Tag: physics

Noise: counterfactuals and possible worlds

tnwjacksonLeave a comment

Dear S.,

Unobservable alternate “worlds”, whether string theoretic, Everettian, or merely “possible”, are counterfactual possibilities.

“The laws could have been any number of different ways,” — these are string theory counterfactuals.

“The wave function could have branched/collapsed1 any number of different ways,” — these are quantum counterfactuals.

Whether you treat them as counterfactuals or as “facts about elsewhere” is not itself a strictly scientific question, it is philosophical2.

Treating them as actual elsewheres is metaphysics, not science. Treating them as formal counterfactuals that emerge from theory is all that is required.

Reification is not the way, dear friend.

Love,

M.

 

  1. These are isomorphic terms
  2. …and there ain’t nuttin’ wrong with that.

Is consciousness substrate-independent?

tnwjacksonLeave a comment

Everybody seems to be talking about artificial intelligence. That’s appropriate, I’m sure, because AI is already having a big effect on our lives and its impact is only going to increase. AI researchers and climate scientists are currently vying with each other for the distinction of being members of the field addressing the “most important issue facing humanity today”. My only rejoinder to that is that since all things evolve, all fields of scientific investigation are subsets of evolutionary theory (and that includes physics). Reductionists may put them apples in their pipes and smoke them….so there, nee-nah nee-nah, etc.

Now that we have settled (once and for all) the important question, namely the hierarchy of scientific fields, we can get on to considering whether artificial general intelligences (or superintelligences) are likely to be conscious. Nested insider this question is another – is consciousness solely a property of biological wetware, or is it “substrate-independent”? That is, if we replicate the kind of information processing that goes on in human brains in a computer program, will that computer program be conscious? This is also relevant to the “simulation hypothesis“, which claims that we should consider it more likely that we live inside a simulated universe than that we are the privileged few who inhabit the “real” (original) universe. The simulation argument uses pretty basic statistical reasoning to make this point, but in order to get off the ground it must include “functionalism”, a.k.a. the substrate-independence of consciousness, as one of its premises.

Functionalism is simply the notion that what mental states do is more important than what they are made of. Thus, the argument goes, there is nothing special about wetware and all mental states are realisable in other “substrates” (like computers). The physicist Max Tegmark, in making this kind of argument, has pointed out that we shouldn’t think there’s anything special about “machines made of meat”, because, just like machines made of silicon, they are “fundamentally” composed of up-quarks and down-quarks. The “only” difference between the two is the arrangement of the quarks. Like Tegmark, I am a physicalist monist, so I agree with the factual component of his assertion, but I don’t see it as a strong argument for substrate-independence.

Now, don’t get me wrong, I think it’s entirely possible that AGIs will become conscious, I just don’t think the quark argument is particularly relevant. Quite a lot is smuggled into the claim that it’s only the pattern/arrangement of quarks that is different. If we accept that all material things are made of quarks arranged in different patterns, then pattern accounts for rather a lot. If you fully reproduce the pattern of quarks instantiated in a conscious meat machine, you will not only create consciousness, you’ll create meat. So by reducing the “substrate” to quarks, one doesn’t motivate an argument for substrate-independence.

We simply don’t yet know which properties of brains and bodies are important for consciousness. All we know is that consciousness evolves in biological (“meat”) systems as a solution to the design problem of integrating multiple sensory inputs. Some of those sensory inputs are interoceptive – they are not simply the brain’s assimilation of the external world, but also include responses to hormones, blood sugar levels, nociceptors, and the rest. Maybe you don’t need all of that to have consciousness and maybe you do – nobody knows what you can and can’t leave out.

A deep intuition at work behind claims of substrate-independence and functionalism is the belief that we can make “models” of things, typically mathematical/computational models, that actually possess the (salient) properties of the things we are modelling. This is an ancient idea – one name for it is Platonism, but it predates even that venerable Greek. We humans are powerfully motivated to understand things. This is our great evolutionary trump card – the ability to abstract from things to principles so that our knowledge becomes more generalizable and less domain-specific. What an awesome power this is and what an incredible extension of this power the evolution of first verbal, and then mathematical, languages was. I have no desire to trivialise the importance of our ability to model reality in order to understand it better. Heck, consciousness itself is a modelling process. But let’s not get overzealous and confuse map with territory. Maps are a useful guide to territory, but they lack many interesting properties of the things they represent.

