretation called the Penrose–Lucas argument that says because humans can believe things that are not proven, therefore human consciousness must be noncomputable, and because human consciousness is not computable, it must be reducible to something that you cannot algorithmically predict its outcome, which would be true of an objective collapse model. Ergo, wave function collapse causes consciousness.

    Again, even if they proved that there is scalable quantum interference effects in the brain, even if they proved that there is gravitationally induced collapse, that alone does not demonstrate OrchOR unless you actually think the Penrose-Lucas argument makes sense. They would just be two facts which we would take separately as fact. It would just be a fact that there is gravitionally induced collapse, a fact that there is scalable quantum interference effects in the brain but there would be no reason to adopt any of their claims about “consciousness.”

    But even then, there is still no strong evidence that the brain in any way makes use of quantum interference effects, only loose hints that it may or not be possible with microtubules, and there is definitely no evidence of the gravitationally induced collapse.


  • bunchberry@lemmy.worldtoScience Memes@mander.xyzdouble slit
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    1 month ago

    Both these figures are embarrassingly bad.

    Hoffman confuses function for perception and constantly uses arguments demonstrating things can interpret reality incorrectly (which is purely a question of function) in order to argue they cannot perceive reality “as it is.,” which is a huge non-sequitur. He keeps going around promoting his “theorem” which supposedly “proves” this yet if you read his book where he explains his theorem it is again clearly about function as his theorem only shows that limitations in cognitive and sensory capabilities can lead something to interpret reality incorrectly yet he draws a wild conclusion which he never justifies that this means they do not perceive reality “as it is” at all.

    Kastrup is also just incredibly boring because he never reads books so he is convinced the only two philosophical schools in the universe are his personal idealism and metaphysical realism, which the latter he constantly incorrectly calls “materialism” when not all materialist schools of thought are even metaphysically realist. Unless you are yourself a metaphysical realist, nothing Kastrup has ever written is interesting at all, because he just pretends you don’t exist.

    Metaphysical realism is just a popular worldview in the west that most Laymen tend to naturally take on unwittingly. If you’re a person who has ever read books in your life, then you’d quickly notice that attacking metaphysical realism doesn’t get you to idealism, at best it gets you to metaphysical realism being not a coherent worldview… which that is the only thing I agree with Kastrup with.


  • There shouldn’t be a distinction between quantum and non-quantum objects. That’s the mystery. Why can’t large objects exhibit quantum properties?

    What makes quantum mechanics distinct from classical mechanics is the fact that not only are there interference effects, but statistically correlated systems (i.e. “entangled”) can seem to interfere with one another in a way that cannot be explained classically, at least not without superluminal communication, or introducing something else strange like the existence of negative probabilities.

    If it wasn’t for these kinds of interference effects, then we could just chalk up quantum randomness to classical randomness, i.e. it would just be the same as any old form of statistical mechanics. The randomness itself isn’t really that much of a defining feature of quantum mechanics.

    The reason I say all this is because we actually do know why there is a distinction between quantum and non-quantum objects and why large objects do not exhibit quantum properties. It is a mixture of two factors. First, larger systems like big molecules have smaller wavelengths, so interference with other molecules becomes harder and harder to detect. Second, there is decoherence. Even small particles, if they interact with a ton of other particles and you average over these interactions, you will find that the interference terms (the “coherences” in the density matrix) converge to zero, i.e. when you inject noise into a system its average behavior converges to a classical probability distribution.

    Hence, we already know why there is a seeming “transition” from quantum to classical. This doesn’t get rid of the fact that it is still statistical in nature, it doesn’t give you a reason as to why a particle that has a 50% chance of being over there and a 50% chance of being over here, that when you measure it and find it is over here, that it wasn’t over there. Decoherence doesn’t tell you why you actually get the results you do from a measurement, it’s still fundamentally random (which bothers people for some reason?).

    But it is well-understood how quantum probabilities converge to classical probabilities. There have even been studies that have reversed the process of decoherence.


