SETI at Home: A Serious Search for Extraterrestrial Intelligence

"SETI@home"

"SETI@home is a scientific experiment that uses Internet-connected computers in the Search for Extraterrestrial Intelligence (SETI). You can participate by running a free program that downloads and analyzes radio telescope data."

This Berkeley project is, in my opinion, the best SETI (Search for Extra-Terrestrial Intelligence) projects around. And, the only practical one that I've encountered.

It records what the radio telescope at Arecibo picks up, stores the data, and then sends the data, one chunk at a time, to the computers of participants. There, the data is analyzed by software that stays out of the way when you're using the computer - like a screensaver. When that chunk is processed, the results are sent back and another chunk received.

In fact, it is a screensaver: except this one is looking for ET.

What makes this project remarkable, in my opinion, is that it is looking for weak signals, any weak signals that aren't the sort that nature produces.

The traditional SETI program involved listening for a relatively short period of time, to a particular section of sky, for strong signals. That would be fine, if someone out there was

• Close to us
• Near one of the stars that scientists think are most likely
• Sending strong, simple, signals our way
• Timed to arrive when the telescope is pointed in that direction

So far, that approach hasn't produced positive results. Maybe that's because there aren't other people out there, and maybe it's because they're there, but weren't sending signals at exactly the right time, in our direction.

SETI@home doesn't make those assumptions.

• The project has scanned the entire sky twice, and is near the end of a third scan
• Data is being combed for weak signals - something other than a loud and clear 'live long and prosper!'
• In principle, the project should be able to "tease out" almost any sort of signal:
  • The hum of an alternating-current power grid (okay, a big, powerful one)
  • Radio-frequency noise from
    • Very large-scale industrial processes
    • The more heavily-populated parts of a planet, which would appear and disappear as the planet rotates
    • Propulsion systems (electrostatic sails, whatever - and, yes, again really big ones)
    • A really big rock concert
    • Something else

Or, maybe a message which, when deciphered, reads, "will you please stop transmitting "Captain Planet" reruns!"

There's more, at "How SETI@home works." "...In the next two years the entire sky as seen from the telescope will be scanned three times. We feel that this will be enough for this project. By the time we've looked at the sky three times, there will be new telescopes, new experiments, and new approaches to SETI. We hope that you will be able to participate in them too!"

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Related posts, at

• "A Serious Search for Other Worlds, Life, and - Maybe - Extra-Terrestrial Intelligence"