"Following Kearns (2011), consider for instance a scenario in which an enduring wall, W, is shrunk down to the size of a brick and eventually brought back in time so as to be used to build (along with other bricks) the original W."
@John Rennie follow up to my question yesterday So does it apply in General relativity also that if the rate of time passing was faster the weight of an object would increase?
OK :-) The four-acceleration is given by the geodesic equation. For a particle falling freely we get a simple equation that relates the acceleration we measure in our coordinates to the spacetime curvature (again measured in our coordinates)
So the equation relates acceleration on the left to curvature on the right.
Oops, I just noticed an error: the "dt" shouldn't be there. That was a copy and paste error. Oh well ...
Anyhow, note that on the right side we have the curvature Γ but also the four velocity 𝑢. So the acceleration is proportional to both the curvature and the speed the particle is moving through spacetime.
That's why the speed affects how fast we see the particle accelerating.
Some philosophers/physicists hold the viewpoint that nature is a very complex set-theoretic structure, and that we are part of that structure. And also that it's our mathematicalbstructure that makes us self aware @ACuriousMind @Amit @Slereah
Stephen Wolfram has this theory
Is this correct to say that these theories are at least incomplete/ at worst wrong
I say they're at least incomplete because qualia are nowhere in any computable structure. Yet we know that qualia exist. But some pholosophers like Daniel Denett are saying that the structure IS qualia
Gerard t'hooft also believes in a cellular automata theory that represents the universes's "beables" that are ontological
Is it correct to say that these theories r incomplete becuz qualia also exist? @ACuriousMind @Slereah @Amit
Yeah, but on what basis do they say that? Do they just take that as their starting point with no justification needed?
Like, how did they reason themselves into that philosophy? I can't think of any justification to this philosophy except the circular justification where u take it as ur starting point
iirc e.g. Dennet denies that qualia, in their standard formulation, make sense as a concept
like, just because I believe in Santa that doesn't make Santa real, and just because I believe I have subjective experiences that doesn't make them real, either
i.e. one branch of computationalism just denies that qualia exist
the position here is we can computationally explain how the mind believes in Santa without Santa needing to exist, and likewise we can computationally explain how the mind believes in subjective experiences without them needing to exist; the claim is that these two beliefs are not fundamentally different in the computationalist viewpoint
@RyderRude Well, the thing about computationalism is that it doesn't really agree that there is a meaningful difference betwen sentient and non-sentient things
it's all just systems performing computation, and at some level of complexity we have historically started to call the abilities of some computational systems "sentience", but this is just a silly category, not some inherent property
You're right that this is incompatible with the Cartesian cogito, ergo sum and a focus on personal sensations as the only certain things I've talked about in the context of Decartes and Hume
but that's the thing: If everyone agreed Descartes and Hume were correct, epistemology and theories of mind would have stopped with them :P
Ok they say they can explain everything about the human using math structure. I think that's where there mistake is. There mistake is in their definition of "everything"
Their definition of everything is "everything that is explainable using math structures"
So it's circular. I'll give an example of something that falls outside their definition of everything
They can't explain the "redness" of red. Cuz they dont count it in their definition of "everything about red"
They just count the wavelength, the mathematical information about red as "everything about red"
@ACuriousMind I think their position is valid, but it also takes itself as the starting point. Their position is : "everything about the world describable using math is describable using math"
And they define "everything about world describablw using math" as "everything about the world"
So it's a consistent position I guess but it take itself as the starting point
You are correct they don't explain "redness" - that's what I mean when I say Dennett denies the existence of qualia. But this isn't supposed to be "let's not count that because we can't explain it", it's supposed to be "we don't need to explain that because we don't think it's actually real"
it's not "qualia don't exist because we can't explain them", it's "we can explain why people believe in qualia without needing to assume their existence"
I think it's uncharitable to represent this as the circular position; in general I tend to assume that any objection I can come up with only minutes after hearing a new theory is something someone else has already thought of :P
Ok I cud understand their argument : "Assume only a deterministic set-theoretic structure exists like Cellular automata. In this, there is a structure corresponding to " People" and a structure corresponding to "light". When " Light" encounters people, the People structure spits out a string "I see light"
It's philosophical zombies in a mathematical structure
my objection would be that the "behavior of people", which includes what they say or think, is already part of "Everything explainable using math structures".
