[patkai]

But what happened to Langton himself? After leaving SFI and the Swarm corp he seems to have disappeared. I met him once - about 12 years ago - and he was the most charming, kind guy who spent three hours and a lunch with me just because I said I don't understand something he said. Then he warned me not to become too much of a generalist and specialise more. He was right, but I didn't listen to him, I was in my 20s and thought I can be a polymath :)

[tim_hutton]

I spoke to Glen Ropella of Swarm about him in 2009 when I was writing a paper and Glen said this: "Most of the people I know related to Swarm refer people to me when they're looking for Chris. It's no mystery, though. He decided awhile back to leave the Swarm/SFI community for personal reasons. So, he's out there. He just doesn't want to work on that stuff anymore, at least as of the last time I talked to him. ... He may well want to interact. I don't know. All I know is I haven't heard from him in awhile."

Chris, if you're out there: Hi!

[api]

I looked for Langton myself years ago when I was very into artificial life and evolutionary computing. IMHO he's one of the greatest unsung geniuses of the past 25 years.

Here's what I consider his greatest work:

http://wiki-app2.tudelft.nl/pub/Education/SPM955xABMofCAS/Le...

To give you one example: that paper is why I think Titan is the most likely world in the solar system where we might find present-day complex life. (Other than Earth of course.)

Why? There's no liquid water on the surface, and it's too cold!

Answer: phase boundaries everywhere. See Fig. 3 from paper.

Titan has a hydrocarbon-based "water cycle" with solid, liquid, and gas all existing at the same time, along with what appear to be seasons. Universal computation occurs in the vicinity of phase boundaries, so I would not be terribly surprised if we found "cryolife" there. It would be radically different from our own, but not really... I agree with people like Langton that life should be considered primarily an informatics phenomenon rather than a conventional chemical reaction or physical state.

If Titan life were intelligent, they'd regard us as hell-beasts with blood of molten water. :) We could never physically touch, as we would vaporize them and they would freeze us solid.

There's a contemporary scientist named Dr. Christoph Adami at Michigan State's new BEACON center who's probably the closest to following in Langton's footsteps.

http://www.mmg.msu.edu/adami.html

Adami expounded upon these ideas by defining life as "a phase of matter in which the dynamics of information processing overcome those of ordinary matter and energy." I am paraphrasing, and possibly butchering it a little... can't find the original quote, but that's the basic idea. Life is a phase of matter -- one whose behavior is dominated by universal Turing-complete computation. You might call living matter "Turium" or something.

The fact that this whole line of reasoning hasn't been taken up more broadly is IMHO some kind of failure of the academic and scientific system.