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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 clust

by 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.

by eloff 9y ago

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.