I’m new to this area and trying to grasp it better, so apologies for not asking directly about the article. I’m confused about how SIA doesn’t run into the same obstacles that multiverse hypotheses do as highlighted by Roger White. Assuming that each universe is sufficiently causally isolated, the existence of one cannot effect the existence of another. So, the odds that our universe contains life is not affected by the existence of other universes. Each roll of the dice is independent. Similarly, we can say that each roll of the dice about whether an agent will exist is independent (or near enough in these sci fi cases).
Michael Huemer also made an interesting argument against Boltzmann brains that seems applicable. He basically said that BBs usually don’t have coherent experiences. Why would they—they’re brains in space! That we have coherent experiences this provides huge evidence against the BB hypothesis. The argument’s basic strcuture: of hypothesis H were true, we would probably have x-like experiences. We don’t, so H is probably not true. (The math in this case works out.)
Let’s run the argument here. If there is a multiverse, we’d expect to be some random observer in the multiverse, which reduces our odds of experiencing anything like what we do experience. That we have our experiences rather than some other type seems to provide evidence that there are fewer people, not more.
I am interested in this stuff because I have interests in ontological parsimony more generally. The SIA arguments seem to suggest that metaphysicians’ best bet is severely against quantitative parsimony. I’m less sure about qualitative. Maybe the odds of every sort of thing existing makes it more likely that any particular thing exists? I don’t see how we stop the train towards modal realism if this sort of thought works.
“However, one could reason as follows. Suppose that the person is cheating. Well then you know that there’s only one room, such that if the cheating hypothesis is correct, cheating would occur in this room. In contrast, if the big casino hypothesis is true, it’s unlikely that this person would be cheating in this room. So the cheating hypothesis gets a big boost.”
I did not follow this.
The Bostrom selection effect point also seems to beg the question. Yea, being outside a casino and being alerted when there are double 6s seems to provide evidence of several rolls, but only because you have a background view about the probability of getting double sixes. We are entitled to no analogous view in the case of getting our particular constants. Almost all the work of the argument seems to be done by the indifference principle assigning equal credence to each possibility. That’s extremely dubious for the usual reasons and also because probabilities with infinities get messy and unworkable, especially in the fine-tuning literature.
I get the sense that I am probably missing something here, but I’m not seeing what it is. Clarifying your casino thought experiment might help, as would clarifying the extent of the argument’s reliance on indifference reasoning.
The point is that in cases where there's a selection effect, it's reasonable to infer a bigger sample from the presence of some particular instance of the sample. If I'll only know about my existence if I'm created, then thinking many got created doesn't commit the inverse gambler's fallacy/
In the casino case, we have reason to assign every dice roll and equal probability. I see no reason that we should do the same with every set of constants in the universe. On what basis can we make such a judgment? In the casino case, it’s straightforward, well-behaved physical probability calculations. In the multiverse case, we are far from such a scenario.
I don’t know whether this issue has any upshot for anthropics, because I suppose we can calculate physical probabilities of agents like us existing in a way that’s impossible with nomologically necessary constants. So maybe the multiverse stuff doesn’t bear on this issue after all?
I suspect that my previous comment about begging the question is wrong. Iirc White himself wants to grant that the odds of getting our constants are low. So I guess the indifference issue is just an independent point
I’m new to this area and trying to grasp it better, so apologies for not asking directly about the article. I’m confused about how SIA doesn’t run into the same obstacles that multiverse hypotheses do as highlighted by Roger White. Assuming that each universe is sufficiently causally isolated, the existence of one cannot effect the existence of another. So, the odds that our universe contains life is not affected by the existence of other universes. Each roll of the dice is independent. Similarly, we can say that each roll of the dice about whether an agent will exist is independent (or near enough in these sci fi cases).
Michael Huemer also made an interesting argument against Boltzmann brains that seems applicable. He basically said that BBs usually don’t have coherent experiences. Why would they—they’re brains in space! That we have coherent experiences this provides huge evidence against the BB hypothesis. The argument’s basic strcuture: of hypothesis H were true, we would probably have x-like experiences. We don’t, so H is probably not true. (The math in this case works out.)
Let’s run the argument here. If there is a multiverse, we’d expect to be some random observer in the multiverse, which reduces our odds of experiencing anything like what we do experience. That we have our experiences rather than some other type seems to provide evidence that there are fewer people, not more.
I am interested in this stuff because I have interests in ontological parsimony more generally. The SIA arguments seem to suggest that metaphysicians’ best bet is severely against quantitative parsimony. I’m less sure about qualitative. Maybe the odds of every sort of thing existing makes it more likely that any particular thing exists? I don’t see how we stop the train towards modal realism if this sort of thought works.
I think White is just wrong for reasons I give here https://benthams.substack.com/p/the-multiverse-and-inverse-gamblers
“However, one could reason as follows. Suppose that the person is cheating. Well then you know that there’s only one room, such that if the cheating hypothesis is correct, cheating would occur in this room. In contrast, if the big casino hypothesis is true, it’s unlikely that this person would be cheating in this room. So the cheating hypothesis gets a big boost.”
I did not follow this.
The Bostrom selection effect point also seems to beg the question. Yea, being outside a casino and being alerted when there are double 6s seems to provide evidence of several rolls, but only because you have a background view about the probability of getting double sixes. We are entitled to no analogous view in the case of getting our particular constants. Almost all the work of the argument seems to be done by the indifference principle assigning equal credence to each possibility. That’s extremely dubious for the usual reasons and also because probabilities with infinities get messy and unworkable, especially in the fine-tuning literature.
I get the sense that I am probably missing something here, but I’m not seeing what it is. Clarifying your casino thought experiment might help, as would clarifying the extent of the argument’s reliance on indifference reasoning.
The point is that in cases where there's a selection effect, it's reasonable to infer a bigger sample from the presence of some particular instance of the sample. If I'll only know about my existence if I'm created, then thinking many got created doesn't commit the inverse gambler's fallacy/
That part I gathered. But doesn’t that just assume a whole bunch of background indifference indifference stuff?
What background indifference stuff that you reject does it accept?
In the casino case, we have reason to assign every dice roll and equal probability. I see no reason that we should do the same with every set of constants in the universe. On what basis can we make such a judgment? In the casino case, it’s straightforward, well-behaved physical probability calculations. In the multiverse case, we are far from such a scenario.
I don’t know whether this issue has any upshot for anthropics, because I suppose we can calculate physical probabilities of agents like us existing in a way that’s impossible with nomologically necessary constants. So maybe the multiverse stuff doesn’t bear on this issue after all?
I suspect that my previous comment about begging the question is wrong. Iirc White himself wants to grant that the odds of getting our constants are low. So I guess the indifference issue is just an independent point