Computer scientists rethink their discipline's foundations

"Suddenly, I didn't know what a computer was anymore," Richard Lipton of Princeton University recalls thinking recently. He's not the only one feeling that way. As Lipton and others seek the path to computers thousands or millions of times faster than today's-devices that will drive scientific and industrial research in scores of fieldsthey have strayed far from transistors, resistors, and wires. They are searching for the future of computation in a realm of new media, from optical materials to quantum circuits to DNA, and even new computing principles, far removed from the kind of sequential logic today's computers have inherited from the era ofgear-and-lever machines. Like any venture into alien territory, this effort can be disorienting for computer scientists reared on silicon microcircuits. "It's like an old joke," says Stuart Kurtz of the University of Chicago. "'Two weeks ago I couldn't spell engineer and now I are one.' That's how