THE VETERAN NEOPHYTE

TINY FUTURES

DAVE JOHNSON

I recently attended the First General Conference on Nanotechnology. The conference was sponsored primarily by the Foresight Institute, an organization based in Palo Alto, California, whose sole self-stated goal is to disseminate information about nanotechnology, to inform the public about the topic, and to just sort of do whatever seems necessary to get society ready, to prepare the ground, for the advent of this world-transforming future technology. (Apple also helped sponsor the conference, a fact I didn't even know until I arrived.) There had been previous "research" gatherings dealing with nanotechnology, but those were primarily for scientists and other gearhead types (most of whom, it should be noted, showed up for this one, too). This, though, was the first such gathering intended for the general public, and the first intended to foster open discussion on the topic by all kinds of people.

It was absolutely fascinating, on lots of levels, and a total blast! It was intellectually and scientifically stimulating, of course, and that's a lot of fun by itself, in a quiet sort of way. But it was also an unparalleled opportunity towatch some really weird people,and that's fun in a much larger, noisier sort of way. Watching wild ideas being bandied about by wild, zealous people is fine sport, and this was the perfect place for it. The enthusiasm among the participants was sizzling, and the whole thing smelled sort of cultish, almost religious in its zeal and drive. As I said, a blast!

I don't want to imply that it was a circus, that the participants were doddering, babbling boobs or mindless, frenzied fanatics. Nothing could be further from the truth. On the contrary, there wereall kinds of people there -- writers, computer folks, venture capitalists, cryonicists, physicists, doctors, marketers, biologists, businesspeople, you name it -- and the ideas being discussed were often taken very seriously. But therewas a healthy contingent of fringe-dwellers and edge-runners, people whose beliefs often set them slightly apart from your average, ordinary citizen (whatever that is). People who like to peek over the edge -- any edge -- to see what's there. Nanotechnology is a precipitous edge indeed.

Nanotechnology has been getting a lot of press lately, but for those of you who haven't heard or read about it yet, let me run you through the basics. Nanotechnology is the brainchild of one Dr. K. Eric Drexler, MIT graduate and technological visionary extraordinaire. (Some of the ideas and concepts of nanotechnology weren't new, but Drexler brought them together, gave them a name, and carried them much further than anyone else had dared.) Simply put, nanotechnology is the ability to precisely and completely control the structure of matter at the molecular or atomic level, by building the desired substance or structure molecule by molecule or atom by atom, placing each in the precise location we want. This capability has implications and ramifications without end, as we'll soon see. But the central spark of the idea -- placing atoms one by one -- remains simple and elegant, and we should be careful to remember that fact as we wander, often lost in the churning chaos, through the landscapes of possibilities that this oh-so-simple idea can generate. (It's equally important, by the way, to remember that nanotechnology is still a fairy tale, though possibly a prophetic one. All the books, meetings, articles, discussions, and press coverage are about something that can't be done, at least not yet. So although the general buzz around the conference tended to use the present tense -- an indication of the rampant confidence most of these people possess -- it's all still a dream, though as compelling and disturbing a dream as any I've ever known, and one that's being dreamt by some very, very capable minds.)

The termnanotechnologyhas been popularized lately, for better or for worse, and has been applied to a number of very different technologies that are decidedlynotwhat Drexler has in mind. Their only similarity with Drexler's nanotechnology is that they involve very small scales. You've probably all seen those electron microscope pictures of little bitty gears and shafts and motors and flaps that have been carved from silicon. There's a large effort under way to build these micromachines, and it's a fascinating technology, but it's not what we're talking about. Those efforts, like many others that are popularly called nanotechnology, are characterized by starting with some block of material -- a bazillion atoms in a chunk -- and carving out bits or adding bits like a sculptor to get the shape you want. The resulting parts are still made of a bazillion atoms; you're still dealing withclumps of atoms at a time. Drexler calls thisbulk technology. Admittedly, the clumps are getting very, very small these days, but it's really just a refinement of the same manufacturing technology we've had since the stone age: take a hunk of material and shape it.

Drexler's nanotechnology -- he promoted the termmolecular manufacturingat the conference, and it's a more descriptive, if less poetic, name -- comes around from the other side. It starts with individual atoms and molecules and puts them together, essentially one piece at a time, to build up the desired material or structure. This is the key distinction between bulk technology and what we're calling nanotechnology.