In order to know whether consciousness is substrate-independent we’re going to need to know which properties of meat machines are relevant to its emergence. The likelihood seems to be that we are going to create AGI before we fully understand consciousness. Maybe we’ll actually come to a better understanding of consciousness with the aid of AGI, either because it helps us to study conscious meat machines, or because one day it claims to be conscious and we are forced to take its word for it. Personally, I don’t think consciousness is all that mysterious and I’m not a fan of the “hard problem“. Until further notice, however, it seems to be a purely biological phenomenon.

So I guess we’re just going to have to see what happens. Until then, let’s not get too carried away with our assertions of substrate-independence and let’s examine the motivating assumptions behind those assertions. As the philosopher John Searle has pointed out, a computational model of a storm is not wet. If we fully reproduce all the information represented by the arrangement of quarks in a system, we will have recreated that system, not modelled it.

(The painting is Max Ernst’s L’ange du Foyer, I could explain how it’s relevant, but I prefer to let you just enjoy the beautiful art)

What is the meaning of life?

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Episode 10! In a decimal system that is surely a milestone; in any other system of counting maybe not, but we’ll take it!

Tim reads from Sean Carroll’s wonderful book “The Big Picture“, and the intrepid evolutionary biologists (your hosts) discuss the meaning of life, conflict between science and religion on this topic, meditation, and a bunch of other stuff. It’s fun!

Spoiler alert – we don’t really know what the meaning of life is, but as Bill Fay (he’s a musician, check him out) says “like my old dad said, life is people“…..

Listen! We compel you to do so and hope you enjoy doing so. Subscribe on iTunes! Rate us on iTunes! Comment on the blog! Use exclamation marks excessively!!!

Thanks 🙂

Physicalism and consciousness

tnwjackson1 Comment

A: You’re always banging on about “physicalism” and “physicalist monism”. Frankly it all sounds like “goo goo ga joob” to me…..

B: Monism is just the belief that there is only one kind of “stuff” in the universe, and physicalism is the belief that that stuff is physical stuff.

A: Right. But what about consciousness? That doesn’t seem very physical to me.

B: Fair enough, there is definitely a sense in which it will always seem like there is more than just the physical. As you say, the contents of our consciousness, our “qualia“, seem profoundly non-physical….and in a sense they are, but not in any sense that requires there to be more “stuff” than the physical.

But I agree – this question of how qualia can exist in a physical universe still needs to be dealt with, it’s a BIG question. You can say “they are just illusions”, and that’s true, but it doesn’t answer the question, it just dodges it. Illusions are things that aren’t what they seem, not things that don’t exist. No one can deny the existence of qualia, not even the most ardent behaviourist, not BF Skinner himself.

A: Uh huh…..deal with it then please.

B: I’ll try. To be honest, I’m not sure anyone has really dealt with it yet, but the way we move forward with all tricky questions is to throw out conjectures which can be critically interrogated, both by others and ourselves. They can be interrogated experimentally, or purely through rational criticism. It’s all part of the process….

A: Righto, conjecture away.

B: We actually have plenty of examples of things that are real, physical phenomena, but seem not to be – rainbows, holograms etc. We also know about things that exist in different states – recordings of any kind, digital storage of information, etc. But any of these analogies can still only get you part of the way to consciousness, because these are things that are experienced, not things that experience.

From a physicalist perspective, consciousness is literally the experience of being part of the physical universe. That sounds like panpsychism….

A: Pan- what now….?

B: “Panpsychism” – the belief that consciousness is fundamental, and thus suffuses everything in the universe.

A: Is that like the Hindu concept of “Brahman”?

B: Something like that yes, I’m no expert on Hinduism, but I think that the concept of “oneness”, of an “ultimate reality”, can be either physicalist or “psychist”. Either way these are forms of monism, it’s just that the psychist form considers consciousness to be fundamental, and believes that the physical somehow emanates from that unified field of consciousness. Theoretical physicists also believe in a oneness and a “unified field”, quite literally – unified field theory is an attempt to unite all fundamental forces and particles in a single field…..which really is a pretty similar idea to Brahman, as I understand it, at least in monist forms of Hinduism.

