There’s also problem 3 (or maybe it’s problem 0): the whole thing assumes that you accept that these other universes exist in any way that would make it desirable to trade with them to begin with. Tegmarkianism isn’t a given, and satisfying the preferences of something nonexistent, for the “reward” of it creating a nonexistent situation where your own preferences are satisfied, is, um, nonstandard. Even doing something like that with things bidirectionally outside of your light cone is pretty fraught, let alone things outside of your physics.
Acausal trade seems to appeal either to people who want to be moral realists but can’t quite figure out how to pull that off in any real framework, so they add epicycles… or to people who just like to make their worldviews maximally weird.
Not really, not for the light cone case. You could maybe make a case that it’s in some way less “real” than anything causally connected to you, but I’m willing to basically assign it reality.
I think the idea of attaching a probability to whether it’s real badly misses the point, though. That’s not necessarily the kind of proposition that has a probability. First you have to define what you mean by “real” or “exists” (and whether the two mean the same thing). It’s not obvious at all. We say that my keyboard exists, and we say that the square root of two exists, but those don’t mean the same thing… and a lot of the associations and ways of thinking around the world “real” get tangled up with causality.
But anyway, as I said, for most purposes I’m prepared to act as though stuff outside my light cone exists and/or is real, in the same way I’m willing to act as though stuff technically inside my light cone exists and/or is real, even when the causal connections between me and it are so weak as to be practically unimportant.
The problem in the “outside the light cone” trade case is more about not having any way to know how much of whatever you’re trading with is real, for any definition of real, nor what its nature may be if it is. You don’t know the extent or even the topology (or necessarily even the physical laws) of the Universe outside of your light cone. It may not be that much bigger than the light cone itself. It may even be smaller than the light cone in the future direction. Maybe you’ll have some strong hints someday, but you can’t rely on getting them. And at the moment, as far as I can tell, cosmology is totally befuddled on those issues.
And even if you have the size, you still get back to the sorts of things the original post talks about. If it’s finite you don’t know how many entities there are in it, or what proportion of them are going to “trade” with you, and if it’s infinite you don’t know the measure (assuming that you can define a measure you find satisfying). For that matter, there are also problems with things that are technically inside your light cone, but with which you can’t communicate practically.
If it’s finite you don’t know how many entities there are in it, or what proportion of them are going to “trade” with you, and if it’s infinite you don’t know the measure (assuming that you can define a measure you find satisfying).
These are baby problems for baby animals. You develop adequate confidence about these things by running life-history simulations (built with a kind of continual actively reasoning performance optimization process that a human-level org wouldn’t be able to contemplate implementing) or just by surveying the technological species in your lightcone and extrapolating. Crucially, values lock in after the singularity (and probably intelligence and technology converges to the top of the S-curve) so you don’t have to simulate anyone beyond the stage at which they become infeasible large.
Not as far as I’ve ever been able to discern.
There’s also problem 3 (or maybe it’s problem 0): the whole thing assumes that you accept that these other universes exist in any way that would make it desirable to trade with them to begin with. Tegmarkianism isn’t a given, and satisfying the preferences of something nonexistent, for the “reward” of it creating a nonexistent situation where your own preferences are satisfied, is, um, nonstandard. Even doing something like that with things bidirectionally outside of your light cone is pretty fraught, let alone things outside of your physics.
Acausal trade seems to appeal either to people who want to be moral realists but can’t quite figure out how to pull that off in any real framework, so they add epicycles… or to people who just like to make their worldviews maximally weird.
Are you proposing that the universe outside of your lightcone might (like non-negligible P) just not be real?
Not really, not for the light cone case. You could maybe make a case that it’s in some way less “real” than anything causally connected to you, but I’m willing to basically assign it reality.
I think the idea of attaching a probability to whether it’s real badly misses the point, though. That’s not necessarily the kind of proposition that has a probability. First you have to define what you mean by “real” or “exists” (and whether the two mean the same thing). It’s not obvious at all. We say that my keyboard exists, and we say that the square root of two exists, but those don’t mean the same thing… and a lot of the associations and ways of thinking around the world “real” get tangled up with causality.
But anyway, as I said, for most purposes I’m prepared to act as though stuff outside my light cone exists and/or is real, in the same way I’m willing to act as though stuff technically inside my light cone exists and/or is real, even when the causal connections between me and it are so weak as to be practically unimportant.
The problem in the “outside the light cone” trade case is more about not having any way to know how much of whatever you’re trading with is real, for any definition of real, nor what its nature may be if it is. You don’t know the extent or even the topology (or necessarily even the physical laws) of the Universe outside of your light cone. It may not be that much bigger than the light cone itself. It may even be smaller than the light cone in the future direction. Maybe you’ll have some strong hints someday, but you can’t rely on getting them. And at the moment, as far as I can tell, cosmology is totally befuddled on those issues.
And even if you have the size, you still get back to the sorts of things the original post talks about. If it’s finite you don’t know how many entities there are in it, or what proportion of them are going to “trade” with you, and if it’s infinite you don’t know the measure (assuming that you can define a measure you find satisfying). For that matter, there are also problems with things that are technically inside your light cone, but with which you can’t communicate practically.
You don’t need certainty to do acausal trade.
These are baby problems for baby animals. You develop adequate confidence about these things by running life-history simulations (built with a kind of continual actively reasoning performance optimization process that a human-level org wouldn’t be able to contemplate implementing) or just by surveying the technological species in your lightcone and extrapolating. Crucially, values lock in after the singularity (and probably intelligence and technology converges to the top of the S-curve) so you don’t have to simulate anyone beyond the stage at which they become infeasible large.