Coffee: Driving the computer industry now or in the future? ---------------------------------------------------------------------------- ---- By Mark Gibbs 07/07/97 Coffee. What IT shop can operate without it? You know, that wonderful, aromatic brew in the staff lounge at 9 a.m. that turns into a viscous, stomach-burning, gut-wrenching, black ooze by 4 p.m. But in IT, we just can't live without it, whatever state it's in. Now it was with some amusement that I read that a nice, hot cup of coffee may one day be pressed into service as a supercomputer. I came across this gem on the site Tasty Bits from the Technology Front (www.tbtf.com). The background to this improbable idea lies in quantum physics and the limitations of conventional computers. With chips, speed depends on how much you can minimize the size of various chip features. Of course, the limit comes when you get features so small you're effectively handling single electrons. Interestingly, the smaller the feature size, the more expensive the fabrication process. This, in turn, makes the fabrication ('fab' plant) correspondingly more expensive. Supposedly, if we could build chips that handle single electrons, the cost of the fab plant would equal the gross national product of every country on the planet. A hope lies in quantum physics. But quantum physics only applies to the subatomic level, which is where the quantum properties of matter become detectable. And this is where something called 'quantum logic' comes in: A particle (an electron, a photon, an atomic nucleus, etc.) can be in multiple states simultaneously. It can, in effect, represent 0 and 1 at the same time. Now you're probably about to frame a deep-penetrating question such as 'Wha'?' and I'm right there with you. This is desperately weird stuff, and I'm not about to make the slightest attempt to explain it. That's not because I'm short of space or anything - I don't understand it, either. But the potential is this: Where a regular computer working with, say, a 24-bit word could, at any moment, represent any of 8,388,608 values, a quantum computer with 24 quantum bits (or, as they snappily call them, qubits) could represent all 8,388,608 values at the same time because each qubit can be in multiple states. If the term that springs to mind at this point is 'massively parallel,' you are quite right. That is, indeed, what this beast is. Or, at least, will be if they can build it. With such a machine, cracking real encryption codes - typically a problem of finding the prime factors of large numbers - becomes practical. In 1994, 1,600 computers on the Internet took eight months to find the prime factors of a 129-digit number. If they were to try the same thing with a 250-digit number, it would take about 800,000 years. On the other hand, a 30-qubit computer would be capable of knocking off the prime factors of a thousand -digit number in a mere 20 minutes! That's real horsepower by anyone's standard. It turns out that using individual particles as qubits is tricky. As soon as you try to determine the state of the particle, your observation stops the process of computation (good ol' Heisenberg's uncertainty principle at work). So some bright chaps at MIT (http:// physics.www.media.mit.edu/ projects/ spins/home.html) have come up with the idea of using lots of particles at the same time, all doing the same thing. They reason that if all the particles are doing the same calculation, determining the state of a small number of them still leaves the rest to complete the process. They suggest that a nice, hot cup of coffee would be a fine collection of particles to use as qubits. Actually, in a real machine, they would use a complex, purified molecule such as caffeine. Using a technique called nuclear magnetic resonance - which is just a matter of shoving radio waves into the liquid to induce the computing 'states' and detect the magnetic response of the atoms - a quantum computer may one day be built. And the hardware required is cheap. So in the future, we may be able to honestly say that the computer industry does, indeed, run on caffeine. How many MIPs to the sip? Let me know at nwcolumn@gibbs.com or (800) 622-1108, Ext. 504. ---------------------------------------------------------------------------- ------- Rohit Khare /// MCI Internet Architecture (BOS) /// khare@mci.net Voice+Pager: (617) 960-5131 VNet: 370-5131 Fax: (617) 960-1009