A: Yeah, sounds kinda similar to me….physicists often use a sort of mystical terminology when they get excited too. They might even start talking about the “mind of God”, and then hastily point out that they mean the “God” of Spinoza, not some man in the sky…

B: Well, yeah, Spinoza was also a monist. Doesn’t he say something like “There is only one substance in the world, and that substance is God,”?

A: Sounds familiar, I never really paid attention in philosophy lectures to be honest – “talk talk talk drone drone drone yawn yawn yawn”. Anyway, get back to your droning about panpsychism, or whatever….

B: I’m not going to rise to that. Come to think of it, a panpsychist could probably either believe that consciousness is fundamental, or that the physical is but that all physical entities are imbued with consciousness, even fundamental particles.

A: Conscious particles?

B: Well, sort of. It’s a bit of a convoluted argument….

A: Can we skip it then?

B: I think it’s important, because it concerns a very deep divide in human thought. If you are a monist, you are committed to the idea that every fundamental building block of reality has a little bit of what it takes to make consciousness. For a physicalist that much should be uncontroversial, because we believe that consciousness is part of the physical universe along with everything else. The disagreement seems to be about whether we should call those building blocks “conscious”, or if we should reserve that term for organisms that are more obviously “aware”, but which are nevertheless built of those blocks. In some traditions, and I think this might apply to monist Hinduism, “consciousness” really seems to mean something like “that from which all other things are constructed”, so it’s sort of built into that definition that consciousness will always be fundamental, no matter what physics has to say….

A: Sheesh….do you ever wonder why people think that philosophy is all just arguing about the number of angels that can fit on a pinhead?

B: It’s true that a lot of the deepest schisms in philosophy are the result of semantic disagreements. But that doesn’t mean that they aren’t important, or that they don’t have a massive causal impact in our world – people will fight and die over their semantic distinctions, and they guide the way we think about and interact with the world in general. This is true of all of us, even scientists. Once we have the fairly basic philosophical insight that words are not entirely precise, and don’t really map onto reality in the same way for everybody, we develop this anxiety about the influence of words and try to escape it altogether. I think this is why some scientists claim philosophy is unimportant – because they think it’s “just” words, and words are unreliable as descriptions of reality. The thing is we can’t escape words – they have been central to human evolution and all our world views are necessarily built from them….which is exactly why philosophy is so important!!

A: Yep yep, off your high horse and on with the story please.

B: Personally, I’m no panpsychist. I feel there is every reason to believe that only very special parts of the physical universe, parts that perform a particular kind and rate of “information processing”, give rise to experience. And it’s not as if there’s this kind of information processing that just happens to give rise to experience, like it’s a coincidence or something. No, that’s epiphenomenalism, which is incoherent. There is…

A: Hang on, hang on….you and your “isms”….

B: “Epiphenomenalism” is the idea that consciousness is non-functional, that it’s just there, we’re experiencing it, but actually it has no influence on “reality”……whatever reality is supposed to be….

A: That sounds pretty stupid.

B: It is. There is an evolutionary context for consciousness. It’s not that our brains perform a particular kind of information processing and so we have experiences; it’s that our brains perform a particular kind of information processing because it gives rise to experience. Consciousness is functional. It is the solution to a design problem – that of how to integrate diverse sources of sensory input so that an organism can act effectively in the world. And consciousness is also about predicting the future…

A: Huh? Like clairvoyance? Now you sound like a mystic.

B: There’s nothing mystical about it, although it might be the source of some of our mystical beliefs. I can make it sound really dry if you want – consciousness is an “affordance-seeking predictive engine”.

A: Yeah, that’s dry. And boring. Stick to the mysticism, it’s more fun.

B: It’s not at all boring! It’s just a way of saying that consciousness allows us to imagine future scenarios, to envision the way the world around us is likely to change over a given time period, so that we can be best placed to either get the things we want, or avoid the things we don’t want to interact with, like predators or other hazards. When you stand on the edge of something tall, it’s not uncommon to have a vision of yourself falling off it – that’s one of the functions of consciousness, to warn us about dangerous things in our environment by predicting what might happen if we get too close…..

