Is sending signals to aliens really a good idea? wrote:f we are not alone in the universe, then -- considering what happened to the Indians after Columbus landed in America -- shouldn't we be keeping a pretty low profile?

That's one of the burning questions in the current scientific search for intelligent extraterrestrial life. The question was debated in front of an enthusiastic crowd of scientists, teachers and amateurs at a SETI Institute conference in Santa Clara over the weekend.

SETI, the Search for Extraterrestrial Intelligence, is a Mountain View-based organization dedicated to leading and enhancing the growing effort to scour the stars for signs that something else living is out there. SETI hopes the conference will become an annual event.

Most agree that the search for intelligent life is a smart idea, which may -- if it pays off -- revolutionize our existence. But some believe that sending signals and information into space about ourselves, without thoughtfully considering who might be listening, may be an idea that could potentially end our existence.

Award-winning science fiction author Robert Sawyer and SETI scientist John Billingham told the crowd that they agreed with famed scientist Stephen Hawking that there was appropriate cause for concern that some advanced life form could exterminate us. They preached the need for some type of international consultation to at least ponder the risk "of shouting in the jungle."

Seth Shostak, senior astronomer at SETI and the host of the "Are We Alone" radio show, scoffed at the idea, calling it paranoia.

He touched upon the concept that aliens may one day pick up our television signals.

"There is this idea that they see 'I Love Lucy' and, because they don't like Fred Mertz's jokes, that therefore they will then destroy the Earth," Shostak said sarcastically. "Now the data we have on alien sociology is very sparse. We have no idea what the aliens might be interested in doing. And if they were going to do something to this planet, this planet has been around for four-and-a-half billion years, why not wipe out the dinosaurs?"

"They did!'' someone shouted out from the crowd, to much laughter.

At the conference, SETI sold T-shirts displaying the Drake equation (N = R* fp • ne • fl • fi • fc • L) -- a formula scientists use to think about the factors that determine how many extraterrestrial civilizations exist in the Milky Way) as well as posters of Spock mind-melding with President Richard Nixon.

The conference openly displayed the often dual nature of SETI's efforts.

SETI is a highly technical and technological scientific effort involving satellites, high-level computer analysis and some of the finest astronomical minds in the world.

On the other hand, most regular folks are far more interested in "Battlestar Galactica" and "Star Trek." SETI folks understand this and say the conference is part of their effort to teach science, raise money and generate public interest in their quest.

"We know a lot about life here on Earth," SETI Chairman John Gertz said. "We know next to nothing about life elsewhere. That's our mission."

The three-day conference at the Santa Clara Convention Center mixed both popular and technical worlds to address that gap.

There were panel discussions on such topics as dark matter and the Fermi paradox (if there are supposedly so many civilizations in the Milky Way, why haven't we found any hard evidence or been contacted by them?). There was a 1.5-billion-year-old moon rock on display. And there was a talk entitled "Is Doomsday 2012 for real, or will you still have to pay taxes in 2013?" -- in addition to a panel where "Star Trek" actors gossiped about their craft.

Star Trek science consultant Andre Bormanis explained how he vetoed an idea to have Capt. Jean-Luc Picard use a high-tech kayak to travel to the molten core of a planet (it takes too long, magma is dangerous, etc.). And he also explained how he lost an argument that no alien society would come to our planet to rob us of our water (the travel costs versus the benefits are way too high.)

The thousand or so attendees of the conference were a mix of professional scientists, teachers and students, who saw it as a kind of Lollapalooza of science. College students Erin Laidy and Janine Myszka said they were entranced with the discussions of "multiverses" existing side by side. West Marin high school freshmen Lena McDonnell and Amy Goetz wandered the conference on the sunny weekend with excitement about looking for life in extreme places on earth.

All were agog at being able to brush shoulders with the high-profile scientists.

Nearby, tapping on her laptop in the convention cafe, was Jill Tarter, the award-winning astronomer and SETI research director whose groundbreaking work was fictionalized by Jodie Foster in the movie "Contact."

Tarter talked about the Allen Telescope Array -- partially funded by Microsoft founder Paul Allen -- whose intent is to massively expand the ability of scientists to search for signs of life in the universe.

"Will it do the job? I can't answer that question," Tarter said.

"If in fact what I'm supposed to be looking for are Zeta rays and we haven't invented Zeta rays, the best we can do is use the tools and technology we have until we get old enough and wise enough to invent something new."

By the way, her take on the Hawking caution:

"For anybody from 75 to 100 light years away, they have heard the old radio broadcasts. For an older advanced civilization "... they know we are here."