Flashback: Still Alone, Still Listening

The last time we visited Kent Cullers '71, he was listening for signs that we're not alone...

Kent Cullers '71 can't be certain he'll find ET in his lifetime. The galaxy, after all, is a mighty big place to search.

But Cullers has reason for optimism as he nears 25 years on his quest to find extraterrestrial life. The search for ET is getting faster and cheaper, thanks to technological innovation.

"I'm not even close to giving up," says Cullers, 54, who earned his physics Ph.D. from the University of California at Berkeley and is believed to be the first blind physicist in the world.

Cullers is director of research and development for SETI Institute, based in Mountain View, California, and made famous by the 1997 movie Contact, which included a character based on Cullers.

SETI (Search for Extraterrestrial Intelligence) uses radio telescopes to scan the vicinity of sun-like stars for signals from another civilization. The organization just wrapped up a systematic survey of 700 nearby stars.

The result: No signs of extraterrestrial civilization. But the search only reached a miniscule portion of the galaxy, which has more than 10 billion sun-like stars, the type considered most likely to support life.

Until now, SETI's exploration has been slowed by the fact that it only has had access to the world's top radio telescopes for limited windows of time. And building the most powerful radio telescopes required enormous--and enormously expensive--dishes such as the 1,000-foot-diameter Arecibo Telescope in Puerto Rico.

Then came the big breakthrough. SETI is creating a new type of telescope that will use 350 smaller dishes (20 feet in diameter) instead of the expensive big ones. The dishes will be scattered over open land at a UC Berkeley observatory near Mt. Lassen in Northern California.

Networked together using computers, these dishes will create a radio telescope as powerful as the ones that use a single, large dish. But the cost will only be 20 percent of the price of building one of those conventional telescopes.

"If computing was not dropping in price the way it is, we couldn't do this," says Cullers.

If all the funding comes through, the Allen Telescope Array (named for Microsoft co-founder Paul Allen, who is footing much of the multi-million dollar bill) should be running by 2007, according to Cullers. It's being built in stages, so smaller versions will be working before that.

Get this: The Allen array will speed up the search for extraterrestrials by a factor of at least 100 and much as 1,000, according to Cullers.

Cullers' role is to create computer algorithms for detecting the faint signals extraterrestrial civilizations may give off. He also is researching how much the Allen array can be expanded in the future to create an even more powerful tool.

He sees the speed of the search growing exponentially in coming decades, greatly increasing the chances of finding extraterrestrial life. "I think success is likely within the next half century," says Cullers.

And what happens if SETI does pick up a signal of civilization? The finding would have to be independently replicated, and other scientists would have to be convinced that it wasn't simply a natural phenomenon.

That's really just a beginning. Cullers points out that detecting a signal is much easier than decoding a signal. He notes that scientists haven't even been able to completely decode the language of dolphins right here on Earth. He keeps a wooden dolphin figurine on his desk to keep him humble.

Then there's the issue of how to respond to any signal that is discovered. SETI doesn't plan to send a message back--that's an issue for others to decide. Cullers points out that there would be no need to rush a response, since it would take several years--at least--to reach the extraterrestrials.

Of course, there's no guarantee SETI will pick up the noise of another world. Cullers says he'll only be disappointed if the search becomes exhaustive and still turns up nothing.

He's enjoying the search itself, not just the object of his quest.

"It's a great goal, but getting there is half the fun," says Cullers. "I get to play with my computer toys all day."

—Mark Kendall

Photo courtesy of NASA