Apparently, there has been some progress in this field since I last dabbled in it. I had just assumed nerddom had lost interest and moved on to something else without fully exploring the possibilities of virtual life and virtual computing. And forgive me for not going into Geek more often to check my mail.

I have a question, one inspired by your hinted-at concept of autonomous software automata. I once read a story about an alien computer virus attacking earth through a radio telescope down-link, and then spreading through the internet to take over the world's computers. (That's just what aliens do, right? Even virtual ones.) The alien malware had hopped from planet to planet, like a galactic plague, parasitizing whatever advanced technology it located.

I originally dismissed this concept, thinking it highly unlikely any code could run on a hardware platform totally unknown, and possibly very different, from anything its designers had ever encountered. The idea of this software being able to infect multiple hardware platforms on a number of unconnected alien civilizations seemed to me unlikely. Parasites are highly evolved to be specific on one, or at most a few, hosts.

But, if I understand you right, and there are certain characteristics all computing devices must share in common, then this concept is not that far-fetched.

Which brings me to another question, the human brain is an analog computing device, and it doesn't seem to have an architecture like our von Neumann or Turing machines. Would we be vulnerable to these hypothetical viruses, especially since our organic brains don't have digital input?

Just because we have constructed theoretical frameworks to generalize our computing machinery doesn't mean that other types of computing machines aren't possible.