In the computer revolution, the optical disk is poised to be the all-purpose storage medium of choice. But before it can fulfill this heady role, it will have to store a whole lot more information than it does today.
Nowadays the zeros and ones of digital information are carved into the surface of a plastic disk as a string of microscopic marks and spaces. As the disk spins under a laser beam, the beam, if it encounters a space, reflects off a shiny aluminum backing behind the semitransparent plastic and triggers a photodetector. When the beam encounters a mark, on the other hand, it scatters. Hal Rosen, a staff member at IBM’s Research Division in San Jose, California, woke up one morning with a simple but powerful idea that builds on this technology. Rosen thought of layering marks and spaces. First he removed the aluminum backing. The plastic still reflected a small amount of light. Then, with a lens directing the laser beam to a specific layer and reading the reflected light, the photodetector could be made to select one level at a time while ignoring the others.
The technique, it turns out, works with any kind of optical disk, though IBM will apply it first to disks for holding computer data. So far, Rosen and colleagues have made optical disks with 6 levels of storage, but we don’t see why we can’t do 20 levels, he says. By adding higher- frequency lasers and new methods of compressing data, Rosen believes he can eventually put 100 billion bytes of information onto a small disk--more than enough for several full-length motion pictures, a whole day’s worth of music, or reams of computer data. Or, says Rosen, with one of these disks you could have a small public library on your desktop.
Dance of the Machine Tool
Giddings & Lewis’s Variax
Innovator: Paul Sheldon
Although computers have liberated designers to create products of almost any shape, the machine tools that carve these shapes from metal blocks have hardly changed since the nineteenth century, when hand-operated cranks positioned the cutting head, or spindle, and steam engines supplied the mechanical power. Then, as now, the spindle and the metal block moved along rigid rails at right angles to each other.
In 1988, Paul Sheldon thought of something better. Why not hold the block of metal in place and let the spindle fly freely, carving out chunks from every conceivable angle like some kind of murderous robotic barber? Sheldon, vice president of research and innovation at Giddings & Lewis in Fond du Lac, Wisconsin, connected two horizontal platforms with three pairs of crossed, pistonlike legs. While the metal block is clamped to the fixed bottom platform, the top platform, which carries the spindle, flops around like a seasick limbo dancer. Of course, appearances deceive: the crossed-leg arrangement is so inherently strong and stable that the machine is five times more rigid than a traditional one, even though it weighs half as much.
The new tool required hugely complex computer software to direct the motion of the platforms. Sheldon and co-worker Ed Kirkham had only $1,000 to build a prototype, which they cobbled together with parts from Radio Shack. The first commercial version, called the Variax, should be ready in the fall.
See Me, Feel Me
MIT’s Phantom Haptic Interface
Innovators: Thomas Massie and J. Kenneth Salisbury
Computers can make you see and hear make-believe worlds, but so far they have left out the sense of touch. Scientists have addressed this need by building devices that can deliver a mechanical resistance to the hand or fingers, but most of them are one-of-a-kind experimental contraptions that cost upwards of $200,000.
A bachelor’s-degree thesis project at the Massachusetts Institute of Technology has changed all that. The student, Thomas Massie, with help from principal research scientist J. Kenneth Salisbury, came up with a less expensive device called the Phantom Haptic Interface. It looks like a desk lamp with three motors at the base and a thimble at the other end and is connected to a personal computer. You insert your finger into the thimble and move it around to feel the objects that exist only in the computer’s memory--sliding it, say, along a virtual tabletop to feel the sudden release of pressure at the edge. Electronic devices track the motion of the finger while the small motors supply the requisite force to the finger.
The key to Massie and Salisbury’s device was a simplifying assumption: most of the sensation that lets a blindfolded person feel the difference between a softball and a hockey puck, they realized, comes through the fingertips and can still be felt with gloves on. That freed them to dispense with the difficult job of conveying texture over the entire hand and to focus instead on the fingertip, keeping their device simple.
So far Massie, who is now president of SensAble Devices in Cambridge, Massachusetts, has sold 20 Phantoms for $20,000 each to Sandia National Laboratories, General Electric, Interval Research Corp., and other high-tech firms and research labs. Someday the Phantom or its successor may train surgeons by giving them the feel of an operation, let automobile designers sculpt body panels with their hands, and make computers more vivid to the blind. It will enable humans to interact with computers in entirely new ways, Salisbury predicts.
Crystalful of Data
Holographic Data Storage System
Innovator: Lambertus Hesselink
The dream of storing computer data in three-dimensional images has persisted for 30 years. It is easy to see why. Holographic images, produced by the interference patterns of two laser beams, have the potential not only to hold vastly more data than any known form of computer storage but also to cough up that data 10,000 times more quickly. Although engineers have had the basic know-how to build such a device for years, they haven’t managed to make one reliable enough for commercialization.
Last year Lambertus Hesselink, an electrical engineer at Stanford University, unveiled a new approach to holographic storage that may mark an end to this long wait. Here’s how it works: the ones and zeros of computer data are first represented as a checkerboard pattern of light and dark squares on a liquid crystal display similar to the ones used in laptop computers. A blue-green laser beam shines right through this display, and a lens focuses the checkerboard image onto a light-sensitive crystal of lithium niobate. When a second, reference laser beam is shone onto the same spot, the data are recorded in the crystal. When the reference beam is tilted slightly--by a mere 2.9 thousandths of a degree, in fact--a second page of data can be recorded on the same spot. All in all, about a thousand pages of data can be written in one volume of crystal 1 millimeter square by 1 centimeter long.
In March 1994, Hesselink demonstrated these techniques with a modest device that holds about 163,000 bits of information and can deliver a 1,650-bit page of data in a few milliseconds. Hesselink and his students first managed to record and retrieve a picture in the lab last summer. We were so happy, he says, we all just jumped up and down and started laughing.
Agents in Cyberspace
Sony’s Magic Link/General Magic’s Telescript
Innovators: Kazuo Imai and Marc Porat
How will we communicate in the future? Will we talk on the telephone? Send faxes, electronic mail, images, voice recordings, or scribbled notes?
All of the above and, if Marc Porat has his way, on the same little device. The cofounder, chairman, and chief executive officer of General Magic of Sunnyvale, California, has developed a grand vision of the future of personal communications: a little electronic trinket with a playing-card-size screen and the kind of icons found on personal computers. General Magic has developed a new computer language, called Telescript, which makes communication with such devices feasible. The power of Telescript is its agents, small computer programs that leave the communication device and migrate within vast networks to do their user’s bidding. Telescript enables you to send a message just by indicating the recipient’s name, while the agent does the grunt work of finding the electronic address.
The first personal communicator to incorporate General Magic’s technology is the Magic Link, a product released in September by Sony (and supported by an AT&T; network). The Magic Link, which weighs a little over a pound, can accomplish almost any personal communication function, says Kazuo Imai, a division president at Sony.
Like the pioneers of the personal computer before him, Porat believes his innovation will contribute more to society than merely providing toys to the upwardly mobile. Three and a half billion people in this world do not own a telephone, and many will get their first ones early in the next century, he says. I believe what they will use will look very much like the kinds of personal communicators we are now developing.