Well, I'm a particle physicist, and I know a lot about relativistic quantum mechanics, which is *not* the same thing as knowing a lot about the mathematical foundations of quantum mechanics (though I have read Eyvind Wichman's lecture notes), *nor* is it the same thing as knowing a lot about the philosophy of quantum mechanics (I'm not sure who is an expert there). But it does seem to me that tossing out the old Copenhagen interpretation of the collapse of the wave function (which is what I was taught in college), and accepting the Everett interpretation (which I know a bit about) *does* seem to imply, at least in my naive perspective, the requirement of a self-aware observer. (Is there any other kind of observer?) I am not comfortable with this conclusion, and I would welcome people to correct me. I do know that some very smart physicists that I respect a great deal seem to accept Everett. Also, some superficial web research shows at least one other interpretation that looks compelling, namely the Penrose interpretation. I don't know very much about the latter, but the descriptions that I have read show that it at least covers some the core issues in relativistic QM that bothered me when I was a young grad student. (Namely the relation of distribution theory to the quantum field theory, and how this relation leads to the requirement of renomormalization of physical quantities.) Like I say, I am not an expert on these issues, but they are things that occasionally cause me to lose sleep at night. And I am interested in them. Is John Baez in this list? He could certainly correct me in many ways. Rowan.