(Copyright © 2000 Piero Scaruffi | Legal restrictions - Termini d'uso )
In this postomous book Von Neumann explores the idea that
a machine could be programmed to make a copy of itself.
Life is a particular class of automata. Life's main property is the ability to reproduce. Von Neumann's automaton was conceived to absorb matter from the environment and process it to build another automaton, including a description of itself. Von Neumann's idea of the dual genetics of self-reproducing automata (that the genetic code must act as instructions on how to build and organism and as data to be passed on to the offspring) was basically the idea behind what will be called DNA: DNA encodes tha instructions for making all the enzymes and the protein that a cell needs to function and DNA makes a copy of itself every time the cell divides in two.
Von Neumann indirectly understood other properties of life: the ability to increase its complexity (an organism can generate organisms that are more complex than itself) and the ability to self-organize.
When a machine (e.g., an assembly line) builds another machine (e.g., an appliance), there occurs a degradation of complexity, whereas the offsprings of living organisms are at least as complex as their parents and their complexity increases in evolutionary times. A self-reproducing machine is a machine that produces another machine of equal of higher complexity.
By representing an organism as a group of contigous multi-state cells (either empty or containing a component) in a 2-dimensional matrix, Von Neumann proved that a Turing-type machine that can reproduce itself could be simulated by using a 29-state cell component.
Turing proved that there exists a universal computing machine. Von Neumann proved that there exists a universal computing machine which, given a description of an automaton, will construct a copy of it, and, by extension, that there exists a universal computing machine which, given a description of a universal computing machine, will construct a copy of it, and, by extension, that there exists a universal computing machine which, given a description of itself, will construct a copy of itself.
TM, ®, Copyright © 2005 Piero Scaruffi