Sorry, but this is wrong. I know it is what most students are still taught but Feynman tells us that it is wrong and I managed to establish that it was wrong in conversation with my late family friend Michael Ellis Fisher, who was in later years regarded as one of the top 6 world physicists. Michael pointed out why it was wrong.
The wave function is a bus timetable for the probability of certain types (technically ensembles) of action happening in an arbitrarily defined field domain. It is also constructed as an epistemic device so that it does not exist in the absence of initial measurements, so only applies to highly controlled systems in labs where you are allowed to assume your measurements predict a field domain precisely over a time period.
There are no systems in the universe, except in two special senses. 'Quantum system' is sometimes used to describe an individual quon or quantum unitary happening. (It would be easy to say quantum of action but in fact Planck meant something different by this - a parameter, not a quon.) That causes no problem other than confusion with the usual meaning of system. The other sense is Bohr's original meaning of quantum system which is an epistemic experimental set up, as described above, and not an entity in its own right.
Crucially, quantum bus timetables can never apply to systems that are systems by dint of being actions connected in determinate series. The timetable has to be written afresh every time an action is known to have occurred. So brains, which are systems by dint of serial cell interactions, can never have quantum level descriptions or wave equations.
This was Chalmers's lament, that experience does not seem to be what you expect. But in the seventeenth century everyone involved in science was aware of this being a false problem. Leibniz makes it an explicit feature of his theory but Galileo, Montaigne, Dcartes, Locke and all the others could see why the 'expectation' is misguided. As Galen Strawson has implied, in an important sense Chalmers put philosophy of mind back 500 years.
The simple point is that however signals are received by 'me's' in brains it will be via a non-optical, non-acoustic, non-taste route. So it is absurd to expect it to behave as if it were any of these. Leibniz makes the clever suggestion that the experience is felt by an action occupying a canvas or membrane, not illuminated by light as such but perturbed by something similar and sensed from within the canvas, not looked at by something else.
As Aristotle said, you cannot ask that because if you change the neuron it is no longer that neuron. If you could change the field of potentials but keep the same domain it might be fair to still say the experiences belonged to the neuron, although this would be getting into semantic quicksand.
I suspect the useful answer would be that if you take away a bit that alters the electroacoustic properties of the condensed matter unit then it is quite likely that the sort of experience we talk about would collapse totally. Like taking away the bridge from a violin. According to Jaan Aru that may be what anaesthetics do - they put a dead finger on the strings half way down.
So any action within the cell would be informed almost exclusively by this body, although the body could itself be informed by, and represent, the wider universe
It make me think of that strange phenomenon: the perfect outline of an eye on an animal’s body. People say it’s down to natural selection, nevertheless what would essentially be a matter of chance results in a true representation – without any consciousness (or what we call like that).
It make me think of that strange phenomenon: the perfect outline of an eye on an animal’s body. People say it’s down to natural selection, nevertheless what would essentially be a matter of chance results in a true representation – without any consciousness (or what we call like that).
Mimicry in animal forms is certainly part of the story. I think we can accept that it arises from natural selection of random mutations but in living systems that have evolved and ability to create almost any shape, with the greatest selection pressure being how those shapes appear to other life forms.
To clarify what the 4E people think the 'embodiment' idea achieves, I think its stems from a sense of naive realism, which we know empirically to be wrong but suits the intuitive approach of modern academic philosophy. We feel pain 'in my foot' so the idea is that we need to explain how a conscious sensation can be felt out there in a foot. The embodied idea is that it is felt there because the bodily interaction of the foot with the sharp stone actually constitutes the mechanism of consciousness. We know this is wrong. We know that 'pain in the foot' is something manufactured in brain cells for the benefit of other brain cells. The sense that it is five feet away down near the ground is just part of the way these feelings are manufactured - in a story that has a 'space' that is not anything to do with the space of physics. (Kant was probably the first to point that out specifically, although it had been argued over for two hundred years by then.)
What makes a domain like a cell have 'consciousness' of our sort is not just being richly informed by potentials. That richness in the happening is a sophisticated representation of more distant happenings, but not in a map-like isomorphic way and not presenting itself in an optical way.
