2009/5/3 Bruno Marchal <marc...@ulb.ac.be>: > I think that if you take a real forest with birds, here and there, you > can interpret some behavior as NAND or NOR, but you will not succeed > ever in finding the computation of factorial(5).
But you can interpret *any* behaviour as a NAND gate, in an ad hoc fashion. It doesn't even need to be consistent from moment. On a Tuesday 3 birds landing could stand for "1" while on a Wednesday 3 birds landing could stand for "0", and on a Saturday it could stand for "1" again. In this way you could take the physical activity carried out by a store-bought computer calculating factorial(5) and map it onto the forest with the birds. Of course, this won't give you the answer to factorial(5) unless you already have the answer, but that just means that the computation is obscured, in the same way a message is obscured if encoded with a one-time pad that is subsequently destroyed and forgotten. In fact, even with the store-bought computer the computation is obscured if there are no intelligent beings around who can understand it. So, if the computation supervenes on the activity of the store-bought computer without regard for whether any external observer is around to understand, then it also supervenes on the activity of the forest with the birds. Other possibilities are that the computation supervenes on physical activity only when an external observer understands it (which poses difficulties for a closed virtual reality with its own conscious observers), or that the computation does not supervene on physical activity at all. -- Stathis Papaioannou --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---