The Origins Podcast with Lawrence Krauss - Geoff Marcy: The Search for Exoplanets and Life Elsewhere in the Universe

Episode Date: July 29, 2022

Geoff Marcy has been pioneer in the search for extra-solar system planets since the first discovery of an exoplanet surround a main sequence star was made in 1995 by Michel Mayor and Didier Queloz. Within months, Marcy and his team had not only confirmed this result but detected numerous other exoplanets. Seventy of the first one hundred exoplanets were discovered by Marcy’s team, including the firs exoplanet located as far away from its star as Jupiter is to the Sun, and the first exoplanet discovered by observing its transit of its host star, a technique that will be used by JWST to explore the atmosphere of exoplanets to search for bio signatures. Marcy was then a Co-PI on the Kepler Mission, which discovered over 4000 exoplanets. For their pioneering work in the creation of this new field Marcy and Mayor shared the international Shaw Prize in 2005. More recently Marcy has turned his attention to methods to probe for intelligent life in the Universe, first as a PI on the Breakthrough Listen Project, and more recently exploring novel methods, including optical techniques to probe for possible signals of intelligence elsewhere. We discussed all of these exciting topics, as well as Geoff’s own origins as a scientist in a thoughtful and fascinating discussion. He has become well known not just as a world renown scientist, but as one of the best communicators of astronomy there is. Our discussion will give a whole new dimension to your thinking about that age-old question: Are we alone in the Universe?As always, an ad-free video version of this podcast is also available to paid Critical Mass subscribers . Your subscriptions support the non-profit Origins Project Foundation, which produces the podcast. The audio version is available free on the Critical Mass site and on all podcast sites, and the video version will also be available on the Origins Project YouTube channel as well. Get full access to Critical Mass at lawrencekrauss.substack.com/subscribe

Hi, I'm Lawrence Krause and welcome to the Origins Podcast. On the last podcast that we aired, Andy Knoll and I discussed the first four billion years of life on Earth, addressing questions of how life affected the Earth, the geology of the Earth, and vice versa. Clearly important questions to try and understand the origin of life and its interaction with our planet, which addressed the more foundational question perhaps of, is it possible that life originated not just here on Earth, but elsewhere, either elsewhere in our solar system on other planets or maybe moons of planets. Equally important, what's the likelihood that life developed elsewhere in the universe on extrasolar planets around distant stars?

Clearly, one of the prime developments that have affected that whole search was the discovery of extra solar planets. The first extrasolar planet was discovered by Michel Mayor and Didier Cuelos, and then immediately followed up by the discovery of other extrasolar planets by Jeff Marcy and his team, who discovered of the first 100 extra solar planets, including the first extrasolar planet located more than 5AU from its star about the distance of our current gas giant planets in our solar system. And equally important the discovery of the first planet that transited its star and dimmed the light of its star. Now the two techniques that have been used to discover extra solar planets looking at the Doppler shift as the star moves in response to the motion of planets around it and this transit

technique were spearheaded by Marcy. And for his work in that regard, along with the discovery of extra solar planets, he and Meyer won the International Shaw Prize in Astronomy. Marcy went on to be one of the co-PIs on the Kepler satellite mission, which discovered over 4,000 extra solar planets. And after that, he's also addressed, in fact, another issue that's relevant to understanding life in the universe, the possibility of intelligent life in the universe, the search for intelligent life for the universe. And he was a principal investigator on the Breakthrough Listen program, and more

recently has considered the interesting question of whether we might use visible signals to look for extra solar life instead of just radio signals, an area of research that he's actively involved in right now. Jeff and I discussed all of these important questions, and it's hard to think of a better person to discuss the search for extrasolar planets and their implications for life in the universe perhaps than Jeff Marcy. And I enjoyed the discussion tremendously. I hope you do too. If you want to watch it without ads, you can go to our Critical Mass Substack site and subscribe. Then you can watch it without ads. The subscriptions go to help support the Origins Project Foundation, a non-profit foundation that supports the podcast

and other activities that help bring science to the public. Or you can go to the Origins Project YouTube channel and watch it there. Or, of course, you can listen to this podcast on any place you can listen to podcasts. However, you listen to it or watch it, I hope you'll consider supporting the foundation in a variety of ways. And more importantly, I hope you enjoy the discussion that Jeff and I had as much as I did. Thanks. Well, Jeff, I'm very happy, really happy that you're finally able to be on my podcast. As you know, for many, many years, I've not only been a fan of your work, but I'm happy to say that I've gotten an O you better as an individual in the last few years as well.

