"A number of years ago, SETI [the Search for Extra-Terrestrial Intelligence] was funded by NASA," Microsoft's chief technology officer Nathan Myhrvold explained last week in Redmond. "But the government was frightened out of doing SETI research by people who made fun of it. I think it's the case of a small and small-minded minority who are hounding the government out of doing something that's actually legitimate science.... I think it's as worthy a study as any other fundamental science."
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Myhrvold does have some authority on the subject. Microsoft's research chief holds master's degrees in geophysics, space physics, and math from the University of California, plus a PhD in theoretical and mathematical physics from Princeton. He also studied cosmology at Cambridge with Stephen Hawking. "I have no idea whether alien civilizations exist," Myhrvold says with voice-cracking excitement. "I have no idea if we'll find them in our lifetime—but if they existed, and if we found them, it would be cool as hell!"
Similar reasoning compelled Paul Allen to donate $1 million per year to SETI research, as have Intel co-founder Gordon Moore and David Packard of Hewlett-Packard. Harvard has a SETI program (http://mc.harvard.edu/seti/), and so does the University of Washington. In conjunction with astronomers at UC-Berkeley, and with help from Sun Microsystems, Starwave, and the world's largest radio telescope in Arecibo, Puerto Rico, SETI researchers at the UW hope to use your PC to search for radio messages from outerspace.
"SETI is no doubt speculative," admits UW Professor Woodruff T. Sullivan, who spends most of his time studying radio emissions from pulsars and quasars. "But I think it's worthwhile to be doing for a certain amount of resources. No doubt it's a long shot, but we have the tools, we know definitely that our radio telescope can communicate with another radio telescope millions of light years away. I mean, it's a fundamental question: Are we alone? And this is the first time we can take a scientific approach to the answer rather than just philosophic."
Sullivan's project, called SETI@home, grew out of research from Paul Allen's Starwave Corp. Three years ago, David Gedye, then Starwave director of online games, designed a Web-based network that could harness the unused processing power of idle home computers to sift through an overflow of galactic radio wave data collected by Sullivan and his colleagues in Berkeley from the Arecibo telescope, as part of their SETI research. When Starwave backed away from SETI@home (part of a larger project called the Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations SERENDIP), Sullivan, Gedye, and UC Berkeley astronomer Dan Werthimer took the project on in their spare time.
SETI@home is triggered when a PC's screensaver comes on, signaling that the computer is idle. The central network then sends a small chunk of data to the PC, which analyzes it and returns the results a few days later to the SETI@home server. SETI@home astronomers then further analyze candidate frequencies thatthe network selected as possible signals.
Using PCs in this way is not new. According to Myhrvold, the world's screensavers currently execute more CPU cycles than any other single application, and distributed networks already coordinate thousands of home PCs on problems (cracking encrypted security codes, for example, or searching for really big prime numbers) that require lots of processing power but don't have the funding for dedicated supercomputers.
"This particular problem is easy to distribute into small parts," explains Werthimer, SETI@home's lead scientist. "You take this part of the sky and X frequency range, and without very much modem time—only a couple minutes, a quarter megabit of data—a PC can download the data, grind on it for a few days, and send it back to our server."
The project so far has registered 80,000 people who are willing to donate spare processing time on their computer—a number that could essentially double SERENDIP's current processing capability.
For the past 20 years, SERENDIP and UC-Berkeley collected radio-wave data from the Milky Way by "piggybacking" on more traditional radio astronomy projects, which measure such things as microwave background noise associated with the Big Bang. SERENDIP can't afford its own time on the Arecibo telescope, so it essentially collects scraps from better-funded projects and filters it for strong and steady radio signals. SERENDIP currently monitors 168 million narrow (0.6Hz) channels every 1.7 seconds—a process generating 200 billion-instructions-per-second for computers to handle. SETI@home would search a sub-set of the SERENDIP data with more sensitivity than currently available.
"We know that the earth is not a very special place," says Werthimer. "The chemicals to make life—carbon, water—are abundant in the universe. There are 40 billion stars in our galaxy, and there are a lot of chances for life. It would be really bizarre if we were the only planet in the universe with developed life."
There are, for example, 1,000 solar-like stars near us in the Milky Way alone. Since radio waves travel at the speed of light (and conveniently aren't absorbed by interstellar gas or dust), Sullivan notes that nearly all of those 1,000 solar systems would already be able to pick up our stray broadcast signals from first-run I Love Lucy transmissions. "The three towers on Queen Anne Hill send radio waves all across the horizon," explains Sullivan, who has published research on radio wave "leakage" from Earth. "Most never hit an antenna and go right on out to space.... Still, almost all SETI is predicated on the idea that there's a beacon out there that someone else has set up for us to find."
Carl Sagan's respected Planetary Society has pledged $50,000 to SETI@home and Werthimer expects SERENDIP supporter Sun Microsystems to donate workstations for SETI@home's network server, but the project still needs another $200,000 to get started. Two years ago, SETI@home had an opportunity to partner with the Microsoft Network but backed away when MSN positioned the project next to "X-Files" sites and other UFO "kooks and nuts," according to Sullivan.
"It's not as popular as saying, 'Let's build warp drives,'" notes Myhrvold. "Unfortunately, we don't know how to do that yet. But it's a kind of exploration, so I think its plenty deserving." (Myhrvold sits on a SETI Institute advisory board but has yet to contribute financially.) "SETI@home would be a screensaver that did something useful," he says. "You don't have to ask: 'Is this good for society?' You have to ask: 'Is it as good as flying toasters?' And I say, 'Yes!' by god."
"Extraterrestrial life is almost certain," adds Werthimer. "The big question is, are they interested in communication? Do they know about radio waves?... Those are much more difficult to answer."
Harvard,s SETI program
UW Professor Sullivan,s SETI project
The Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations