bunchberry
@bunchberry@lemmy.world
- Comment on Quantum physics 23 hours ago:
Well, what is boring and non-boring I guess is in the eye of the beholder. What I moreso was referring to is what is difficult to wrap your head around.
The nondeterminism is kind of unavoidable as long as you don’t want to change the mathematics of the theory itself, but I also don’t really consider nondeterminism to be that unintuitive or difficult to “understand.” I mean, throughout most of human history, it wasn’t that common for humans to actually believe in determinism in the Laplacian sense of being able to make absolute prediction to the future based on complete knowledge of the past, that was largely popularized with the rise of Newtonian mechanics, and even by the 19th century you had even a lot of materialist philosophers calling it into question on grounds of logical consistency. Personally, I think the strong desire to maintain Laplacian determinism is really a physicist thing. They work with Newtonian mechanics first and it becomes so intuitive some don’t want to let it go when it comes to quantum mechanics. But I doubt if you went and talked to the average person, most probably wouldn’t be that strongly adherent to Laplacian determinism.
The kinds of views I was talking about are more things like people who try to interpret the state vector as literally representing a physical wave spreading out in space that collapses like a house of cards when you perturb it, or try to envision a literal multiverse where everything is just a big “universal wave function.” A lot of these bizarre views are not only unintuitive but they run into a lot of problems in logical consistency and there have been mountains papers and books published on the subject trying to work out all the conceptual issues. If you are a person just learning QM the philosophical interpretation around it bothers you, if you listen to people who talk about these weird things, you will need to read through dozens of books and maybe even hundreds of papers just to get a general idea of what is going on, and even then most of these interpretations still have no resolved their mountain of conceptual issues.
To me this really bothered me when I got into quantum computing for the first time. I wanted to not just learn the math but have some sort of intuition of what is actually going on. I then went down a rabbit hole of reading tons and tons and tons of books and academic papers to try and find some way to make the math make sense on a philosophical level. What I ultimately came to realize is that most of this confusion is just self-imposed in the sense that they are based on assumptions which are not actually demanded by the mathematics and entirely optional (such as interpreting a list of probability amplitudes a literal entity in a physical space) and thus most can be stripped away.
You can’t strip away every aspect of QM that makes it unique, because it clearly does differ from classical mechanics, but by dong this you do really hone down on what actually makes QM unique and what is genuinely an unavoidable consequence of the mathematics. And what you get down to is just interference effects, which arise from the fact that probability amplitudes are complex-valued, thus can cancel each other out, which can’t occur in classical probability theory. Nondeterminism and context-dependence then follow from this as a necessity for the theory to be logically consistent, but both of those are fairly easy to have an intuition for.
- Comment on Quantum 1 week ago:
no that’s dialectics
- Comment on Quantum physics 1 week ago:
I am saying that assigning ontological reality to something that is by definition beyond observation (not what we observe and not even possible to observe) is metaphysical. If we explain the experiment using what we observe then there is no confusing or contradiction, or any ambiguity at all. Indeed, quantum mechanics becomes rather mechanical and boring, all the supposed mysticism disappears.
It is quite the opposite that the statistical behavior of the electron is decoupled from the individual electron. The individual electron just behaves randomly. There is no interference pattern at all for a single electron, at least not in the double-slit experiment (the Mach–Zehnder interferometer is arguably a bit more interesting). The interference pattern observed in the double-slit experiment is a weakly emergent behavior of an ensemble of electrons. You need thousands of them to actually see it.
- Comment on Quantum physics 2 months ago:
What is it then? If you say it’s a wave, well, that wave is in Hilbert space which is infinitely dimensional, not in spacetime which is four dimensional, so what does it mean to say the wave is “going through” the slit if it doesn’t exist in spacetime? Personally, I think all the confusion around QM stems from trying to objectify a probability distribution, which is what people do when they claim it turns into a literal wave.
To be honest, I think it’s cheating. People are used to physics being continuous, but in quantum mechanics it is discrete. Schrodinger showed that if you take any operator and compute a derivative, you can “fill in the gaps” in between interactions, but this is just purely metaphysical. You never see these “in between” gaps. It’s just a nice little mathematical trick and nothing more. Even Schrodinger later abandoned this idea and admitted that trying to fill in the gaps between interactions just leads to confusion in his book Nature and the Greeks’ and Science and Humanism.
What’s even more problematic about this viewpoint is that Schrodinger’s wave equation is a result of a very particular mathematical formalism. It is not actually needed to make correct predictions. Heisenberg had developed what is known as matrix mechanics whereby you evolve the observables themselves rather than the state vector. You can also do a similar trick and derive continuous evolution of the observables in between interactions in matrix mechanics, but what you get is, again, observables continuously changing, not the evolution of a wave function.
The wave function is purely a result of a particular mathematical formalism and there is no reason to assign it ontological reality. Even then, if you have ever worked with quantum mechanics, it is quite apparent that the wave function is just a function for picking probability amplitudes from a state vector, and the state vector is merely a list of, well, probability amplitudes. Quantum mechanics is probabilistic so we assign things a list of probabilities. Treating a list of probabilities as if it has ontological existence doesn’t even make any sense.
- Comment on Is Everyone Conscious in the Same Way? | Simon Roper 2 months ago:
i’d agree that we don’t really understand consciousness. i’d argue it’s more an issue of defining consciousness and what that encompasses than knowing its biological background.
Personally, no offense, but I think this a contradiction in terms. If we cannot define “consciousness” then you cannot say we don’t understand it. Don’t understand what? If you have not defined it, then saying we don’t understand it is like saying we don’t understand akokasdo. There is nothing to understand about akokasdo because it doesn’t mean anything.
- Comment on Is Everyone Conscious in the Same Way? | Simon Roper 2 months ago:
Bruh. We literally don’t even know what consciousness is.
