Answering the Doubters
Despite the plausibility of developing nanotechnology, there are skeptics. Their criticisms, however, are poorly informed. For example, chemist David Jones, a Nature columnist, was quoted in Scientific American that the construction of a molecular assembler was doomed because individual atoms are “amazingly mobile and reactive. They will combine instantly with ambient air, water, each other, the fluid supporting the assemblers, or the assemblers themselves.”
Proposals involving reactive molecular tools, however, specify that the environment should be inert-either vacuum or a noble gas; there would be no “ambient air” to react with. And because the molecular tools are positionally controlled, they will not react with each other or the assembler itself-for the same reason that a hot soldering iron does not react with the skin of the person who wields it.
I am commonly asked how long it will be before we can make molecular computers, before inexpensive photovoltaic cells bring cheap, clean solar power, before ultralightweight spacecraft dramatically lower the cost of space exploration. The scientifically correct answer is: I don’t know. But looking at one technology that nanotechnology can improve-computing-gives one perspective. From electromechanical relays to vacuum tubes to transistors to integrated circuits, we have seen steady declines in the size and cost of logic elements and steady increases in their performance for the last 50 years. Extrapolation of these trends suggests that for the computer hardware revolution to stay “on schedule” will require the development of molecular manufacturing by about 2010 or 2020.
Of course, extrapolating past trends is a philosophically debatable method of technology forecasting. While no fundamental law of nature prevents us from developing nanotechnology on this schedule (or even faster), there is equally no law that says this schedule will not slip. Much worse, though, such trends imply that there is some ordained schedule-that nanotechnology will inevitably appear regardless of what we do or don’t do. Nothing could be further from the truth. How long it takes to develop this technology depends very much on what we do. If we pursue it systematically, it will happen sooner. If we ignore it, or simply hope that someone will stumble over it, it will take much longer. Fortunately, by using theoretical, computational, and experimental approaches together, we can reach the goal more quickly and reliably than by using any single approach alone. Just as Boeing can design, “build,” and “fly” airplanes in a computer before making them in the real world, we can do the same for molecular manufacturing. We can quickly eliminate most of the false starts and blind alleys and rapidly focus on the best approaches.
Like the first human landing on the moon, the Manhattan project, or the development of the modern computer, the advent of molecular manufacturing will require the coordinated efforts of many people for many years. How long will it take? A lot depends on when we start.