In Douglas Adams’ book “Hitchhikers Guide to the Galaxy” they built ‘Deep Thought’ – a supercomputer designed for one purpose and one purpose only – to find the answer to the great question of life the universe and everything. Perhaps the SETI program’s intent is not quite as ambitious…or is it? The purpose of SETI@home is to analyze the cumulative data of radio telescopes looking for communications from Extraterrestrial intelligence.
The logic is quite simple, just about every household and every business has at least one computer. The vast majority of these computers are connected to some form of high speed Internet service and most of them are never shut down. That’s a vast amount of processing power just sitting idle waiting to be used. In 1995 David Gedye purposed the utilization of this power to analyze data being received from the SETI radio telescopes. This laid the ground for SETI@home which was officially born 1999. Anyone anywhere with the willingness to spare a few bits of their unused processing power could download a small program to assist in the search for the existence of life in the endless expanse of space.
To the user at home, if they happen to be sitting in front of their idle computer, all they will see is a fairly normal looking screen saver. In the background, however their computer will be downloading, analyzing, and sending data to and from UC Berkley. The Arecibo telescope in Puerto Rico receives and records about 35 gigabytes of data every day. Their computers do some basic analysis looking for larger transmissions – the equivalent to alien recitation of the War and Peace for example – but they don’t have the capacity to search through all the nitty gritty. So, they send the 35 GB tapes on to California by good old fashion postage snail mail. UC Berkley chops the data up into easily transmittable packages of .25 MBytes they like to call “work-units” and these are what your computer works on, hence the name.
Today SETI@home has almost 5.5 million users in over 200 countries, which means that if even half those users were signed on (or off as the case may be) at the same time it would have the processing power of a quarter of a billion processors. Its cumulative CPU processing power is 2.05e+06 GFlops. For the sake of comparison the Department of Energy’s National Nuclear Security Administration’s computer, RodeRunner, billed as the greatest supercomputer in existence today, houses 6,562 dual core AMD processors giving it a processing power of 1.026e+06 GFlops. For those who think all this time and processing power is being wasted; who think that if an answer were out there we would have found it by now. May I remind you that Deep Thought took 7.5 million years to tell us “42.”
