Coming back to physics, there's an assumption you and other commenters are silently making, which is that quantum mechanics is even applicable to macroscopic objects like humans. The largest objects which have been shown to act wave-like are a few thousand atoms large. While it's indisputable that at the lowest level the universe is fundamentally quantum mechanical, it's a little brazen to extrapolate that over more than 20 orders of magnitude. As a physicist myself, I'll believe it when I see it, and I'm looking forward to getting results from proposed experiments like FELIX and its successors.
https://en.wikipedia.org/wiki/Free-orbit_experiment_with_las...
It follows from schrodinger equation, it provides no exception for macroscopic objects. You can say quantum effects indeed happen at the lowest level, and macroscopic behavior follows what happens at the lowest level. It's a question of reducibility.
> The largest objects which have been shown to act wave-like are a few thousand atoms large.
Large objects have wave-like behavior, e.g. you can't determine their size with femtometer resolution, they don't suffer from ultraviolet catastrophe and have macroscopic quantum effects like superconductivity.
Nervous system evolved from ability to respond to external stimuli to centralized control of various processes to evaluation of risks/benefits of actions and finally to predictive modeling of external processes. Rudimentary concept of “self” and understanding of surrounding environment exists in various animals, so why is it strange that an animal with most complex brain has the most sophisticated concept of “self” and it’s placement in the ultimate surrounding environment - the universe?
But this understand of the surroundings and capability to react to stimuli comes with a subjective experience, which is what is actually meant with "consciousness". This is the hard problem of consciousness[0].
0: https://en.wikipedia.org/wiki/Hard_problem_of_consciousness
I don’t think I understand the problem enough to understand why it’s a problem.
There's no need for such subject to exist.
For example, most people assume that, so far, computers do not have any inner experience.
A computer could, conceivably, execute the same functions as our brain, yet have no inner experience of anything. Numbers get in, numbers get out, without any inner experience being needed.
So why is it wrong to explain this by the necessary recursiveness of predictive modeling that includes modeling “self”? We observe the temperature but we also observe ourselves observing the temperature. First is the signal, second is the introspection of the model evoked by that signal - the feeling.
It is understandable that having an model of an observer can be useful to a brain.
But how/why does that opens a window to an actual observer, and not just a model, is the question.
And we only know that - an actual observer exists - through first hand experience. It is our most immediate and certain knowledge (Cogito, ergo sum), everything else can be questioned. Yet, there's nothing in physics or computer science that gives a hint to this being the case.
Are you sure that observer has your personality, mind and memories? Are you sure that observer is involved in any way with the world, other than observing it?
Or are those other things just part of the machinery, and quite illusory. For example our perception of time, coherent thought and personality aren't all that consistent, as we know from various experiments and observations.
Here is the crux of my point:
If there's an actual observer, let's call it "primal consciousness", but they are observing the world through the lens of a mind, which is a complex, self-referential, reactive process running on a brain and body, we don't need to say that any particular physical process "creates" consciousness. We can settle with physical processes create something complex and interesting, which runs models of itself and the world, which "primal consciousness" observes. The "mind machine" running on the physics does not contain the observer, it's observed by the observer.
That doesn't "solve" the hard problem, but it's a model with different properties and consequences than some of the other models.
It's not "wrong", it's just not parsimonious. A system can model itself without being conscious, any time you have state in a program you are doing this.
Saying that an active model of self "is" what we experience as the consciousness we experience doesn't tell us why we have that experience.
We can just as easily imagine a complex machine with an active self-model that isn't conscious, as one that is.[1] So an active self-model doesn't tell us about consciousness. This shows them to be different concepts, not different names for the same concept. Which means neither "is" the other, and "is" is not an explanation.
[1] (To be a little more picky, we can't imagine that if we insist they are the same thing, but that leads to circular reasoning here. Our questioner can imagine both, and for an explanation to explain it needs to address the question, not wave it away by offering something circular.)
It all sort of falls apart when we only talk about whether an object other than ourselves is conscious or not.
As far as we know[2], we can't distinguish consciousness of other objects by observation. A hypothetical non-conscious machine might tell us it is conscious; we will never know if it's GPT-3000 talking or if it's another being like ourselves. So eventually we'll probably decide that it's moot, and treat it as conscious if it behaves convincingly and consistently like it is.
[2] That could change, it's not ruled out.
But that doesn't deal with the "hard problem" of consciousness, which is ourselves.