A: Hold on, how do you differ between “consciousness” and just “awareness”? Couldn’t I be aware of dangerous things in the environment without actually having visions of them, or without any kind of prediction of the future?

B: It’s difficult to disentangle awareness and consciousness in either an evolutionary context or in terms of the words themselves. I mean, to be “conscious” of something is to be aware of it, right? And if you consider human consciousness as some sort of end point of an evolutionary series that stretches all the way back to our distant single-celled ancestors, it’s going to be pretty hard to draw a line with consciousness on one side of it and “mere awareness” on the other side of it. Single-celled organisms are aware of their environments; they can sense them in a number of ways. Our consciousness, whatever it is, is descended from that awareness. I don’t really know to what extent the sensorium of an amoeba is integrated, but as organisms become more complex and their ability to sense the world becomes more refined, I imagine there is a greater need to integrate sensory inputs to create a unified picture of the world, and that is consciousness.

A: That sounds pretty straight-forward, but I’m not getting the “prediction” part, and I don’t get how all this leads to dreams and imagination and all the things that fill our consciousness and seem completely un-physical.

B: Yeah, it’s really hard to connect all those dots and articulate a simple explanation that really nails human consciousness. It’s hard to even do that for oneself, let alone put it into words that can give someone else that “Ah-ha!” moment…

A: Aw, life’s so hard to understand, isn’t it? Anyway, your “Ah-ha!” moments don’t mean you really understand, do they? They could just be the standard illusion of certainty everybody suffers from….

B: That’s very true. Regardless, I think it’s something like this: the integration of sensory inputs serves to create a sort of coherent “model” of the world, full of relevant affordances…

A: What are those again?

B: “Affordances” are basically things we can interact with. The thing is, the brain doesn’t create this model from scratch every moment of the day, that would be way too inefficient. It builds a model and then updates it only as new and unexpected things are detected. So the model is always a sort of expectation of how the world is going to be, which is only really updated whenever something that wasn’t included in that prediction occurs. That’s called “prediction error”. And since the brain has this capacity to actually build this integrated model based on sensory inputs, when those sensory inputs stop, the modelling capacity doesn’t just switch off. That’s essentially what dreams are – the brain continuing its task of model-building, but now unconstrained by sensory input. So really, the brain is always making predictions, and as predictive abilities become more sophisticated, organisms can benefit from anticipating potential future occurrences by ensuring they are in the right place at the right time to take advantage of, or avoid, anything that might come their way. When some organisms actually became “meta-aware”, of this…

A: What? You’re going off the deep-end now….

B: Aware of being aware. Like we are. Being aware of this predictive process means being able to control it to some degree, to actually plan for the future. But there’s a bit of a danger there I think, because obviously our predictions aren’t always accurate and a lot of our modern neuroses come from us doing too much predicting – we get caught up in our fantasies and can no longer tell which of the threats in our environment are actual, and which are the products of our own minds.

A: Right, like paranoia.

B: Exactly. It’s important for us to stop paying attention to that stuff from time to time, to take a break from all the self-generated predictive activity that usually fills up consciousness. It’s basically taking a break from our “selves” and directing our attention outwards and just enjoying the sensation of being a conscious part of the physical universe…..

A: That kinda makes sense, but now you’re starting to sound like a mystic of the self-help guru variety. I’m not sure I entirely got your explanation of consciousness as predictive though, and none of this is really convincing me about physicalism, either.

B: It’s a tough sell. Anyway, I’m tired, you’re tired – let’s talk about this again another time….

– TNWJ

 

Painting by Genevieve Camille Jackson – Cadeau de la Terre-Mere (A gift from Mother Earth), 2017 Acrylic on canvas 100×80

 

Permanent Evolution Podcast Episode 2

sympatheticpeople1 Comment

Episode two of the Permanent Evolution Podcast.

Part 1 – Morals and the Louis C.K. case study; are we becoming more moral? is there progress in history?

Part 2 – Cultural evolution continued; can a complex world view be coherent?

Part 3 – Is reality coherent? Is “evolution” just another catch-all metaphor?

NB.

When Joha says “immoral”, it sometimes sounds like he’s saying “moral”……

Teleology is “goal-directed by knowledge”, as opposed to teleonomy – “goal-directed by law”.

