The Four Hundred

For centuries, wizards, magicians, and kitchen chemists have searched for ways of transforming materials of limited value into gold. With the exception of Coca Cola, little progress has been made toward realizing that dream. Still, the possibility remains fixed in the human psyche; the intriguing and eternal "what if." Of course, we think it's impossible. But, then again, for centuries flight was regarded in generally the same fashion. Yet here we are, cued in long security lines, presenting our shoes for inspection, our sense of wonder replaced by impatience.

With the help of science, we are discovering that yesterdays' alchemists were simply visionaries without proper tools. They had the right idea; nearly worthless objects can be changed into things of great value if, that is, you can manipulate their molecular structure. Until recently, that hasn't been possible, but the exploding science of nanotechnology promises that one day in the not so distant future, someone will rearrange the atoms of a lump of coal to produce a diamond.

That same technology, we are assured, will revolutionize computing; a statement most of us accept as being self-evident. And indeed, rudimentary quantum computers, based on the spin of subatomic particles called qubits, have already been constructed. But what seems so manifest and inevitable today could hardly have been obvious in 1959.

That was when a modern alchemist first envisioned a world of micro-miniaturization, and described its golden benefits.

The wizard who foresaw the creation of molecular devices and predicted the coming revolution in computing was physicist Richard Feynman. As wizards go, Feynman had some impressive credentials, most notably his work at Princeton and Los Alamos on the Manhattan Project, and a shared Nobel Prize, awarded in 1965.

But 44 years ago (which would be about 30 years before nanotechnology even became a defined discipline), Feynman gave a presentation at Cal-Tech at the annual meeting of the American Physical Society. His speech, as he hoped it would, motivated a generation of nanotechnology researchers, many of whom found in Feynman's words the inspiration for a lifelong career.

The title of Feynman's talk, "There's Plenty of Room at the Bottom," must have appealed to an audience of budding scientists eager to fashion reputations as well as contributions. In 1959, nobody was investigating what Feynman called "the staggeringly small world that is below," so there were lots of opportunities to make ground-breaking contributions and to earn the envy and respect of your colleagues.

Feynman told his audience he wanted to talk about "the problem of manipulating and controlling things on a small scale." In the past when he had broached the subject with friends, people would extol the wonders of miniaturization; tiny electrical motors the size of a fingernail, and even a device that could write the Lord's Prayer on the head of a pin. But the wizard in him thought, why stop there? "Why cannot we write the entire 24 volumes of the Encyclopedia Britannica on the head of a pin?"

And because nothing is impossible to a wizard, he began ruminating about how it could be done. He reasoned that the head of a pin is a sixteenth of an inch across and calculated that it would have to be magnified by 25,000 diameters to be equal to the area of all the pages of the encyclopedia. "Therefore," he determined, "all it is necessary to do is to reduce in size all the writing in the encyclopedia by 25,000 times."

Sounds almost mundane by the standards of today's technology, but remember this was 1959. To put things in perspective: Alaska had only been a state for a year; the first satellite was launched by the Russians only two years before; Eisenhower was the president, computers filled entire rooms, and my wife was one year old. There were no cell phones, no DVDs, no fax machines, no moon landings, no space stations, no Internet providers, and the word digital referred to fingers, not revolutions. Feynman was talking about something that was conceivable within the parameters of physics but had never been done before. And only a handful of people on the planet even had an inkling of how such a thing might be possible.

If Feynman hadn't hooked his audience yet, he probably did when he began to describe how such miniaturization might work. The human eye, he reasoned, could resolve an image of about 1/120 of an inch. "That is roughly the diameter of one of the little dots on the fine half-tone reproductions in the encyclopedia." If demagnified 25,000 times, it would, Feynman said, still be 80 angstroms in diameter, or 32 atoms across. Another way of looking at it was that the area that comprised each dot would then contain about 1,000 atoms. "So," he concluded, "each dot can be easily adjusted in size as required by the photoengraving, and there is no question that there is enough room on the head of a pin to put all of the Encyclopedia Britannica."

As an aside, fifteen years ago IBM experimented with polymers hoping to develop a new type of storage in which huge amounts of information could be stored as holograms. The company anticipated that several billion bits of data--more than the entire bulk of the Encyclopedia Britannica, researchers boasted--could be shrunk onto a dollop of polymer film the width and thickness of a dime. Although larger than the head of a pin, Feynman would have been delighted with the effort.

