At a time when "computer" meant a 16-ton behemoth with 15,000 vacuum
tubes, could anyone have foreseen a Pentium laptop? Desktop analysis?
'Round-the-clock information via the Internet?
After the dizzying advances of the last five decades, little seems out of reach in the next:
Computers made of biological, not silicon, components.
Disks that can store the entire Library of Congress in the size of a coin.
Systems that can respond to where you look--or even what you think.
"It is not far-fetched to say, 'Wait, and almost everything will be possible,'" believes Chip Holt, vice president of Xerox's Joseph C. Wilson Center for Research and Technology.
That's progress. Computer power has been marching forward at an almost eerily predictable rate for a quarter-century, doubling roughly every 18 months. In the future, "capabilities of the machines will outstrip anything we can think of today," says Jack Brown at Motorola.
How long can these rates of improvement keep up? Many in the industry expect silicon technology to "hit the wall" around 2010 to 2015, when submicron semiconductor features become so tiny as to be just a few molecules thick. Then, a major shift in computing fundamentals appears likely.
A possible first step: augmenting the conventional. "Silicon as a technology will be very hard to replace," argues Greg Papadopoulos, vice president and chief technology officer at Sun Microsystems Computer Co . "The capital investments are unparalleled in industry. The question then becomes: What can you do with that fabrication technology?"
Adding iron to silicon, for example, could increase densities two- to four-fold, and such experiments have been going on for a decade. One problem to overcome, though: iron rusts. IBM and Hughes Electronics have added germanium to conventional silicon, offering substantial reductions in power consumption, weight, and size for comparable performance.
Another alternative is optical computing, using fiber optics to transmit and process data at the speed of light. Forest Baskett, Silicon Graphics' senior vice president and chief technology officer, foresees "smart optic communications." However, latency problems--the lag in switching back and forth from electro- and optical systems--remain to be solved.
Some scientists believe optics have a bright future in computer storage. IBM researchers are using technology initially developed for a new type of optical microscope to develop CD-like storage techniques that would pack a hundred times more data on a disc than the next-generation CDs known as DVDs. A disc-like surface with silicon-dioxide layers is finely marked with an electronic beam, then covered with metal film. Sensors would then read interactive light scattered from the metal strips. Theoretically, features of just 20 angstroms would be possible at access speeds of 100 Mbits/sec, versus 5,000 angstroms for Digital Video Discs.
"The pieces exist, and experiments agree with the theory," says H. K. Wickramasinghe, manager, physical measurements, at IBM's Thomas J. Watson Research Center. What is needed is a practical manufacturing process to finely stamp the discs, he says.
Merger of man and machine? In the long term, researchers are looking at molecular-based systems, and the sci-fi-sounding field of biocomputing. A molecular biocomputer might use