(2)Possible, but I can still imagine large civilizations of people whose utility function is weighted such that "99.9999% death plus 0.0001% superman" is inferior to "continued mortal existence."
You have to keep in mind that subjective experience will be 100% superman. The whole idea is that the MWI is true and completely convincingly demonstrated by other means as well. It is like if someone would tell you: you enter this room and all you will experience is that you leave the room with one billion dollars. I think it is a seducing prospect.
Yet another analogue: Assume that you have the choice between the following two scenarios:
1) You get replicated million times and all the copies will lead an existence in hopeless poverty
2) You continue your current existence as a single copy but in luxury
The absolute reference frame may be different but the relative difference between the two outcomes is very similar to those of the above alternative.
Possible additional motivation could be given by knowing that if you don't do that and wait a very very long time, the cumulative risk that you experience some other civilization going superman and obliterating you will raise above a certain threshold. For single civilizations the chance of experiencing it would be negligible but for a universe filled with aspiring civilizations, the chance of experiencing at least one of them going omega could become a significant risk after a while.
Your aliens are assigning zero weight to their own death, as opposed to a negative weight. While this may be logical, I can certainly imagine a broadly rational intelligent species that doesn't do it.
Consider the problems with doing so. Suppose that Omega offers to give a friend of yours a wonderful life if you let him zap you out of existence. A wonderful life for a friend of yours clearly has a positive weight, but I'd expect you to say "no," because you are assigning a negative weight to death. If you assign a zero weight to an outcome involvi...
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.