Sorry, but this is wrong. I know it is what most students are still taught but Feynman tells us that it is wrong and I managed to establish that it was wrong in conversation with my late family friend Michael Ellis Fisher, who was in later years regarded as one of the top 6 world physicists. Michael pointed out why it was wrong.
Alright. It sounds like my guess wasn’t very good as to what you meant by ‘action’, but on the other hand, it sounds like we are in agreement that there likely aren't any isolated systems involved here. Probably it’s safer to consider me a confused math PhD rather than a confused physics student. Math people tend to get hung up on different things!
A mathematician, a physicist, and an engineer are riding a train through Scotland.
The engineer looks out the window, sees a black sheep, and exclaims, "Hey! They've got black sheep in Scotland!"
The physicist looks out the window and corrects the engineer, "Strictly speaking, all we know is that there's at least one black sheep in Scotland."
The mathematician looks out the window and corrects the physicist, " Strictly speaking, all we know is that is that at least one side of one sheep is black in Scotland."
An engineer is working at his desk in his office. His cigarette falls off the desk into the wastebasket, causing the papers within to burst into flames. The engineer looks around, sees a fire extinguisher, grabs it, puts out the flames, and goes back to work.
A physicist is working at his desk in another office and the same thing happens. He looks at the fire, looks at the fire extinguisher, and thinks "Fire requires fuel plus oxygen plus heat. The fire extinguisher will remove both the oxygen and the heat in the wastebasket. Ergo, no fire." He grabs the extinguisher, puts out the flames, and goes back to work.
A mathematician is working at his desk in another office and the same thing happens. He looks at the fire, looks at the fire extinguisher, and thinks for a minute, says "Ah! A solution exists!" and goes back to work.
An engineer, a physicist and a mathematician have to build a fence around a flock of sheep, using as little material as possible.
The engineer forms the flock into a circular shape and constructs a fence around it.
The physicist builds a fence with an infinite diameter and pulls it together until it fits around the flock.
The mathematicians thinks for a while, then builds a fence around himself and defines himself as being outside.
The process of physics could be framed this way:
Construct a math model that is meant to describe or predict some measurable physical thing.
Experiment to test the predictions of your model under the circumstances in which it is meant to apply.
If the model’s predictions are correct to a sufficient number of digits — rejoice!
Optional: Interpret all this as saying something about reality.
Physicists report their interpretation of the math (step 4) to the outside world, but this obscures exactly what information they have based that interpretation on.
So for instance, if a physicist describes the double slit experiment and says it shows that photons behave like a wave (as well as a particle), what that means in practical terms is just that the old math model where the photon was described as a particle gave an incorrect answer in this situation, and they have a new model where the photon is described by a wave that works instead. Viewed this way, you can see it’s not a definitive description. There might be yet another model that works even better, where the photon is represented by a third completely different mathematical object (indeed this is true based on my limited understanding of quantum electrodynamics).
The other notable thing is that often the physicists will describe two things that mathematically are quite different with the same words when speaking in ordinary language. They’re kind of stuck doing that because the only way we have to describe the thing properly is math — and to do it takes hundreds of pages of math.
The sorts of issues you mention with the wave function (limited applicability, the fact it relies on a very simplified isolated system model of its subject etc.) are true of physics models in general. It's a little more dramatic when QM is misapplied because its predictions are so strange. But everything done in physics is simplified as much as possible (this is both practically necessary, and often useful because it can lead to ‘deeper’ mathematical insights). Also, it’s typical for the physicists to assume a step of the math goes the way they want it to, without quite being able to prove it. This disturbs mathematicians, but is tolerated because the resulting final output often still agrees well with experimental data. All our current physics models/theories (even QED) give slightly wrong answers.
The picture I’m trying to paint here is that viewed from the math side, physics looks much more like a game of trying to piecemeal construct models that fit particular situations, and gleaning what insight we can from the ones that work, rather than being a machine for telling you definitively that reality is a certain way and only that way — I hope I’m making sense. I just say this to explain why, when I hear a statement from the land of physics, I’m very curious what the math behind it was exactly. Particularly this:
The answer to James's objection is that we need to find a quantum of action that connects all the synaptic potentials in the dendritic tree of a neuron to the resulting spike current. There are actually quite a range of options that would do but nobody has yet pinned down which fits best.
