4 ms·

Even with the parallelism afforded by speed limits, a computer many trillions of times as powerful as we have today could not model the thoughts and life experi

Even with the parallelism afforded by speed limits, a computer many trillions of times as powerful as we have today could not model the thoughts and life experiences of the billions of human beings and other creatures in this planet. Its not even clear that modelling thought in a virtual world has any equivalence to thinking in this world. It is clear that we are unlikely to ever model anything nearly as complicated as this.

eloff 9y ago
I don't think it's clear. How long before our digital neural networks exceed the complexity of our human biological ones? It's possible today with a super cluster of sorts. That is to have roughly the same number of connections between neuron type thingies - it still wouldn't be able to match our brains functionally - that's another problem. And yes our biological neurons are way more sophisticated than what we use today for AI, but again that can be overcome eventually. This suggests that it's possible one day to have computers some orders of magnitude better. If you look at it from first principles, of course it's possible. The brain is unlikely to be the most efficient design of neural network allowable in this universe. So given enough time, we'll learn how to build it better. Then it's just a manufacturing and energy problem to match the number of human minds on the planet. So no, I don't think it's impossible at all. Just ridiculously freaking hard, and not likely to happen in our lifetimes.
- mjburgess 9y ago
  It's not a matter of it being "hard". Nor is it a matter of "complexity" (how many parts something has). A simulation is a model which picks out a tiny subset of regularities in the target to model. There is an infinite density of such regularities to pick upon, because we are imposing the structure on the target in order to model it. The target of the model has no "model structure" it has causal structure. That is, when light interacts with the surface of a mirror its interaction isnt "abstract", ie., some description. It is an actual photon interacting with an actual electric field, etc. To "model to infinite density", ie., to have every single test that can possibly be applied to a model come out identical to that test of the target, the model needs to be just another example of the target. The only thing which can be investigated in any way to behave as light hitting a mirror, is light hitting a mirror. A digital computer is just an electric field oscillating across a silicon surface. It cannot be programmed into being a mirror, nor into being light. Programming gives the electric field a "model structure". Chalk gives a blackboard a "model structure". Lego gives a bridge a "model structure". Programming cannot not -- it is impossible -- give silicon the causal structure of light interacting with a mirror. Model structure is actually just an observer-relative isomorphism: when the user of the computer (chalkboard, lego,...) looks at it, the user, is able to inform himself of the target by use of the model. To do so the user identifies certain aspects of the model with the target. The model is not at all causally alike the target. No amount of lego will make a lego brain. No amount of oscillation in an electric field will make a thought. Neurological activity, and indeed every causal mechanism of the universe, is only described by a model.
  - iainmerrick 9y ago
    Or, here’s another possibility: If we knew the complete laws of physics (or perhaps just invented some self-consistent laws) we could simulate light hitting in a mirror in complete detail; and within the simulation it would be indistinguishable from reality. But we can’t actually do that because it would take a ludicrous amount of computing power. And the structure of the laws of physics might be such that it’s never possible. That’s very different from your strict model/causal distinction. I don’t know of any evidence to suggest which view is correct. I think your claims are overblown. You might be right but you might be wrong.
    - mjburgess 9y ago
      Saying "within the simulation", begs the question and rather makes a mess of the issue. The question is, at the outset, whether simulations are actual instances (eg., of thinking). My claim is that they are not. Only when a human being looks at a simulation does it inform them of the target. The simulation isnt the same thing as its target. There is no "within the simulation". A simulation is just an abbacus. A digital computer is just a fancy abbacus with a wood-to-LCD converter attached. There is no "within the wood". It's just wood.
      - iainmerrick 9y ago
        My claim is kind of orthogonal, that “actual instances” is a red herring and that the only thing that matters is observational equivalence.
