Dear Conrad,

Finally (!), here are the specific comments on your essay.

I think you did a nice job overall, although this year's question, related to aims and intentions, was so wide that it was easy to get lost by trying to deal simultaneously with too many subjects! I think that's why, for a lot of us, our essays this time were less focussed than last time --- good examples, I think, are essays by Cristinel Stoica, Philip Gibbs... and me! You also covered a lot of ground in your essay, and you deflected the question from aims and intentions to meaning.

You made interesting parallels between your three "technologies", but I found your ideas in section 3 (On Being Physical) to be the most interesting and provocative, starting with your assertion that physics is where biology was before Darwin. Usually, we say that physics is the most advanced science, and that biology has a lot of catching up to do. But if you really ask the deepest questions about physics, as you do, and consider it as a functional system (instead of as a given set of laws that are to be taken as axioms and not discussed further), then, of course, there is still a lot that is still very mysterious.

For instance, you point out that physics "is not crunching numbers" and does not conform to "mathematical patterns". It is true that it is hopeless to simulate perfectly physics with our current computers. On the other hand, numbers are such a generic form of abstraction, anything that operates on anything can be said, I think, to operate on some sort of "number". And if the patterns of physics are not mathematical, what are they? Isn't mathematics supposed to be the general study of structure? Is there even such a thing as a non-mathematical structure? Theses questions are not easy, I agree!

In the middle of page 5, I found your challenge of creating a universe ex nihilo to be fascinating! As you point out, how do you even start? The meaning of anything is always defined relative to other meaningful things... of course, these are exactly the type of questions that lead me to consider some sort of co-emerging scheme...

I agree with you that "we're spoiled by living in a world where these problems are already solved". Maybe if, in the future, we are able to construct simulated worlds in our computers, we will better understand what it takes to start with nothing and build up a self-referential recursive logical system that makes sense.

I think your emphasis on physics as a construction based on the recursive functionality of measuring is a very interesting way to address the problem. You write: "Each successful measurement records a fact, adding to the fixed structure of historical fact that's needed to support further measurement. While outcomes are unpredictable, they're always selected to maintain consistency with all the other relevant facts produced by other measurements, always reconfirming the same unchanging laws, the same spacetime structure." I believe that something like that can be used to explain the regularity and lawfulness of our universe without taking it simply as granted.

Your most provocative claim, by far, is that "the complex structure of physics probably also emerged in stages, from simpler self-defining systems". You elaborated more on this idea in other works --- we'll have to discuss this further someday!

That's all for now. In the past month, I've spent so much time reading essays (and other related content suggested by them) that it will take some time before I get my life back on track -- I am almost 2 months late in grading my students' lab reports, and they are getting restless. But I'll still be thinking regularly about these issues! This contest made me realize that thermodynamics and information theory have a lot of deep, incredibly relevant content about the fundamental nature of reality --- and that I do not master these concepts as well as I would like. So I'll keep on learning, keep on elaborating my ideas... and I'll keep in touch!

Marc

Marc - your comment is more than adequate to fulfill my hope for a substantive response to my essays; it means the world to me that somebody connects with these ideas. Sorry to have kept you from your lab reports - I had a difficult 30 years trying to fit these pursuits into real life, but am now thankfully in "retirement".

You're right that many of the best essays here lost focus, given the breadth of the theme - which I somewhat perversely broadened further. My hope was to put the approach of my previous physical essays in a wider context. Ironically, though I repeated the idea of recursive selection many times in this essay, I didn't do a very good job bringing out its meaning! - in particular, its potential to make physics more meaningful. So I'm very thankful you saw what I'm after. Along with a few of the other essays and comments, yours will definitely help me push further.

On your comment - "numbers are such a generic form of abstraction, anything that operates on anything can be said to operate on some sort of 'number'. And if the patterns of physics are not mathematical, what are they? Isn't mathematics the general study of structure?"