You are starting from the premise that there is this thing out there called “consciousness” that needs some sort of unique “explanation.” You have to justify that premise. I do agree there is difficulty in figuring out the precise algorithms and physical mechanics that the brain uses to learn so efficiently, but somehow I don’t think this is what you mean by that.
We don’t know how anesthesia works either, so he looked into that and the best he got was it interrupts a quantom wave collapse in our brains
There is no such thing as “wave function collapse.” The state vector is just a list of probability amplitudes and you reduce those list of probability amplitudes to a definite outcome because you observed what that outcome is. If I flip a coin and it has a 50% chance of being heads and a 50% chance of being tails, and it lands on tails, I reduce the probability distribution to 100% probability for tails. There is no “collapse” going on here. Objectifying the state vector is a popular trend when talking about quantum mechanics but has never made any sense at all.
So maybe Roger Penrose just wasted his retirement on this passion project?
Depends on whether or not he is enjoying himself. If he’s having fun, then it isn’t a waste.
- Comment on Is Everyone Conscious in the Same Way? | Simon Roper 2 months ago:
The only observer of the mind would be an outside observer looking at you. You yourself are not an observer of your own mind nor could you ever be. I think it was Feuerbach who originally made the analogy that if your eyeballs evolved to look inwardly at themselves, then they could not look outwardly at the outside world. We cannot observe our own brains as they only exist to build models of reality, if our brains had a model of itself it would have no room left over to model the outside world.
We can only assign an object to be what is “sensing” our thoughts through reflection. Reflection is ultimately still building models of the outside world but the outside world contains a piece of ourselves in a reflection, and this allows us to have some limited sense of what we are. If we lived in a universe where we somehow could never leave an impression upon the world, if we could not see our own hands or see our own faces in the reflection upon a still lake, we would never assign an entity to ourselves at all.
We assign an entity onto ourselves for the specific purpose of distinguishing ourselves as an object from other objects, but this is not an a priori notion (“I think therefore I am” is lazy sophistry). It is an a posteriori notion derived through reflection upon what we observe. We never actually observe ourselves as such a thing is impossible. At best we can over reflections of ourselves and derive some limited model of what “we” are, but there will always be a gap between what we really are and the reflection of what we are.
Precisely what is “sensing your thoughts” is yourself derived through reflection which inherently derives from observation of the natural world. Without reflection, it is meaningless to even ask the question as to what is “behind” it. If we could not reflect, we would have no reason to assign anything there at all. If we do include reflection, then the answer to what is there is trivially obvious: what you see in a mirror.
- Comment on Crystals 3 months ago:
Orch0R 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, Orch0R 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.
- Comment on double slit 3 months 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.
- Comment on I don’t understand quantum physics 4 months ago:
Yes, there are a lot of intuitive understandings if the literature if you’re willing to look for it. The problem is that most people believe in a Newtonian and by extension Kantian 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.
- Comment on Electrons are easy 4 months ago:
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.
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?
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.
- Comment on Electrons are easy 4 months ago:
Why do you keep asking that? I already explained I’m not claiming observations = no interactions in extensive detail and you turn around and ask me that gain.
- Comment on Electrons are easy 4 months ago:
Saying that observations are a special kind of interaction does seem to be privileging humans, though? What is different from measurements/observations and any other interaction?
- Comment on Electrons are easy 4 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 all systems, 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.
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.
- Comment on Electrons are easy 4 months ago:
If you suggest every observation is an interaction then you inherently are getting into the relational interpretation. Which I am not saying you’re wrong to do so, I think it is the most intuitive way to think about things, but it is not a very popular viewpoint.
- Comment on Electrons are easy 4 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? They just inventing confusing terms then getting frustrated people are confused about them.
- Comment on Electrons are easy 4 months ago:
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.
- Comment on answer = sum(n) / len(n) 4 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.
- Comment on The theory that we live in a simulation involves simulants running their own simulations; wouldn't that require impossibly more resources for the main sim? 4 months ago:
If our technology is limited so we can never see beyond something, why even propose it exists? Bell’s theorem also demonstrates that if you do add hidden parameters, it would have to violate Lorentz invariance, meaning it would have to contradict with the predictions of our current best theories of the universe, like GR and QFT. Even as pure speculation it’s rather dubious as there’s no evidence that Lorentz invariance is ever violated.
- Comment on The theory that we live in a simulation involves simulants running their own simulations; wouldn't that require impossibly more resources for the main sim? 4 months ago:
My issue it is similar: each “layer” of simulation would necessarily be far simpler than than the layer in which the simulation is built, and so complexity would drop down exponentially such that even an incredibly complex universe would not be able to support conscious beings in simulations within only a few layers. You could imagine that maybe the initial universe is so much more complex than our own that it could support millions of layers, but at that point you’re just guessing, as we have no reason to believe there is even a single layer above our own, and the whole notion that “we’re more likely to be an a simulation than not” just ceases to be true. You can’t actually put a number on it, or even a vague description like “more likely.” it’s ultimately a guess.
- Comment on The theory that we live in a simulation involves simulants running their own simulations; wouldn't that require impossibly more resources for the main sim? 4 months ago:
I have never understood the argument that QM is evidence for a simulation because the universe is using less resources or something like that by not “rendering” things at that low of a level. The problem is that, yes, it’s probabilistic, but it is not merely probabilistic. We have probability in classical mechanics already like when dealing with gasses in statistical mechanics and we can model that just fine. Modeling wave functions is far more computationally expensive because they do not even exist in traditional spacetime but in an abstract Hilbert space that can grows in complexity exponentially faster than classical systems. That’s the whole reason for building quantum computers, it’s so much more computationally expensive to simulate this that it is more efficient just to have a machine that can do it.