Drexler also postulates a nanomachine he calls anassembler. It's a general-purpose atom positioning machine, sort of a nano-scale robot, complete with sensors to detect the atom or molecule, some sort of "gripper" to hold and position it, and a powerful computer to control the thing. This is the little bugger that really cuts nanotechnology loose. If you have assemblers, you have the proverbial general manufacturing machine: you can build anything, including more general manufacturing machines. (Actually, these days people talk more about "mills" than individual robot-like assemblers. Mills are like production lines, with conveyor belts rather than arms, and a continuous flow of material. Although in this column I'll use the wordassembler what I really mean is this: a machine that can arrange atoms and molecules in a general way, and therefore can be used to build anything we can think of.)

OK, so now that we have a handle on what we're talking about, let's play that game we all love so much, Predicting the Future. If wecouldbe atomic bricklayers, if wecouldcommand the structure of matter, just what sorts of strange things would we build? Here's where we can really have some fun. The ramifications of being able to build things atom by atom are of course myriad. Nanotechnology is one of those ideas that, when planted firmly in human minds, seems to serve as a catalyst, breeding innumerable possible future scenarios. It's a technology (a nonexistent one, remember!) that could conceivably touch and transform every important aspect of our lives.

Many scenarios are immediately apparent. For one thing, molecular manufacturing promises materials that are lighter, stronger, cheaper, and just generally better in every way. As any materials scientist will be happy to tell you, materials in the real world are generally riddled with defects. Carving away at them or adding other bulky bits to them as we do today doesn't change that fact, and actually often exacerbates it. But if we could build up our materials atom by atom, each precisely placed, the resultant material would be atomically precise, atomicallyperfect! This would mean that we could build much, much lighter weight structures, using lots less material to do the same job. That in itself has enormous benefits, but it's just the beginning: beyond improving existing materials, we could build anynewmaterial we can think of, as long as it's allowed by the laws of nature.

And the manufacturing processes themselves could be made amazingly efficient, using cheap and plentiful raw materials, producing virtually no waste, and consuming very little energy, if any at all. At the conference there was much talk, only partly tongue in cheek, of a tabletop nanofabricator,about the size of a microwave oven, with four rubber feet and a fan in the back, plugged into the wall. According to Drexler's calculations we could feed this thing 1.6 kilograms per hour of feed stock solution (acetone, I think he said: a cheap and plentiful source of carbon and hydrogen) and 0.8 kg/hr of atmospheric oxygen, and out the other end would come 1.0 kg/hr of diamond (or whatever carbon material you have in mind), 1.5 kg/hr of chemically pure water, 1.1 kW of waste heat, and, as a by- product of the process, 3.6 kW of surplus electricity. (Why plug it in? So that you can deliver the electricity to the power grid.)

With manufacturing processes like that, economics is suddenly turned on its ear. Some say there would be no more poverty, that since with assemblers we'd be able to make nearly anything for nearly nothing, precious materials would no longer be precious; we could make treasure from garbage! Some say we could make food, or better yet, create new materials and technologies that let us make full use of the food we already produce, bringing an end to world hunger.

Going even further out on an already shaky limb, let's examine some medical implementations. If we could build assemblers, we could build other nano-scale robots to do our bidding. Tiny observation machines could be injected into our bloodstream to seek out and report any damage, effectively giving doctors eyes into your body at the cellular level. How about nanogoop that you pour on a wound that disinfects it, seals it, and accelerates the regeneration of lost tissue? The cryonicists -- people who have themselves frozen for some hopeful future awakening -- have pinned most of their hopes for resuscitation on some sort of cell-repair machines that can go in and repair the tissue damage due to freezing. One speaker at the conference, an MD researching organ cryopreservation, planted his tongue firmly in his cheek and went truly wild with his speculations. Get this: subcutaneous "smart" armor that could see a blow or a bullet coming andreact, bracing itself or maybe even pulling your skin away from the danger! He went on to talk about the "tradeoffs involved in becoming a flying person," a topic "no one has talked about before." (The conclusion was effectively that wings are very inconvenient and would really get in the way when you weren't flying, but they're probably worth the trouble.)

