To: all-ai Subject: GSB, Friday 5:30, 7AI --text follows this line-- This is a good week to come to GSB. One reason is that Carlin Vieri will be there, and Carlin Vieri is rich. He might buy you a beer, and then tell you his life's story. One story he might tell is how he became rich. It has to do with "reversible computation". A unnamed and nonexistent government agency gave him a large sum of money- very large- to build a reversible computer. Because he doesn't want to lose his money, except by occasionally springing for a malt beverage or two, he can't tell you much more than that. But I can. Reversible computers are energy saving devices. They save energy by destroying as few bits as possible; it's a quantum thing, or maybe stat mech. He's going to build a computer that runs big complicated problems that have results expressible in very few bits. Like, say, programs that factor 512-bit numbers. His computer is going to do all sorts of work and then spit out just one or two lines to the screen. Everytime it needs a bit it will borrow it, and always return it. It will only run a bit deficit when somebody looks at a result. In fact, so long as the person who looks at the result doesn't tell anybody, energy is conserved. This is why only big government agencies that have opaque buildings set back behind hills and fences in suburban Virginia purchase reversible computers and factor numbers. These agencies can factor as many numbers as they want and use no energy, because nobody else knows they are doing it. Sort of like Schroedinger's cat: if an RSA code cracks and nobody is there to hear it, does it make a sound? There are rumors that if these agencies even *thought* of mentioning that they factor private citizen's numbers there would be a brown-out along the entire eastern seaboard. It is vitally important to the nation's power grid that these agencies are allowed to factor in their own seperate peace. That is where Carlin comes in. At this week's G I R L S C O U T B E N E F I T Tom Knight will explain how Netscape's random number generator consumes thousands of kilowatt-hours worth of energy every year, and why web-weenies may want to invest in uninterruptible power supplies.