Arthur C. Clarke didn't know if there was life on other planets, but he felt it was a scary prospect either way; he said, "Two possibilities exist: either we are alone in the universe or we are not. Both are equally terrifying." Seth Shostak isn't ready to be terrified, he's ready to be astounded, and if things go his way, he will be among the first to give a positive answer to the question. He is the senior astronomer at the SETI Institute in California, SETI being the Search for Extraterrestrial Intelligence. As such, he has to explain why nothing has been found yet, and he also has to arrange for increasingly sophisticated tools to be targeted on the question. In addition, he gets to advise Hollywood about science fiction movies. In _Confessions of an Alien Hunter: A Scientist's Search for Extraterrestrial Intelligence_ (National Geographic), Shostak has provided a stimulating introduction to his work, his motivations, and just what those aliens might be doing to ring us up to say hello. There is plenty of technical detail in his book, but Shostak is a funny writer who has good jokes (often pertinent analogies) on almost every page.
Since he is the public face of SETI, he often interacts with the public about his work. He has been accosted by Christians who insist that scripture mentions no aliens, but many others oppose his organization's efforts on non-religious grounds, grounds that he fairly discusses. After all, there has been some sort of search for signals from the aliens for fifty years, and SETI celebrates a 25 year anniversary this year. Why aren't there signals? If SETI hasn't succeeded yet, Shostak wants us to know that it is premature to call it a failure: "We have carefully examined only 0.0000005 percent of a single galaxy." He gets the objection that it is silly to be looking for ETs out there when they are already here. He'd be delighted to have no more need for SETI because aliens are already physically here. "Frankly, if the evidence were good enough, my colleagues and I would abandon our antennas and begin crawling the countryside. It would be easier and cheaper." The worry about a governmental anti-ET conspiracy comes up in SETI's work pretty often. Even if SETI finds a signal that certainly comes from a conscious being up there, the argument goes, the government won't let people know about it. Shostak has convincing evidence that this is not the case, because the signals have already been captured and the public became fully aware in both instances. Well, that's not quite true. In the first instance, he himself got the signal. Shostak tells the enticing story of how he and his colleagues on 24 June 1997 thought they had the real thing. Long before they could rule out other causes, Shostak was getting calls from the media, like the reporter who called from the New York Times and started the conversation, "So, Seth, what about that signal you're following?" No cover-up would have been possible; the story was out there, and confirmations from other teams were being sought. The attempts at confirmation took over 24 hours to do fully, and showed that the signal was manmade. The other instance was a hoax in 1998, a website report that hacking into another SETI organization had found signals coming in. This turned out to be a straightforward prank, but again, there was no cover-up; attempts at verification were public, and if they had been positive, that would have been public knowledge. This is the way, Shostak says, that if we find signals the world is going to be told about them, in a open scientific manner.
There are some wonderful anecdotes here, like when the guy from the studio art department working on the sci-fi movie _Contact_ called up and said, "So, Seth, what does it look like when you fly through a wormhole?" Movies show such near-lightspeed travel as "some snazzy computer animation that looks as if you're flying through a pig's intestine at high speed," but what would really happen is that the universe would collapse to a bright point ahead and a bright point behind, and everything else dark. Guess which version made it into the film? For the remake of _The Day the Earth Stood Still_, he was consulted on dialogue, which included scientist-speak like "It was moving at nearly three times ten to the seventh meters per second," which he helpfully changed to human-speak: "It's moving too goddamn fast - a tenth the speed of light!" The brushes with Hollywood aren't what keep Shostak in his game, though, nor, he says, is it the pay or the health insurance. He likes what he does because SETI addresses a really big question, and because it will continue to get better at asking the question because receptors are going to get bigger and computers are going to get faster. It is hard to read this likable book from a personable and knowledgeable researcher and not feel that his optimism is justified.
