Sure, I agree. The issue is the word "computer" means not "device we have made" but "universal turing machine". Ie., a computer is any system which realises a

Sure, I agree. The issue is the word "computer" means not "device we have made" but "universal turing machine". Ie., a computer is any system which realises a function from the Naturals to the Naturals. Physics barely, if at all, has any use whatsoever for those functions. It is a very important point. Computer scientists (ie., discrete mathematicians) are not the people who are even able to describe, engineer and build whatever is needed for an AI -- if, as I claim, continuous dynamical properties are needed. (As, for example, they are needed by pretty much every system.)