Continuing discussion with Daniel Varga:

It's difficult to discuss the behavioral dispositions of these imagined cosmic civilizations guided by a single utility function, without making a lot of assumptions about cosmology, physics, and their cosmic abundance. For example, the accelerating expansion of the universe implies that the universe will eventually separate into gravitationally bound systems (galactic superclusters, say) which will be causally isolated from each other; everything else will move beyond the cosmological horizon. The strategic behavior of such a civilization may be very different if it expects a rival or it expects no rivals to have formed independently in its supercluster. It's the difference between expecting a future of unimpeded expansion and expecting to have to negotiate or fight.

Regarding my multipronged flame attack on your supposed intellectual sins :-) ... OK, you're not a platonist. "Tegmark's multiverse" is just an inventory of possible formal structures for you, and you want to know which ones could describe a universe that contains time. That's still a hard question. ata says, quite reasonably, that there had better be some form of sequential structure, so you can have temporal succession and temporal dynamics. But we also regard relativity as providing a model of time, only then you don't have a universal time. Technically, you don't have a total order on the set of all events, only a partial order. So will we say that any partially ordered set can provide a model of time? Then I wonder about generalizations of relativity in which you have more than one timelike direction. Is that a formal generalization which exceeds the possibility of an interpretation in terms of time? I think that phenomenon - formal overgeneralization - exists and is hardly talked about, again because of our dereliction of integrated ontology in favor of our combination of rigorous formalism and fuzzy thinking about how the formalism relates to reality. You can see this in logic, I believe. Classical logic is formalized, and then the formal system is generalized, and the new formalism is treated as if it describes "a logic", but one may reasonably ask if it has become simply a set of rules of symbolic manipulation that no longer corresponds to any valid form of reasoning. I would not want to say that non-Euclidean geometry is not a geometry, so some forms of formal generalization will retain a connection to their alleged meaning, but the whole issue is hardly addressed.

As for "emergent time". You say you agree with Barbour, but you think time is real. Well, I don't know what you mean by time then. To me, time is about change. Becoming, not just being. Things aren't just sitting there inertly in static eternity; change is real. And I do not at all see how change can be "emergent". There may be parts of reality that don't change, and parts of reality that do, and maybe there's a definable boundary. But talking of emergent time makes it sound like you're trying to have it both ways at once: you don't have time and you do have time. You have a universe without change, and yet if you look at it differently it is changing.

I don't buy that. Either change is real or it isn't. You may have a static description of a changing reality. That is, it may be possible to talk about the set of all physical events in the history of the universe, and say things about their relationships and the patterns they form, without referring to time or change; but that doesn't mean you can start by postulating that reality consists of a set of physical conditions in timeless stasis, and then somehow get time back by magic. It's a matter of interpretation of the formalism. Either it refers to time or it doesn't.

Feel free to refute me by explaining what the emergence of time could possibly mean (even better, the emergence of time from memory).