For ourselves, we are in no doubt about the direct experience of our own consciousness. We might convince ourselves that it's just an active self-model, processing, because of how we think of data processing machines these days. But we shouldn't, for one because that's a weak explanation that doesn't explain, and for two because there are other active self-models in the universe, and also in the much larger abstract realm of "unexecuted" self-models that could exist (pick an RNG seed and set of rules of your choice). We don't experience those, so the one(s) we do experience are notably distinct, for no obvious reason.
it seems to me the only rebuttal is "sure, self-models can exist but it's concievable that they can exist without an observer, so why is there an observer?" and to me it sounds similar to "sure, an eye can exist without abiogenesis, so why do we only find it in organisms that resulted from abiogenesis?"
an eye is just a collection of amino-acids, nothing prevents an eye from spontaneously assembling in a primordial soup and we recognize that's absolutely impossible. however i would posit that due to configuration of physical interactions in our universe, it's virtually guaranteed for an eye to develop in any life-form that is exposed to star's radiation in earth-like conditions.
similarly, just that we can think of p-zombie doesn't mean it's a simpler system to natually occure. we don't have understanding of building blocks of consciousness like we do with chemistry and biology but the answer to the why question seems to be quite simple: we observe ourselves because we evolved to. and we can find more and more primitive examples of self-observation in more and more primitive animals, so it's not some binary phenomena.
The hard problem of consciousness is not just about the why, it's also about the how. That's exactly the magical part: how subjective, non-physical experiences (supposedly) come from physical interactions. Brushing it off as "evolution" is not sufficient to explain the how.
Coming from engineering background, I would say we need to be looking for self perpatuating loops of neuronal activity (“strange loops” may be quite appropriate concept), but how would we go about looking for them - I have no idea because I’m not up to date on modern brain scanning tech.
> Consciousness isn't magic, because chinese room in conscious
That doesn't explain anything.
Does that explain to the person experiencing consciousness why they are? No it doesn't.
It just says "something else is conscious so you are too". Which is not an explanation, it's circular.
Is it relevant if the Chinese room is conscious as well? Not really.
I am curious, though. Do you consider a system (such as a Chinese room) to be conscious if it's only implicit, by writing down the rules it should run, without actually performing any of the rules? What if it's so implicit that we don't even write down anything, we just refer to it by name, and assume we would create the rules if we needed to as the first steps in execution? Is it conscious when nothing happens at all, but it could happen? If yes, does that mean every possible thing that could occur is conscious even if it doesn't occur? Every physical possibility is conscious? The whole world of abstract mathematics is conscious? If the answer to any of those is no, where do you draw the line between conscious things (Chinese room) and not-conscious things?
>without actually performing any of the rules?
Chinese room works like human mind, so it should run to be conscious.
I'm with you but is this experimental result not new though? It seems like they're on our side and confirming what should be a non-surprising result, which is good work.
Well, panpsychism is a thing and is actually having a bit of a renaissance.
It’s not so simple. Suppose you’re in a box and observe a quantum experiment, and then I open the box and observe you. Then before I open the box you’re in a superposed state |x> + |y>, corresponding to the two possible outcomes x and y. Fine, no problem so far. But what is your own subjective experience? You, subjectively, inside the box, will only ever observe yourself to be in |x> or |y>, never |x> + |y>. Even if from the outside your brain can be said to be in a superposed state, your experience of the world is not superposed.
If you somehow had an experience of "both outcomes simultaneously", that would violate the quantum mechanical prediction that there is no mutual information between the two superpositions. There are two brain states, an x state and a y state, and they know nothing about each other.
To each brain state (with the limited information available to it) it would appear that something "definite" had happened, even though in the global picture, a superposition still exists.
When people compare QM theories they often do so on basis of the original experiments that were used to develop them. But as a discipline physics has moved well past those. Superposition has been proven and tested to exist, and we have long since moved past that phase and started building things, like quantum computers, on top of it. At this point, pretty much the only way superposition doesn't exist is that every time a physicist does something that superposition needs to work, a devil figures out what kind of result is needed to fake it and does that.
Trying to challenge superposition would kind of get same kind of results from physicists as trying to challenge the existence of electrons would get from people who build circuits. Like, if you have some interesting new theory, I am intrigued, but do understand that to get people to follow it you will need to explain how it replicates the results of what superposition would do in so many different cases that you won't be able to enumerate them in a week.
For your experience of the world to be superposed it would mean that you carry out a quantum experiment with two mutually exclusive outcomes |x> and |y> and you actually experience the superposed result |x>+|y>. This would be like opening the box in the Schroedinger's cat experiment and actually observing the cat to be |alive>+|dead>, instead of either alive or dead. Maybe it's possible, but such an experience has never been reported.
So it's "possible" but would never happen in a trillion lifetimes of the universe. You can tell the difference between that and "impossible" by watching the quantum mechanics work for a few isolated particles, and observing what it means for them to fall out of superposition equilibrium. But in practical terms, it's equivalent to impossible.
