A.
BRIEF INTRODUCTION:-
The twentieth century, now approaching its end, has been one of rapid
technological innovation and consequent social and legal change. From railroads
to space travel, from
computers to nuclear power
and genetic engineering, new
technologies have emerged in succession, each promising to upset settled
expectations and change societys established patterns of human interaction. By
consequence, in the past few decades many have come to believe that it is
necessary to begin thinking about the impact of new technologies before they
arrive. Such forward thinking has been applied to fields as diverse as space
travel, artificial intelligence, and genetic engineering, with constructive
results for the legal debate.
Nanoechnology, the molecular manufacturing, at present still little more than a
blip on the horizon, promises (or threatens) to create changes far more drastic
than any of those listed above. It involves manipulating matter on an
atom-by-atom or molecule-by-molecule basis to attain desired configurations.
This description, though simple, is wholly accurate. Its simplicity, however,
conceals a great deal of complexity in both the application and
implications.Nature shows that molecules can serve as machines because
living things work by means of such machinery. Enzymes are molecular machines
that make, break, and rearrange the bonds holding other molecules together.
Muscles are driven by molecular machines that haul fibers past one another. DNA
serves as a data-storage system, transmitting digital instructions to molecular
machines, the ribosomes, that manufacture protein molecules. And these protein
molecules, in turn, make up most of the molecular machinery just described.
Putting these natural molecular machines to work is nothing new, of course, as
every living thing does so constantly. Nor is deliberate human programming of
those machines particularly new, as it is what genetic engineering (or even
selective breeding) is all about. What makes nanotechnology different is that
it attempts to go farther than natural mechanisms would allow. Using special
bacterium-sized assembler devices, nanotechnology would permit on a
programmable basis exact control of molecular structures that are not readily
manipulable by organic means (e.g., diamonds, or heavy metals).
With nanotechnology, atoms will be specifically placed and connected, all at
very rapid rates, in a fashion similar to processes found in living organisms.
Trees, mammals, and far less complex organisms make use of molecular machinery
to manufacture and undertake repairs at a cellular and subcellular level. The
key to the application of nanotechnology will be the development of processes
that control placement of individual atoms to form products of great complexity
at extremely small scale.
B.
WHAT NANOTECHNOLOGY CAN DO:-
Full-fledged nanotechnology
promises nothing less than complete control over the physical structure of
matterthe same kind of control over the molecular and structural makeup of
physical objects that a word processor provides over the form and content of a
document. The implications of such capabilities are significant: to dramatize
only slightly, they are comparable to producing an ocean liner from the
mechanical equivalent of a single fertilized egg.
Using nanotechnology, production would be carried out by large numbers of tiny
devices, operating in parallel, in a fashion similar to the molecular machinery
already found in living organisms.
These nanodevices, however, would not suffer from the constraints facing
living organismsi.e., they would not have to be made of protein, or other
substances readily extractable from the natural environment, nor would they
have to be capable of reproducing themselves. Instead, they could be
constructed of whatever material, and in whatever fashion, is most suited to
their task. Known as assemblers, these tiny devices would be capable of
manipulating individual molecules very rapidly and precisely.
The process of using such assemblers to manufacture products may be hard
for many readers to visualize; the following passage explains how this could
work.
Today, some medicines are made through biotechnological processes, for example
those using recombinant DNA. Under these processes the DNA of living creatures
(usually bacteria) is altered. The creatures are reprogrammed to produce
whatever substance is desired by assembling component atoms into the correct
configurations: hydrogen here, carbon there, and so on. Although this approach
represents a revolution in pharmaceutical technology, it has distinct
limitations. Because biotechnology is based on altering the program of living
organisms, only substances that can be handled by living organisms can be
manufactured and only mechanisms possessed by living organisms can be used. It
is as if clothing were manufactured by training spiders and silkworms to weave
their product in particular patterns. By contrast, modern textile technology
represents a far more powerful, more versatile, and easier approach to
manufacturing clothing.
Nanotechnology represents a similar approach to the manufacture of other goods,
including pharmaceuticals. Imagine the power and complexity of todays
computer-driven textile looms put into machines orders of magnitude smaller
than the period at the end of this sentence. Instead of weaving cloth, such
machines would seize individual atoms using selectively sticky manipulator
arms, then plug those atoms together (somewhat like assembling Lego blocks)
until chemical bonding took place. By
repeating these steps according to a programmed set of instructions, a
nanotechnological approach would be able to produce substances that
conventional biotechnology could not (say, because they are toxic to living
organisms, or use elements that living organisms cannot handle efficiently) and
would be able to do so with greater speed and lower expense.
Such advantages would increase in proportion to the complexity of the
desired molecules.
With relatively mature technology, we might expect to see general-purpose
chemical synthesizers using nanotechnology. The desired molecule would be
modelled on a computer screen, the assemblers would be provided with the proper
feedstock solutions, and the product would be available in minutes. This
application of nanotechnology would be relatively simple. More complex
applications might use groups of assemblers programmed to produce molecules and
then hook them together into larger structurese.g., rocket engines or computer
chips.
Besides allowing such efficient
and powerful manufacturing capabilities, more sophisticated applications of
nanotechnology could be used for far more subtle applications.
For example, specially designed nanodevices, the size of bacteria, might
be programmed to destroy arterial plaque, or cancer cells, or to repair
cellular damage caused by aging. After performing their tasks, the devices may
be induced to self-destruct, or remain in a surveillance mode, or, in some
cases, integrate themselves into the bodys cells. Such devices would have
dramatic implications for the practice of medicine, and for society as a whole.
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