The " Shape" or "color" of a person is not part of "everything explainable using math". But Denett just denies that the qualia that he feels exist. So he excludes that from his definition of "everything"
But if you relax the criteria of "computation" to include quantum computation, it's a different matter. I think it's a nice way to see how we slowly move our goal posts in accordance with evidence. We once thought physics and computation are about accuracy of predictions. Now we are forced to kind of separate predictivity from computation
So here's an interesting thought experiment. Suppose we have the precise rules for the cellular automata. all physics are explained, whatever experiment we do, we got the algorithm to predict the result to any accuracy. Do we then conclude that the automata is nature at a fundamental level? Or, perhaps still, this is just a model and we don't know if that's how nature "does it"?
A bit of a rough theory of everything, but on the other hand the previous' guy's idea was "everything is water", so it was pretty good by those standards
@RyderRude Back then you drank the kykleon of the Elysian mysteries
Well then, reflect what a noise is produced by your belly, which is but small. Shall not the air, which is boundless, produce these mighty claps of thunder?
While finding mode coefficients from the mode expansion of a field on some spacetime, we use the orthonormality condition of the basis. What if the orthonormality holds only on an interval of the full spacetime
E.g. In half Minkowski space the plane wave basis looks like $e^{i\omega_\vec{k} t} \sin(k x)$ upto some normalization factors. But when I want to use the orthonormality of the sine functions it is defined only for an interval of the half line. The integral $\int \sin(kx)\sin(mx)dx$ does not converge on the half line...
I guess I would just have to use Euler's formula and use the fact that Fourier transform of unity is the dirac delta function :)
@Amit Not really, because other rule sets can behave identically to the set of our chosen automata. Even worse, if you can determine that two different rule sets always result in the same outcome you've solved the Halting Problem.
FWIW, I asked 't Hooft a question about CA, but he didn't respond.
In classical cellular automata, cell states are updated at the tick of a global clock. I suppose that the clock pulses could be generated locally, so each cell stays in sync with its neighbours, but I think that means every cell must participate in this local clock synchronisation process, even the totally empty cells. — PM 2RingOct 16, 2022 at 12:35
@PM2Ring You are very correct. But actually my question is motivated by trying to figure out whether it's even "worse": can we even conclude that any automata is "computing" in real nature, or could a totally different mechanism yield the same results?
Cool, I didn't know in 2022 t'Hooft was still active here
@Amit Well, if two computing machines are actually executing the same algorithm, then we consider them to be equivalent. If the universe is a computer, we can't see the actual "hardware" they're running on, all we see is the output of the computations.
@Amit Exactly. We're doing damn well if we can even get an accurate idea of the rule set. We have no chance of knowing the inner mechanism of the black box.
But even if we do have perfect knowledge of the ruleset, that doesn't mean we can then make useful predictions of any physical phenomenon. We're still in a similar situation as what we have today, where we can easily compute some stuff to useful precision, but in general there's plenty of stuff where the calculations are intractable.
The most well-known CA is (probably) Conway's Game of Life (GoL). People have been playing with it and studying it for ~50 years. It has a very simple ruleset, and we now have clever algorithms that can generate billions of generations per second if there are periodic sub-patterns. But the GoL community is still discovering new stuff in relatively small patterns.
Qualia are a side-issue. It may be the case that that universe can be accurately modelled as if it's a giant computation. But that doesn't necessarily imply that there really is some meta-computer hardware generating the universe.
OTOH, it may be the case that some elements of reality cannot be captured by any finitely-describable computational rule. If I understand correctly, Penrose is claiming that consciousness is in that category. But I can't decide if he's being scientific, or that's just a quasi-religious belief that he's attached to.
@RyderRude I think computationalism is probably true but not useable as a foundational theory. That is, I do believe in the primacy of our sensations much like Hume, but within the theory of science I then construct based on that I have to conclude physicalism and computationalism is true - but true only in the secondary fallible sense that any idea derived from sensations can ever be true
It would be crazy surprising however to actually find out that nature is deterministic. At least that metaphysical question may one day be answered by physics.
@PM2Ring I do think Penrose is motivated by belief, but as long as he "plays by the rules" of good science, it's just as well having someone like him attacking this problem from a new perspective
@ACuriousMind Do u buy a modified version of computationalism where u accept qualia exist and that computationalism is true only within your subjective experience instead of as the primary objective nature of reality?
There are also subtle points to Penrose arguments I am not qualified to comment on. He claims that in a way Godel's theorem shows that a computation cannot "understand" things
I am very much with Nigel and his famous "What is it like to be a bat" article that I find it impossible to deny the existence of subjective experience - it would be denying my own existence, which is incoherent
@Amit I agree. Sure, it has diminished his reputation a bit in some quarters, but it's good to have someone who's a good physicist thinking about this stuff. And as I said the other day, his dad was a psychologist, so it's not unreasonable for him to have a strong interest in this stuff from an early age.