But I remember we first met many, many years ago when I was chairman of the physics department at Case Western Reserve and you came to give a talk. Do you remember that? Absolutely, very vividly for all sorts of reasons. And I remember meeting you and chatting with you in your office. And you were very gracious. I actually think you even gave me some slides. Back, those were in the days, I think, when we used slides. And I said, wow, I'd really like that image.

And you said, okay, here's a slide. I think you gave it to me. And I was just shocked and impressed. So you're very generous even then. And by the way, I'm kind of wearing this shirt in honor of you, just so you know. Amazing. Because I'm going to talk about what it seems to me as I think about what you've done in your career. This notion of charge, not only just the little aliens, but the notion of charge of basically boldly going, well, where no one has gone before, but boldly going in a way that, you know, we'll just damn the torpedoes full speed ahead, as Richard Feynman once said, but someone else said it before him as well.

And I want to, I want to ask, this is an origins podcast, as you know, and I want to go back to your origins, which I've been learning about a little bit. You're born in Michigan, but you grew up in California. Is that right? That's exactly right. Yeah. How old were you when you moved to California? Four. Okay. Do you remember Michigan?

I remember being knee deep in snow in Detroit, in the suburbs of Detroit, and that's it. Okay. Well, and then you quickly got out for Southern California, right? You grew up in Southern California? Absolutely, yeah. My whole childhood, public education, the San Fernando Valley, but nobody's perfect. Yeah, that's okay. Now, were your parents professionals or with academics or what did they do? Yeah, it's interesting. My mother majored in anthropology, got her bachelor's degree in anthropology.

She used to talk to me about early hominids and the latest discoveries of hominids on the East African Savannah. So I was very much imbued with the sense of sort of wonder about our own roots as a species. But my dad was a mechanical engineer, worked on thermal cooling systems. And he worked on airplanes, jets, and eventually later on the space shuttle. Wow. Why you were a young kid? Yeah, yeah. He would tell me about his, you know, he was proud, of course, to,

have a contract, his group, of course, with NASA and helping with the cooling system. I think he told me he worked on the so-called auxiliary power unit of the space shuttle. Okay. I kind of almost know what that was because I was a nerd as a little kid and I used to, well, I used to study the spacecraft. Well, I wanted to be an astronaut when I was younger and I wanted to be the first Canadian astronaut because they didn't have them back then. Yeah.

But I think I even, I wrote a letter. I'm not sure I ever sent it trying to convince NASA. what a what a what a what a coup it would be what a public relations could be to have someone from another country but I don't think I resent it since I was probably about 14 at the time but anyway so this but it's interesting when when I hear this so the combination of your parents is kind of interesting your your own work in a way spans the two things your mother's interest in early humans and therefore sort of origins of life issues and modern humans your father's technical work as an engineer And your work in some sense has combined the two. Your technical work as an astronomer has led us to new thresholds about thinking about origins of life in the universe. So it's kind of nice how you've got to merge those. Yeah, I feel lucky about my parents, that's for sure.

Did they encourage your interest in science, or how did that arise? You know, that's a good question. And the answer is yes, of course. And I can remember every afternoon and especially evening, they really, really required me to do my homework and especially the science and math homework. So I would sit at my little desk in my little bedroom and they would sometimes peer over my shoulder and make sure I did my homework and try to help me with my homework. But I can remember it.

You know, it's one of these situations where your parents are imbuing you with some set of values that you're not even aware of as a child. And I remember, you know, now in retrospect, thinking, gee, they were telling me that my school work was important and that learning the basics, English and math and a little science was important. Oh, yeah. Well, in fact, we'll get back. I want to, we'll probably talk about education later. We'll see where we go. But, but, that, that being taught to value those things at home, I guess, is really important. And it's and it affects people throughout the rest of their lives. But what made you want to do sort of physics and astronomy versus something else?

When I was 13 years old, I remember so clearly my mom and dad bought me a poster of the solar system. And it had the sun and then the nine planets. And it had some of the moons. I remember back then Jupiter had only 12 moons that were known. And I put it up on the next to my bed and I would lie in my bed looking at that poster and thinking about how far away the planets were and how beautiful they were and the rings of Saturn were unbelievably exquisite. And then the moons going around and around. And I just thought, wow, this is this is amazing. The distances are huge and we know so much.

