OK, and could you now explain how you start from not knowing what it takes to emulate a brain and then deduce from that that it's impossible to emulate a brain?

OK, and could you now explain how you start from not knowing what it takes to emulate a brain and then deduce from that that it's impossible to emulate a brain? Your original argument was a supposed reason why emulation is in fact impossible, not why it might later turn out to be impossible, which is why I (and others) disagree - which you still haven't established, though, as far as I can see.