The Conversation hosted a public Q&A session on Reddit where Seth Shostak, Senior Astronomer at the SETI Institute, explained why the search for intelligent life is so important and why we may soon find it.
Question – Why are we continuing to research? For example, isn’t it true that radio waves become almost indistinguishable from background noise within light years of their origin?
Answer – We can detect radio waves billions of light years away, and without too much trouble. The idea that it is impossible to distinguish them from noise at a small distance is false. With a large enough antenna, you can still find the signal.
But the most important point is that we now know two things that we did not know 20 years ago. First, planets, including those that might resemble Earth, are incredibly numerous in the visible universe. There could be a billion billion cousins of our world. Second, life began very early on Earth.
If intelligent life doesn’t exist elsewhere, then we’ve done much better than just winning the lottery. And if you think we’re that special… well, think you might be wrong. And this possibility makes it worth trying to answer the question experientially, rather than saying “I already know the answer.”
When you do eventually find intelligent life beyond Earth, who will govern the announcement? Is there a protocol to follow before this becomes public?
There is a document. In short, he says, check the signal to make sure it’s really extraterrestrial. Then announce it to the whole world, and consult the international community before transmitting a response.
But, in reality, it will be a wild ride in the media, and scientists will do their best to learn as much as possible about the signal.
How would such a contact take place? Stephen Hawking thinks that, given the way we humans deal with many less intelligent life forms on Earth, do you believe it’s likely that higher life forms don’t have our best intentions? mind at the moment of contact?
We are likely to develop strong artificial intelligence (AI) in this century. This suggests that any signal we might pick up would be from an AI on their side. To attribute to this “intelligence” the kinds of motives described in many posts here seems largely unfounded. We have no idea what they might be interested in, but destroying us seems a bit too self-centered.
Can you tell us about the WOW signal and its importance?
It was nothing more than a drift plot on a computer’s line printer that appeared once. Not a second time, even though we only looked for him a minute later. There were a lot of spot sightings like this in the days of SETI, and there’s no evidence that they were extraterrestrial signals.
How often does something happen that makes you say, “That could be it”?
Thanks to our computer programs filtering out interference, a “this could be it” moment happens very rarely. The last good time dates back to 1997.
What do you think of the Fermi paradox, that maybe life isn’t so abundant, because if it was, it would have already contacted us?
Fermi’s paradox is a great extrapolation from a very local observation. We don’t see any obvious evidence of galactic colonization around here. So they couldn’t be there. Really ? I don’t see any evidence of megafauna in my garden, so maybe there isn’t…
You can come up with many ideas as to why galactic colonization is not a desideratum for advanced intelligence, and the fact that people can invent plausible reasons should lead you to consider the paradox an interesting idea, but not as a very significant observation.
What do you think of panspermia – the idea that life exists throughout the universe in microbial form distributed by celestial bodies like asteroids?
Panspermia could exist, although most astrobiologists I’ve talked to about it believe that while bacterial spores can survive a trip inside a solar system, they wouldn’t jump from a solar system to the other.
Why do scientists keep looking for water and oxygen when looking for intelligent life?
Chemistry suggests that carbon-based molecules are probably the best bet for biology. But SETI makes no assumptions about this.
How many people in your field are concerned about Bill Watterson’s quote that “The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us”?
First of all, the assumption (she never tried to contact us) is a statement without any proof. The erased part of that quote…that we’re not worthy to be contacted…is more about Watterson than humanity.
Seth Shostak, Principal Astronomer, SETI Institute