The English chemist John Dalton first proposed the scientific theory of the atom two hundred years ago. Since then we have seen chemists come to understand the elements and their interactions, we have seen engineers make and use new materials to improve our lives, we have seen physicists demonstrate that even atoms are divisible, and we have seen warriors unleash the power of the atomic nucleus. In these two centuries we have amassed an enormous understanding of - and wielded an increasing control over - the fundamental units of matter.
Today, in the young field of nanotechnology, scientists and engineers are taking control of atoms and molecules individually, manipulating them and putting them to use with an extraordinary degree of precision. Word of the promise of nanotechnology is spreading rapidly, and the air is thick with news of nanotech breakthroughs. Governments and businesses are investing billions of dollars in nanotechnology R&D, and political alliances and battle lines are starting to form.
Yet there remains a great deal of confusion about just what nanotechnology is, both among the ordinary people whose lives will be changed by the new science, and among the policymakers who wittingly or unwittingly will help steer its course. Unsurprisingly, some of the confusion is actually caused by the increased attention - sensationalistic reporting and creative license have done little to prepare society for the hard decisions that the development of nanotechnology will make necessary.
Much of the confusion, however, comes from the scientists and engineers themselves, because they apply the name "nanotechnology" to two different things - that is, to two distinct but related fields of research, one with the potential to improve today's world, the other with the potential to utterly remake or even destroy it. The meaning that nanotechnology holds for our future depends on which definition of the word "nanotechnology" pans out. Thus any understanding of the implications of nanotechnology must begin by sorting out its history and its strange dual meaning.
Nanotechnology got going in the second half of the twentieth century, although a few scientists had done related work earlier. For instance, as part of an 1871 thought experiment, the Scottish physicist James Clerk Maxwell imagined extremely tiny "demons" that could redirect atoms one at a time. And MIT professor Arthur Robert von Hippel became interested in molecular design as early as the 1930s; he coined the term "molecular engineering" in the 1960s. Usually, though, the credit for inspiring nanotechnology goes to a lecture by Richard Phillips Feynman, a brilliant Caltech physicist who later won a Nobel Prize for "fundamental work in quantum electrodynamics." He is best remembered today for his clear and quirky classroom lectures and for his critical role on the presidential commission that investigated the Challenger accident. On the evening of December 29, 1959, Feynman delivered an after-dinner lecture at the annual meeting of the American Physical Society; in that talk, called "There's Plenty of Room at the Bottom," Feynman proposed work in a field "in which little has been done, but in which an enormous amount can be done in principle." "What I want to talk about," Feynman said, "is the problem of manipulating and controlling things on a small scale. As soon as I mention this, people tell me about miniaturization, and how far it has progressed today ... But that's nothing; that's the most primitive, halting step in the direction I intend to discuss."
Feynman described how the entire Encyclopaedia Britannica could be written on the head of a pin, and how all the world's books could fit in a pamphlet. Such remarkable reductions could be done as "a simple reproduction of the original pictures, engravings, and everything else on a small scale without loss of resolution." Yet it was possible to get smaller still: if you converted all the world's books into an efficient computer code instead of just reduced pictures, you could store "all the information that man has carefully accumulated in all the books in the world ... in a cube of material one two-hundredth of an inch wide - which is the barest piece of dust that can be made out by the human eye. So there is plenty of room at the bottom! Don't tell me about microfilm!" He boldly declared that "the principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom" - in fact, Feynman saw atomic manipulation as inevitable, "a development which I think cannot be avoided."
In his lecture, Feynman pointed out several avenues for research that would later come to define nanotechnology, such as making computers much smaller and therefore faster, and making "mechanical surgeons" that could travel to trouble spots inside the body. Feynman admitted that he didn't have a clear conception of how such tiny machines might be used or created, but to help get things going, he offered two prizes: $1,000 to the first person to make a working electric motor that was no bigger than one sixty-fourth of an inch on any side, and another $1,000 to the first person to shrink a page of text to 1/25,000 its size - the dimension necessary to fit the Encyclopaedia Britannica on the head of a pin. (He awarded the former prize in 1960, the latter in 1985.)
