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Subject:
Nanotechnology: apocalyptic development?
Quintus Arrius
11/6/2003 11:30:04 AM
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| One possible disaster facing the earth in the not too distant future is the grey goo problem, a hazard of the development of nanotechnology. Another even more likely scenario is utter war.
What is nanotechnology?
The normal progress of technology is towards making smaller and smaller versions of things by progressively reducing the size of the components.
Nanotechnology reverses that approach, and instead of making things progressively smaller, starts with the most basic building blocks possible - individual atoms and molecules. Devices are then built up using the minimum number of these fundamental building blocks. What results is the smallest possible device allowed by the laws of physics - further miniaturisation is fundamentally impossible.
The foundations for nanotechnology were laid in a speech given on December 29th, 1959 to the American Physical Society by later Nobel Laureate Professor Richard P. Feynmann, entitled "There's plenty of room at the bottom". In it, he described how, merely by "writing" using direct manipulation of atoms on the surface of a metal, it was physically possible to store the full text of every book ever written in a pamphlet you could carry in your hand. Furthermore, if one were to encode the information somehow, much more space could be saved - the full sum of recorded human knowledge could be stored in a piece of dust barely visible to the unaided eye. He offered no description of how this might be achieved, but noted that there is nothing in the laws of physics to prevent us from doing it - it's just a matter of technology.
But the possibilities extend well beyond the maximum possible density of data storage. Nanotechnology also encompasses mechanical devices and computers too small to see even with a normal microscope. The name "nanotechnology" refers to the fact that such devices would be of the order of a few nanometres across - a nanometer being one millionth of a millimetre.
Assemblers
A nanotech assembler is a device which can physically rearrange matter, atom by atom, according to some program to produce a desired result. The first faltering steps towards this aim have already been taken - a team of scientists in San Jose has managed to write the letters "IBM" (their sponsor) in individual xenon atoms on a crystal of nickel.
The aim of nanotechnology is to be able to manipulate matter atom by atom to produce whatever you want. The ultimate device - nanotech's "killer app" - would be a universal assembler. Such a device would incorporate some significant computing power, molecular manipulators, and some form of power conversion - either running on ambient heat or possible solar powered.
A simple example of the sort of thing a universal assembler could do would be to turn graphite (from the lead of a pencil) into diamond. Both are simply different arrangements of identical carbon atoms. The assembler would simply alter their arrangement, atom by atom. And since all organic matter contains lots of carbon (by definition - and that includes things like old plastic bags, used tyres, horse manure etc.) you could use that as raw material for your little diamond factory. And since you have control over the very atomic structure of the diamond, every one you turn out will be flawless and as big as you like in any shape you like. Want a greenhouse in your garden made of a single greenhouse-shaped diamond? No problem. Want a rocket engine combustion chamber lighter and stronger than anything ever built? Done.
Of course, the universal assembler won't just do carbon atoms. In principle it will be able to assemble anything, given the constituent atoms. Most of the things we throw away contain carbon, hydrogen, oxygen, nitrogen, and a couple of dozen other common substances. All this garbage could be used as raw material for universal assemblers. These devices will be able to turn toxic chemical waste into rump steaks, horse manure into life-saving drugs, and lawn cuttings into petrol - for free. They'll be able to swim the seas, gobbling up oil spills and turning them into plankton, or cruise your bloodstream in their millions converting fat deposits on your artery walls into pleasant, side-effect free euphoric drugs.
Of course, developing and building a universal assembler will be expensive. Although they will most likely be too small to see with the naked eye, they will be the most complex devices ever made. The cost will be immense - for the first one. We are familiar with the concept of "economies of scale" - building the first Ford Model T cost millions of dollars, but because millions were built, they could each be sold for a reasonable price.
But even economies of scale don't apply to molecular assemblers. The first one will be vastly expensive. The second and subsequent ones will not be cheap - they will be free. The first task for the first assembler off the production line will be to build a copy of itself, using the discarded pr |
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