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This seems like such faulty and backwards reasoning to me. The experiment of detecting anomalies at the subatomic level is very interesting and that work shoul

• jamesaguilar 13y ago
  > But, why must we say such anomalies lead to "we are living in a simulation"? That is not the main argument that we are living in a simulation. The main argument is the following disjunction (from wikipedia). Either: * human civilization is unlikely to reach a level of technological maturity capable of producing simulated realities, or * a comparable civilization reaching this technological status will likely not produce a many simulated realities for any of a number of reasons, such as, diversion of computational processing power for other tasks, ethical considerations of holding entities captive in simulated realities, etc., or * any entities with our general set of experiences are almost certainly living in a simulation. Personally I think the biggest prima facie weakness in this argument is that while we will probably reach a point where simulating a human mind is feasible, and we will probably do so when that time comes, it may take a lot of computational mass to simulate a person. Thus, any recursive simulations would get smaller and smaller in terms of the number of thinking entities in them.
  • nikbackm 13y ago
    > it may take a lot of computational mass to simulate a person It might be sufficient to simulate one person. The rest of the universe (including all other humans) just serve as inputs in the simulation.
    • mistercow 13y ago
      If each simulated universe can only contain one actual person, then the simulation argument doesn't hold up, since the vast majority of people would still be living outside of simulations.
  • platz 13y ago
    The main argument as you state it doesn't describe any relation with (nor does it mention) the actual measurements performed. I think it's fine to consider such an argument in it's own right. Where I take issue is the subsequent attempt at validation of the conjecture, with the previously mentioned physical experiment.
  • mistercow 13y ago
    I would say it probably doesn't take a lot of computational mass to simulate a person. We're each doing it right now with a glob of meat the size of a grapefruit, and that's just what evolution was able to come up with. So simulating a universe where minds are a low-level primitive, and everything else is simulated lazily and using lots of shortcuts is reasonably plausible. But that's not the kind of world we find ourselves in. Our minds appear to be constructed of the same stuff as the rest of the world. If we're to accept the simulation argument, then our definition of "simulated reality" must imply a physics implementation that is high enough fidelity to support minds as high level structures - you have to actually be able to build compact working brains in the simulation. Alternatively, we'd have to suppose that a brain is actually just a very convincing facade, usually sitting inert until someone observes it, at which point it reflects the inner workings of the person's mind at whatever level of detail is necessary to convince the observer that it is the mechanism behind the mind. Both of these seem far less plausible.
    • jamesaguilar 13y ago
      > But that's not the kind of world we find ourselves in. Our minds appear to be constructed of the same stuff as the rest of the world. If we're to accept the simulation argument, then our definition of "simulated reality" must imply a physics implementation that is high enough fidelity to support minds as high level structures - you have to actually be able to build compact working brains in the simulation. Devils advocate, but there could simply be level-of-detail heuristics, where the mind is explainable in terms of physics, but not implemented that way (unless you look). Similarly, for people who take damage to their brains, the model for that person's new brain could simply be derived during that simulation step and substituted. That's just a high level view of how a lazy simulation could still produce minds that appear to by implemented using physics.
      • mistercow 13y ago
        That's what I was saying in the "Alternatively, ..." part. But this does suggest an avenue of testing the simulation hypothesis that might be more useful than looking at purely physical anomalies. The physics engine might be simplified, but edge cases will likely be subtle and difficult to distinguish from gaps in our theories of physics. But if the simulation is using heuristics to gauge whether a brain is being observed, and making it correlate to the mind primitive backing it as needed, then we should eventually be able to construct scenarios where those heuristics are wildly inaccurate. If we could, for example, trick the simulation into presenting a completely inactive brain while its was conscious, that would be informative.
  • nitrogen 13y ago
    Thus, any recursive simulations would get smaller and smaller in terms of the number of thinking entities in them. I'm glad this flaw in the simulation argument is well known. The simulation argument reminds me of Anselm's ontological argument in a way. I wonder if anyone has tried to create a set of "Laws of Simulation" analogous to the laws of thermodynamics, which would define a limit to how much pseudoreality can be simulated by a given amount of "true" reality.
    • jamesaguilar 13y ago
      Well, it's not so much a flaw as something that bears empirical testing, someday. If we find that we can easily simulate a perceptual volume of the universe in a relatively smaller amount of physical space, this part of the argument will be sound.
      • nitrogen 13y ago
        You're right. I think "unstated, untested assumption" would be better than "flaw" in that context. If indeed it turns out that a simulation can be more compact in its host universe, then maybe everything really is a simulation, and it's simulations all the way down to infinity. But this would defy my intuitive sense of the nature of reality (derived from things like the conservation of matter and energy, and the geometric idea that four inches of space won't fit within three inches of space), and would effectively allow infinite computation within a finite space.