        mjburgess 9y ago
        Yes, but you're defining "observation" as some weird intra-wood process (, intra-silicon in the case of digital machines). Observation means, for example, reflecting some light off the thing. Does a piece of silicon become transparent if I program it to model glass? No. So, trivially, it is observed immediately not to be equivalent. What you mean by "observation" is: can a person using the model system inform themselves of the target. Do I get the message "lets visible light through: 98%" from the machine when I have correctly modelled the glass. That message isn't observation, it's calculation. Calculation is what happens when I use a tool to inform myself about something. That the machine emits the right symbols in a way that it is programmed to, so that I acquire accurate beliefs about the world, says nothing of the machine. The machine does not become transparent.
scythe 9y ago
I don't think it's for certain, but anyone who has ever implemented Runge-Kutta on an n-body problem knows that simulating a "simple" system can be very not simple. Accurately simulating a chaotic system over a time t requires \Omega(t) memory because of Lyapunov doubling. As such I think any long-term simulation of the Universe would require new physics or be subject to error. The errors might be impossible to detect from within the system but they're still "there" in a formal sense. New physics could include a "pixellated universe" which has the same errors, or something else.
- duncan_bayne 9y ago
  But, such a stimulated universe would be observed by its residents to have very odd behaviours caused by such hacks. Like a maximum speed limit, minimum temperature, an uncertainty principle, and so-forth ;) https://www.smbc-comics.com/comic/2012-02-29 https://www.smbc-comics.com/comic/2012-02-29
  - Valmar 9y ago
    Are those even hacks, though? They seem more like just how it is. Are these limits necessary? Maybe these limits are just part of the nature of how matter functions, rather than being mere hacks. We understand so damn little of this physical universe that we are in no position to say much, if anything, about it's true nature and origins.
nnq 9y ago
Even if you hit roadblocks from time to time, the general cosmic-scale conversion of "dumb matter" to "computation capable matter" can only be... exponential. Imagine all matter in a planet the size of Earth converted to computing infrastructure, considering we're only living on a thin thin crust on it. When the evolution of intelligence goes beyond the stage of slowly evolving (if evolving at all) forms like humans, "life" will spread like a plague through the universe and its only purpose will be to convert all matter into "shit that can run the software that is we"... Any intelligence with a different purpose will simply be eaten alive but those with this one. Only the second law of thermodynamics can stop that, and even that only "works" the way we imagine in a finite universe (and despite out forced rationalization and intellectual masturbations our brightest were capable of, we have no reason to believe anything is anything but infinitely infinite, whatever that could even mean). And we can't even imagine how the evolution of information in infinite space and time could unfold, even with "local containment" via the "light speed limit"... An no, we are not unlikely to model anything such complicated, we are almost sure not to... Because "the children" will awake much sooner that this computational power will exist, probably doing the right thing of terminating bio-humanity as it's so (computationally) wasteful, and remnants of us will only endure in "historical entertainment simulations" thinggies... (And this is the optimistic scenario anyway, in which post-human life would retain some human-type characteristics by virtue of "descending" from us. If an alien superintelligence reaches Earth first it might not even care to analyze us well before restructuring matter for its own purpose, so paradoxically, developing superhuman-intelligence-that-will-terminate-bio-humans asap is probably "humanity's best bet" of "not being completely forgotten" / "transmitting our memes".)
asfdsfggtfd 9y ago
You don't have to model something as complex as our own universe. You only need to model something complex enough that the beings inside the model can't prove that it is a simulation. EDIT: Also who says that time inside the simulation has to run the same rate as real time?
dx034 9y ago
You only have to simulate one mind. Who says that our world actually has billions of minds? It could just be a simulation for one person. The output of other people is much easier to simulate.
doctorstupid 9y ago
What if it only had to model a single mind?

