Turing's cathedral
Monday, February 27, 2006, 02:42 AM - Beautiful Code, Theory
The digital universe was conceived by Old Testament prophets (led by Leibniz) who supplied the logic, and delivered by New Testament prophets (led by von Neumann) who supplied the machines. Alan Turing (1912-1954) formed the bridge between the two.
In a digital computer, the instructions are in the form of COMMAND (ADDRESS) where the address is an exact (either absolute or relative) memory location, a process that translates informally into "DO THIS with what you find HERE and go THERE with the result." Everything depends not only on precise instructions, but on HERE, THERE, and WHEN being exactly defined. It is almost incomprehensible that programs amounting to millions of lines of code, written by teams of hundreds of people, are able to go out into the computational universe and function as well as they do given that one bit in the wrong place (or the wrong time) can bring the process to a halt.
Biology has taken a completely different approach. There is no von Neumann address matrix, just a molecular soup, and the instructions say simply "DO THIS with the next copy of THAT which comes along." The results are far more robust. There is no unforgiving central address authority, and no unforgiving central clock. This ability to take general, organized advantage of local, haphazard processes is exactly the ability that (so far) has distinguished information processing in living organisms from information processing by digital computers.
READ Turing's Cathedral by George Dyson.
marta
Friday, March 3, 2006, 03:37 PM
Apuntando en wishlist... ¡¡gracias!!
No hay ningun motivo por el que no haya comentarios en español. En realidad este es un blog de notas para mi con cosas que no tengo tiempo de traducir o explicar y por eso está en inglés. En mi vanidad, me gusta pensar que le resulta util a otros...
Monday, February 27, 2006, 09:01 PM
Marta, no se si has leido un libro que se llama "Gödel, Escher, Bach, un grácil y eterno bucle", pero si no lo has hecho te lo aconsejo. Trata de computación, lógica, lo que es computable y lo que no, y establece analogías con piezas de Bach y cuadores de Escher. Es muy entretenido y muy instructivo.
(( Lo siento por contestar en español. ))
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