Yes... and it may be there's a kind of math that describes the contextual structure of meaning. I suspect the math of quantum physics and relativity already take us a long way toward that. Though even if there's a way to express this kind of relationship mathematically, I don't think it will be the abstract structure of relations that explains how and why this system works.

What's so cool and impressive about math is that just beginning with some simple ideas, you get marvelously complex abstract patterns... some of which are even indispensable in physics. And this is all intellectually "under control," so to speak - it all works by necessity, and we can see exactly how it works, very satisfying. On top of that, there are these strange connections between seemingly unrelated fields of mathematics, tantalizingly mysterious.

So I easily see why people want to take math as the basis of everything - as our intellectual ancestors did 2,500 years ago. The problem is that you have to begin by "positing" some kinds of basic elements and relations to derive everything from. This would be a very small price to pay if you could actually get the derivation! But if you end up having to posit some remarkably subtle and complex structure, and still need "symmetry breaking" to get the two dozen or so empirical parameters in the Standard Model, you have to wonder if nature is cooperating.

The point for me is that many mathematical structures are empirically meaningful. That means there's a context for them; they're not just "posited" in the abstract. Numbers are meaningful because there are so many kinds of things to count in the world... though at the level of quantum field theory, even counting gets complicated and ambiguous. So I lean toward making the empirical structures more basic than the abstract.

If we take "meaning" or "observing" as in some way fundamental, then just as you say, this leads to some kind of "co-emergence" - since structures can only be observable in the context of other observable structures. So even if we can summarize this mutual contextuality in equations, it may not be abstract structures that are "doing the work." To me that clearly seems to be the case in biology, based on actual interactions between particular molecules. The math is crucial for understanding how populations evolve, but doesn't actually do the evolving.

As for my "most provocative claim" that the physics of our universe emerged from simpler self-defining systems... apparently not everyone gets provoked by that, so I'm more than a little thrilled by your comment. I have some further ideas about this that I find quite difficult to express clearly, but which you will certainly hear about at some point. Meanwhile I'll be very happy to learn about your ongoing self-education.

Best of luck getting life on track, and with many thanks,

Conrad

a month later

Hi, Conrad, little by little I am trying to catch up with the ongoing dialogues, now with a more relaxed timeline. I copy here the comment I left on Marc's forum, only so that you notice (I also answered you on mine, some time ago).

---------

ok, and now I reply to Conrad's comment (which I'll replicate in his forum, so that he notices it).

> But random events are only "selection" if there's something useful to select. The "collapse" of the wave function can only support a macroscopic world because it's selecting from a set of possibilities that are somehow highly structured - evolved? - to help other measurements happen, in the macroscopic environment.

Let me try to rephrase this idea, adding more redundancy, so you can assess whether I get you correctly - or not. I am trying to parallel this sentence made in the realm of physics to some analogous statement that could be done in biological evolution. In biology, a mutation progresses only if it gives rise to an organism that is at least as fit as its parent. Out of the many branches of the wavefunction, the ones that progress are the ones that give rise to a world that can still progress. Or, if we want to link it with Marc's idea, to a world that still contains the observer that was observing the universe an instant before.

If this is what you meant... it makes full sense to me. We should, however, make an effort to try to derive why the permanence of observers requires the laws of quantum mechanics to be the way they are. Because as you well say: quantum mechanics is not just blurriness, it's blurriness with a very specific structure. If we manage to derive some property of the physical world out of the hypothesis of co-emergence, the hypothesis becomes plausible in an Occam's razor context. That is, the world with the co-emergence hypothesis is simpler to understand than without it. Until we manage that feat, it is just an interesting idea, right?

> And I think simplest explanation for the Born rule - why probabilities are squared, in computing the outcome of a measurement - is that at bottom, every "collapse" is a mutual selection between a thing and its context, so the same outcome has to be randomly chosen from each side of the interaction.

