Small Wonders

Quantum mechanics' uncertainty principle says that before an atomic particle is measured, it exists in all possible states, all superimposed on one another. An electron, for example, is best described by what physicists term a "probability wave function," a mathematical expression that describes the chance that the electron is traveling at a range of speeds over a range of places. Once you measure its speed or position, quantum reality decoheres, the indefinite wave function "collapses," and either its speed or its position becomes definite. But not both at once.

Marcus says, "Once a measurement has been made, then all of the possible ways that things could have come out vanish, leaving only the way in which things did come out."

Re-enter the quantum dot, which connects the classical and quantum worlds. Inside the dot, electrons can be trapped and controlled for certain amounts of time. The theory of quantum computing shows that if information is stored in the dot's trapped electrons, before the electrons are measured all of the superimposed possibilities form an ultra- complex database.

If quantum computing comes about, less space will hold more information.

Think of it this way: Today's transistors, or microswitches, can be controllably switched to either state 0 or state 1 -- the either/or phenomenon that makes electronic computing possible. The 0s and 1s are coded bits of classical information. Computing capacity depends on how many switches can be built and interconnected.

In quantum computers, quantum bits, or "qubits," can be in both state 0 and state 1 at the same time, superimposed on one another. Theoretically, the ability to create databases of qubits and connect to them will shrink computers and increase their powers of calculation astronomically. But in the present, qubits have not been realized, because it is impossible to access the data without causing decoherence to set in, which destroys the information. And what is the use of storing information in the quantum universe, when attempts to access it import chaos and destroy the data?

Despite this almost ontological problem, Charles Marcus and many of his nanotechnologist colleagues believe that further experimentation with quantum dots could well lead to the development of a quantum computer. In the meantime, Marcus is also working on fabricating quantum wires to connect the quantum universe to the classical world. In that pursuit, he's in a collective that includes Hongjie Dai, Mike Crommie, Paul McEuen, and thousands of other experimentalists.

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Paul McEuen shows a visitor his lab. "My mom was disappointed. She thought it would be full of beakers and Dr. Frankenstein stuff," he grins. It looks like a weekend hobbyist's basement full of water heaters, gaffer's tape, and abandoned screwdrivers. But the water heaters are $250,000 refrigerators full of liquid helium and quantum dots.

It costs a lot of money to do nanotech, which is why university labs are umbilically tied to the U.S. government. The National Science Foundation is heading up a task force of scientist-bureaucrats from NASA, the Department of Defense, the Department of Energy, and several other federal agencies; this group is trying to control developments in nanotechnology, and, to this end, the U.S. government is planning to spend hundreds of millions of dollars on basic nanoscience research over the next two years. It is likely that nanotech manufacturing will become profitable once it passes the research stage. That's why the labs of multinational cybercorporations like IBM and Raychem are also heavily invested in nanotech research.

Those involved in nanotechnology regularly express a degree of social consciousness often missing in experimentalists. McEuen does not necessarily believe that nanotechnology will solve humanity's problems; he does hope that as biology, chemistry, and physics continue to intersect in the pursuit of nanosolutions, human beings will connect more deeply with their environment. "If everybody lives the way we live here," he says, "the planet is doomed. We'll run out of raw materials and kill everything."

But the technology of the infinitesimal is amoral. It is a tool that spans two viewpoints of reality -- classical physics and quantum mechanics -- with wonderful power. The results of nanoinvention -- which will likely include powerful weapons applications, as well as, one can hope, more benign and useful devices -- will change how the world operates its machines. But it cannot change how people operate in the world.

In 1995, the Rand Corp., a government-linked think tank located in Santa Monica, published a study on the potential of nanotechnology. The Rand paper relied heavily on the writings of K. Eric Drexler and the Foresight Institute.

The Rand Corp.'s authors concluded that nanotechnology would best be used to "take advantage of indigenous resources found on asteroids, comets, or planets for mining; defending Earth against impacts; or tools to assist extensive colonization of the solar system on a reasonable time scale." There was no mention of ending world hunger.