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I dont understand the simulation argument. If I have a quantum computer, dont I have to use at least N particles to simulate an N particle system? What am I gai

I dont understand the simulation argument. If I have a quantum computer, dont I have to use at least N particles to simulate an N particle system? What am I gaining by using a physical system to simulate a physical system?

charles-salvia 10y ago
No you could use more coarse grained representations of distant objects or less frequently observed objects. If our Universe is a simulation, for example, given that the speed of information is limited, there's no reason to completely simulate, say, whatever is happening in the Andromeda galaxy right now. If we send an observer there, the simulation could just lazily produce more fine-grained renderings.
- ZeroFries 10y ago
  Ok so that might apply one level deep, but not 2+ levels, which I think the simulation argument is mostly based on (the more levels the higher the probability your universe is a nested universe).
- dave_sullivan 10y ago
  Say you had a computer operating near planck scale (or some max bound on physical density of a computer system), could you use that to represent more information than would fit in the physical space? The simulation argument is "If we ever create a simulation, we'll create more, so we're probably in one of those simulations, unless we were first or are unique at cosmic scales." Would lazy loading make it harder to simulate our own universe at similar scales (harder to build a simulation in a simulation?) At some point, unless we're living in a limited simulation that can itself not be fully simulated, aren't we getting something for nothing? And if it is in fact limited, how do you show that? Edit: basically what zerofries said...
  - charles-salvia 10y ago
    I think you're asking, if we took all the matter in the Universe and converted it into a giant computer, would we be able to fully simulate our own Universe? I think the answer is that if our Universe is currently, say, nested N levels deep in a simulation hierarchy, the Universe we currently observe may appear much more vast than it actually is, but since the speed of information is limited, we could never prove this. So while the number of estimated atoms in the observable Universe is something like 4×10^79, the actual number of simulated particles may be far, far less. Certainly, the information that comes to us via the light from distant galaxies is incredibly coarse grained and time-lagged, and if we're in a simulation it may well be that no finer grained representation actually exists (assuming there are no observers in those galaxies). I don't actually know if I believe the simulation argument, and all of this is currently (perhaps forever) non-falsifiable. By the time we're able to even send an observer to some distant galaxy ~5 billion light years away, the Universe would have expanded even more, making the galaxy even further away. But the limitations imposed on the speed of information via light cones seems to make it very computationally feasible to simulate a Universe that appears much larger and detailed than it actually is. So in other words, the inhabitants of Universe at level N of the simulation hierarchy should be able to simulate a lower-entropy coarse approximation of their Universe at level N + 1, that would be indistinguishable from Universe N to the simulated inhabitants of N + 1, provided that sufficient restrictions on the speed of information and the number of observers is enforced. But intuitively it seems there should be a limitation here, in that as N increases the level of nested computational resources available would need to decrease, until you hit a low entropy "leaf Universe". But that doesn't really affect the probabilistic angle of the simulation argument.
    - visarga 10y ago
      > if our Universe is currently, say, nested N levels deep in a simulation hierarchy Maybe the simulation hierarchy is like a neural net - where hierarchy represents more abstraction and meaning - the higher we go, the more exotic the universes and more capable of carrying meaning by integrating information from below. Such a neural-net hierarchical universe could be seen as "God".
      - 10y ago
AgentME 10y ago
>If I have a quantum computer, dont I have to use at least N particles to simulate an N particle system? If we're in a simulation, we can't assume too much about the host reality's physics. Quantum computers or something else capable of simulating quantum physics simply could be easy to make in the host reality. >What am I gaining by using a physical system to simulate a physical system? We run simulations all the time for entertainment and research.

charles-salvia 10y ago

No you could use more coarse grained representations of distant objects or less frequently observed objects. If our Universe is a simulation, for example, given that the speed of information is limited, there's no reason to completely simulate, say, whatever is happening in the Andromeda galaxy right now. If we send an observer there, the simulation could just lazily produce more fine-grained renderings.

ZeroFries 10y ago
Ok so that might apply one level deep, but not 2+ levels, which I think the simulation argument is mostly based on (the more levels the higher the probability your universe is a nested universe).
dave_sullivan 10y ago
Say you had a computer operating near planck scale (or some max bound on physical density of a computer system), could you use that to represent more information than would fit in the physical space? The simulation argument is "If we ever create a simulation, we'll create more, so we're probably in one of those simulations, unless we were first or are unique at cosmic scales." Would lazy loading make it harder to simulate our own universe at similar scales (harder to build a simulation in a simulation?) At some point, unless we're living in a limited simulation that can itself not be fully simulated, aren't we getting something for nothing? And if it is in fact limited, how do you show that? Edit: basically what zerofries said...
- charles-salvia 10y ago
  I think you're asking, if we took all the matter in the Universe and converted it into a giant computer, would we be able to fully simulate our own Universe? I think the answer is that if our Universe is currently, say, nested N levels deep in a simulation hierarchy, the Universe we currently observe may appear much more vast than it actually is, but since the speed of information is limited, we could never prove this. So while the number of estimated atoms in the observable Universe is something like 4×10^79, the actual number of simulated particles may be far, far less. Certainly, the information that comes to us via the light from distant galaxies is incredibly coarse grained and time-lagged, and if we're in a simulation it may well be that no finer grained representation actually exists (assuming there are no observers in those galaxies). I don't actually know if I believe the simulation argument, and all of this is currently (perhaps forever) non-falsifiable. By the time we're able to even send an observer to some distant galaxy ~5 billion light years away, the Universe would have expanded even more, making the galaxy even further away. But the limitations imposed on the speed of information via light cones seems to make it very computationally feasible to simulate a Universe that appears much larger and detailed than it actually is. So in other words, the inhabitants of Universe at level N of the simulation hierarchy should be able to simulate a lower-entropy coarse approximation of their Universe at level N + 1, that would be indistinguishable from Universe N to the simulated inhabitants of N + 1, provided that sufficient restrictions on the speed of information and the number of observers is enforced. But intuitively it seems there should be a limitation here, in that as N increases the level of nested computational resources available would need to decrease, until you hit a low entropy "leaf Universe". But that doesn't really affect the probabilistic angle of the simulation argument.
  - visarga 10y ago
    > if our Universe is currently, say, nested N levels deep in a simulation hierarchy Maybe the simulation hierarchy is like a neural net - where hierarchy represents more abstraction and meaning - the higher we go, the more exotic the universes and more capable of carrying meaning by integrating information from below. Such a neural-net hierarchical universe could be seen as "God".
    - 10y ago

AgentME 10y ago

>If I have a quantum computer, dont I have to use at least N particles to simulate an N particle system? If we're in a simulation, we can't assume too much about the host reality's physics. Quantum computers or something else capable of simulating quantum physics simply could be easy to make in the host reality. >What am I gaining by using a physical system to simulate a physical system? We run simulations all the time for entertainment and research.