Then there are, of course, the "dark" scenarios. If it's possible to build assemblers, it will probably also be possible to builddisassemblers: imagine scavenger nanostuff whose programming has gone out of control, so that it disassembles anything it comes into contact with and just builds more copies of itself (I can see you artificial life fans pricking up your ears). This is known as the "gray goo" scenario. (Speculations about this sort of out-of-control goo cause equally energetic counter- speculations: encrypting the program so that a one-bit error turns it to hash; anti-goo goo -- so-called "blue goo" -- that recognizes and destroys the gray stuff; using a "broadcast architecture" so that the machines have no autonomy at all, and thus can't get out of control in the first place; and so on.)

Machines building copies of themselves opens up a Pandora's box of implications and problems: if these machines are the least bit autonomous and there's the possibility of mutation -- of nonfatal errors when building new copies -- they'll naturally begin to evolve! Drexler makes the good point that at the atomic level things are either exactly right or exactly wrong, that nanomachines are wrought in a fundamentallydigitalmedium and are therefore brittle, so errors will tend to be catastrophic and bring things to a screeching halt. But it seems to me that the nanomachines we're talking about -- machines that can sense their environment, harvest raw materials, and build copies of themselves, including their own instructions -- are so complex that a digital error, a bit error, maynot bring everything to a halt, and may indeed change the operation of the machine in subtle, mysterious ways. Anyone who has ever programmed a computer can testify to that.

You can also bet that if one group of people has this technology and another doesn't, and those groups don't like each other, the results could be many kinds of ugly. Nanoweaponry could be more insidious and invisible than any biological weapon, more tenacious than radiation, and ultimately more destructive than any bomb.

Good or bad, many of these scenarios seem pretty far out there. Which brings up a very good question: will it really ever happen? Will we ever be able to build a general manufacturing machine? Can we ever gain that degree of control over matter? Naturally, Drexler thinks so, and so do many others. It's instructive to take a look at some of the practicalities involved. First there's the problem of scale. Obviously, there are an awful lot of atoms in a piece of material that's, say, the size of your fist. Won't it take a long, long time to build up something that size atom by atom? Well, we can do the arithmetic to find out: Let's assume that we could put individual atoms together at a rate of 100 atoms per second. And let's say we want to build 12 grams of diamond. (Diamond is a very popular material in these nano-examples, not because of its worth and beauty but because of its amazing hardness and stability and the fact that it's made of carbon, a very common element.) If you've ever taken a chemistry course you know that 12 grams of carbon contains 6.02 x 1023 atoms (Avogadro's number, remember?). A hundred atoms per second is 864,000 per day, assuming no time off for the little buggers. This is about 3.15 x 109 atoms per year. So we could get our 12 grams of carbon in only, let's see, 6.02 x 1023 atoms divided by 3.15 x 109 atoms per year is roughly 2 x 1014 years. That's two hundred million million years! About fifty thousand times the estimated age of the earth! To build less than half an ounce of carbon. Hmm. Clearly we're going to have to do something drastic, numbers-wise, for this to be at all useful. Because of the extreme scales involved, the numbers quickly fly wildly out of control.

Well, the only way I've heard discussed to bring those numbers under our control is to fight back with large numbers of our own, in this case large numbers of nanomachines (or conveyor belts, or whatever) working simultaneously. And the only way to get that many machines is to build nanomachines that can reproduce, that can build copies of themselves. It's like the old story about the blacksmith shoeing a horse, who charged a penny for the first nail, two pennies for the second, four for the third, and so on: he became rich on one horse. Back to our example, we'd need about 1.0 x 1017 machines working simultaneously, each placing 100 atoms a second, to get our 12 grams in under 24 hours. How long will it take to make that many machines? Well, if each machine can build a copy of itself in one hour (a conservative estimate: an average bacterium does it faster), and we start with one machine, I come up with something like 56 hours. Very doable. And, of course, if we let it go for one more hour, we have twice what we need! When you've got geometric progression on your side, you've got afriend!