So if you’ll tolerate another guess, my other thought is this could be something someone was trying to do with some alternative form of quantum field theory?
Btw it’s rare, but there are a few interesting places in real life where wave function type quantum effects turn up. Modelling the position of electrons in either very thin wires or on either side of a very thin gap is both an example in class and relevant to real life electronics. Quantum tunnelling is the reason we can’t make computer chips smaller. On the other hand, apparently it's also used in ordinary usb sticks to wipe the memory.
The picture I’m trying to paint here is that viewed from the math side, physics looks much more like a game of trying to piecemeal construct models that fit particular situations, and gleaning what insight we can from the ones that work, rather than being a machine for telling you definitively that reality is a certain way and only that way — I hope I’m making sense. I just say this to explain why, when I hear a statement from the land of physics, I’m very curious what the math behind it was exactly.
Imagine the cow is a sphere in a frictionless environment.. One of my economics professors use to go on about how models are just simplifications of the world, and they only apply where the assumptions are met. Not that it stopped any other economists from claiming they know exactly which policy we should enact!
The picture I’m trying to paint here is that viewed from the math side, physics looks much more like a game of trying to piecemeal construct models that fit particular situations, and gleaning what insight we can from the ones that work, rather than being a machine for telling you definitively that reality is a certain way and only that way — I hope I’m making sense.
Hi @ScoutB. I am familiar with the things you raise but this isn't what bothered me. We may be at cross purpose but I am not talking about reality being a certain way. At the quantum, or individual dynamic unit, level it isn't any way that we would recognise, as Leibniz realised.
My concern is not the waviness or weirdness (which isn't) of a wave function. It is that it is not a descriptor of individual dynamic unit, 'action' or, technically, field excitation. I am not sure what a wave function is to be honest. There are wave equations, for sure. These are bus timetables for the probabilities of making certain observations within a field domain arbitrarily chosen by a human that has no intrinsic identity as a unit. They refer to infinite but parameterised classes (ensembles) of possible excitations within that domain.
Von Neumann and others raised the hare of a 'wave function' that 'undergoes linear progression', or evolution, and is then reduced or collapses to a single value. People like Roger Penrose still hold this view. But quantum theory never required it and it is now clear, perhaps most transparently illustrated by the Bell/Aspect story, that this is wrong. Nothing progresses. The creation and annihilation and connecting 'action' that constitute a field excitation form a single indivisible event that either occurs in its entirety or does not occur. This was the central point Fisher made me understand. Once that is accepted, things like tunneling and double slits cease to be weird. They fit exactly with the fundamental sort of account Leibniz told us we would find. Field excitations are, both mathematically and physically, like chess moves in a game played on computers with no pieces or board. The probability of any sequence of moves depends on certain rules, but with a degree of uncertainty. Tunnelling by knights is no problem.
If you can tell me what a 'wave function' is supposed to be, beyond a wave equation that has been parameterised for a certain field domain I would be interested, but so far I have come to doubt it exists. For me this is important because conscious experiences belong to intrinsic dynamic individuals and Leibniz's idea that these are the same individuals that underlie physics seems a good bet to me. In modern physics that makes them field excitations. These units have rules of probability of occurrence that include cyclicity but there is no reason to think that they cycle, any more than buses.
So if you’ll tolerate another guess, my other thought is this could be something someone was trying to do with some alternative form of quantum field theory?
It is something various people have been trying to gto do with conventional QFT but some follwoing the von Neumann wave function approach and others, like me, just sticking to the requirements of generalised QFT.
Surely these effects are everywhere in everyday life. As in the blue colour of a blue tit's head, which relies on diffraction and interference. But there is nothing weird about them. Tunnelling isn't weird. Brian Josephson and I have exchanged emails or sat in the Fellows Garden and talked about these things for years. Brian has a rather different view of how mind arises but he has never pulled me up on my analysis of the foundations.
I apologise for fulfilling Godwin's law in my last post, which was a bit rambling because I was tired but trying to join in.
I am interested by the body mind duality at a philosphical level, not least because I was not diagnosed with ME for ten years and it affected my mind tremendously. I had all sorts of strange cognitive experiences due, I...
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