Subject: The Biggest Brain on the Planet Date: Fri, 22 Sep 1995 16:30:44 -0400 (EDT) Here are some notes on the talk Danny Hillis -- founder of Thinking Machines, designer of the fastest computer ever, Genetic Algorithm demigod -- gave as one of the keynote speakers for the Java Day conference yesterday. You may note that it has nothing to do with Java. He put up a number of graphs of various technological developments over time. Number of internet hosts, average cpu power, price of developing a new chip. All were plotted on semilog paper, and all were basically straight lines, which means they rise exponentially. His conclusion: something funny is going on. In no other area of human culture is growth exponential. We in the tech fields are used to seeing those kind of curves, so we're not surprised, but really, it's quite bizarre. E.g., the auto industry looks for growth of one or two percent a year. There's two places this can go: either back down just as fast, or level out. Let's assume it'll level out (making it an ogive curve). If you back up from this curve (and plot it on normal paper) it looks like a step function. In physics, step functions describe phase transitions. Therefore we are (maybe) in a phase transition, moving from one mode of living to another. He then went back to the origin of life in an effort to enumerate the other phase transitions in human history. 1. Analog life: as he put it, little drops of oil that absorbed chemicals from their environment; when they got to a certain size, they split, and some chemicals went in one half and some in another. The mixtures that were better at absorbing absorbed more thus split more... simple evolution. 2. Digital life: the invention of DNA, the most robust language in history. "You're binary-compatible with bacteria." He pulled out a vial of white powder which was actually DNA (joke about it causing problems at customs); you can order DNA to spec these days; they have a standard one-letter code for each of the standard sequences; this particular DNA spelled his name. "So if anyone wants 10 to the 30th copies of my business card, let me know." "If I were really aggressive, I'd have spliced it into a virus and sneezed on you." 3. Cells differentiated, then learned to communicate with one another, then form communities, finally becoming multicellular life forms -- so the unit of evolution was now the individual. 4. The Pre-Cambrian Explosion: 300 mil. years ago -- the explosive growth of species, the invention of most animal and plant life forms as we know them today -- he attributes it to the language (DNA) getting better somethow -- "Maybe it became object-oriented?" 5. Nervous Systems (email for cells) - analog 6. Digital neurons - allowed computations, which allowed *learning* -- adaptation was accelerated by orders of magnitude (there's that log scale again) -- "You eat a bad fruit, you get sick, you don't eat that fruit again... Where before it took your ancestors 300 generations to stop eating that fruit..." Okay, not -your- ancestors, cause they'd have died before reproducing, but you get the point. 7. Language -> culture -> the unit of selection changed again, now it's the group 8. Writing Then he went into the currently zeitgeisty thought that the net is becoming the *source* of information, not just its carrier (analogous to the peripheral nervous system -> brain distinction). This plus its complexity will lead to more emergent behaviours. For example, net lag is an emergent behavior. "There's no one to call when the Internet is slow." He told a great story about the early days of ARPANet. There were only a few hundred machines on the Internet. He recalls a 1/2" thick directory with the name, email, and bio of everyone on the Internet. Each machine had a full routing table, where it kept track of how long it took a packet to get to every single other host. The other hosts would periodically ask around, see who's the fastest router to get to the destination they're looking for. So one day there was a bug in the routing software, and one host's routing tables got filled with zeros. So it thought the transmission time to get to any other host was 0 seconds. "Not bad," thought all the other hosts, "If he can get this packet through to point B in 0 seconds, I'll just send it to him." So all Internet traffic was going through this one host. Naturally, when everything ground to a less than slow crawl, what did everyone do? Sent email to the network administrator. Which got routed through this one machine... The routing tables were instantly updated and cached, plus now every machine was advertising that it could get packets sent in (time to flaky host + 0 seconds), so turning off the flaky machine didn't help. The solution was finally to turn off every single machine on the Internet and reboot. Can you imagine doing that today? The concept doesn't even make sense. I was hoping he would talk some about what he sees on the other side of the phase transition. Instead he closed with some loosely tied comments about java. I chatted with him later, and he said, "Yes, I have lots of ideas, but we'll have to talk about them later." I said I'd call him on that in email one day. ----------------------------------------------------------------------------- Copyright © 1995 Alexander D. Chaffee (alex@stinky.com). All rights reserved. See more at http://www.stinky.com/almanac/