All music and field-recordings/soundscapes by Tim.

Painting by Genevieve Jackson.

Permanent Evolution

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Permanent evolution

A: What is “evolution”?

B: Evolution is descent with modification.

A: Oh? As simple as that? So……can we go home now?

B: Slow down – sometimes simple explanations are the hardest to understand – so let me unpack this one a bit.

Evolution is the ubiquitous process through which all that was came to be all that is, and through which all that is will become all that will be. That might seem cryptic or hand-wavy, but it’s just a simple statement. Evolution is prosaic.

Evolution is not “natural selection”. Natural selection is not a “type” of evolution. Natural selection is a particular kind of constraint that shapes the consequences of evolution in biological systems. It is not the only kind of constraint that shapes biological evolution, but it’s an important one. Natural selection is one of the best ideas ever produced by hairless apes, because it explains why some of the results of evolution look the way they do (to us).

Evolution is just descent with modification. The future states of a system depend upon (are descended from) prior states. Systems (ones that are actual) are not static – future states are different from prior states. That is evolution: breathtakingly simple and utterly universal.

There are those that wish to defend the word “evolution” from this interpretation, as though it might be tarnished by it. “Following this argument,” they (might) say, “the weathering of a rock, its transformation from a boulder into sand, would be considered its ‘evolution’.” Indeed. As would the transformation of the sand back into rock, were that the sand’s fate. I repeat: evolution is prosaic.

“Change is the only constant.” A truism that happens to be true. Aristotle thought that the default state for all things was for them to be at rest. He thought energy had to enter a system in order for movement to be initiated. He used this logic to construct his “prime mover”, or “unmoved mover”, argument. Aristotle was wrong. Heraclitus (a precursor of Aristotle) was closer when he said “everything is in flux and nothing is at rest”. Modern physics refutes Aristotle’s argument – at the “bottom” all is change, all is movement. In fact, Aristotle had it precisely backwards – “energy” is required to prevent change, not to cause it, and even then it’s just a temporary preservation of some “pattern” or another. “All patterns are ephemeral!”, cries the evolutionist.

A: A bit morbid, these evolutionists…

B: Death and taxes, my friend.

Anyway, change is constant, but not all change is permissible, because future states descend from prior states. Future states are constrained by prior states. Evolution, as manifest in the actual universe, is a process that takes place across time. Yes my dear, time is real! The past constrains the future and the deepest level at which we can observe this is by considering the laws of physics themselves. Since evolution is a process in time, if evolution is ubiquitous time must be fundamental and the laws of physics therefore cannot be “outside time”. Lee Smolin hits the nail on the noggin: the laws of physics evolved. Once evolved, they constrained all future evolution. They are one of the earliest “selection pressures”.

A: Why don’t the laws of physics keep evolving then?

B: Huh? I dunno….maybe they do, but maybe they are heavily constrained by something else. I didn’t claim to know everything…..and I was on a roll, do you have to keep interrupting?

A: Sorry….

B: That’s OK, it was a good question. Anyway, let me sum this up so we can get on with our lives.

Evolution is like this: change is constant, but every system has a set of degrees of freedom which constrain its possible future states. These are the selection pressures or “principles of selection”, or whatever semantically isomorphic phrase one wishes to coin. Different systems….

A: Semantically what?

B: “Semantically isomorphic” – it just means a different choice of words with the same meaning.

A: Well why didn’t you just say that?

B: I think my facial expression says it all right now. Aaaaaanyway:

Different systems have different principles of selection (and working these out is the hard, explanatory task of the evolutionary sciences). Selection pressures themselves evolve, of course, and the laws of physics are an example. The biological sciences have identified thousands of examples, some of which constitute “natural selection”. Systems of ethics are another example – they evolved and they constrain future evolution.

Got it?

A: Sorry what? I was just checking my Instagram feed…

B: Ah. Fair enough I guess. Have you ever read any Marx?

A: Huh? I thought we were done with all this intellectualising once you got through the evolution schtick?

B: We are, but this is funny – one of Marx’s most famous slogans was “permanent revolution!”; little did he know that reality was in a state of permanent evolution!

A: That’s not funny.

B: Oh.

– TNWJ