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Regarding the cost of simulation, you might find what Dr. Michio Kaku said during his AMA. >I mentioned that a digital computer cannot simulate even a simple r

Regarding the cost of simulation, you might find what Dr. Michio Kaku said during his AMA. >I mentioned that a digital computer cannot simulate even a simple reality, since there are too many molecules to keep track of, far greater than the capabilities of any digital computer. We need a quantum computer to simulate quantum reality, and hence, once again, the weather is the smallest object that can simulate the weather. Therefore, I don’t think we live in a simulation, unless the simulation is the universe itself. -Dr.Michio Kaku

Damorian 7y ago
This assumes we're simulated from a universe with identical laws and finitude, which I would never even consider.
andrewon 7y ago
But a digital computer at present in this world may not be a good reference to the capability of the computer that supposedly simulate this world. We know nothing about the "real" world that computer resided, and nothing about that computer.
- joe_the_user 7y ago
  If we have posited a thing with unknown properties and say maybe that is generating our universe, we've pretty much taken the opposite position to Occam's Razor, which is often stated as "Entities should not be multiplied without necessity." https://en.wikipedia.org/wiki/Occam%27s_razor https://en.wikipedia.org/wiki/Occam%27s_razor
  - andrewon 7y ago
    Occam's Razor is a good principle for choosing scientific hypotheses. But I think when it comes to studying big questions like fundamental fabric of this physical world, we are at a lost here. Essentially we elect to believe, without justification, that the world got to follow a reductionist paradigm - if the world can be made simpler, it must not be more complex.
- roywiggins 7y ago
  Right, but that is then a totally unfalsifiable idea. You can't prove the non-existence of something you can't begin to define.
  - andrewon 7y ago
    I guess that's the gist of all these arguments -- they are ideas not something we can prove or disprove.
- stromgo 7y ago
  We do know that the real world is richer than the simulated world, since it holds a computer that runs the simulated world. Therefore if you exist, then it's more likely that you're the result of evolution in the real world than the result of evolution in the simulated world. Imagine the warehouse-size computer that is needed to simulate a bacterium here on Earth. Computers are dusty, and dust contains bacteria, so if you're a bacterium, then it's more likely that you're one of the billions of bacteria in the dust on the computer, than the bacterium being simulated by the computer. The same reasoning should hold for other worlds.
  - mistermann 7y ago
    Unless I misunderstand what your conception of a simulation is, I don't see why a virtual world is limited by the constraints of the parent world, any more than video games are limited by the constraints of our world? I would think this would apply to the individual molecule tracking requirement above as well.
  - fpoling 7y ago
    The assumption that real world is richer than simulated world is just that, an assumption. For one it assumes that both are finite.
    - pegasus 7y ago
      It's logically necessary, not just an assumption. The simulated world with all its richness is by definition a strict subset of the simulating world. So the latter must be richer than the former.
      - fpoling 7y ago
        This is not true for infinite sets where a subset can be equivalent to the whole.
      - mistermann 7y ago
        Could you possibly explain/reason why this must be, without using "by definition"? Many people in this thread agree with you on this, but I don't understand it (see my other comment using a video game analogy). Is the richness you describe in your comment implicitly constrained to that which exists physically perhaps?
- yyyk 7y ago
  If we don't know anything about the "real" (or at least, "realer") world, I don't see how we can argue for a simulation either. If we don't know the "real" rules, how can we make any proposition? At best we might argue that our world is inconsistent, but we cannot say that's any more or less likely than a simulation (who says the world has to make any sense?). The only semi-useful simulation arguments have to assume the "real" world is sorta like our world or at least functioning according to math. But that returns us to the simulation cost problem.
trophycase 7y ago
Thank you for this quote. I've long felt this. Another thing about the simulation hypothesis is that it seemingly offers no explanatory power. That is, I'm not sure how a universe that is "simulated" and one that isn't (thinking about it more I'm not actually sure what the difference is) would actually differ. Maybe would explain the observer effect in QM cause of lazy loading or something?
- naasking 7y ago
  The simulation hypothesis is not intended to provide explanatory power on the matter you're looking for. It provides explanatory power on other questions though. A simulation is also indistinguishable from the real thing from the inside, or it wouldn't be a faithful simulation.
rubatuga 7y ago
Even a Commodore 64 could simulate our universe given enough time and memory. Our only clock source is the passage of time itself so even if it was being simulated extremely slowly we would never notice.
- posterboy 7y ago
  a c64 would need infinitely more memory to address the infinite memory. I'm not sure whether that means uncountably infinite memory
  - Simon_says 7y ago
    Not really. Imagine something like a Huffman encoding. Every node in a tree can have a finite address while the tree has infinitely many nodes.
- Abishek_Muthian 7y ago
  > Even a Commodore 64 could simulate our universe given enough time and memory Given enough energy, we ourself could snap a universe into existence as well by clapping our hands?
vidarh 7y ago
This is flawed thinking I've seen show up in a lot of arguments. I even had this argument with Kurzweil at some point. If we want to create a realistic simulation, we only need to simulate things with sufficient fidelity to convince observers. That basically means: - Only things that have been observed needs to gain some form of persistence - Each simulated entity should have error margins that account for their continued existence, or their allowable location and other factors. Once an error margin for an aspect of a simulated entity exceeds the factors of the pseudo-random instantiation of that entity or class of entities, you do not need to explicitly retain or simulate the state of that entity. E.g. you don't need to retain the state of an "NPC human" longer than ~120 years at most; most you can discard much sooner; most details you never need to generate in the first place because it is not known to the entity that observes it. - Over time, perturb the simulation back towards the outcome of a static generator function that takes time as a parameter, to wipe out state and simulation. That is, "undo" all changes the "players" in the simulation do in as plausible way as possible. Do that, and you only need to simulate the "players" you want to simulate and those entities closest in time and space to them most of the time. There'll be a "halo" of other entities that slowly reverts to the baseline simulation. I keep wanting to use this approach as a simulation basis for a game, in fact. E.g. consider Elite: When you leave a starsystem, all the ships in it despawns. If you go straight back, it breaks immersion. The approach above applied to it would instead record a cone from the last known position of each ship that grows over time by likely speeds and directions. As more and more of the larger end of the cone expands outside the starsystem, you increase the chance that they despawn. If you return rapidly, you find ships have moved a believable distance. Or Minecraft: Currently mobs despawn outside of a given area, and simulation only runs within a certain number of chunks from the player. But most things stay exactly as they were. As such all player modifications must be saved. But for many things you can create functions that makes the world more dynamic with less simulation. E.g. if trees slowly grow and age and fall down, and rot, and new trees grow, then that means that the longer since a player has been in a given chunk, the more of the players modifications can be discarded and replaced by a generator function with time as one of the parameter. We've pruned simulations since some of the earliest generative games. To address the quote: We don't need to simulate the weather in its full apparent complexity, as long as the observed aspects of the weather falls within parameters that makes them plausible but sufficiently unpredictable. For most detail of the weather, that just means it needs to conform to the overall parameters. E.g. you don't need to simulate raindrops that "player" sees; just the overall volume of rain in the overall area if it is near a "player". Even less detail if further away.

