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I can think of one: you can't simulate an atom. If you read too much into supercomputing and think that they can simulate atoms, then go tell CERN to stop sear

I can think of one: you can't simulate an atom. If you read too much into supercomputing and think that they can simulate atoms, then go tell CERN to stop searching for sub-particles and simulate them instead. Otherwise, I think you know what I mean. Besides, a real system depends on initial conditions. You can't simulate those.

zAy0LfpBZLC8mAC 12y ago
You are confused about the order in which these things happen: 1. We form a hypothesis about how something works. 2. We do experiments to try to falsify said hypothesis. 3. If a certain amount of experimentation fails to falsify the hypothesis, we conclude tentatively that the hypothesis is a correct model of reality, namely, we promote it to a theory. 4. We use that theory to simulate the real thing computationally. (4) is the whole point of doing steps (1) to (3) - and all VMG is saying is that there is no reason to assume that (1) to (3) couldn't lead to (4) with regards to the brain, just as there is no reason to do so with regards to atoms, which in turn is why we do operate CERN instead of just asserting that atoms cannot be understood.
- crististm 12y ago
  Yes you are correct in 1-4 but I think that your hypothesis is wrong wrt to simulation: You don't know the initial conditions which are a _huge_ part in determining the outcome of the simulation. Maybe you will limit your precision to Plank constant. Can you measure with that precision?
  - zAy0LfpBZLC8mAC 12y ago
    I don't know the initial conditions of what?
    - crististm 12y ago
      Now this question clarifies why you think too much into simulating reality: http://en.wikipedia.org/wiki/Initial_condition http://en.wikipedia.org/wiki/Initial_condition look for nonlinearity EDIT: You can't simulate a brain without considering the quantum effects at atomic levels. You can't simulate quantum effects. QED.
      - zAy0LfpBZLC8mAC 12y ago
        I wasn't asking for a random example of a system that I don't know the initial conditions of, but what specifically you meant when you tried to construct an argument for the impossibility of emulating a brain.
      - chriswarbo 12y ago
        > You can't simulate a brain without considering the quantum effects at atomic levels. That's wild speculation. At the very finest level of detail, we can simulate a brain in this way. At the very coarsest level of detail, we can simulate it as a thermodynamic heat bath. The correct level of detail for the emergence of intelligent behaviour is likely somewhere in-between. > You can't simulate quantum effects. What? Of course you can! Classical computers take an exponential amount of time, but it's still a finite problem. The whole field of Computational Chemistry is based on simulating quantum effects!
        crististm 12y ago
        "The correct level of detail for the emergence of intelligent behaviour is likely somewhere in-between." I think this is your speculation. :) "Classical computers take an exponential amount of time" It is not a matter of time it takes to simulate, but of the details. You don't know which details matter and which don't. You don't know if you need infinite precision or you can stop at Plank's level. Thus, since you don't know a lot of things, you can't be sure that what you simulated was indeed the real thing or something that you imagined/theorized to be the real thing.
        chriswarbo 12y ago
chriswarbo 12y ago
Simulating subatomic particles is a huge part of the work done at CERN. That's how they predict what signals to expect from their experiments. They can't run simulations instead of their experiments, since they're looking for new fundamental Physics; in other words, they're trying to find out which of their simulations describes the world best. AI research isn't looking for fundamental results; we have a good theory of computation, and a good-enough theory of Physics to describe our brains. We know which simulation to run. The remaining problems are 'only' to do with resource usage: which computations/arrangements-of-atoms can give us good-enough results in short-enough time? If we could efficiently run O(2^n) algorithms, AI would be unnecessary; we could just brute-force everything (including brain emulation).
- crististm 12y ago
  Exactly because "they can't run simulations instead of their experiments" you can't simulate an atom and thus a brain.
  - zAy0LfpBZLC8mAC 12y ago
    Is there anything physical we can simulate that does involve atoms?
    - crististm 12y ago
      Is that a trick question? The answer is: it depends on what you consider a satisfying result. You can stop higher than atoms anytime you think the result satisfies your experimental measurements.
      - zAy0LfpBZLC8mAC 12y ago
        No, I am simply trying to understand your argument. It seemed to me that your argument was "There are details of how an atom works that we currently don't know how to simulate. A brain's behaviour is a result of the behaviour of the atoms it consists of. Therefore, it's impossible to simulate a brain to any degree of accuracy at all." Using the same logic, and given that most everything we interact with is made of atoms, one could deduce that it's impossible to simulate anything at all, except for electron beams, maybe. That seems to me to be obviously in contradiction to how well we can navigate and manipulate the world in our day-to-day lives (let alone in engineering), which depends on us simulating the world all the time, at least to some degree. Now, I'd be interested in understanding how you reconcile that.

