When I read Neal Stephenson's novel The Diamond Age for the first time, I thought that his ideas of future technology, specifically nanotechnology, were extreme and fantastic. Now I know better. If you've read the novel, bear with me - I haven't lost sight of the delicate barrier between reality and fantasy quite yet. If you haven't, I highly recommend it. I cannot speak for the social implications; however, the technology appears an accurate map of a possible future. And it changes everything.

"At the atomic level, we have new kinds of forces and new kinds of possibilities, new kinds of effects. The problems of manufacture and reproduction of materials will be quite different. I am, as I said, inspired by the biological phenomena in which chemical forces are used in repetitious fashion to produce all kinds of weird effects (one of which is the author)."
- Richard Feynman "There's Plenty of Room at the Bottom"

The essentials of nanotechnology were first proposed by legendary physicist Richard Feynman in his 1959 lecture There's Plenty of Room at the Bottom. He begins his talk discussing the possibilities of miniaturization, and ends with a mind-boggling (especially in 1959!) exploration of arranging substances atom by atom.

K. Erik Drexler, in his ground-breaking treatise Engines of Creation: The Coming Era of Nanotechnology, outlines the possibilities of this infant science.

His biggest error was the conservative nature of his predictions. In 1986, the basic accomplishments of nanotechnology seemed at least several decades away. Just two years after publication, the first of his predictions came to pass with the manufacture of an artificial protien. Thirteen years later, we have seen the advent of hypertext and the world wide web, advancements which he felt would be necessary to fully discuss the ramifications of speeding technology. Most recently, we have witnessed the arrangement of individual xenon atoms with the use of a scanning-tunnelling microscope.

But I'm getting ahead of the story.

What exactly is nanotechnology? The term has come into common usage for many different purposes, some of them more appropriate than others. For our purpose, we will abandon the definition by measurement of any technology smaller than about 1,000 nanometers. For us, let "nanotechnology" be the technology of creating man-made arrangements of atoms, also known as molecular manufacturing.

A nanomachine might consist of as much as a billion atoms. It would have a kind of robot-arm for grabbing and assembling molecules. The arm would move very rapidly - the smaller an appendage the faster it can move. The nano-arm would be about 50 million times smaller than a human arm, and therefore could move 50 million times faster. Also included in the tiny machine would be devices to allow mobility, digestion of fuel, and programming. The machine could detect and grab the appropriate type of atom and use it as a building block, attaching it at the correct juncture of whatever structure was being created.

One of the foremost advantages of nanotech is that it can be done cheaply (whether supply-side economics will allow it to stay cheap is a matter for another essay). After the initial investment of design and programming, nanomachines literally build themselves. These basic nano-workhorses are called assemblers. Imagine a single assembler much like the one described above, of about a billion atoms in size, placed in a closed system filled with fuel and building material. Drexler describes the exponential growth, assuming an assembler could build a copy of itself in a little over 1000 seconds. The new assembler would immediately begin building, and there would be two more in another 1000 seconds. In ten hours, there are 68 billion assemblers. Given unlimited fuel and building material, assemblers would outweigh the Earth in about two days.

The apocalyptic nature of exponential growth has some pundits worried. Called the "grey goo" effect, it is nonetheless an unlikely scenario. The Nanotechnology Site makes the analogy that assemblers are to natural, replicating systems (such as bacteria) what a car is to a horse. A horse's biology makes a tremendous investment in the ability to use a variety of fuels so the horse can survive in nature. Because of this, the horse has a digestive system that takes up much of the volume of the horse's body, and while it can process a variety of substances, it processes none of them with any great efficiency. A horse is a flexible system able to survive a wide variety of environments. A car, on the other hand, could be considered quite delicate and inflexible compared to a horse. It can tolerate only one type of fuel, and that fuel must be processed and administered by human hands. A car is not self-repairing and therefore is vulnerab le to breakdown. Unless a car is specifically built to do so, it does not "survive" well off a paved road. Obviously, even if cars could self-replicate, they would be extremely dependent upon human intervention. Cars are unlikely to run off into the wild and breed uncontrollably.

It would be impractical in the extreme to create assemblers that could use a variety of fuels and survive in nature. Not only impractical, but dangerous and unnecessary. Current theory calls for nanomachines existing in closed systems, built as inflexibly as any other man-made machine.

Finally, assemblers that can only make copies of themselves would be of little use. Imagine again that vat of assemblers with fuel and building material. They have come to the end of their pre-programmed self replication, and arrange themselves in the shape of scaffolding to build whatever article is intended. They then receive new instructions, and begin grabbing different types of atoms from the surrounding fluid.

Because assemblers build atom by atom, there is no need to ask an assembler to build materials we currently manipulate with comparitavely clumsy, bulk-scale tools. Anything the laws of nature will allow can be assembled. Where exceptional hardness is needed, diamond can be built. The strongest cable could be built from carbene. Errors would be rare and the material constructed would be virtually flawless. Limitations of current materials could be easily and cheaply surpassed. For example, the expensive tiling on the outer surface of a space shuttle could be replaced with the best possible alternative that could be designed, rather than settling for the most feasible and useable material available with bulk technology.

So what do we do with assemblers? Stay tuned for Nanotechnology Part II: The Possiblities...

Catherine Connor [site]

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