>>Our QC cannot by definition /record/ its observation (or even the >>fact that it made one), because that would be irreversible,
> That's why the document he signs just says the electron went through one
> and only slot but it doesn't say which one. The observer knows but then
> the memory of the outcome of the experiment is erased, it's brain is put
> into exactly the same state it was in before the experiment; if Copenhagen
> is right this will have no effect and we will still not see interference,
> but if we do...
>>so we are forbidden from assuming that it /made/ an observation;
> The observer told us he did and he's a reputable scientist, besides
> we can always repeat it with others.
That's my point: the observer /can't/ tell us anything. Ever. The act of doing so violates reversibility. Your "document" is part of the state of the observer, and it has to be reversed too or the experiment is meaningless (which it is anyway). That's no different from putting ordinary recording gadgets at the slots: the pattern goes away, and we get a simple result. Just because you put a "mind" in between the slots and the recorder doesn't change the fact that you're recording. If we insist that the observer maintain quantum coherence and be reversed, then /no measurement is ever made/, and no document is ever produced to tell us about it.
-- Lee Daniel Crocker <firstname.lastname@example.org> <http://www.piclab.com/lcrocker.html> "All inventions or works of authorship original to me, herein and past, are placed irrevocably in the public domain, and may be used or modified for any purpose, without permission, attribution, or notification."--LDC