For example, the Copenhagen interpretation of QM abandons both locality and realism - particles don't have definite states, and they also communicate at infinite speed (but in a way that can't carry information).
Your friend is in the monad, now you are too. No big deal.
How did they manage to get the paper accepted in the (supposedly selective) Nature Physics journal though? Is there something we are missing?
A possible lack of absoluteness of observed events has implications for what observations may or may not be reconcilable using existing scientific methods.
> "From the point of view of the friend, the measurement result was determined long before Wigner had asked about it, and the state of the physical system has already collapsed. When now exactly did the collapse occur? Was it when the friend had finished their measurement, or when the information of its result entered Wigner's consciousness?"
This to me, shows just how hand-wavy the whole superposition/quantum collapse stuff really is. I have to say I side with Einstein with his view that everything is already in one state or the other. We don't cause the system to choose a state when we measure it. We simply discover the state it was already in. It is one thing to assign a probability to which state we will find it in. It is quite another to create an entire theory around quantum measurement.
There is nothing mysterious about this paradox. The friend performs the measurement ans discovers the state of the particle/system. Wiger doesn't know about it, but that doesn't mean it's not in that state, he just isn't aware of it yet. The fact this is a paradox just seems like silly mind games.
Superposition isn't particularly hand-wavy. It's the basis of various technologies, and of precise numerical models we use to build technologies.
Quantum collapse is hand-wavy, and that's because it is not well understood. It might not exist (in which case superposition of mind-states is a thing), or it might exist (in which case mind-states may be definite). Quantum mechanics that we can calculate doesn't give an answer either way, even though it gives lots of other answers very precisely and correctly.
> Wiger doesn't know about it, [...] just seems like silly mind games.
When only applied to a single measurement it does seem like silly mind games, you're not wrong.
The motivation for those thought experiments was to try to reason back from the consequences found from more complex behaviour observed with multiple measurements, back to a simple system with only one measurement.
But when you have many measurements with entanglement, of which there are numerous physical experiements and confirmations by now, the idea that there are just multiple, correlated probabilistic states ready to be observed that we're not yet aware of is not consistent with physically measured behaviours. Those measurements aren't hand-waving, they are hard data, even though my explanation here is hand-waving and doesn't go into it.
> I side with Einstein with his view that everything is already in one state or the other
Numerous experimental results now contradict this view, or require other strange things to be true about the world (for example superdeterminism was mentioned in the article).
Actually, it is Bell's Theorem / Inequality and related experiments that are relevant here. https://en.wikipedia.org/wiki/Bell%27s_theorem
These experiments were really the nail in the coffin for Einstein's position for most physicists. Having to admit non-local hidden variables is a pretty distasteful result.
An observer changing the outcome is a very real repeatable experiment with non wavey results.
https://physicsworld.com/a/do-atoms-going-through-a-double-s...
It's similar to the problem that has been highlighted here by OP, to quote the artical I posted
"Indeed, the results of both Truscott and Aspect’s experiments shows that a particle’s wave or particle nature is most likely undefined until a measurement is made. The other less likely option would be that of backward causation – that the particle somehow has information from the future – but this involves sending a message faster than light, which is forbidden by the rules of relativity. "
https://en.wikipedia.org/w/index.php?title=Wigner%27s_friend...
The paradox seems to rest on magical thinking about consciousness, and if one simply accepts that a conscious observer can be in a superposition like any other piece of matter, the paradox is resolved.
And, from the article:
For Wigner, this was an absurd conclusion. Instead, he believed that once the consciousness of an observer becomes involved, the entanglement would “collapse” to make the friend’s observation definite.
But what if Wigner was wrong?
Well, obviously Wigner is wrong, sorry for being flippant.
In this paper (preprint here: https://arxiv.org/pdf/1907.05607.pdf), the magical thinking about consciousness seems to be transmuted into "“Absoluteness of Observed Events” (i.e. that every observed event exists absolutely, not relatively)". The authors (it appears to me) mean by this that if an observer performs an experiment, while this observer is himself in a superposition, we have to regard the outcome of the experiment as absolute (i.e. not in a superposition) because it was made by a (conscious) observer.
In my opinion, both "Absoluteness of Observed Events", and the equivalent from the layman's article, "When someone observes an event happening, it really happened", is a disingenuous and confusing way of talking about observers who are in a superposition. We have crossed over from "quantum mechanics is weird" to "these superficially intuitive but clearly false assumptions about quantum mechanics are weird".
(by the way, I read the article here: https://theconversation.com/a-new-quantum-paradox-throws-the... because that site doesn't think I'm a robot and then redirects me to the homepage after filling out the captcha)