By Alexandra Witze / The Dallas Morning News
Science is about to embark on a fantastic voyage.
Imagine robotic construction workers that could tirelessly assemble machines atom by atom. Imagine those machines performing a host of tasks in a world too small for even the nimblest fingers.
The mini-machines might build a solar cell from scratch. They might digest toxic waste, molecule by molecule. They might even act like the fearless surgeons in the 1966 movie Fantastic Voyage â€“ zipping through a person's bloodstream while fending off hostile white blood cells.
In the nanoworld, robots shrink so tiny that the aorta becomes a Niagara Falls. This is one vision of nanotechnology, the discipline that aims to make nanodreams a reality.
Some scientists believe that the technology could reshape society in a fusion of science and fiction worthy of Isaac Asimov. Researchers in national and international labs are just beginning to understand nanotechnology's many possibilities.
"There are many consequences which we have not even imagined yet," said Dr. Ralph Merkle of Zyvex.
Those unknowns create a dark subplot as the story of nanotechnology unfolds. A few researchers warn that the technology might stream out of control, unleashing a devouring horde of mini-machines onto society. These unstoppable "nanobots" would make unending copies of themselves, consuming resources until they ran out.
Mainstream scientists aren't worried. They have tried to distance their research from such science-fiction overtones.
In fact, the future of nanotechnology may be far more uneventful than any invasion of nanomachines, says Nobel Prize-winning chemist Richard Smalley.
"I'm not worried about nanobots taking over the world any time soon," says Dr. Smalley, director of the Center for Nanoscale Science and Technology at Rice University in Houston.
Last month, leading scientists gathered in Washington, D.C., to discuss the societal implications of nanotechnology. The group will soon publish a detailed response to those who fear nanotechnology.
"We look now to the real contributions, the real discoveries," says Dr. Mihail Roco of the National Science Foundation, who coordinated the conference. "They are so exciting that you don't need excitement from fiction."
Nanotechnology was still in the realm of fiction on Dec. 29, 1959, when physicist Richard Feynman gave a lecture to a packed room at the California Institute of Technology. He spoke of rearranging matter atom by atom and thereby shrinking the entire Encyclopaedia Britannica to fit on the head of a pin. Many people now believe that lecture was the birth cry of nanotechnology.
"There's plenty of room at the bottom," Dr. Feynman told the crowd. Researchers should learn, he said, how to construct materials from the "bottom up" â€“ not carve them from the "top down" out of bigger chunks of matter. Scientists needed to work on the scale of nanometers, or billionths of a meter, where atoms join to form molecules.
"In the year 2000, when they look back at this age, they will wonder why it was not until the year 1960 that anybody began seriously to move in this direction," he said.
Yet in the year 2000, researchers are still taking baby steps toward bottom-up construction. Dr. Feynman lectured in a time before miniaturized technology, before microscopes were developed that could photograph individual atoms. The field languished for decades.
But in 1986, an unorthodox scientist named K. Eric Drexler, whose background was in aerospace engineering, published a popular book called Engines of Creation. In it, he prophesied a future of precisely built molecular machines that could alter industries from manufacturing to environmental cleanup.
Fleets of nanomachines could do the world's work, Dr. Drexler suggested. Humans could enjoy the luxury of saving time, energy and natural resources. Hard labor would become a thing of the past.
The heart of his vision was the nano-sized assembler, a machine that could routinely snap together molecules to create any desired component. Once one assembler was made, it could build others just like itself.
With an assembler, molecular nanotechnology could become a reality, Dr. Drexler suggested.
Engines of Creation sold well and triggered fresh interest in the idea of nanotechnology. In 1992, Dr. Drexler testified in front of Sen. Al Gore and a congressional subcommittee about the wonders that nanotechnology might one day provide. He founded the Foresight Institute, a nonprofit institute in Palo Alto, Calif., to "help prepare society for anticipated advanced technologies" â€“ including, of course, nanotechnology.
Chris Peterson, president of the Foresight Institute and Dr. Drexler's wife, says that other scientists are only now catching on.
"Finally people are ready to listen to some of the broader issues that Foresight was actually established to address," she says.
