BRING ON THE NANOBUBBLE.(The Talk of the Town)

In the early sixties, investors stumbled on a neat trick: if a company had "tron" or "tronics" in its name, its stock was a hit. This was the dawn of the computer age, and a host of businesses straight out of "The Jetsons"--Astron, Transitron, Videotronics--became the darlings of Wall Street. The boom ended badly, as booms so often do. In 1962, the stock market plunged, and the trons and tronics were knocked flat, most of them for good. But investors have short memories. At the end of the decade, they fell for tech stocks again (the magic word this time around was "Silicon"). Later, it was P.C.s, then biotech, and, more recently, dot-coms. Infatuation and disillusionment: it's the American way.

Now investors have found a new crush: nanotechnology. Nanotech involves designing, manipulating, and building things at atomic and molecular levels--tinkering with the building blocks of matter. Most applications for it are years or even decades away, but Wall Street has caught on to it, and in the past year companies with any sort of nano connection--Nanometrics, Nanogen, Nanopierce, Nanoproprietary--have seen their stocks rise sharply. This boom is in its early days, since most nanotech companies are still tiny and privately held. But the scent of untold riches is already in the air. Josh Wolfe, who started the first nanotech venture-capital firm, compares it to the Internet circa 1993, before Netscape went public. He thinks the first big nanotech I.P.O. could happen in the next year.

The idea for nanotech can be traced back to a lecture delivered, in 1959, by the future Nobel laureate Richard Feynman, who argued that there was no reason, theoretically, that humans couldn't move and control atoms. It took researchers thirty years to prove him right--in 1989, I.B.M. scientists arranged atoms in the shape of the company logo--and only in the past few years have real nanotech businesses emerged. So far, nanotech has been used to make pants that won't stain, tiles that won't chip, and windows that won't get dirty. I.B.M. has used it to increase twentyfold the amount of data that can be stored on computer hard drives. In the near future, nanotech will help us produce cheaper solar cells, cheaper and more reliable flat-screen televisions, and an entirely new form of semiconductor. But we're also told that soldiers will eventually wear light, flexible nanotech armor that is bulletproof and able to repel chemical and biological agents. Most dramatically, many scientists think that nanotechnology will transform the way drugs are made and delivered; there's also a chance that it will become central to the fight against cancer, allowing doctors to target and kill individual cancer cells while leaving healthy cells alone.

The very fact that nanotech is so bewilderingly broad in its potential applications--from window-cleaning to ...