When we first started exploring space, we only knew about the eight planets in our Solar System. Today, we know that in the Milky Way galaxy, there are more planets than there are stars.
Additionally, there are organisms on Earth called “extremophiles” that thrive in extreme or hostile environments, similar to those found on many exoplanets.
With so much potentially habitable real estate in the Universe, it is natural to wonder if it actually is inhabited. SETI, the Search for Extraterrestrial Intelligence, is trying to find out.
JILL TARTER: When we used to ask the question, "Are we alone?" We used to ask the priests and the philosophers. We used to ask them, "What should we believe?" But what any of us believe isn't going to change the way the Universe is. And so, the appropriate thing is to do a scientific exploration, to go and try and find out what is. We want to know how we stack up against the cosmos. Are we unique? Are we one of many? And if we are one of many, how intelligent are we relative to something else out there?
Speaker: Welcome to the Berkeley Forum. We're so lucky to be starting off this season with Dr. Jill Tarter tonight. In 2004, she was named one of the "Time 100 Most Influential People in the World." She has served as the President of the California Academy of Sciences. She has an asteroid named after her. So without further ado, please welcome Dr. Jill Tarter to the stage.
TARTER: Thanks, Charlie. All right, are the mics working?
SPEAKER: Yeah.
TARTER: Good. My name is Jill Tarter. My title is Emeritus Director of SETI Research. I'm often introduced as being the woman who was the inspiration for Ellie Arroway, played by Jodie Foster in the movie "Contact."
I was back visiting Cornell for some symposium. When I got there, Ann Druyan, Carl's wife, and Carl took me off to the corner. And Ann said, "Carl's writing a science fiction book. I think you might recognize one of the characters, but I think you're gonna like her." Carl sent me a pre-publication copy. I was going, "Wait, wait, Carl doesn't know this about me. How did he, how, how?" And it turns out, when I was a fresh Ph.D., I got invited to a meeting in Washington, and I walked into a room of 80 female Ph.D.s in all kinds of STEM fields- life-changing experience for me.
I told Carl about this meeting and we did a little bit of amateur demographics, and it turned out that many of those women had their fathers die when they were young, just like me. When I was about eight years old, I was down in the Florida Keys. And I remember one night walking along the edge of the Gulf, holding my dad's hand and looking up in the sky, and seeing these magnificent stars. And I just had this idea that on some planet around one of those stars, there would be a creature walking along the edge of an ocean with their parent. And I don't know what set of circumstances led me to have that particular worldview, but it's been with me for a long time. And I said, "Okay, I'm gonna be an engineer." Then, sadly, my dad died a couple of years later. And I had told my dad I was gonna be an engineer, and then I just got stubborn about it. That was it. I've never had any other job except thinking about life beyond earth.
Over my career, we have discovered planets around other stars, exoplanets. When we started, we only knew about nine in our solar system. And then we demoted one of those. But now we know that in the Milky Way galaxy, there are more planets than there are stars. And additionally, we now know about organisms that we call "extremophiles"- forms of life living in environments which, when I was a student, I was taught, utterly no chance, that's gonna be sterile. No reason to look for life there. But of course, life is there. And now, it makes it just seem natural to ask the question, 'Well, with all that potentially habitable real estate out there, is any of it actually inhabited?' SETI, the acronym, is the Search for Extraterrestrial Intelligence- but that's actually a misnomer.
We don't know how to define intelligence. We certainly don't know how to detect it at a distance. What we can perhaps do is find evidence of someone else's technology that is detectable over these vast distances between the stars. We've been looking for electromagnetic radiation, signals either at radio wavelengths or at optical wavelengths, but we're specifically looking for the kinds of signals that, as far as we know, nature can't produce, but our technologies do it all the time.
We have different ways of doing that. And in my case, teams that I've worked with look for technosignatures; so we write software that's looking for those particular patterns. I've had the privilege of being in at the beginning. My first year in graduate school, UC Berkeley acquired the first real desktop computer that had ever been manufactured, the PDP-8/S. And it had no language, you had to program the 11 things that it could do by setting all the ones and zeros.
As I was finally getting ready to finish my graduate degree, that piece of equipment, that computer was obsolete, and it was given to an X-ray astronomer by the name of Stuart Bowyer. He figured out a way that we could take the data and we could analyze it looking for signals that were engineered. And so he came and recruited me to work on his SETI project at Hat Creek Observatory, and I programmed that PDP-8 to be the processing engine for that search.
You have to be very careful in this kind of work about deciding whether or not what you have detected, what shows up in your data, is actually real, coming from the sky, or whether what you're finding in your data is coming from your own equipment, noise that you generate. And so we have this problem of deciding whether what we've detected is us or them.
Over time, that gets to be more and more problematic as there are more satellites orbiting. And so we've had to try and get clever, and we certainly spend a good half of our computing resources trying to discriminate between us and them. And now, we're on a threshold where we can begin to think about using artificial intelligence to help us with this search, to look at the data in a bias-free way, and say, 'Not is there this pattern, but is there any pattern?' I think that's going to open up a lot of new channels for SETI research in the future. For me, the fun part was getting started with this.
This idea of working on something that might not succeed during your career is a little dicey, and it takes a certain kind of personality to be eager to do that. The real reason to work on this question is to know whether it's possible for us to have a long future. There are so many challenges on this planet today. Maybe our future is not very long because of mistakes that we have made in terms of living on this planet in a sustainable manner. So a successful detection means that it's possible to have a long future as a technological civilization. I don't expect them to solve our problems but I do expect, if we succeed, to be inspired by knowing that somebody else made it through this technological adolescence, and we can too, we simply have to find the way.
This is a really large search, and our tools for doing the search are getting better all the time, and now, exponentially faster. It makes me mad to be old because I'm not going to be around long enough to see the end of that story or the beginning of the next phase of our searching. Now, in my cheerleading role, I'd like to work on establishing an endowment so that this kind of activity, this scientific exploration can be funded stably into the future because that's what it's probably gonna take.