Today, Dr. Drexler has become something of a recluse; he no longer speaks to reporters or at most conferences. But he and Ms. Peterson are busy revising Engines of Creation for a new edition.
Last year, it was Rice's Dr. Smalley â€“ not Dr. Drexler â€“ who testified at House and Senate hearings on the benefits of investing in nanotechnology research. The government has invested $422 million in nanoresearch â€“ and none of that will be used to build an assembler, Dr. Roco says.
Meanwhile, Dr. Smalley, and many other academic scientists, say that basic research being done today doesn't reflect the original Engines of Creation vision.
"I call it the silly side of nanotechnology," Dr. Smalley says.
Dr. Vicki Colvin, another Rice researcher, adds that "to a chemist, the idea of a molecular assembler is anathema."
Scientists cite two main problems with making an assembler. One is that atoms are naturally attracted to each other through interactions called van der Waals' forces. Each atom's coat of negatively charged electrons is tugged toward the positively charged nucleus of a neighboring atom. So moving individual atoms next to one another, with the precision required to build something so complex as an assembler, would be as impossible as assembling Michelangelo's David with magnetized Tinkertoys.
A second problem is control. An assembler would need to be able to control the position of not just one atom, but the entire clump of atoms it was sticking the new one onto. That calls for a more delicate precision than a single probe, reaching out with its manipulative "fingers," could conceivably achieve.
"There is an irreducible fatness of the fingers that makes it impossible to have the total control that you need," Dr. Smalley says.
Assembler the key
But not everyone has given up on the dream of the assembler.
Zyvex became the first company founded to try to turn the Engines of Creation vision into reality. So far, its president, James Von Ehr II, has invested $5 million of his money in the gamble that the molecular assembler can be made, and that Zyvex will be the first to make it.
After three years, his company is still working to get its laboratory fully staffed and equipped.
"What we're trying to do is way out there on the risk frontier, the knowledge frontier," Mr. Von Ehr says.
But he thinks the assembler is an achievable dream.
"It seems to me inevitable that [someone] will be there in 50 years," he says. "I think that by pushing it ... we might be there in 10 years. If we did nothing, it would happen without me."
Yet even if an assembler could be built, other scientists worry about what might be done with it.
In April, some consequences of nanotechnology exploded into public view. Dr. Bill Joy, chief scientist at the computer giant Sun Microsystems, wrote a long article in Wired magazine about possible future dangers of genetics, robotics and nanotechnology.
Dr. Joy raised some issues that Engines of Creation had addressed: the possibility that an assembler could run out of control, replicating itself like Star Trek's runaway "nanites," until the creatures had devoured all available resources. Terrorists might get hold of such omnivorous nanomachines, spreading them in areas that they wished to wipe out, Dr. Joy wrote.
In Engines of Creation, Dr. Drexler had envisioned unleashing good nanomachines to fight the bad ones â€“ a sort of miniature civil war.
While most nanotechnology researchers dismiss such a scenario, others argue it's an even more compelling reason to continue.
Instead, says Zyvex's Dr. Merkle, "the right thing to do is move forward with development of the technology in a framework that encourages development by responsible groups."
The Foresight Institute has drawn up just such guidelines for nanotechnology developers, although signing the guidelines is voluntary. They begin with the principle that "artificial replicators must not be capable of replication in a natural, uncontrolled environment."
Going too far?
But such precautions aren't warranted, argues Harvard University chemist George Whitesides.
"We certainly cannot build a self-replicating robot at any size," he says. "The idea of building one on a nanometer scale does not make sense."
There are real concerns about developing nanotechnology, says Dr. Whitesides, who participated in the recent conference on its societal impact. But the problems piggyback on nanotechnology's great promise, he argues.
Better ways to make portable communications could mean easier ways to eavesdrop on people, he notes. Faster ways to screen a person's genetic makeup could lead to lost privacy of medical information.
The darkest visions of nanotechnology â€“ and the brightest â€“ will become clearer as the science moves from imagination to reality, says Dr. Evelyn Hu, an engineer at the University of California, Santa Barbara.
"I think what Drexler was talking about, what Richard Feynman was talking about," she says, "is a vision that is still ahead of us with all its positive, beneficial aspects and all its scary aspects."