Proof of aliens could come within 25 years, scientist says

[Temujin]

'Chances that we'll find ET are pretty good'
Proof of aliens could come within 25 years, scientist says

By Clara Moskowitz
Space.com
updated 8/16/2010 3:52:33 PM ET

ANTA CLARA, Calif. — Proof of extraterrestrial intelligence could come within 25 years, an astronomer who works on the search said Sunday.

"I actually think the chances that we'll find ET are pretty good," said Seth Shostak, senior astronomer at the Search for Extraterrestrial Intelligence Institute in Mountain View, Calif., here at the SETIcon convention. "Young people in the audience, I think there's a really good chance you're going to see this happen."

Shostak bases this estimation on the Drake Equation, a formula conceived by SETI pioneer Frank Drake to calculate the number (N) of alien civilizations with whom we might be able to communicate. That equation takes into account a variety of factors, including the rate of star formation in the galaxy, the fraction of stars that have planets, the fraction of planets that are habitable, the percent of those that actually develop life, the percent of those that develop intelligent life, the fraction of civilizations that have a technology that can broadcast their presence into space, and the length of time those signals would be broadcasted.

Reliable figures for many of those factors are not known, but some of the leaders in the field of SETI have put together their best guesses. Late great astronomer Carl Sagan, another SETI pioneer, estimated that the Drake Equation amounted to N = 1 million. Scientist and science fiction writer Isaac Asimov calculated 670,000. Drake himself estimates a more conservative 10,000.

But even if that lower value turns out to be correct, at the rate they're going, it wouldn't take scientists too long to discover an alien signal, Shostak said.

"This range, from Sagan's million down to 10,000 that's the range of estimates from people who have started and worked on SETI," said Shostak. "These people may know what they're talking about. If they do, then the point is we trip across somebody in the next several dozen or two dozen years."

The SETI quest is set to take a leap forward when the Allen Telescope Array, a network of radio dishes under construction in northern California, is fully operational. By 2015, the array should be able to scan hundreds of thousands of stars for signs of extraterrestrial intelligence, Shostak said.

But while humans might be able to discover an alien signal within that timeframe, interpreting what ET is trying to tell us could take much, much longer.

Shostak admitted such a task would be very difficult. An alien civilization may be as technologically advanced compared to us as Homo sapiens are to our hominid relatives Neanderthals.

"We could give our digital television signals to the Neanderthals, and theyll never figure it out. And they're not stupid," he said.

Yet simply having proof that we are not alone in the universe would likely be a world-changing achievement, Shostak added.

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While I want to be optimistic, the fact that the Inverse Square Law makes omnidirectional signals their bitch and reduces them to being received at only about a light year or two out, I'm really not convinced. Direct signals will be almost impossible to intercept unless we're in the line of communication. Even then, we may only get a snippet of the signal, what some have speculated the Wow! signal was.

[General Zod]

I'll believe it when it happens. Trying to say we'll have proof of aliens in <x> years seems a lot like some fortune teller trying to predict the end of the world. If they don't find anything in 25 years they can just change their projections to another 25.

[Starman7]

I'm also skeptical: considering the extremely short range over which we can detect omnidirectional signals, and how unlikely it is that aliens would turn their radio transmitters to the Solar System on a hoot, I don't think we'll be receiving any signals we can detect without some new transmission system or a radical improvement in our detectors.

[Temujin]

I'll believe it when it happens. Trying to say we'll have proof of aliens in <x> years seems a lot like some fortune teller trying to predict the end of the world. If they don't find anything in 25 years they can just change their projections to another 25.

Ironically, I just remembered seeing Shostak on a special in the past week and I could have sworn he was predicting proof by 2020-2025. Even if the special in question was a few years old, it's already a revision in their predictions.

I'm also skeptical: considering the extremely short range over which we can detect omnidirectional signals, and how unlikely it is that aliens would turn their radio transmitters to the Solar System on a hoot, I don't think we'll be receiving any signals we can detect without some new transmission system or a radical improvement in our detectors.