  • For the first question, I would recommend reading the philosopher and physicist Francois-Igor Pris who not only seems to understand the deep philosophical origins of the problem, but also provides probably the simplest solution to it. Pris points out that we cannot treat the philosophical ramification in isolation, as if the difficulty in understanding quantum physics originates from quantum physics itself. It must originate from a framework in which we are trying to apply to quantum physics that just breaks down, and therefore it must originate from preconceived philosophical notions people have before even learning of quantum physics.

    In other words, you have to go back to the drawing board, question very foundational philosophical notions. He believes that it originates from the belief in metaphysical realism in the traditional sense, which is the idea that there is an objective reality but it is purely metaphysical, i.e. entirely invisible because what we perceive is merely an illusion created by the conscious mind, but somehow it is given rise to by equivalent objects that are impossible to see. For example, if you have a concept of a rock in your mind, that concept “reflects” a rock that is impossible to see, what Kant had called the thing-in-itself. How can a reality that is impossible to observe ever “give rise to” what we observe? This is basically the mind-body problem.

    Most academics refuse to put forward a coherent answer to this, and in a Newtonian framework it can be ignored. This problem resurfaces in quantum physics, because you have the same kind of problem yet again. What is a measurement if not an observation, and what is an observation if not an experience? You have a whole world of invisible waves floating around in Hilbert space that suddenly transform themselves into something we can observe (i.e. experience) the moment we attempt to look at them, i.e. they transform themselves suddenly into observable particles in spacetime the moment we look.

    His point is ultimately that, because people push off coming up with a philosophical solution to the mind-body problem, when it resurfaces as the measurement problem, people have no idea how to even approach it. However, he also points out that any approach you do take ultimately parallels whatever solution you would take to the mind-body problem.

    For example, eliminative materialists say the visible world does not actually exist but only the nonvisible world and that our belief we can experience things is an illusion. This parallels the Many Worlds Interpretation which gets rid of physical particles and thus gets rid of all observables and only has waves evolving in Hilbert space without observables. Idealists argue in favor of getting rid of invisible reality and just speak of the mind, which if you read the philosophical literature you will indeed find a lot of academics who are idealists who try to justify it with quantum mechanics.

    Both of these positions are, in my view, problematic, and I like Pris’ his own solution based on Jocelyn Benoist’s philosophy of contextual realism which is in turn based off of Ludwig Wittgenstein’s writings. Benoist has written extensively against all the arguments claiming that reality is invisible and has instead argued that what we experience is objective reality as it is exists independent of the observer but dependent upon the context of the observation. Thus he is critical of pretty much all of modern philosophers who overwhelmingly adhere either to metaphysical realism or to idealism. There is no mind-body problem under this framework because reality was never invisible to begin with, so there is no “explanatory gap.”

    Apply this thinking to quantum mechanics then it also provides a solution to the measurement problem that is probably the simplest and most intuitive and is very similar to Carlo Rovelli’s interpretation. Reality depends upon context all the way down, meaning that the properties of systems must be context variant. And that’s really the end of the story, no spooky action at a distance, no multiverse, no particles in two places at once, no language of observer-dependence, etc.

    Whenever you describe physical reality, you have to pick a coordinate system as reality depends upon context and is not “absolute,” or as Rovelli would say, reality depends upon the relations of a system to every other system. Hence, if you want to describe a system, you have to pick a coordinate system under which it will be “observed,” kind of like a reference frame, but the object you choose as the basis of the coordinate system has to actually interact with the other object. The wave function then is just a way for accounting for the system’s context as it incorporates the relations between the system being used as the basis of the reference frame and the object that it will interact with.

    Basically, it is not much different from Copenhagen, except “observer-dependence” is replaced by “context-dependence” as the properties of systems are context variant and any physical system, even a rock, can be used as the basis of the coordinate system. But, of course, if you want to predict what you will observe, then you always implicitly use your own context as the basis of the coordinate system. This is a realist stance, but not a metaphysical realist stance, because the states of particles are not absolute, there is no thing-in-itself, and the reality is precisely what you perceive and not some waves in Hilbert space beyond it (these are instead treated as tools for predicting what the value will be when you measure it, and not itself an entity). Although, it is only whether or not they have a property at all that is context variant.

