by Clara Kim ‘02

"Are we alone?" This question has long engaged many extraterrestrial-searching enthusiasts. Soon from the comfort of your own home or dorm room, you too can participate in the search for an ET. Beginning in April of 1999, thousands of home computers and their owners will join the Search for Extraterrestrial Intelligence (SETI) program through a distributed computational project. SETI works on dozens of projects with an emphasis on extraterrestrial life. Their largest project right now is Project Phoenix, a program that looks for radio signals in the vicinity of sun-like stars.

A part of Project Phoenix is the SETI@home project, which aims to harness the unused processing power of personal computers to interpret radio signals from the sky. All of this data, once collected, will be analyzed at a fraction of the cost of using supercomputers for the same task.

One can sign up for the SETI@home project at the website http://setiathome.ssl.berkeley.edu/. SETI@home is supported by the UC Berkeley SETI program, SERENDIP, which stands for the Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations. This project "piggybacks" other programs that gather data from the Arecibo Observatory in Puerto Rico. SETI acts as a supporter of the SERENDIP project and therefore of SETI@home.

After downloading the program as well as your first data chunk from SETI, the computer will utilize its processor during screen saver mode to analyze radio data from the Arecibo radio telescope. At what cost to you? Since the computer only needs to transfer data to SETI for five minutes every few days, only the cost of electricity and the loss of your favorite screen saver are incurred. Fortunately, the program provides a colorful screen saver that relays its computational work. The display can show one of four screens: the analysis of data, a progress report, a world map showing all SETI@home enthusiasts, or a map of the sky highlighting the data's sources with a superimposed map of the constellations.

The project will continue for two years, at which time the visible sky will have been scanned three times by the collective help of hundreds of thousands of personal computers. As early as August 1998, over 100,000 people had signed up to participate. The processing power is amazing, already exceeding any other SETI project in processing capabilities by two-fold. Once they have enough computers to look at each piece of incoming data, some pieces of data will be sent to more than one computer. If its budget allows, the project could expand to cover a wider bandwidth of radio frequency. This would increase the chance that your very own computer could find the first data signal from a civilization far, far away.

The work and concept behind the software is surprisingly straightforward and simple. The Arecibo radio telescope, an enormous bowl 1,000 feet in diameter, gathers data from the sky constantly. The SETI@home project takes the data and breaks it into 0.25-MB chunks. Each home computer receives a chunk and begins analyzing the data for strong signals. The software looks at about four million combinations of frequency, bandwidth, and chirp (the drift in frequency with time). The data is analyzed once more when it reaches SERENDIP's database. At this database, a server version of the SETI@home software sifts through the background noise and runs pattern detection algorithms on the remaining data.

The interest and sponsorships for the project have spanned across several seemingly unrelated areas. Paramount Pictures as well as Sun Microsystems have donated to the project in the shared hope of success. Donations have been received from Microsoft's co-founder, Paul Allen, as well as Intel's co-founder, Gordon Moore. The Planetary Society, which was founded by Carl Sagan, has become a co-sponsor to SETI@home. And of course there is the backbone of the project: over 100,000 computer owners who are willing to donate PC time to the cause.

If aliens are not a good enough reason to spare PC time, there are other distributed computational projects that might suit your fancy. For instance, your home computer can help calculate the quadrillionth bit of Pi at PiHex (http://www.cecm.sfu.ca/projects/pihex/pihex.html). At Distributed Net, home computers work to crack encryptions, sometimes as a part of a contest (http://www.distributed.net). Finally, GIMPS, the Great Internet Mersenne Prime Search, holds an ongoing project requiring billions of processor time to find the largest prime numbers possible (http://www.mersenne.org/prime.htm).

Deep in the night, most computers sit quietly awaiting their next task. Now the power of these still machines can be harnessed, and all you have to do is pick the project. For myself and over 100,000 other computer owners, there is a deep captivation in the SETI@home project: the hope of finding a hidden signal among the stars.