Wow, this is truly interesting. I do understand the part that the outcome of the random choice has to be compatible for both sides of the system. That's what entanglement is about, right? Once an interaction develops, subsystems become coupled. Now, how do you derive Born's rule from here? I always thought it was a starting point, not something to be derived. Can you point me to some textbook to follow this idea?

So nice to keep thinking of the ideas triggered by the two of you. And I still have a lot to read in my agenda. By the way, forgot to mention. I have now read "Theory of nothing", excellent book! The style is a bit messy, which I guess is natural if it emerged from a discussion list. But still, there's a lot of good original stuff in there, providing raw material to start thinking from a new perspective. I guess this combination (messy, and yet still providing good input) is valid for "The user illusion", which seemed to interest you both. Moreover, "Theory of nothing" helped me to put a context to Marc's co-emergence.

Best!

inés.

    Hi, Conrad, sorry, it's me again. I just wanted to add a small comment. Ever since I read your essay, I had the impression it triggered a certain undefined question in me, but I could not pin it down. But fortunately yesterday I had a (mild) headache, and it all rained down on me. I finally sized it.

    You claim that things only make sense within a context. My question is whether you believe this applies for qualia as well. My headache seemed to have a meaning in itself. Something was happening to me, the sensation certainly had a meaning (uh, this is not good..) and it felt independent of any context. Is this an illusion? Do you believe qualia to acquire their meaning only in certain contexts? They are experienced as something primary, that may provide the context for other meanings, but do not depend on other contexts themselves. Is this only apparent in your view? Or moving one step back, is this question correctly posed?

    The main stream in neuroscience (to whom I mainly adhere) claims all events in our inner life (the events that we access through introspection) are no more than patterns of neural activity. If we consider one such pattern, it seems to be a dry form, something that in itself has no meaning at all. Just some neurons firing. But we kind of believe that within a context, such activity acquires a meaning. It is triggered by certain events, and in turn, it triggers other patterns, which are not arbitrary patterns, but are somehow associated to the initial pattern. And a (hopefully) sensible orchestra of neurons fire in a way that drive the behavior of the subject in some meaningful way, at least, inasmuch as the subject often survives (if he/she does not, end of that branch of the story, some other subject will make it better).

    The tricky point of this scenario is that if we describe the process at the level of neurons, we miss the sensation altogether. We can explain the phenomenon, but not the feeling. I understand that when looking at a strawberry, some of my neurons fire in a specific pattern, Yet, I still experience "red", and even the raw sensation has a meaning to me (I actually like the red color a lot). I can believe the idea that my sensation of red is nothing more than a concept that arises from the association with all the experiences that I keep in my conscious or mainly unconscious memory of all the events that involved red things, such as strawberries, blood, sunsets, roses and so forth. If a student asks me "Why do I experience the sensation of redness? Why is that sensation meaningful to me?" I reply "Because all the red things you have seen in your life have a certain common denominator. Your nervous system has learned to associate the activity of the red cones of your retina with the neural pattern corresponding to that common denominator". I give this reply because it sounds sensible to me. But honestly speaking, I fear I am still not quite answering the question.

    Any thoughts? Does this question have any meaning? Or to be more precise: can you grasp a context in which this question has a meaning?

    best! inés.

      Ines - I was very glad to see your posts, and will respond as soon as I have time to think a little. We were away at a conference, and have now my 2-yr old granddaughter as guest for a few days, precluding anything but fond mutual babble. Thanks!

      15 days later

      Hi Inés, sorry for the long delay... I'll respond to your second "small comment" first, since it poses such a big and interesting question.

      >> You claim that things only make sense within a context. My question is whether you believe this applies for qualia as well. My headache seemed to have a meaning in itself... it felt independent of any context. Is this an illusion?

      Yes, I do think context is still important here. The headache feeling is in contrast to the experience of feeling fine, or of aching in some other part of my body... and how it affects me depends on whether I can rest now or have difficult work to do, etc. A color appears the way it does in the context of other colors. I think the concept of basic "qualia" derives from the mistaken attempt in the 18th century to break experience down into irreducible atoms of sensation.

