http://www.post-gazette.com/pg/03298/234442.stm Alien hunt in space may score by 2025 Saturday, October 25, 2003 By Michael Woods, Post-Gazette National Bureau E.T., the extraterrestrial, may prowl neighborhoods on Halloween with Hollywood's other soft-and-squishy renditions of intelligent alien life forms. But when might we humans actually, finally encounter the real thing? Probably in your lifetime. By 2025. The leading experts in the search for extraterrestrial intelligence at the SETI Institute in Mountain View, Calif., recently completed the most systematic calculations ever performed on when the human race is likely to contact intelligent alien life for the first time. Their answer: within 22 years. And they suspect that our first interstellar interlocutor might end up being a super-intelligent machine rather than anything biological. Seth Shostak unveiled SETI's predictions at an international astronomy conference in Germany earlier this month. He and co-author Alexandra Barnett will go public with their findings Nov. 1 when their new book, "Cosmic Company: The Search for Life in the Universe," is published by Cambridge University Press. "There are as many stars in the universe as there are grains of sand on Earth's beaches," said H. Paul Shuch, executive director of the New Jersey-based SETI League Inc. "About 10 percent may have planets with intelligent life. That's your haystack. "We investigated the rate at which astronomers will be scanning those stars for radio signals, and concluded that it will take about one generation to find the needle." Shuch, who attended Shostak's presentation in Germany, nevertheless joined other scientists in chiding Shostak for so starkly predicting first contact by 2025. "My respected colleague should know better," Shuch said. "It is safe to say that by 2025, our newest and greatest SETI technology will have been up and running long enough to make a detection -- if." "Ifs" include: that extraterrestrial life exists in detectable civilizations relatively close to Earth that are still primitive enough to use radio signals.
The search accelerates Organized searches for extraterrestrial life began in the 1960s with radio telescopes -- antennas shaped like satellite dishes that can capture electronic signals transmitted from other planets. Scientists look for signals with patterns that suggest they were sent intentionally and are not simply stray transmissions from energy sources. Earthlings also have tried to reach out to extraterrestrials. In 1974, the Arecibo Observatory in Puerto Rico, the largest radio telescope in the world, sent a digital message toward the M13 Global Cluster. It will arrive in about 25,000 years. The Pioneer 10 spacecraft launched in 1972 carried humanity's first message-in-a-bottle -- a plaque bearing an illustration of a man and a woman and a diagram identifying Earth's location in the galaxy. It is now 9 billion miles away. The search for extraterrestrials has been intermittent, however. In 1993, a budget-cutting U. S. Congress canceled NASA's SETI program. By the late 1990s, there had been barely two years of continuous observations for extraterrestrial messages. Now the pace has picked up, and this figures heavily in Shostak's prediction that intelligent life will be detected by 2025. The SETI Institute's Project Phoenix, launched as a successor to the NASA program, employs Arecibo and other radio telescopes in West Virginia and Australia. Computers monitor millions of radio channels simultaneously, focusing on relatively close stars likely to host planets hospitable to life. All these stars are within 200 light-years of Earth. A light-year is 5.9 trillion miles, the distance light travels in a year at 186,000 miles per second, so that would be about 1,180 trillion miles. Anyone with an Internet connection can join the search by downloading a free program at http://setiathome.ssl.berkeley.edu, which uses spare computer time to analyze radio telescope data. One thing that has slowed the search for extraterrestrials is the need for researchers to share telescope time with astronomers doing other work. Project Phoenix, for instance, can make SETI observations at Arecibo for only three weeks each year, allowing it to scan only 60 star systems annually. SETI soon will get its first "dedicated" telescope, called the Allen Telescope Array, which will provide continuous observations. A project of the SETI Institute and the University of California at Berkeley, the Allen array will employ 350 dishes, each about 20 feet in diameter. It will be built 250 miles north of Berkeley with $12.5 million contributed by Paul Allen, co-founder of the Microsoft Corporation, and Nathan Myhrvold, Microsoft's former chief technology officer. When completed around 2006, the Allen array will survey about 1,000 star systems annually, Shostak said. Future upgrades could greatly increase the telescope's scanning speed. The pace will accelerate further if an international consortium gets funding for another full-time SETI telescope, called the Square Kilometer Array. NASA and the European Space Agency both plan SETI-related missions, as well. NASA's Terrestrial Planet Finder vehicle would search space for planets like Earth. The European agency's Darwin project would involve a flotilla of six space telescopes scanning for life on Earth-like planets. By the early 2020s, Shostak calculates, scientists will have scanned enough star systems that the odds are excellent that they will have found signals from an alien civilization.
Man meets machine? "Seth Shostak is a very capable scientist," said NASA's Marc Rayman. "I think it would be wonderfully exciting if the prediction proved correct. But our understanding is so immature that it's hard for me to see how we could expect such a fantastically important result in such a short time." Dr. Stuart A. Kingsley, director of the Columbus Optical SETI Observatory in Ohio, searches for laser beacons from extraterrestrial civilizations. "In this game one probably needs to be somewhat optimistic to remain motivated," he noted in an interview. "There have been many optimistic predictions of success in just a few years, but where are the results?" Shostak acknowledged "many" reasons why his calculations might be wrong. "Nevertheless, the intention is to improve upon existing 'gut feeling' speculation," he added. As for E.T.'s appearance? "I doubt if they will be the aliens you see in the movies," he said. "Those are human hopes and fears about extraterrestrial life. We may find biological intelligence, actual living things. Then again, it is entirely possible that it will be machine intelligence." Biological aliens may share some of humanity's architecture, with eyes and ears up high for good data input and appendages like arms and legs, Shostak said. They might be about human size, too, but probably not bigger than an elephant or smaller than a golf ball because extremes don't survive well. "In a general sense, we're pretty well designed," Shostak observed, "and it may be a basic pattern for life." Shostak nevertheless thinks humans are likely first to contact super-intelligent machines -- machines capable of reproducing themselves that have come to dominate their planets. They may view biological life forms much as humans view domestic pets or wildlife. "It's entirely possible that biological intelligence is just one step on the road to another kind of intelligence -- machines 100,000 times smarter than humans that take control," he said. Humans should hope the first encounter with aliens will be long-distance, Shostak suggested. "I would be very leery of visitors, to be honest," he said. "There would be few reasons for aliens to appear. Ask yourself, why did Pizarro visit the Incas?"
|