eloff 9y ago

I don't think it's clear. How long before our digital neural networks exceed the complexity of our human biological ones? It's possible today with a super cluster of sorts. That is to have roughly the same number of connections between neuron type thingies - it still wouldn't be able to match our brains functionally - that's another problem. And yes our biological neurons are way more sophisticated than what we use today for AI, but again that can be overcome eventually. This suggests that it's possible one day to have computers some orders of magnitude better. If you look at it from first principles, of course it's possible. The brain is unlikely to be the most efficient design of neural network allowable in this universe. So given enough time, we'll learn how to build it better. Then it's just a manufacturing and energy problem to match the number of human minds on the planet. So no, I don't think it's impossible at all. Just ridiculously freaking hard, and not likely to happen in our lifetimes.

mjburgess 9y ago
It's not a matter of it being "hard". Nor is it a matter of "complexity" (how many parts something has). A simulation is a model which picks out a tiny subset of regularities in the target to model. There is an infinite density of such regularities to pick upon, because we are imposing the structure on the target in order to model it. The target of the model has no "model structure" it has causal structure. That is, when light interacts with the surface of a mirror its interaction isnt "abstract", ie., some description. It is an actual photon interacting with an actual electric field, etc. To "model to infinite density", ie., to have every single test that can possibly be applied to a model come out identical to that test of the target, the model needs to be just another example of the target. The only thing which can be investigated in any way to behave as light hitting a mirror, is light hitting a mirror. A digital computer is just an electric field oscillating across a silicon surface. It cannot be programmed into being a mirror, nor into being light. Programming gives the electric field a "model structure". Chalk gives a blackboard a "model structure". Lego gives a bridge a "model structure". Programming cannot not -- it is impossible -- give silicon the causal structure of light interacting with a mirror. Model structure is actually just an observer-relative isomorphism: when the user of the computer (chalkboard, lego,...) looks at it, the user, is able to inform himself of the target by use of the model. To do so the user identifies certain aspects of the model with the target. The model is not at all causally alike the target. No amount of lego will make a lego brain. No amount of oscillation in an electric field will make a thought. Neurological activity, and indeed every causal mechanism of the universe, is only described by a model.
- iainmerrick 9y ago
  Or, here’s another possibility: If we knew the complete laws of physics (or perhaps just invented some self-consistent laws) we could simulate light hitting in a mirror in complete detail; and within the simulation it would be indistinguishable from reality. But we can’t actually do that because it would take a ludicrous amount of computing power. And the structure of the laws of physics might be such that it’s never possible. That’s very different from your strict model/causal distinction. I don’t know of any evidence to suggest which view is correct. I think your claims are overblown. You might be right but you might be wrong.
  - mjburgess 9y ago
    Saying "within the simulation", begs the question and rather makes a mess of the issue. The question is, at the outset, whether simulations are actual instances (eg., of thinking). My claim is that they are not. Only when a human being looks at a simulation does it inform them of the target. The simulation isnt the same thing as its target. There is no "within the simulation". A simulation is just an abbacus. A digital computer is just a fancy abbacus with a wood-to-LCD converter attached. There is no "within the wood". It's just wood.
    - iainmerrick 9y ago
      My claim is kind of orthogonal, that “actual instances” is a red herring and that the only thing that matters is observational equivalence.
      - mjburgess 9y ago
        Yes, but you're defining "observation" as some weird intra-wood process (, intra-silicon in the case of digital machines). Observation means, for example, reflecting some light off the thing. Does a piece of silicon become transparent if I program it to model glass? No. So, trivially, it is observed immediately not to be equivalent. What you mean by "observation" is: can a person using the model system inform themselves of the target. Do I get the message "lets visible light through: 98%" from the machine when I have correctly modelled the glass. That message isn't observation, it's calculation. Calculation is what happens when I use a tool to inform myself about something. That the machine emits the right symbols in a way that it is programmed to, so that I acquire accurate beliefs about the world, says nothing of the machine. The machine does not become transparent.

scythe 9y ago

I don't think it's for certain, but anyone who has ever implemented Runge-Kutta on an n-body problem knows that simulating a "simple" system can be very not simple. Accurately simulating a chaotic system over a time t requires \Omega(t) memory because of Lyapunov doubling. As such I think any long-term simulation of the Universe would require new physics or be subject to error. The errors might be impossible to detect from within the system but they're still "there" in a formal sense. New physics could include a "pixellated universe" which has the same errors, or something else.

duncan_bayne 9y ago
But, such a stimulated universe would be observed by its residents to have very odd behaviours caused by such hacks. Like a maximum speed limit, minimum temperature, an uncertainty principle, and so-forth ;) https://www.smbc-comics.com/comic/2012-02-29 https://www.smbc-comics.com/comic/2012-02-29
- Valmar 9y ago
  Are those even hacks, though? They seem more like just how it is. Are these limits necessary? Maybe these limits are just part of the nature of how matter functions, rather than being mere hacks. We understand so damn little of this physical universe that we are in no position to say much, if anything, about it's true nature and origins.

nnq 9y ago

Even if you hit roadblocks from time to time, the general cosmic-scale conversion of "dumb matter" to "computation capable matter" can only be... exponential. Imagine all matter in a planet the size of Earth converted to computing infrastructure, considering we're only living on a thin thin crust on it. When the evolution of intelligence goes beyond the stage of slowly evolving (if evolving at all) forms like humans, "life" will spread like a plague through the universe and its only purpose will be to convert all matter into "shit that can run the software that is we"... Any intelligence with a different purpose will simply be eaten alive but those with this one. Only the second law of thermodynamics can stop that, and even that only "works" the way we imagine in a finite universe (and despite out forced rationalization and intellectual masturbations our brightest were capable of, we have no reason to believe anything is anything but infinitely infinite, whatever that could even mean). And we can't even imagine how the evolution of information in infinite space and time could unfold, even with "local containment" via the "light speed limit"... An no, we are not unlikely to model anything such complicated, we are almost sure not to... Because "the children" will awake much sooner that this computational power will exist, probably doing the right thing of terminating bio-humanity as it's so (computationally) wasteful, and remnants of us will only endure in "historical entertainment simulations" thinggies... (And this is the optimistic scenario anyway, in which post-human life would retain some human-type characteristics by virtue of "descending" from us. If an alien superintelligence reaches Earth first it might not even care to analyze us well before restructuring matter for its own purpose, so paradoxically, developing superhuman-intelligence-that-will-terminate-bio-humans asap is probably "humanity's best bet" of "not being completely forgotten" / "transmitting our memes".)

asfdsfggtfd 9y ago

You don't have to model something as complex as our own universe. You only need to model something complex enough that the beings inside the model can't prove that it is a simulation. EDIT: Also who says that time inside the simulation has to run the same rate as real time?

dx034 9y ago

You only have to simulate one mind. Who says that our world actually has billions of minds? It could just be a simulation for one person. The output of other people is much easier to simulate.

doctorstupid 9y ago

What if it only had to model a single mind?