      On the other hand, it's a remarkable feature of the human kind of consciousness that we can isolate certain parts of our experience and feel them as primary, unique in themselves. The User Illusion explains this to an extent - if it's true that consciousness can't handle more than 50 bits/second, then to be conscious of something requires us to "discard" and keep unconscious the vast amount of sensory data and thought-processing that provides a background context for what we perceive.

      Rather than think of this as an "illusion" though, it seems to me a great achievement, even something we can cultivate through art and poetry - the ability to set up mental contexts in which we can pay attention to a certain color or feeling and appreciate it just for what it is, in itself. Though I guess this ability has its downside too, if there's a headache or other kinds of trouble.

      >> The tricky point of this scenario is that if we describe the process at the level of neurons, we miss the sensation altogether. We can explain the phenomenon, but not the feeling.

      That's right. Different things make sense at different levels. If we describe the process at the level of molecular interaction, for example, we get a lot of understanding of how neurons work, but we miss what makes this system alive. We only understand that at the level of organisms and all their interdependent subsystems. Then it turns out that the very existence of neurons and the complex molecules they're made of depends on the evolution of these self-replicating beings.

      Likewise we need neurobiology to understand how our visual systems work, but what we see as a certain shade of red only exists at a higher level. I think our ability to appreciate these specific aspects of our experience depends on being able to give them names, "red" in contrast to "blue" and "green" - even though the names are only pointers into the much richer detail of actual awareness.

      There is something here that seems truly inexplicable, though. What actually appears, when the right kind of context gets set up, is so unique. Why does red look that way, to me? As you suggest, there's something there that goes beyond my past experiences with red things. The question is especially poignant for me, because my son Felix inherited a gene that doesn't let him distinguish red from green. So we know different people see colors very differently, and we can understand the neurobiology. But the sensation itself, so distinct for each one of us? Probably the most we can hope to explain is the context that makes it possible.

      This makes a segue to your other question, about quantum mechanics, though my response to that will have to wait for another day. But I think there's a real parallel. If we set up the right kind of experimental context, we get a certain value for the momentum of a particle, say. The equations give us the probability of any particular result - but what actually shows up is unpredictable, and in a way inexplicable. At the quantum level, no "collapse of the wave function" should be possible, due to the linearity of the equations. There is only the reality of a definite result in the higher-level context of the measuring apparatus.

      Many thanks for your notes! and best regards,

      Conrad

      4 days later

      Inés - again after many delays, I'm responding to your note above.

      >> Out of the many branches of the wavefunction, the ones that progress are the ones that give rise to a world that can still progress. Or, if we want to link it with Marc's idea, to a world that still contains the observer that was observing the universe an instant before.

      That's an interesting way of putting it, and does capture the point I wanted to make. I developed the analogy with biological evolution a bit further in a previous essay. I certainly agree that for these ideas to be useful, we need to show that they entail many of the specific features of quantum mechanics. We evidently live in a world where each observer's viewpoint and local context keeps getting carried forward very reliably, from moment to moment, always with small changes reflecting its interaction with other viewpoints. Ideally we could demonstrate that to do this, the universe needs to have the kind of complex and finely-tuned physics that our world in fact has, at the quantum level.

      >> I do understand the part that the outcome of the random choice has to be compatible for both sides of the system. That's what entanglement is about, right? Once an interaction develops, subsystems become coupled. Now, how do you derive Born's rule from here? I always thought it was a starting point, not something to be derived.

      Entanglement means that when two systems interact, their quantum states become coupled, so that a subsequent measurement made on one of them constrains the results of a measurement made on the other. Such interactions don't "collapse" the wave function of either system. In fact, the big mystery of QM is how this "collapse" happens at all. Every interaction described by the theory just entangles things, so it's very unclear under what circumstances what we call a "measurement" can take place.

