ADDRESSING THE FOURTH ANNUAL FORESIGHT Conference on Molecular Nanotechnology in 1995, Adm. David Jeremiah, a former vice chairman of the Joint Chiefs of Staff, made a bold prediction. The "military applications of molecular manufacturing have even greater potential than nuclear weapons to radically change the [world] balance of power," he said.
The risk in trying to stop others from using the technology to gain a strategic advantage, Jeremiah continued, was that "the uninformed policy maker is likely to impose restrictions on [the] development of technology in such a way as to inhibit commercial development, ultimately beneficial to mankind, while permitting those operating outside the restrictive bounds to gain an irrevocable advantage."
It was an ominous, if not unfamiliar, statement to the assembled crowd, some of whom were undoubtedly excited by the potential of exploring the area of science Jeremiah was referring to, an area physicist Richard Feynman had labeled the "room at the bottom."
The "bottom" of which Feynman spoke and later wrote is the low end of the scale of matter--atoms and molecules. Twenty years later, researcher Eric Drexler coined the term "nanotechnology" for the science Feynman envisioned--building materials, structures, and machinery from the molecule up.
Absent the kind of regulation Jeremiah feared, scientists and businessmen have taken research into the construction and potential application of nanoscale materials and run with it. The consequence has been a growing diversity of products and processes integrated into both consumer and military realms.
Although the general public has begun to more broadly feel the impact of nanotechnology, researchers are just beginning to explore the potential for early nanotech developments and applications to harm human and animal health and the environment. In the age of terrorism, the potential of certain nanotechnologies and nanomaterials to be used to do both good and bad requires not just the exploration of the possibilities of this mushrooming field of science but also broad anticipation of possible threats.
The science of small
To understand the potential of all things nano it is necessary to look at the special properties that scientists have observed when investigating this tiniest of scales. And when scientists say tiny, they mean tiny.
When talking about the nanoscale, scientists are most commonly referring to science measured at lengths less than 100 nanometers (one-ten-millionth of a meter) in at least one dimension. To give a sense of scale, a single water molecule is approximately one-tenth of a nanometer at its widest. By comparison, hemoglobin--the globular protein responsible for carrying oxygen from the lungs to the body's tissues--is 5 nanometers wide; the polio virus, among the smallest viruses, is 20 nanometers wide and long; and the smallpox virus is approximately 200 nanometers by 300 nanometers; most bacteria are a thousand nanometers wide or larger.
The term nanoscience really refers to more than working with a lone atom or single small molecule. In biology, for example, nanoscience deals with the scale at which biochemical processes inside cells take place of at which nerve transmissions occur. Synaptic junctions between nerve cells in the brain are 20-40 nanometers wide and between nerve cells and muscles 3-4 nanometers wide.
To date, nanoscience most commonly refers to the manipulation of individual atoms and molecules to create larger structures. Because these masses are so small, gravity's effect is greatly diminished and the conventions of friction are altered. Known to biophysicists as "life at low Reynolds number," the nanoscale is the realm where viscous forces dominate: Moving through water is like swimming through molasses. What are normally perceived to be weak forces between molecules dominate on the nanoscale. This is what allows geckos, which have millions of 2-nanometer-wide hairs lining their leer, to adhere to glassy, smooth surfaces. This same property would also theoretically limit the movement of nanoscale robots--they could easily stick to each other or to the first surface they run into.
On the nanoscale, the wave properties of electrons dominate over the usual particle-like properties; quantum properties are observable. One consequence of this is that particles of the same material appear to have different colors according to their size and shape.
Many current applications of nanoscience have exploited these nanoscale characteristics and incorporated them into traditional technologies and consumer items, giving them value-added features--creating fabrics that repel stains, super-strong armor and …
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