That's another thing you never hear scientists discuss during those television specials. You always hear how "our signals" have been traveling for about a century, but never how they are indistinguishable from intergalactic background radiation.

[Steel]

That's another thing you never hear scientists discuss during those television specials. You always hear how "our signals" have been traveling for about a century, but never how they are indistinguishable from intergalactic background radiation.

More important than that is actually the fact that while an analogue signal has structure you can pick out a digital signal is indistinguishable from random noise at any range. Now that all our communication is digital nobody on another planet is going to pick anything out of the soup of static. So really theres a 50 light year wide pulse travelling out from us, and if you aren't looking in that gap, you'll never know we were here.

[Gil Hamilton]

Sounds like SETI is fishing for more funding or not to lose funding. "Hey guys, we are totally going to find an ETI signal any day now! So, uh, please don't cut our budget?"

[Temujin]

In light of yesterdays article I guess Hawking felt the need to jump on the bandwagon and reiterate his fear mongering about alien contact.

Do we dare let aliens know we’re here?
Stephen Hawking’s warning stirs a buzz among SETI experts

By Clara Moskowitz
Space.com
updated 8/17/2010 8:34:30 PM ET

ANTA CLARA, Calif. — Even if humanity could reach out to an intelligent alien civilization, scientists are polarized over whether we should.

Famed astrophysicist Stephen Hawking has argued that the extraterrestrials we contacted would be likely to harm us, a view that divided the experts here at the SETIcon convention.

"No one can say that there is no risk to transmitting," John Billingham, former chairman of the SETI (Search for Extraterrestrial Intelligence) Committee of the International Academy of Astronautics, said via a statement read at the convention Sunday. "Personally, I agree with Hawking and think it may be unwise to transmit."

However, Douglas Vakoch, director of interstellar message composition at the SETI Institute, said of aliens: "Even if they tend to be hateful, awful folks, can they do us any harm at interstellar distances?"

Up to now, the efforts of SETI have concentrated on receiving and recognizing signals from non-natural sources in space.

Hawking, 68, claimed that any civilization with which humanity could communicate is likely to be much older and more technologically advanced than ours. So they would probably have the ability, and possibly the motive, to eradicate humanity and strip-mine our planet for parts. It would be safer not to actively broadcast our presence, he said.

Billingham said listening for signs of life is safe, but sending out signals of our own could be asking for trouble. He recommended establishing an international conference to decide whether the whole world supported "active SETI," or METI (Messaging to Extraterrestrial Intelligence).

Canadian science-fiction author Robert Sawyer agreed that international opinion should be consulted before a small group of scientists made any "arrogant" choice on behalf of the planet.

"We've got to stop and think about this, whether this is a wise thing to do," Sawyer said.

But Seth Shostak, senior astronomer at the California-based SETI Institute, said such a conference is unlikely to be productive. "The idea that we can solve this problem with international consultation strikes me as naivete of the first order," Shostak said.

He argued that the whole issue is moot because Earth has been radiating signals into space for decades.

Every radio and television broadcast in history has beamed out electromagnetic radiation to the cosmos — an effect scientists refer to as leakage. While these signals haven't been particularly powerful or targeted to extraterrestrials, a sufficiently advanced civilization would have no trouble detecting them, Shostak said.

"This horse has left the barn," he said. "Any society that could possibly be a threat to us can easily know at least that we're here. There's no point in losing sleep over this."

Furthermore, he and other experts questioned the logic of an alien civilization wanting to attack Earth.

Vakoch said it would take quite a lot of time and energy for extraterrestrials to come all the way to Earth to wage war or try to extract resources from our planet. The cost of traveling here to collect them, not to mention transporting those resources back to the aliens' home, would far outweigh the benefit, he said.

Shostak agreed.

"It's completely analogous to ordering a book from Amazon and paying $60,000 for shipping," Shostak added.

Bolding mine. It's nice to see them at least trying to put things in perspective. If they are out there, they may very well know that Earth harbors life already. And it's not like they have to worry about us or need our resources. Hell, they're probably taking bets on whether we make it through the next century without destroying ourselves.