Of course, this was 1966 or 1967. But it really did throw me, I think, for the long duration about the beauty and the puzzles of the solar system and the universe at large. Did you, what about school? Did they encourage you? You know, I went to public schools the whole time, elementary school, junior high school, high school. And I thought my education was quite good. You know, I had teachers who seemed to be able to teach math and English. And I was lucky to take classes, you know, in writing. So I was learning how to construct a paragraph.

And then, you know, I took the usual biology and chemistry and physics classes. I wasn't very good at them. I was really sort of a B plus student. I struggle. But I feel very lucky that, you know, in public education, I had good classes. Yeah, that's nice. I mean, the teachers were supportive.

They basically encouraged you to continue. I was reading, as I've been reading about your lady, which has been kind of fun, somewhere someone said that Carl Sagan was a hero of yours. And is that true? He was. I don't know if they made that up. No, he really was inspirational. I remember reading one or two of his,

books and watching him on TV. And I was especially impressed with the way he married social justice issues, like the need for equality of all people's, equality for cross-genders. And he was very interested in equality for all nationalities around the globe. And he looked at the whole sort of throw of history as a as a sort of a long story of people gathering together. He saw the human species as a sort of a team and how we should try to pull together as a team. And he used to talk about what would the advanced civilizations say as they descended toward Earth and looked over the Earth and saw squabbling in wars with discrimination and financial inequities and so on.

And he argued, I thought, very persuasively and passionately, that we should pull together as a species and try to help each other. Certainly, I mean, he tried to think globally in that way with the golden record was certainly a good example of where you tried to think about what would humanity as a species want to leave as an imprint in the cosmos in Voyager as it went out if it was ever discovered. And I think that's probably the first time any organization officially tried to represent humanity, all of humanity and not some country or not some individual. It was kind of an interesting idea.

One could argue about what they chose. Yeah, right, exactly. Well, I give him full credit for viewing we homo sapiens as a sort of fledgling species in the galaxy struggling, and we should try to encourage coherence and cooperation. You know, the other thing he did, I guess he was political, I mean, his work on nuclear winter, which, by the way, after the fact was probably wrong, but nevertheless, had tried to raise attention and point to yet another danger of nuclear weapons in a world that still has now,

still has 10,000, over 10,000 nuclear weapons far more than anyone could ever imagine. Another theme that he raised repeatedly, which I loved, was he talked a lot about equality for women. And he talked a lot about the fact that over the globe, those countries in which the lives of women, were improved and the education of women were improved, those countries thrive. And they were financially better off, socially better off. So he was, I thought, a passionate and wonderful

advocate for equality for women. Yeah, yeah. And we'll get to that because I know that influenced you in your younger days too, especially when you were a student in a variety of places. I was reading about that. Did you watch Cosmos? Did that have any impact? Oh, I loved Cosmos, yeah. And there's some of those episodes are just indelibly, you know, seared into my brain. I thought they were beautiful. The overall philosophy of learning our place in the universe, how small we are, but indeed how important we may well be as an intelligent species in civilization. So he captured the grandeur and the puzzles, but also the sort of human spirit, you might say. of our human place in the universe.

Yeah, no, he was very grand. And I remember, yeah, I got to meet him a few times when I was at Harvard and he used to come to visit there. But I didn't watch Cosmos, maybe because I grew up in Canada. And so for me, it was another individual, Jacob Bernowski, who really had an impact on me in terms of the grandeur of the human condition and culture,

but also the wonder and joy of communicating science, which obviously, as you know, is something that's that has played a part in my life. But you have been well known, especially after your first discoveries, which gave you more of a platform, as being interested in communicating. Absolutely. Did the example of Sagan, did that influence you?

It's something you thought of doing when you were a young person about wanting to communicate science? Well, it's funny you mentioned that. You've reminded me of something I'd forgotten when I was in fifth grade, my fifth grade teacher, Wayne Tate, at Plummer Elementary School. He one day he came up to me and he said, Jeff, I'll tell you what, you should be a teacher. And I've never forgotten that. I mean, out of the clear blue. And I don't know what it was about me that made him think that.

