The science behind the search for extraterrestrials
By Tania Barjesteh

Staff Reporter

Published: Wednesday, February 9, 2011
Updated: Wednesday, February 9, 2011 19:02
Does extraterrestrial life exist? Dr. Seth Shostak believes it does. Shostak, senior astronomer with the Search for Extraterrestrial Intelligence (SETI) Institute, says it's less likely that life is not out there.
On Jan. 28, 2011, the Modesto Area Partners in Science invited Shostak to Modesto Junior College to deliver his presentation, "When Will We Discover ET?" Although the title evokes images of wrinkly, little aliens with glowing fingers roaming the universe in flying saucers, Shostak's ideas regarding the existence of extraterrestrial life are much more down to earth.
"It comes down to numbers as you might have suspected," says Shostak.
He says that with the billions of stars in the universe and billions more planets that surround them, it is improbable that life has not developed on another earth-like planet in another galaxy.
"Biology is just a cosmic infection," says Shostak.
Something like bacterial life, he says, is very likely to exist on other planets, but the existence of intelligent life is more difficult to theorize.
According to a survey commissioned by the National Geographic Channel and conducted by the Center for Survey and Research Analysis at the University of Connecticut, approximately 60% of the 1000 Americans polled believe life exists on other plants. Also, a great majority of them think extraterrestrials are more advanced than humans.
If there are intelligent extraterrestrials out there, Shostak doesn't think they would be very interested in Earth. He likens it to his lack of interest in the ants in his backyard.
He and SETI are interested in them however, and researchers are looking, or rather listening, for intelligent life as often as they can.
SETI's ongoing experiment consists of using large satellite dishes all over the world to listen to multiple radio frequencies for "narrow band signals". Why these signals?
"Because those are the types of signals transmitters make," says Shostak.
Skeptics have criticized SETI for having found nothing in 50 years of research. Shostak says this is due to the limited time researchers are allowed to use the equipment they need.
"It's like trying to do cancer research but always having to borrow the microscope," he says. "It's very slow going."
According to Shostak, SETI is now trying to develop its own facility at the University of California, Berkley's radio astronomy lab that they can use all the time to try and help speed up the process.
" doubling in speed every 18 months on average," says Shostak. "If [this experiment] is going to succeed, it's going to succeed in two dozen years."
He does admit that there are things that could go wrong. The experiment may succeed if all the scientific assumptions behind the work are correct, he says.
Shostak also speculated on what these intelligent extraterrestrials might look like. Ultimately, he says it's hard to tell, but his theory is that they will be thinking machines. His argument is that biological life forms take their time evolving. Gradually, they become intelligent and invent computers. With the relatively fast advancement of technology and the creation of artificial intelligence, they eventually "invent their own successors".
"The evolution of synthetic intelligence would be very short compared to the evolution of...biological intelligence," says Shostak.
There are many questions still left unanswered and much speculation, but Shostak and SETI are continuously working to reveal a little more of the universe every day.

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