zAy0LfpBZLC8mAC 12y ago

You are confused about the order in which these things happen: 1. We form a hypothesis about how something works. 2. We do experiments to try to falsify said hypothesis. 3. If a certain amount of experimentation fails to falsify the hypothesis, we conclude tentatively that the hypothesis is a correct model of reality, namely, we promote it to a theory. 4. We use that theory to simulate the real thing computationally. (4) is the whole point of doing steps (1) to (3) - and all VMG is saying is that there is no reason to assume that (1) to (3) couldn't lead to (4) with regards to the brain, just as there is no reason to do so with regards to atoms, which in turn is why we do operate CERN instead of just asserting that atoms cannot be understood.

crististm 12y ago
Yes you are correct in 1-4 but I think that your hypothesis is wrong wrt to simulation: You don't know the initial conditions which are a _huge_ part in determining the outcome of the simulation. Maybe you will limit your precision to Plank constant. Can you measure with that precision?
- zAy0LfpBZLC8mAC 12y ago
  I don't know the initial conditions of what?
  - crististm 12y ago
    Now this question clarifies why you think too much into simulating reality: http://en.wikipedia.org/wiki/Initial_condition http://en.wikipedia.org/wiki/Initial_condition look for nonlinearity EDIT: You can't simulate a brain without considering the quantum effects at atomic levels. You can't simulate quantum effects. QED.
    - zAy0LfpBZLC8mAC 12y ago
      I wasn't asking for a random example of a system that I don't know the initial conditions of, but what specifically you meant when you tried to construct an argument for the impossibility of emulating a brain.
    - chriswarbo 12y ago
      > You can't simulate a brain without considering the quantum effects at atomic levels. That's wild speculation. At the very finest level of detail, we can simulate a brain in this way. At the very coarsest level of detail, we can simulate it as a thermodynamic heat bath. The correct level of detail for the emergence of intelligent behaviour is likely somewhere in-between. > You can't simulate quantum effects. What? Of course you can! Classical computers take an exponential amount of time, but it's still a finite problem. The whole field of Computational Chemistry is based on simulating quantum effects!
      - crististm 12y ago
        "The correct level of detail for the emergence of intelligent behaviour is likely somewhere in-between." I think this is your speculation. :) "Classical computers take an exponential amount of time" It is not a matter of time it takes to simulate, but of the details. You don't know which details matter and which don't. You don't know if you need infinite precision or you can stop at Plank's level. Thus, since you don't know a lot of things, you can't be sure that what you simulated was indeed the real thing or something that you imagined/theorized to be the real thing.
        chriswarbo 12y ago

chriswarbo 12y ago

Simulating subatomic particles is a huge part of the work done at CERN. That's how they predict what signals to expect from their experiments. They can't run simulations instead of their experiments, since they're looking for new fundamental Physics; in other words, they're trying to find out which of their simulations describes the world best. AI research isn't looking for fundamental results; we have a good theory of computation, and a good-enough theory of Physics to describe our brains. We know which simulation to run. The remaining problems are 'only' to do with resource usage: which computations/arrangements-of-atoms can give us good-enough results in short-enough time? If we could efficiently run O(2^n) algorithms, AI would be unnecessary; we could just brute-force everything (including brain emulation).

crististm 12y ago
Exactly because "they can't run simulations instead of their experiments" you can't simulate an atom and thus a brain.
- zAy0LfpBZLC8mAC 12y ago
  Is there anything physical we can simulate that does involve atoms?
  - crististm 12y ago
    Is that a trick question? The answer is: it depends on what you consider a satisfying result. You can stop higher than atoms anytime you think the result satisfies your experimental measurements.
    - zAy0LfpBZLC8mAC 12y ago
      No, I am simply trying to understand your argument. It seemed to me that your argument was "There are details of how an atom works that we currently don't know how to simulate. A brain's behaviour is a result of the behaviour of the atoms it consists of. Therefore, it's impossible to simulate a brain to any degree of accuracy at all." Using the same logic, and given that most everything we interact with is made of atoms, one could deduce that it's impossible to simulate anything at all, except for electron beams, maybe. That seems to me to be obviously in contradiction to how well we can navigate and manipulate the world in our day-to-day lives (let alone in engineering), which depends on us simulating the world all the time, at least to some degree. Now, I'd be interested in understanding how you reconcile that.