    If two observers have interacted with the same particle, they will agree as to its state, as you do not get disagreements of the actual values of those particles, only whether or not they have a state at all. They would not be verbal disagreements either, because if an observer measures the state of a particle then goes and tells it to someone else, then it also indirectly enters their context as they would become correlated with that particle through their friend. You only get disagreements if there is no contact. For example, Wigner’s friend paradox, where his friend has measured the particle but has not told him the results nor has he measured it himself, from his context it would indeed have no state.

    The “collapse” would then not be a collapse of a physical “wave” but, again, reality is context variant, and so if you interact with a system, then it changes your relation to it, so you have to update the wave function to account for a change in context, kind of like if you change your reference frame in Galilean relativity. Everything is interpreted through this lens whereby nature is treated as context variant in this way, and it resolves all the paradoxes without introducing anything else. So if you can accept that one premise then everything else is explained. By abandoning metaphysical realism, it also simultaneously solves the other philosophical problems that originate from that point of view, i.e. the “hard problem” does not even make sense in a contextual realist framework and is not applicable.


  • Yes, there are a lot of intuitive understandings in the literature if you’re willing to look for it. The problem is that most people believe in a Newtonian view of the world which just is not compatible with quantum physics, so it requires you to alter some philosophical beliefs, and physics professors don’t really want to get into philosophical arguments, so it’s not really possible to reach a consensus on the question in physics departments. Even worse, there’s rarely a consensus on anything if you go to the philosophy department. So it’s not really that there are not very simple and intuitive ways to understand quantum mechanics, it’s that it’s not possible to get people to agree upon a way to interpret it, so there is a mentality to just avoid interpretation at all so that students don’t get distracted from actually understanding the math.


  • I think you are just trying to fight rather than actually have a discussion so I’m not really interested in going on, but I will say one last thing to clarify what I am saying for other people who might be reading.

    If you say observation = interaction then this inherently leads you to RQM which is like the definition of the interpretation. As I said at the beginning, I do support this interpretation, I think it’s the most reasonable approach, but it should be made clear this is a rather fringe point of view and not supported by most academics. You can see in the paper below only 6% of academics support it. And you clearly don’t seem to support it yourself as you seem to be pushing back against that rather than just agreeing with my statement it is the most intuitive way to think about things.

    https://arxiv.org/abs/1301.1069

    The plurality there support the Copenhagen view where observation really is given a special role.

    Without going the route of RQM then you end up with something that is just objectively false as the wave function would be incapable of spreading out since particles are always interacting with things, rendering quantum phenomena impossible.

    You can clarify instead by saying observation → interaction, that is to say, an observation implies an interaction, i.e. it inherently always entails an interaction but not interactions are observations, however, if you do this, you end up with the measurement problem. That is to say, you need to actually construct a theory to account for what kinds of interactions actually qualify as a measurement/observation. To quote John Bell…

    What exactly qualifies some physical systems to play the role of ‘measurer’? Was the wavefunction of the world waiting to jump for thousands of millions of years until a single-celled living creature appeared? Or did it have to wait a little longer, for some better qualified system . . . with a PhD?

    https://philpapers.org/rec/BELAM

    Specifying a theory of measurement is known as an “objective collapse” model and they make different predictions than traditional quantum mechanics because depending on where you set the threshold for what kind of interaction qualifies as an “observation” changes how much the wave function can spread out before being collapsed again by such an “observation.”

    There are several models of this like the Ghirardi–Rimini–Weber theory and the Diósi–Penrose model but these are ultimately more than just other interpretations of quantum mechanics but ultimately entirely new theories.

    It is not so simple just to say “observation is an interaction” and then pretend like the job is done, or else there would be no confusion in interpreting quantum mechanics at all. There is a lot more clarification that has to be made in order for it to make sense.




