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Wednesday, November 25, 1998 Published at 16:57 GMT


Screening for life in the machine

The screensaver program will search for life

By BBC News Online Science Editor Dr David Whitehouse

One hundred people a day are signing up to search for life in space using down time on their PC's.

It is called SETI@home - Seti is the Search for Extra-terrestrial Intelligence. It uses the power of idle PC's to sift through data obtained by radio telescopes. Somewhere in that data could be a signal from an alien civilisation.

The project does not officially begin until next April, but 100 people have been selected to test-drive this new search for intelligent life in space.

If all goes well, the finished product will roll out next April for the 100,000-plus people who have already signed up to participate. Every day 1,000 more sign-on.

PC screensaver

The computer program is essentially a screensaver that begins when your desktop computer is idle.

"It is a way of harnessing the power of idle computers," said SETI@home project scientist Dan Werthimer, a research physicist at the University of California Berkeley's Space Sciences Laboratory.

"It increases our computing capacity and our chance of finding extraterrestrials."

SETI@home is a way for scientists to more thoroughly analyse the data they receive daily from their ongoing survey of the sky using the giant Arecibo radio dish in Puerto Rico.

Extra capacity

This 20-year-old search is called SERENDIP IV - the fourth incarnation of a project designed to search for life in space.

Unfortunately, the computer capacity available to SERENDIP is sufficient to look for only the most obvious signals from extraterrestrial civilisations, Werthimer said.

"In terms of science, SERENDIP is very powerful, but it only looks for a very restricted class of signal," he added. Seti@home does a very good job of analysing a small set of data very thoroughly."

Data from the radio telescope is broken down into small chunks - typically a range of wavelengths - through which the screensaver program can search for patterns that may indicate a deliberate broadcast from a distant civilisation.

Guarenteed fame

Any one whose computer finds such a signal is going to become very famous.

"You can download enough data through the Internet in five minutes to keep the computer analysing for several days," said computer scientist David Anderson, project director and a long-time volunteer.

"The computer then sends back a summary of the interesting stuff it found, and gets another chunk of data."

As the computer works away at the data, the computer screen displays a three-dimensional graph charting the signal analysis.

"The point of the latest test is to get the bugs out of the software so we are ready to go for 100,000 people in April," Werthimer said.

Star Trek

SETI@home will get help from those who have already found life in space. Paramount Studios has donated $50,000 to the search and is tying the project to the launch of the latest Star Trek movie, "Star Trek: Insurrection," on 11December.

But whatever interesting signals may turn up from SETI@home, the scientists are stressing that they must be checked by professionals to make sure they are not due to radio interference from Earth or orbiting satellites.

"We're asking people not to call the press when they see a spike on the screen," Werthimer said. "We get strong signals all the time and they turn out to be false alarms."

Nevertheless, someday, perhaps you could be the person to find life in space.

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