@ACuriousMind I agree. Computationalism MAY be true within subjective experience. computationalism as objective reality cant explain subjective experience, because you'd just get philosophical zombies.
But I do find the computationalism convincing enough that I think we're trapped in a very weird place here: it is through sensation that we experience the world but the best models for interpreting that experience ultimately have to disregard the subjective, pretend that it doesn't exist even though "one level higher" it is the one thing we cannot reject
I have physicalism as an application running inside of a more fundamental radical skeptic operating system, to make an analogy I'm not sure how to feel about
It's the agreement among the sentient beings about whats out there that makes computationalism seem very attractive to me. All sentient beings agree about the events of spacetime
@Amit I'm a bit suspicious of some of his arguments regarding that. I read his "The Emperor's New Mind" when it was new, and I re-read it ~10 years ago. And I occasionally re-read bit & pieces from time to time. I tend to agree with Douglas Hofstadter: consciousness involves Strange Loops that somehow manage to cross levels of abstraction.
A discussion between Chomsky & Penrose could be interesting... if it happened a few decades ago when they were both still near their intellectual peaks. But they'd probably need to spend a few months learning each other's worldview and communication style, first.
But ultimately I have to admit I think that I really need to reject computationalism as fundamental not because of the Inconsistence but because it is unusable as a foundation for morality. Computationalists tend to be utilitarians but I don't really think you can get even that out of it if you really believed in it
Even if computationalism is true, and there is a perfect computational description of how human consciousness works, i.e., a program for consciousness, I expect that program is far too complicated for humans to understand. I guess it's a Gödelian thing: an information processing system cannot process structures that are as complicated as it is.
@PM2Ring Interesting. I didn't read his book but I think perhaps I could judge what he says better if I first have a better grasp of Godel's theorem
@user726941 I managed to get through that interview. Peterson and the other guy were constantly leaning in to try and learn something from the wise sage lol, that's how it looked to me. But Penrose always repeats more or less the same verbal explanation for his view, which I find insufficient in itself to really understand him
@PM2Ring ok i got a counter argument. the human brain's computation system is "more powerful" than an animal's. So we should be able to explain an animal's qualia as a computation. But we cant answer what it is like to be a bat
In any case, it is very handwavy to say that qualia are unprovable Godel sentences
Becuz there's no indication that qualia are sentences
@PM2Ring The usual approach among computationalists is to deny qualia exsists so that computationalists can claim that they've explained everything that exists using math. But they define everything that exists as "everything they can explain using math"
@RyderRude again, I think that is a mischaraterization: the reason they deny qualia is not "in order to" claim they've explained everything by computation/physicalism. It is because they believe in physicalism that they deny any objective existence of qualia.
Mathematician / scifi author Rudy Rucker has a nice simple informal proof of Gödel Incompleteness in Infinity and the Mind. FWIW, Rucker is a direct descendant of the philosopher Georg Hegel.
there is an important difference between motivated reasoning (I already believe X, but Y contradicts X, so I must deny Y even though it is obviously true) and proof by contradiction (I believe in X, and Y contradicts X, so Y cannot be true), even though it can be hard to tell the difference in practice
I may be telling it inaccurately.. but he tells the judge "Newton taught us that all is governed and predictable by forces between particles... since I am made of particles I had no choice but do what I did.."
The judge ponders this a bit and says "Oh ye, but since I am also made of the same particles, I have no choice but sentence you to life in prison"
Determinism vs. free will is absolutely an important part of theories of justice
but it's not quite the same as the discussion about consciousness and computationalism we're having, even though almost all computationalists are also determinists in the traditional sense
I agree computationlism is consistent. I personally don't like it becuz it seems like it starts with itself with no justification. Not that that's a problem in the "circular logic" sense.
But yeah, these discussions inevitably have to go "circular". I can't fault computationlism
Becuz it's all a belief. U gotta start with ur belief
it's a bit hard to imagine for us today in our individualist modern societies, but for a large period of human thought the "certain facts" from which philosophy started wasn't the rationalist cogito, ergo sum or the skeptic "I can trust only my senses", it was some other "fact" about the world that people believed in
Things like the ontological proof of God's existence or Plato's world of ideas look deeply absurd to many modern humans who have been exposed to at least some folklore version of the scientific method, but I see no reason to doubt that some people did (and do) genuinely believe it.
from the "outside" view, my conviction in the primacy of my own sensations and my reason is just due to the success the enlightenment thinkers had in spreading their ideas
it's very hard to realize today how radical enlightenment philosophy was compared to what came before it
(and you can see how successful it was just by the fact that we call it "enlightenment" rather than some more neutral term)
there isn't really one particular "enlightenment philosophy", it's more a name for a collection of ideas that all emerged in a relatively narrow timespan and mostly rejected traditional ideas about reason and society
In German, the foundational text is Kant's "Was ist Aufklärung?" (what is enlightenment?) and we should remark that "Aufklärung" actually doesn't relate to light at all but means the process of "clearing something up".