Damorian 7y ago

This assumes we're simulated from a universe with identical laws and finitude, which I would never even consider.

andrewon 7y ago

But a digital computer at present in this world may not be a good reference to the capability of the computer that supposedly simulate this world. We know nothing about the "real" world that computer resided, and nothing about that computer.

joe_the_user 7y ago
If we have posited a thing with unknown properties and say maybe that is generating our universe, we've pretty much taken the opposite position to Occam's Razor, which is often stated as "Entities should not be multiplied without necessity." https://en.wikipedia.org/wiki/Occam%27s_razor https://en.wikipedia.org/wiki/Occam%27s_razor
- andrewon 7y ago
  Occam's Razor is a good principle for choosing scientific hypotheses. But I think when it comes to studying big questions like fundamental fabric of this physical world, we are at a lost here. Essentially we elect to believe, without justification, that the world got to follow a reductionist paradigm - if the world can be made simpler, it must not be more complex.
roywiggins 7y ago
Right, but that is then a totally unfalsifiable idea. You can't prove the non-existence of something you can't begin to define.
- andrewon 7y ago
  I guess that's the gist of all these arguments -- they are ideas not something we can prove or disprove.
stromgo 7y ago
We do know that the real world is richer than the simulated world, since it holds a computer that runs the simulated world. Therefore if you exist, then it's more likely that you're the result of evolution in the real world than the result of evolution in the simulated world. Imagine the warehouse-size computer that is needed to simulate a bacterium here on Earth. Computers are dusty, and dust contains bacteria, so if you're a bacterium, then it's more likely that you're one of the billions of bacteria in the dust on the computer, than the bacterium being simulated by the computer. The same reasoning should hold for other worlds.
- mistermann 7y ago
  Unless I misunderstand what your conception of a simulation is, I don't see why a virtual world is limited by the constraints of the parent world, any more than video games are limited by the constraints of our world? I would think this would apply to the individual molecule tracking requirement above as well.
- fpoling 7y ago
  The assumption that real world is richer than simulated world is just that, an assumption. For one it assumes that both are finite.
  - pegasus 7y ago
    It's logically necessary, not just an assumption. The simulated world with all its richness is by definition a strict subset of the simulating world. So the latter must be richer than the former.
    - fpoling 7y ago
      This is not true for infinite sets where a subset can be equivalent to the whole.
    - mistermann 7y ago
      Could you possibly explain/reason why this must be, without using "by definition"? Many people in this thread agree with you on this, but I don't understand it (see my other comment using a video game analogy). Is the richness you describe in your comment implicitly constrained to that which exists physically perhaps?
yyyk 7y ago
If we don't know anything about the "real" (or at least, "realer") world, I don't see how we can argue for a simulation either. If we don't know the "real" rules, how can we make any proposition? At best we might argue that our world is inconsistent, but we cannot say that's any more or less likely than a simulation (who says the world has to make any sense?). The only semi-useful simulation arguments have to assume the "real" world is sorta like our world or at least functioning according to math. But that returns us to the simulation cost problem.