  • bunchberry@lemmy.worldtoScience Memes@mander.xyzElectrons are easy
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    2 months ago

    That’s not what I’m saying. My point is just that observation = interaction has a lot of implications. Particles are always interacting, so if the wave function represented some absolute state of a system, then the statement would just be incorrect because the wave function would be incapable of ever “spreading out” as it is constantly interacting with a lot of things yet we don’t “collapse” it in the mathematics until it interacts very specifically with us.

    The only way it can be made consistent is to then say that wave functions are not absolute things but instead describe something relative to a particular system, sort of like how in Galilean relativity you need to specify a coordinate system to describe certain properties like velocity of systems. You pick a referent object as the “center” of the coordinate system which you describe other systems from that reference frame.

    You would have to treat the wave function in a similar way, as something more coordinate than an actual entity. That would explain why it can differ between context frames (i.e. Wigner’s friend), and would explain why you have to “collapse” it when you interact with something, as the context would’ve changed so you would need to “zero” it again kinda like tarring a scale.

    Often we leave out the referent object and it becomes implicit, such as if we say a car is traveling at 50 km/h, there is an implication here “relative to the earth.” That is implied so it doesn’t really need to be said, but people can become confused and think 50 km/h is really a property intrinsic to the car because we always leave it out.

    That’s where a lot of confusion in QM comes from: we usually are concerned with what we will observe ourselves, what will actually show up on our measuring devices, so we implicitly use ourselves and our measuring devices as the referent object and by extension forget that we are describing properties of things relative to a particular coordinate system and not absolute.



  • bunchberry@lemmy.worldtoScience Memes@mander.xyzElectrons are easy
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    2 months ago

    Physicists seem to love their confusing language. Why do they associate Bell’s theorem with “local realism”? I get “local,” that maps to Lorentz invariance. But what does “realism” even mean? That’s a philosophical term, not a physical one, and I’ve seen at least 4 different ways it has been defined in the literature. Some papers use the philosophical meaning, belief in an observer-independent reality, some associate it with the outcome of experiments being predictable/predetermined, some associate it with particles having definite values at all times, and others argue that realism has to be broken up into different “kinds” of realism like “strong” realism and “weak” realism with different meanings.

    I saw a physicist recently who made a video complaining about how frustrated they are that everyone associates the term “dark matter” with matter that doesn’t interact with the electromagnetic field (hence “dark”), when in reality dark matter just refers to a list of observations which particle theories are currently the leading explanation for but technically the term doesn’t imply a particular class of theories and thus is not a claim that the observations are explained by matter that is “dark.” They were like genuinely upset and had an hour long video about people keep misunderstanding the term “dark matter” is just a list of observation, but like, why call it dark matter then if that’s not what it is?

    There really needs to be some sort of like organization that sets official names for terminology, kinda like how the French government has an official organization that defines what is considered real French so if there is any confusion in the language you at least have something to refer to. That way there can be some thought put into terminology used.


  • We can’t see wave functions. It is a tool used to predict observations but itself cannot be observed, and cannot be an observable object as it exists in an abstract Hilbert space and not even in spacetime. It is only “space” in the sense of a state space, kind of like how if I have a radio with 4 knobs, I can describe the settings with a single point in a 4 dimensional space. That doesn’t mean the radio actually is a 4 dimensional object existing in this state space, it only means that we can represent that way for convenience, and the dimensions here moreso represent degrees of freedom.

    If you believe everything is a wave function then you believe the whole universe is made out of things that cannot be observed. So how does that explain what we observe? Just leads to confusion. Confusion not caused by the mathematics but self-imposed. Nothing about the mathematics says you literally have to think everything is made out of waves. In fact, Heisenberg’s original formulation of quantum mechanics made all the same predictions yet this was before the Schrodinger equation was even invented.