To him, enlightenment was the process of a human endowed with reason ending their self-inflicted Unmündigkeit (apparently the English word for this is "nonage", which I've never heard before) - and that Unmündigkeit is the inability to use your own reason without external guidance.
So the "enlightenment" here is not about happiness, it is about discarding traditional patterns of obeisance, about a new, radical, individualistic notion of humanity where it is our own innate reason that guides us and not external factors
Kant credited Hume with awakening him from a "dogmatic slumber" and the fact that we today usually associate the word "dogma" with Christian churches tells you who the main "target" or "opponent" of enlightenment was
:63272617 Given that it has been public domain for hundreds of years, I'm sure of it
e.g. Kant has a quote where he says he had to give up knowledge to make room for faith or something like that but I assure you that when you hear this without context you will definitely make the wrong assumptions about what he meant by "knowledge" or "faith"
@ACuriousMind In this case I didn't see a reason not to take this quote at face value, that is, just look up what the pre Socratics said.. but you are probably right and more context is needed
I'm not a Kantian as such but I think there is something very important about his conception of duty: Because we are endowed with reason, we are duty-bound to use it - it is irrational to have reason and not use it. This is not duty to anything outside of us, but duty baked into the very nature of what it means to have reason.
All beings must strive to figure out the world, to give answers to the questions of philosophy - what can I know? what must I do? what can I hope? - and not to do that is giving up part of yourself
Just what is it that you want to do? Well, we wanna be free, we wanna be free to do what we wanna do And we wanna get loaded and we wanna have a good time And that's what we're gonna do
again: this is not duty to anything outside of us - the whole point is using my reason to figure out what I must do, and not rely on anyone else's guidance just because they hold power over me
@ACuriousMind You didn't. But when you say beings must, have a duty, etc. It often quickly leads to okay so let's bake this into our educational system, and then inevitably the question is, what about those who don't fit in to this ideal..
it is precisely when we do not use our reason - when we accept external pressures guiding our actions instead of fulfilling the duty we have to reason - that we end up in Unmündigkeit - paternalism, as you call it
to me it is a deeply individualistic philosophy at its core, even though there is a line of reasoning that takes the categorical imperative and ends up in very strict societies
but then again, the way we end up with these strict rules in these scenarios is only because by the power of our reason we all, by ourselves, agree this is how it should be. there is nothing here that directly obligates you to obey anything but the commands of your own reason
@ACuriousMind It's a difficult point, because you know of course of the argument that people "drift" and get "pushed" to places in an "unconscious" way very often. Not everyone accepts that, and some would say an unconscious act is just a conscious decision to ignore something...
@Amit well, the reason I say I'm not a Kantian is because Kant himself ends up in very strange (to me) places like arguing you should never start a revolution no matter how unjust you think what's going on is
I think he got something very right about the nature of reason and then took a wrong turn somewhere because he wanted to use the universality of reason to get everyone else to act exactly like him
I didn't know that, but from all I heard about Kant it feels to me like he found it more important to be self-consistent than to be critical in some sense.
I think it's almost impossible to talk ethics without bringing in society
Which gets back to context. To properly understand a philosopher we need to have some understanding of the cultural / social context they were operating in.
@ACuriousMind You can often manage without being totally consistent nor inconsistent -- leave some things open. I think many philosophers answered what they could and left questions they couldn't answer just by presenting them and leaving it there...
@PM2Ring indeed - Kant's enemies aren't other individualists who have more pluralist visions of society, they are the dogmatists who don't believe in individualism and freedom as the idea that it is we ourselves who ultimately determine what we must do.
again, an idea reflected very darkly in the existentialist "we are doomed to be free"
For example, I don't think Kant would accept it useful to say something like: there is a constant conflict between an individual and society. Often, it was thought that society must win because society can manage without a single individual but not the other way around. On the other hand, it can be argued that every individual inherently values his own freedom above anything else... the resolution of this conflict is yet to be settled...
every time I start ranting about Kant I end up realizing how much I understand existentialism as a response that removes the focus on the universality of reason but leaves the fundamental idea about duties we have to ourselves simply by virtue of existence
@Amit well, in order to really understand how Kant ends up in the weird places we'd really need to start discussing in much more detail wtf a categorical imperative is :P
the categorical imperative, especially the various formulations that are allegedly equivalent, is somewhere between a very simple idea and something I'm not sure I have ever understood