trophycase 7y ago

Thank you for this quote. I've long felt this. Another thing about the simulation hypothesis is that it seemingly offers no explanatory power. That is, I'm not sure how a universe that is "simulated" and one that isn't (thinking about it more I'm not actually sure what the difference is) would actually differ. Maybe would explain the observer effect in QM cause of lazy loading or something?

naasking 7y ago
The simulation hypothesis is not intended to provide explanatory power on the matter you're looking for. It provides explanatory power on other questions though. A simulation is also indistinguishable from the real thing from the inside, or it wouldn't be a faithful simulation.

rubatuga 7y ago

Even a Commodore 64 could simulate our universe given enough time and memory. Our only clock source is the passage of time itself so even if it was being simulated extremely slowly we would never notice.

posterboy 7y ago
a c64 would need infinitely more memory to address the infinite memory. I'm not sure whether that means uncountably infinite memory
- Simon_says 7y ago
  Not really. Imagine something like a Huffman encoding. Every node in a tree can have a finite address while the tree has infinitely many nodes.
Abishek_Muthian 7y ago
> Even a Commodore 64 could simulate our universe given enough time and memory Given enough energy, we ourself could snap a universe into existence as well by clapping our hands?

vidarh 7y ago

This is flawed thinking I've seen show up in a lot of arguments. I even had this argument with Kurzweil at some point. If we want to create a realistic simulation, we only need to simulate things with sufficient fidelity to convince observers. That basically means: - Only things that have been observed needs to gain some form of persistence - Each simulated entity should have error margins that account for their continued existence, or their allowable location and other factors. Once an error margin for an aspect of a simulated entity exceeds the factors of the pseudo-random instantiation of that entity or class of entities, you do not need to explicitly retain or simulate the state of that entity. E.g. you don't need to retain the state of an "NPC human" longer than ~120 years at most; most you can discard much sooner; most details you never need to generate in the first place because it is not known to the entity that observes it. - Over time, perturb the simulation back towards the outcome of a static generator function that takes time as a parameter, to wipe out state and simulation. That is, "undo" all changes the "players" in the simulation do in as plausible way as possible. Do that, and you only need to simulate the "players" you want to simulate and those entities closest in time and space to them most of the time. There'll be a "halo" of other entities that slowly reverts to the baseline simulation. I keep wanting to use this approach as a simulation basis for a game, in fact. E.g. consider Elite: When you leave a starsystem, all the ships in it despawns. If you go straight back, it breaks immersion. The approach above applied to it would instead record a cone from the last known position of each ship that grows over time by likely speeds and directions. As more and more of the larger end of the cone expands outside the starsystem, you increase the chance that they despawn. If you return rapidly, you find ships have moved a believable distance. Or Minecraft: Currently mobs despawn outside of a given area, and simulation only runs within a certain number of chunks from the player. But most things stay exactly as they were. As such all player modifications must be saved. But for many things you can create functions that makes the world more dynamic with less simulation. E.g. if trees slowly grow and age and fall down, and rot, and new trees grow, then that means that the longer since a player has been in a given chunk, the more of the players modifications can be discarded and replaced by a generator function with time as one of the parameter. We've pruned simulations since some of the earliest generative games. To address the quote: We don't need to simulate the weather in its full apparent complexity, as long as the observed aspects of the weather falls within parameters that makes them plausible but sufficiently unpredictable. For most detail of the weather, that just means it needs to conform to the overall parameters. E.g. you don't need to simulate raindrops that "player" sees; just the overall volume of rain in the overall area if it is near a "player". Even less detail if further away.