OK, so maybe we can handle the scale problem, as long as we're willing to let machines self- reproduce. What about the problem of actually reaching in there and grabbing atoms or molecules? Is it really possible to build molecular "hands"? Well, there are several technologies, each making rapid progress, that are converging on this capability. Scanning Probe Microscopyis a technology that shows great promise in positioning individual atoms (by now you've probably all seen that picture of "IBM" spelled out in individual atoms on a plate). Molecular biotechnology is another promising avenue: molecular biologists are gaining an amazing degree of control of the molecules of life, a degree of control that looks as though it will continue to increase quickly. (In a sense, using bacteria to manufacture insulin, as is done today,is molecular manufacturing; it's just that most of the nanomachinery was borrowed from living things, rather than designed from scratch.) The point is that there are many paths that may lead us to atomic control of matter, not just one.

But there are also some compelling arguments against the "full" vision, the future in which everyone has assemblers and we can make anything we want. First off, an assembler is a very, very complex machine, much more complex than anything humans have ever built, and I'm honestly not convinced that human beings are capable ofever deliberately building something like that. (Accidentally, maybe, but that's another story.)You try to design a machine, constructed entirely from sticky marbles, that can build a copy of itself from ambient sticky marbles floating nearby. Oh yeah, and it has to also be fully programmable, so that it can be instructed to build anythingelse (also from ambient sticky marbles). To my knowledge, no human has ever succeeded, atanyscale, in building a purely mechanical machine that can build a copy of itself. But that's exactly what an assembler needs to be.

Even if we can get the mechanics together, there's still The Software Problem; complex software is always buggy, and the more complex it is, the further from "correct" it will be and the more unpredictable will be the results of such errors. Anyone who says otherwise doesn't know what they're talking about. The software to control a machine that can sense its environment, locate the appropriate parts, grab them, turn them the right way, and stick them to other parts is going to be more complex than anyone today knows how to write.

Then there's this sad fact: no technology is ever equally available to all people at its introduction, or for that matter for as long as there's some advantage, economic or otherwise, to maintaining controlover it. And the advantages to maintaining control of this one are obviously huge. What if you're the first one on the block with that tabletop machine (four rubber feet, remember) cranking out intricately structured diamond struts and electricity? Are you going to stop building your struts and start building copies of your machine for everyone else, or would you be tempted to sell those excellent struts (that no one else can make yet) for just a little while first, and build up a nest egg? OK, I'll giveyouthe benefit of the doubt, but what about that snake oil salesman over there? What do you think he would do? How about your government? If they had it first would they give a copy to you? To another country? These are hard questions, very hard indeed.

There is, of course, one piece of irrefutable proof that nanotechnology can ultimately work: life itself. In a very real way, weare nanotechnology. What are we but a mass of autonomously running nanomachines frantically making copies of themselves and each other? What are we but "out of control" nanostuff that has attained a very high level of organization? Some theorists believe that the odds of the emergence of life are better than previously thought, perhaps even that it's inevitable. They believe that matter has an inherent tendency to organize itself, and that we are the result of that tendency. (I get this creepy image of matter sort of turning around to look at itself.) If we gain total control over matter, perhaps we will also, as part of the bargain, gain total control over life. Now that would be something to write home about!

RECOMMENDED READING

• Engines of Creation by K. Eric Drexler (Doubleday, 1986). The first book detailing Drexler's ideas.
• Unbounding the Future by K. Eric Drexler and Chris Peterson, with Gayle Pergamit (Morrow, 1991). A popular account of the implications of nanotechnology.
• Nanosystems by K. Eric Drexler (Wiley Interscience, 1992). A nanoengineering textbook with detailed designs and calculations. The ultimate in theoretical engineering.
• Blood Music by Greg Bear (Arbor House, 1985).
• Whole Earth Review No. 67, Summer 1990.
• Nick and the Glimmung by Philip K. Dick (Piper Books, London, 1988).

DAVE JOHNSON and his brother Doug decided to dig to China one fine morning long ago, but it turned out to be harder than they thought. The digging slowed and finally stopped around lunch time, both of them exhausted and hungry after digging perhaps 14 inches. They decided to finish the next day. That night, falling asleep, Dave decided to dive through head first, so he'd be right side up when he got to the other side. Dave still hasn't been to China. *

Thanks to Jeff Barbose, Michael Greenspon, Bill Guschwan, Bo3b Johnson, Lisa Jongewaard, Ted Kaehler, and Ned van Alstyne (aka Ned Kelly) for reviewing this column. *

Dave welcomes feedback on his musings. He can be reached at JOHNSON.DK on AppleLink, dkj@apple.com on the Internet, or 75300,715 on CompuServe.*