But why stop there, Feynman mused? Why not miniaturize all of the volumes contained in all of the world's great libraries. Based on the size of The Library of Congress and several European national libraries, he estimated that there are approximately "24 million volumes of interest in the world." If each book was roughly the size of one encyclopedia and--as he had shown--you could get 24 volumes on a single pinhead, then miniaturizing the world's accumulated wisdom would require a space equivalent to a million pinheads. Feynman calculated that arranging the pinheads in a square, 1,000 to a side, would form an area of about three square yards.

I can envision the rapt attention that must have gripped his audience. Imagine hearing for the first time that the world's great books, all 24 million volumes, could be contained in a space equivalent to about 35 pages. "When the University of Brazil...finds that their library is burned," Feynman said, "we can send them a copy of every book in our library...in an envelope no bigger or heavier than any other ordinary air mail letter."

But you could go even smaller, Feynman theorized. Much smaller. If DNA molecules use approximately 50 atoms to code one bit of information about a cell, then even using double that amount, 100 atoms for each bit, all 24 million volumes could be contained "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."

Then Feynman told them about the tools necessary to achieve such levels of miniaturization, and how molecular data could be written and retrieved. He talked about "computing machines" which filled rooms and wondered "why we can't make them very small." He envisioned wires that were "10 or 100 atoms in diameter," and circuits "a few thousand angstroms across."

It took a while, but Feynman proved to be right on target. A few years ago researchers from Rice and Yale, lead by Mark Reed head of Yale's electrical engineering department, created the first reusable switch comprised of about 1,000 molecules.

Feynman envisioned computers with "millions of elements" that could even "make judgements." He said that "everybody who has analyzed the logical theory of computers has come to the conclusion that the possibilities of computers are very interesting--if they could be made to be more complicated by several orders of magnitude." And Feynman had ideas on what that might look like.

He predicted the design of modern computer chips and circuit boards, component manufacturing at a submicroscopic level and machines that could do optical recognition. And when devices became too small for big, clumsy people to manipulate, he suggested building "small but movable machines" to do the work for us. "How many times," he asked, "when are you working on something frustratingly tiny, like your wife's wrist watch, have you said to yourself, 'If I only could train an ant to do this?' What I would like to suggest is the possibility of training an ant to train a mite to do this."

Molecular machines are no longer idle speculation. Five years ago, scientists at Bell Labs built the first primitive self-assembling molecular "motor."

Long before Hollywood shrank a submarine and its crew and injected them into the veins of a dying man in order to perform a life-saving surgical procedure, Feynman had thought of the idea. A colleague of his had posed the question: What if in surgery, you could swallow the surgeon? "You put the mechanical surgeon inside the blood vessel and it goes into the heart and 'looks' around. It finds out which valve is the faulty one and takes a little knife and slices it out. Other small machines," said Feynman, "might be permanently incorporated in the body to assist some inadequately-functioning organ." He admitted that this sounded like "a very wild idea," but it's not so wild anymore.

Feynman was even bold enough to consider what he called "the final question;" whether atoms could not only be manipulated but arranged in any order we desired, creating designer shapes. He thought it might be possible in what he called "the great future."

Well, the great future arrived in 1990. Physicist Donald Eigler was able to position individual xenon atoms on a nickel surface. He placed them in a pattern forming the letters "IBM."

Tennessee Williams once lamented that "The future is called 'perhaps,' which is the only possible thing to call the future." Feynman, I think, would disagree. Forty-four years ago he shared a vision of what was possible with a room of eager scientists. Today, every industrialized nation in the world is investing billions of dollars into his vision, which we now call nanotechnology. Granted, the future is uncertain, but it doesn't mean it can't be shaped. Feynman, I suspect, would have sided with Victor Hugo, who was a wizard in his own right and steadfastly maintained that if it's compelling enough, "There is nothing like a dream to create the future."

The future, it appears, is finally catching up with Feynman. But the work is far from done. Recently I heard a radio program on which two physicists speculated that computers still have the possibility of a one billion-fold improvement in efficiency.