Chemist Richard Smalley (1943-2005) is best known for his work on large molecules of beautiful structure — buckminsterfullerene and carbon nanotubes and the like — for which he shared a Nobel prize. A couple of years back he attempted to engage in a "debate" with K. Eric Drexler (of nanotechnology fame) over the real-world feasibility of molecular assemblers. The transcript of the exchange is fascinating reading, particularly in the way it illustrates a profound failure to communicate between the two participants. Smally concludes his side of the conversation with a metaphor:

I see you have now walked out of the room where I had led you to talk about real chemistry, and you are now back in your mechanical world. I am sorry we have ended up like this. For a moment I thought we were making progress.

... and after some further technical discussion closes with:

But, no, you don't get it. You are still in a pretend world where atoms go where you want because your computer program directs them to go there. You assume there is a way a robotic manipulator arm can do that in a vacuum, and somehow we will work out a way to have this whole thing actually be able to make another copy of itself. I have given you reasons why such an assembler cannot be built, and will not operate, using the principles you suggest. I consider that your failure to provide a working strategy indicates that you implicitly concur—even as you explicitly deny—that the idea cannot work.

I'm rather persuaded by Smalley's arguments that the nanotech vision is simply that: a vision, a fantasy, a dream without any solid scientific foundation. That's a sad conclusion from the viewpoint of those who want magic in the world. They've spent countless hours writing countless web pages devoted to anti-Smalley rhetoric.

Many people are vulnerable to what I call the "Anthropic Fallacy". They reason: "If I can't figure out how to do it, then it can't be done!" Thus if I can't figure out how feature X evolved, then evolution must be wrong. If I can't figure out how intelligent observers could exist in a universe with different fundamental physical constants, then those constants can't be different. And so forth.

There's a converse (or inverse?) to the Anthropic Fallacy, the equally wrong "Pollyanna Principle". It goes: "If I can't figure out why it won't work, then it has to work!" The army of nanotech enthusiasts are profoundly optimistic in their logic, as they envision a lovely clean self-replicating molecular assembler merrily chunking along, just like a program in a computer.

Smalley's argument suggests that the real world, alas, isn't so tidy — and that to get to the shiny nano-assembler one must first solve a huge number of knotty chemical problems, problems that won't go away with a few waves of the hands. Maybe there's magic out there, but discovering the spells to conjure it will take a lot of hard work.

(see Chemical & Engineering News', v. 81 n. 48 (1 Dec 2003), "Point Counterpoint: NANOTECHNOLOGY — Drexler and Smalley make the case for and against 'molecular assemblers'"; cf. BindingEnergy (14 Jun 1999), SafetyInComplexity (15 Apr 2000), AntiAnthropism (26 May 2000), CosmicChaos (14 Apr 2001), FabuloTech (15 May 2001), TechnoTime (5 Nov 2001), ...)

TopicScience - 2005-12-07

(correlates: ArgumentByItalics, AppropriateUnits, AllYourBaseAreBelongToUs, ...)