Although Feynman's lecture is, in retrospect, remembered as a major event, it didn't make much of a splash in the world of science at the time. Research in the direction he suggested didn't begin immediately, and nanotechnology was slow to take off. Feynman himself didn't use the word "nanotechnology" in his lecture; in fact, the word didn't exist until 15 years later, when Norio Taniguchi of the Tokyo University of Science suggested it to describe technology that strives for precision at the level of about one nanometer.
A nanometer is one billionth of a meter. The prefix "nano-" comes from the Greek word nanos, meaning dwarf. (Scientists originally used the prefix just to indicate "very small," as in "nanoplankton," but it now means one-billionth, just as "milli-" means one-thousandth, and "micro-" means one-millionth.) If a nanometer were somehow magnified to appear as long as the nose on your face, then a red blood cell would appear the size of the Empire State Building, a human hair would be about two or three miles wide, one of your fingers would span the continental United States, and a normal person would be about as tall as six or seven planet Earths piled atop one another.
In 1981, scientists gained a sophisticated new tool powerful enough to allow them to see single atoms with unprecedented clarity. This device, the scanning tunneling microscope, uses a tiny electric current and a very fine needle to detect the height of individual atoms. The images taken with these microscopes look like tumulose alien landscapes - and researchers learned how to rearrange those landscapes, once they discovered that the scanning tunneling microscope could also be used to pick up, move, and precisely place atoms, one at a time. The first dramatic demonstration of this power came in 1990 when a team of IBM physicists revealed that they had, the year before, spelled out the letters "IBM" using 35 individual atoms of xenon. In 1991, the same research team built an "atomic switch," an important step in the development of nanoscale computing.
Another breakthrough came with the discovery of new shapes for molecules of carbon, the quintessential element of life. In 1985, researchers reported the discovery of the "buckyball," a lovely round molecule consisting of 60 carbon atoms. This led in turn to the 1991 discovery of a related molecular shape known as the "carbon nanotube"; these nanotubes are about 100 times stronger than steel but just a sixth of the weight, and they have unusual heat and conductivity characteristics that guarantee they will be important to high technology in the coming years.
But these exciting discoveries are the exception rather than the rule: most of what passes for nanotechnology nowadays is really just materials science. Mainstream nanotechnology, as practiced by hundreds of companies, is merely the intellectual offspring of conventional chemical engineering and our new nanoscale powers. The basis of most research in mainstream nanotech is the fact that some materials have peculiar or useful properties when pulverized into nanoscale particles or otherwise rearranged.
Seen this way, mainstream nanotechnology isn't truly new; we've been unwitting nanotechnologists for centuries. One official from the National Science Foundation told Congress that photography, of all things, is a subset of nanotechnology - and a "relatively old" one at that! But if the term "nanotechnology" is to be used that loosely, why not reach much further back into history? Renaissance artists used paints and glazes that got their appealing color and iridescence from nanoparticles. The ancients, too, found uses for nanoparticles of soot. On and on it goes, back through the ages.
A great many of today's mainstream nanotechnologists are simply following in that tradition, using modern techniques to make tiny particles and then finding uses for them. Among the products that now incorporate nanoparticles are: some new paints and sunscreens, certain lines of stain- and water-repellent clothing, a few kinds of anti-reflective and anti-fogging glass, and some tennis equipment. Cosmetics companies are starting to use nanoparticles in their products, and pharmaceuticals companies are researching ways to improve drug delivery through nanotech. Within a few years, nanotechnology will most likely be available in self-cleaning windows and flat-screen TVs. Improvements in computing, energy, and medical diagnosis and treatment are likely as well.
In short, mainstream nanotechnology is an interesting field, with some impressive possibilities for improving our lives with better materials and tools. But that's just half the story: there's another side to nanotechnology, one that promises much more extreme, and perhaps dangerous, changes.
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