Hmmm, it seems that most of your arguments are in plain probability-theoretical terms: what is the expected utility assuming certain probabilities of certain outcomes. During the arguments you compute expected values.
The whole point of my example was that assuming a many world view of the universe (i.e. multiverse), using the above decision procedures is questionable at best in some situations.
In classical probability theoristic view, you won't experience your payoff at all if you don't win. In a MWT framework, you will experience it for sure. (Of course the rest of the world sees a high chance of your loosing, but why should that bother you?)
I definitely would not gamble my life on 1:1000000 chances, but if Omega would convince me that MWI is definitely correct and the game is set up in a way that I will experience my payoff for sure in some branches of the multiverse, then it would be quite different from a simple gamble.
I think it is a quite an interesting case where human intuition and MWI clashes, simply because it contradicts our everyday beliefs on our physical reality. I don't say that the above would be an easy decision for me, but I don't think you can just compute expected value to make the choice. The choice is really more about subjective values: what is more important to you: your subjective experience or saturating the Multiverse branches with your copies.
"Finally, your additional motivation raises a question in its own right: why haven't we encountered an Omega Civilization yet?"
That one is easy: The assumption I purposefully made that going omega is a "high risk" (a misleading word, but maybe the closest) process meaning that even if some civilizations went omega, the outsiders (i.e. us) will see them simply wiped out in an overwhelming number of Everett-branches, i.e. with very high probability for us. Therefore we have to wait a huge number of civilizations going omega before we experience them having attained Omega status. Still, if we wait too long, (since the probability of experiencing it is nonzero) some of them will inevitably manage in our Everett-subtree and we will see that civ as a winner.
To make this calculation in a MWI multiverse, you still have to place a zero (or extremely small negative) value on all the branches where you die and take most or all of your species with you. You don't experience them, so they don't matter, right? That's a specialized form of a general question which amounts to "does the universe go away when I'm not looking at it?"
If one can make rational decisions about a universe that doesn't contain oneself in it (and life insurance policies, high-level decorations for valor, and the like suggest this is p...
We have a sample of one modern human civilization, but there are some hints on how likely it was to happen.
Major types of hints are:
Data for:
Data against:
To me it looks like life, animals with nervous systems, Upper Paleolithic-style Homo, language, and behavioral modernity were all extremely unlikely events (notice how far ago they are - vaguely ~3.5bln, ~600mln, ~3mln, ~200k or ~600k, ~50k years ago) - except perhaps language and behavioral modernity might have been linked with each other, if language was relatively late (Homo sapiens only) and behavioral modernity more gradual (and its apparent suddenness is an artifact). Once we have behavioral modernity, modern civilization seems almost inevitable. Your interpretation might vary of course, but at least now you have a lot of data to argue for your position, in convenient format.