Tegmark cosmology implies not only that there is a universe which runs this one as a simulation, but that there are infinitely many such universes and infinitely many such simulations. In some fraction of those universes, the simulation will have been designed by an intelligent entity. In some smaller fraction, that entity has the ability to mess with the contents of the simulation (our universe) or copy data out of it (eg, upload minds and give them afterlives). My theism is equal to my estimate of this latter fraction, which is very small.
Tegmark cosmology implies not only that there is a universe which runs this one as a simulation, but that there are infinitely many such simulations.
I’m not sure that this is true. My understanding is that IF a universe which runs this one as a simulation is possible, THEN Tegmark cosmology implies that such a universe exists. But I’m not sure that such a universe is possible. After all, a universe which contains a perfect simulation of this one would need to be larger (in duration and/or size) than this one. But there is a largest possible finite simple group, so why not a largest possible universe? I am not confident enough of my understanding of the constraints applicable to universes to be confident that we are not already in the biggest one possible.
There is a spooky similarity between the Tegmark-inspired argument that we may live in a simulation and the Godel/St. Anselm-inspired argument that we were created by a Deity. Both draw their plausibility by jumping from the assertion that something (rather poorly characterized) is conceivable to the claim that that thing is possible. That strikes me as too big of a jump.
I’m not sure that this is true. My understanding is that IF a universe which runs this one as a simulation is possible, THEN Tegmark cosmology implies that such a universe exists. But I’m not sure that such a universe is possible.
You’re right, that is an additional requirement. Nevertheless, it seems very highly likely to me that such a universe is possible; for it to be otherwise would imply something very strange about the laws of physics. The most-existant universe simulating ours might exist to a degree 1/BB(100) times as much as our universe exists, though; in that case, they would “exist”, but not for any practical purposes. This seems more likely than our universe having some property we don’t know about that makes it impossible to simulate.
Yes, but unfortunately, there are many measures to choose from, and you can’t possibly tell which is correct until you’ve visited Permutation City and at least a dozen of its suburbs.
I agree with the question. It may make sense to attach “probabilities of existing” to universes arising in a chaotic inflation model, but not, I think, in an “ultimate ensemble” multiverse, which seems to be the one being examined here.
But, to be honest, I had never even considered the possibility that a particularly large bubble universe might contain a simulation of a much smaller bubble. Inflation, as I understand it, does make it possible for a simulation of one small piece of physical reality to encompass an entire isolated ‘universe’.
Not yet, as far as I know. Big World cosmology seems to be going in the right direction, but it’s not yet understood well enough that we should be coming to any epistemological or ethical conclusions based on it.
Right. Actually, forget about both of those; all that matters is whether it actually does modify the simulation’s contents or copy out data that includes a mind at least once. And, come to think of it, the intervention would also have to be inside our past or future light cone, which might lower the fraction pretty substantially (it means any outer universe which instantiates our entire infinite universe, but makes only finitely many interventions, doesn’t count).
Although—there are some interpretations of consciousness under which, upon death, the fraction of enclosing universes which copy out minds doesn’t matter, only the proportions of them with different qualities. In that case, the universe would act as though there were no gods or outer universes until you died or performed enough iterations of quantum suicide, after which you’d end up in a different universe. I’m not sure how much credence I give to those interpretations.
It seems to me that, if we insist on using simulation hypotheses as a model for theism, this has to be narrowed still further. Theism adds the constraint that though $deity is simulating us, no-one is simulating $deity; He’s really really real and the buck stops with Him. We live in the floor just above reality’s basement; isn’t that nice.
I think that this might be what Eliezer’s quote about “ontological distinctness” refers to, but I’m not sure.
Monotheism requires that, but theism doesn’t. And unless there are some universes that are for some reason impossible to simulate, Tegmark cosmology implies that there are no universes for which there are no universes simulating them. Is-God-of is a two-place predicate.
If one were interested in salvaging the correspondence, one could argue that there’s a chain of simulators-simulating-simulators and it’s that chain (which extends down to “reality’s basement”) that theists label as a deity.
That said, I see no point in allowing ontology to get out ahead of epistemology in this area. Sure, maybe all this stuff is going on. Maybe it isn’t. Unless these conjectures actually cash out somehow in terms of different expectations about observable phenomena, there seems little point to talking about them.