    People take the wave formulation way too literally and ultimately it just produces much of this confusion. They are misleadingly taught that you can think of things turning into waves by starting with the double-slit experiment, except it is horribly misleading because they think the interference pattern they’re seeing is the wave function. Yet, (1) the wave function is associated with individual particles, not the interference pattern which is formed by thousands, millions of particles. There is nothing wave-like visible with just a single particle experiment. (2) Even the interference pattern formed by millions of particles does not contain the information of the wave function, only a projection of it, sort of like its “shadow” as the imaginary terms are lost when you apply the Born rule to it and square it. (3) They also like to depict a literal wave moving through two slits, but again there are imaginary components which don’t map to anything physically real, and so the depiction is a lie as information has to be removed in order to actually display a wave on the screen.

    The moment you look at literally anything that isn’t the double-slit experiment, the intuitive notion of imagining waves moving through space breaks down. Consider a quantum computer where the qubits are electrons with up or down spin representing 0 or 1. You can also represent the state of the quantum computer with a wave function, yet what does it even mean to imagine the computer’s internal state is a wave when there is nothing moving at all and the state of the quantum computer doesn’t even have position as one of its values? You can’t point to that wave even existing anywhere, you get lost in confusion if you try.

    This cloud is described by a mathematical object called wave function. The Austrian physicist Erwin Schrödinger has written an equation describing its evolution in time. Quantum mechanics is often mistakenly identified with this equation. Schrödinger had hopes that the ‘wave’ could be used to explain the oddities of quantum theory: from those of the sea to electromagnetic ones, waves are something we understand well. Even today, some physicists try to understand quantum mechanics by thinking that reality is the Schrödinger wave. But Heisenberg and Dirac understood at once that this would not do.

    To view Schrödinger’s wave as something real is to give it too much weight – it doesn’t help us to understand the theory; on the contrary, it leads to greater confusion. Except for special cases, the Schrödinger wave is not in physical space, and this divests it of all its intuitive character. But the main reason why Schrödinger’s wave is a bad image of reality is the fact that, when a particle collides with something else, it is always at a point: it is never spread out in space like a wave. If we conceive an electron as a wave, we get in trouble explaining how this wave instantly concentrates to a point at each collision. Schrödinger’s wave is not a useful representation of reality: it is an aid to calculation which permits us to predict with some degree of precision where the electron will reappear. The reality of the electron is not a wave: it is how it manifests itself in interactions

    — Carlo Rovelli, “Reality is Not What it Seems”

    It is more intuitive to not think of wave functions as entities at all. But people have this very specific mathematical notation so burned into their heads from the repeated uses of the double-slit experiment that it is very difficult to get it out of their heads. Not only did Heisenberg instead use matrix transformation rather than the Schrodinger equation to represent QM, but it is also possible to represent quantum mechanics in even a third mathematical formulation known as the ensemble in phase space formulation.

    The point here is that the Schrodinger equation is just one mathematical formalism in which there are multiple mathematically equivalent ways to formulate quantum mechanics, and so treating these wave functions wave really existing waves moving through a Hilbert space which you try to imagine as something like our own spacetime seems to be putting too much weight on a very specific formalism and ultimately is the source of a lot of the confusion. Describing the whole universe as thus a giant wave in Hilbert space evolving according to the Schrodinger equation is thus rather dubious, especially since these are entirely metaphysical constructs without any observable properties.


  • bunchberry@lemmy.worldtoScience Memes@mander.xyzanswer = sum(n) / len(n)
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    2 months ago

    I agree experience is incalculable but not because it is some special immaterial substance but because experience just is objective reality from a particular context frame. I can do all the calculations I want on a piece of paper describing the properties of fire, but the paper it’s written on won’t suddenly burst into flames. A description of an object will never converge into a real object, and by no means will descriptions of reality ever become reality itself. The notion that experience is incalculable is just uninteresting. Of course, we can say the same about the wave function. We use it as a tool to predict where we will see real particles. You also cannot compute the real particles from the wave function either because it’s not a real entity but a description of relationships between observations (i.e. experiences) of real things.