        • jamesaguilar 13y ago
          Well, I'm fairly certain that what we know about physics so far bars 1:1 simulation of this universe at 1:1 speed using anything less than all the atoms in this universe (not much of a simulation then, eh?) But we might be able to devise a simpler physics that still supports intelligent life. :)
          • rbanffy 13y ago
            You could make some approximations. That's pretty much the core of the argument. It's somewhat implicit that the true nature of the containing universe is not granular like ours.
  • Archaeoculus 13y ago
    >it may take a lot of computational mass to simulate a person I don't understand much of what's going on here, but couldn't it possibly take virtually no computational mass in order to simulate a person? I mean, if you tie the whole system together such that if you simply switch the smallest of switches from 0 to 1 that sends out desired changes rippling out through the rest of the system, it wouldn't matter how much mass it took. Why does it have to take a lot of mass to simulate a person - does what's outside necessarily have to be more complex than what's on the inside?
• jballanc 13y ago
  Brian Greene does a very good job of explaining the logic in this conversation with Robert Krulwich: https://www.wnyc.org/radio/#/ondemand/91859 https://www.wnyc.org/radio/#/ondemand/91859 . If you have a spare 50 minutes, it's really really worth your time to listen. In sum, the argument goes like this: if there is more than one universe, then there will be some universes that are larger than ours, some that are smaller, some that are younger and some that are much, much older. If we, in our universe, have evolved intelligence sufficient to construct machines to simulate simple mammalian brains, then it is reasonable to assume that beings in a much larger, much older universe would have computational power far in excess of ours. So much so, that not only would they be able to simulate entire smaller, younger universes, but those simulations may themselves have the ability to simulate even smaller, younger universes. Turtles all the way down, so to speak. So even if the very biggest, oldest universes form the long tail of all possible universes, the fact that they could simulate universes that simulate universes that simulate universes means that, all else being equal, the probability that our universe is real is much less than the probability that we are, in fact, in a simulation.
  • powertower 13y ago
    To simulate a universe you'd need to be able to solve, or at least approximate with great accuracy, the n-body problem. And we can't even do that with n >= 3 (without restrictions). To simulate a small universe you're talking about one hell of a large "n". Some physics are fundamentally not workable with logic and processing power due to exponential growth requirements for each additional n (and it makes no difference how large or advanced that other universe is)... Those same physics require something much more fundamental, the fabric of space-time itself with some energy/motion introduced into it. Hence the only way to "simulate" a universe is to create one... But then it's not a simulation at all.
  • almosnow 13y ago
    "... construct machines to simulate simple mammalian brains", you fell for it man, marketing does marvels what we are capable of doing is just building a machine with the same number of components (i.e. transistors if you want) as some simple mammalian brains (i.e. neurons), then the guys at wired or discovery channel do their part and tell that "that's an artificial brain"
• eurleif 13y ago
  >This seems like such faulty and backwards reasoning to me. It's not backwards, it's the scientific method: come up with a hypothesis (the universe is a simulation), find a prediction made by that hypothesis (physical anomalies), then test for that prediction. Of course alternate explanations are possible, but the usefulness of the test is determined by the prior probabilities we assign to the various possible explanations; the basic form of reasoning is not backwards.
  • platz 13y ago
    In that frame of mind, ok, not it's backwards. But I don't think the test provides grounds for warranting this hypothesis; it does not seem to follow from the test you could deduce the hypothesis. I must admit I feel there is an alternate explanation for results/test.
• joe_the_user 13y ago
  I'm glad to see someone call this circus what it is. Yes, these people are imagining the unimaginable and then making certain predictions concerning the qualities of the processes? If a "simulation" was created by some intelligent entity, how could we know what error corrections it would have, what short-cuts it would involve, how fine or coarse-grained the steps involved would be and so-forth? Any "necessary flaw" we might imagine would be something these much smarter and advanced entities would imagine and compensate for. As others have noted, Quantum effects imply you couldn't have a 1-1 simulation of very much in a universe resembling this one. But since our whole universe is supposedly being simulated, what reason do we have to assume the simulating universe has the same laws? But then what reason do we have to make guesses about the form "anomalies" would take?? On the other hand, indications that events in our universe are happening the context of some sort of "substratum" doesn't mean at all such a substratum was created by an intelligent entity - quantum effects "simulate" Newtonian effects but QM isn't a computer but simply deeper level of reality. It's hard to describe all the different fallacies that seem to be at work.