I agree completely... the whole "measurement paradox" comes from historical confusion (to be fair, confusion which was shared by some of its founders). Einstein taught us that we don't get to ask the question "what's happening on Alpha Centauri right now?" It's an intuitive question to want to ask given our everyday experience, but it turns out to be the result of fuzzy thinking: the word "now" just doesn't make sense in this context. Similarly quantum mechanics teaches us that questions like "what would I have observed if I had done a different measurement", or "what is the state really", or (David Deutsch's favorite) "where did the number get factored?" are just not well-defined. The struggle is figuring out which words and concepts taken from our everyday experience still make sense in the quantum world --- which questions we really get to ask. It's true that that's less clear for quantum mechanics than it is for relativity, and it's upsetting to imagine that words like "state" (and "would"!) might be among those that we have to let go of. But I strongly suspect that most of the "paradoxes" that trouble QM will turn out to be in this category. At least that's what I think when I'm in hard-core analytic philosophy mode ;-) Cris On Jul 27, 2013, at 7:34 PM, Gareth McCaughan <gareth.mccaughan@pobox.com> wrote:
I mean, there isn't actually any good reason to think that conscious observers are treated specially by the universe; it's just a sad historical accident that early speculation about how QM works happened to treat conscious observers (or at least their "measurements") specially.