      Born's rule is usually presented as a basic postulate of QM, as you say. But apparently it's possible to describe QM mathematically in different ways, and Born's rule is sometimes derived from other axioms. For example, you could look at this paper and this one. But these arguments are way over my head - you're much better equipped to follow them than I am.

      Here's what I think I understand about this, though. Ordinary statistics assigns probabilities to various outcomes that together sum to 1. Quantum statistics are different, in that the various outcomes have "probability amplitudes" that sum to 1. No one really knows what that means, but to get the actual probability of an outcome when a measurement is made, you basically square the amplitude.

      Now the thought I offered so cryptically in my comment in Marc's thread is that this squared amplitude is just the probability that (a) the measured system selects a particular outcome at random, and (b) the observing system also happens to select that same outcome at random.

      In effect, the results of a measurement in QM are "doubly random" - that is, a measurement only happens when both the object and the observer accidentally make the same choice.

      In classical physics, by contrast, when we measure something, the observed information was already there to begin with. The measured object had definite properties all along, and this information just gets copied over to the observer. But in QM the information only comes to exist in the course of the measurement, through a kind of accidental agreement between object and observer. I'm trying to understand this as a kind of natural selection.

      There is an interpretation of QM that explains the Born rule just this way, called the "Transactional Interpretation". Ruth Kastner has done a remarkable job developing it - she has an interesting website and a couple of books - the more recent one is a popularization (that I haven't read), the earlier one a more technical treatment. This treats every interaction as a mutual agreement between an "emitter" and an "absorber", through a theory involving time-reversed action. It's a fairly well-accepted interpretation, though largely ignored in the physics community, though I don't know why time-reversed action should be considered any less reasonable than the more popular many-worlds interpretation, for example.

      My own feeling is that the somewhat cumbersome mechanics of this theory isn't really needed. Kastner is a self-described "realist", and her work is useful to me mainly as confirmation that my thoughts about the Born rule work out at a technical level. But in the conversation with you and Marc, we're imagining reality as somehow "co-emerging" in processes that evolve meaningful information between "agents" and "observers", and I'm not sure the underpinnings of Ruth's theory are relevant here.

      I've been trying to work out my intuitions about all this through several FQXi essays, hoping to pull it all together into some more coherent presentation. But that's as much clarification as I can manage at the moment!

      With thanks and best wishes -- Conrad

      Hi, Conrad, thanks a lot! This and the previous answer are truly interesting. I will follow the links and books you pointed out to me, calmly, in the weeks to come. Your discussions make a whole lot of sense, I actually wish the judges of the contest can put these discussions also into their equations. I specifically will go through the references of quantum mechanics, Born's rule, and so forth. And I will certainly think further about the idea that even if experiences may be perceived as primary and unique, they still do depend on context. It is not only a very interesting idea, it could have a whole lot of applications. Not only in the game industry, mind you, if we could really understand it, we could cure chronic pain by manipulating the context. Would that be a "sensation industry"? Or "perceived reality industry"? I guess these are not novel technologies, but.. how far could we get? Actually, this does connect to my present research, where I try to construct a metric (a notion of distance) between subjective experiences (color in particular, recently). I had just never thought about it in this way, it's quite remarkable how discussing with other people clarifies what one does every day. Or should I say, "constructs" what one does every day? And... we are back again in the co-evolution paradigm, where your thoughts act as a measuring device in the network of linearly overlapped memes inside my head, sharpening and delineating the concepts that guide my daily research :D

      Regarding Tor Nørretranders' User Illusion, I believe I share some of your thoughts. I definitively like the first part best. I have the impression that the author did not go through the regular academic career, and maybe that has made me uncomfortable at times, both with the repetitions, and the messages passed (we scientist are rather limited, sometimes). But in any case, I do feel grateful to the author, because he gave me a whole lot of seeds that inspired interesting thoughts, and that is enough for me to truly like a book. That is what I am looking for when I read something (book or essay), and happily leave for somebody else the hard work of rational criticism (constructive or not).

      A real pleasure... so thanks again!

      inés.

      Write a Reply...