Nanotechnology and gene engineering:
A new science has been born which may solve this problem, as well as many other problems previously regarded as unsolvable. That science is called molecular nanotechnology, defined as 'thorough, inexpensive control of the structure of matter based on molecule-by-molecule control of products and by products; the products and processes of molecular manufacturing.' (Drexler, 1991, p. 19) Nano means one-billionth, as in one-billionth of a second (nanosecond) or one-billionth of a meter (nanometer). In the world of molecular manufacturing, we will think in terms of nanomachines and nanomotors, and in the world of its products we will speak of nanocomputers and nanomedicine. The challenge of research in nanotechnology will not be how to make things smaller, the top-down method, but how to make molecules and collections of molecules larger, a bottom-up approach.
Human beings have always tried to control the environment (i.e., matter) around them, but until recently have only been able to do so in a crude and visible fashion. It is a bit staggering to think of being able to control and manipulate matter at the molecular level, but in fact scientists have doing just that for a number of years. Chemists have been able to build larger molecules, and biotechnologists have been able to manipulate genes and proteins (hence genetic engineering and protein engineering). Molecular modeling through the use of computers is already firmly established, and more recently the techniques of virtual reality have enabled researchers to don gloves and goggles and actually walk around the image of a molecule and to maneuver two molecules together (molecular docking). (Rheingold, p. 14-15)
Nanomachines that are used for molecular manufacturing can already be found in nature, most prominently RNA and DNA, as well as enzymes which contribute to cell repair and reproduction and to the fabrication of proteins. And we already have man-made molecular machines such as artificial antibiotics which are 'programmed' to seek out specific disease organisms and destroy them. The next step will be accomplished when scientists can manipulate the same molecules in different ways by changing inputs or stored instructions. Custom-built molecules which can process information and fabricate or manipulate other molecules can be used to assemble other molecular machines and could replicate themselves, just as in nature. Primitive nanoassemblers could build better assemblers, which could build even better assemblers, which could build a wide variety of products and accomplish a wide variety of tasks, which could alter the way that we live! The idea of molecular entities both reproducing themselves and also behaving as building blocks not only has models in nature but also in computer science. Many of us by now have had some experience with computer viruses which are usually premised on some form of self-replication. Researchers already write computer programs that have only the purpose of writing other, more advanced computer programs. Using tools to build better tools is an ancient tradition.
Nanocomputers might not be products of silicon and solder molecules: naturally occurring molecules can be induced to change state back and forth, acting as a switch, through pulsing laser light or minor electrical charges. Trillions of such molecules, whether natural or synthetic, could form a nanocomputer that would produce unimaginably vast storage and processing capabilities.
Possible use of nano technology:
The environment: Drexler suggests that molecular manufacturing will leave no waste and therefore no pollution. Molecules can be devised which will clean up the toxic wastes and other ground and water pollution produced in the 20th century. Other molecules will be able to consume the excess carbon dioxide in the atmosphere and solve the problem of the greenhouse effect and holes in the ozone layer. Products made through nanotechnological means could be disassembled and therefore recycled. Molecular manufacturing will need to consume little to no natural resources and will use very little energy. Forest land and plains which have been cleared for lumber or for farming and grazing could be quickly restored.
Medicine: Nanorobots could be injected into the bloodstream and consume fatty cells or plaque in the walls of the blood vessels. They could also repair cell damage caused by cancer or AIDS. They could rebuild severed limbs and organs. Nanomedicine could reverse the effects of aging; we would not be able to live forever, but we could live a very long time (though, as Drexler points out, after several decades of bad TV we may long for the peace of the grave). Nanomouthwashes could eliminate gum disease and tooth decay. Nanomachines could act as security guards and attack any foreign entity in the body. And all could be programmed to leave the body through normal elimination when their work is complete.
Manufacturing: Almost any product we now use and many that we have never thought of could be made through molecular manufacturing. Materials would be stronger, more durable, very inexpensive, and could even be 'smart' enough to self-repair tears or fraying. Factories with smokestacks would be a thing of the past. Housing, food, clothing, appliances, all would be cheap, abundant, and flawless.
Transportation: Lightweight and fast spacecraft could be made inexpensively, and space travel could be available to anyone. Molecular tunneling machines could rapidly and at low cost create thousands of miles of tunnels underground, paving the way for a national or international subway system with trains which could operate at aircraft or spacecraft speed. Automobiles, for those who still wanted one, would be very cheap, very light, and very safe. They would burn clean, inexpensive fuels very efficiently at high mileage. They could be loaded with all the luxury options anyone could ever want and still be easily affordable.
Computers and information technology: A desktop computer composed of trillions of nanocomputers would possess more power and speed than all of the world's computers of today put together. Nanocomputers could make possible three-dimensional images so realistic that they could be photographed. The virtual reality technologies of today and the near future would seem primitive compared to those made possible by nanocomputing. Research being done now into ubiquitous computing could lead, through nanocomputers, to a scenario much like we see in the TV series Star Trek and Star Trek: The Next Generation in which one needs only to speak and the computer will respond to requests for information, for changes in temperature and lighting, for food, and so on. Advanced computing problems posed by artificial intelligence and hypertext systems would be easily solvable and in turn would contribute greatly to the easy use of nanocomputers. Cables resembling string could be run anywhere and would enable one to hook into a worldwide data network. Small devices the size of a pocket calculator could readily contain the information and knowledge of every volume in the Library of Congress.