Tegmark cosmology implies not only that there is a universe which runs this one as a simulation, but that there are infinitely many such universes and infinitely many such simulations. In some fraction of those universes, the simulation will have been designed by an intelligent entity. In some smaller fraction, that entity has the ability to mess with the contents of the simulation (our universe) or copy data out of it (eg, upload minds and give them afterlives). My theism is equal to my estimate of this latter fraction, which is very small.
I’m not sure that this is true. My understanding is that IF a universe which runs this one as a simulation is possible, THEN Tegmark cosmology implies that such a universe exists. But I’m not sure that such a universe is possible. After all, a universe which contains a perfect simulation of this one would need to be larger (in duration and/or size) than this one. But there is a largest possible finite simple group, so why not a largest possible universe? I am not confident enough of my understanding of the constraints applicable to universes to be confident that we are not already in the biggest one possible.
There is a spooky similarity between the Tegmark-inspired argument that we may live in a simulation and the Godel/St. Anselm-inspired argument that we were created by a Deity. Both draw their plausibility by jumping from the assertion that something (rather poorly characterized) is conceivable to the claim that that thing is possible. That strikes me as too big of a jump.
There isn’t a largest finite simple group. There’s a largest exceptional finite simple group.
Z/pZ is finite and simple for all primes p, and if you think there is a largest prime I have some bad news...
Doooohhh!
Thx.
You’re right, that is an additional requirement. Nevertheless, it seems very highly likely to me that such a universe is possible; for it to be otherwise would imply something very strange about the laws of physics. The most-existant universe simulating ours might exist to a degree 1/BB(100) times as much as our universe exists, though; in that case, they would “exist”, but not for any practical purposes. This seems more likely than our universe having some property we don’t know about that makes it impossible to simulate.
If one accepts general Tegmark, is there any natural measure for describing how common different universes should be in any meaningful sense?
Yes, but unfortunately, there are many measures to choose from, and you can’t possibly tell which is correct until you’ve visited Permutation City and at least a dozen of its suburbs.
I agree with the question. It may make sense to attach “probabilities of existing” to universes arising in a chaotic inflation model, but not, I think, in an “ultimate ensemble” multiverse, which seems to be the one being examined here.
But, to be honest, I had never even considered the possibility that a particularly large bubble universe might contain a simulation of a much smaller bubble. Inflation, as I understand it, does make it possible for a simulation of one small piece of physical reality to encompass an entire isolated ‘universe’.
Not yet, as far as I know. Big World cosmology seems to be going in the right direction, but it’s not yet understood well enough that we should be coming to any epistemological or ethical conclusions based on it.
Clarifying: I’m guessing that by ‘ability’ you mean ‘ability and inclination’?
Right. Actually, forget about both of those; all that matters is whether it actually does modify the simulation’s contents or copy out data that includes a mind at least once. And, come to think of it, the intervention would also have to be inside our past or future light cone, which might lower the fraction pretty substantially (it means any outer universe which instantiates our entire infinite universe, but makes only finitely many interventions, doesn’t count).
Although—there are some interpretations of consciousness under which, upon death, the fraction of enclosing universes which copy out minds doesn’t matter, only the proportions of them with different qualities. In that case, the universe would act as though there were no gods or outer universes until you died or performed enough iterations of quantum suicide, after which you’d end up in a different universe. I’m not sure how much credence I give to those interpretations.
What does “fraction” mean here?
It seems to me that, if we insist on using simulation hypotheses as a model for theism, this has to be narrowed still further. Theism adds the constraint that though $deity is simulating us, no-one is simulating $deity; He’s really really real and the buck stops with Him. We live in the floor just above reality’s basement; isn’t that nice.
I think that this might be what Eliezer’s quote about “ontological distinctness” refers to, but I’m not sure.
Monotheism requires that, but theism doesn’t. And unless there are some universes that are for some reason impossible to simulate, Tegmark cosmology implies that there are no universes for which there are no universes simulating them. Is-God-of is a two-place predicate.
If one were interested in salvaging the correspondence, one could argue that there’s a chain of simulators-simulating-simulators and it’s that chain (which extends down to “reality’s basement”) that theists label as a deity.
That said, I see no point in allowing ontology to get out ahead of epistemology in this area. Sure, maybe all this stuff is going on. Maybe it isn’t. Unless these conjectures actually cash out somehow in terms of different expectations about observable phenomena, there seems little point to talking about them.
Nitpick: Will isn’t the only self-identified theist you’d have to convince of that.