But maybe he saw that I enjoyed helping other people and teaching them and connecting with them. And so, and then of course, Carl Sagan, as you say, resonated with that. And there were other great teachers. One I can't help but mention here is George A. Bell. He was a wonderful astronomer, a professor at UCLA, and he got his Ph.D. at Caltech and discovered clusters of galaxies, famous for the so-called A-Bell catalog of clusters of galaxies. But he was a passionate teacher. and he ran his own science school,

and I was lucky to take two classes from him. And he also said to me, you know, teaching is the greatest honor that you can do as a scientist. Oh, that's wonderful. Well, you know, we'll get to that because part of, it was interesting to me that I didn't realize it at the time, but, you know, part of the attention you got

for discovering exoplanets was due to the nature of discovery. But I think compared to your collaborators and other people, people turned to you because you were able to talk to, in addition to having made the discoveries, were able to convey not only the excitement and passion, but talk about the science to journalists. And I remember that vividly the colloquium you gave it at case when I was chair. It was clear that, you know, that you enjoyed that, that sense of communication, that ability to do that, and that, therefore made you a person that. that journalists would seek out, which I suppose at times in groups of large collaborations,

but people might sometimes feel jealous or at least some sense of that because people are turning to you. But in my experience, journalists have turned to people who will talk to them, first of all, who are interested in talking to them and can convey the information. Yeah, I mean, you've hit on a number of important topics there. And I do love teaching, and I get a lot of joy about it. Still to this day, yesterday, was teaching a fifth grade student about the universe and also how to play tennis. So I remembered even yesterday how much I enjoy and really feel it's our obligation as adults to be teachers as well.

But as you pointed out, when your ability to connect with the broad audience, when that ability is great enough, people do turn to you. when that happened to me. And then I tried hard to make sure my collaborators got as much attention and credit. And I, you know, frankly failed. I mean, I know that I tried hard, but I was not able to make sure that my collaborators got as much credit, as much attention, got their, you know, the accolades should have gone more to them. Well, you know, look, I mean, it's not, it's not your fault.

in a general sense because I've experienced this. Journalists want to pick an individual and they always, you know, you probably had this experience too in the old days, but they always want to glory, they want to make everyone seem like the next Einstein whenever they're a scientist. Yeah. And so it's not, and I'm not criticized journalists in that sense. People like public interest stories and they want to turn to an individual.

So journalists will naturally sort of hold on to that and try and, and try and glorify that in the sense because that's, That's what captures the story. And often that's what will interest their editors in allowing them to do a story. So it's just a part of the problem of modern journalism that they don't really convey science for what it really is, which is a team effort in many ways. And also an effort of baby steps. Every new discovery is revolutionary and groundbreaking.

And as I say, the next science is done. And they don't realize that science is often done by lots of little baby steps. But that doesn't make for good headlines or good press or something. newspapers. Yeah, that's exactly right. It's very tricky. And obviously, what you're saying is that the public relations side of science is treacherous. We are sending, unbeknownst to us, a false message about the process of science, which often involves mistakes, team efforts, false starts, blind alleys, and other people helping to redirect and eventually, hopefully, getting the right answer. Well, look, I don't want to make it seem like it was just a cushy ride for you because it wasn't, and I want to go back.

So you went to UCLA, which was your local university or basically? That's right. And did physics and astronomy, right? Yeah, I went back and forth between majoring in physics and astronomy, and eventually I just did both. Yeah, okay. But astronomy clearly was your passion. I mean, you just had at what point, was it only into graduate school that you decided you wanted to do astronomy or what point did you decide? Well, what happened when I graduated with my bachelor's degree, I knew I wasn't smart enough to ever be a scientist. And I just thought I will continue the ride in physics or astronomy as long as the world will let me. And then I'll just have to be thrown out on the street. And I was very clear about that. And I applied to graduate schools thinking maybe I'll be able to get a master's degree somewhere. And I applied to both physics programs and astronomy programs.

I got into a few of each. And I just felt lucky that UC Santa Cruz accepted me. A few other places did too. And I knew that astronomy was more my passion. So I thought, well, look, if I'm going to fail, that's fine. But I'd like to fail enjoying the ride for the few years in graduate school. and then I'll go off and try to live on normal life. Well, you know, it's interesting.

There's an important lesson there in the sense that you recognize, which I think is a lot of people look at the alternatives and don't think and try and judge them. I see students all the time trying to judge them in terms of where they're most likely to get a job or the most money or something. And I always say it's just crazy to think of that because first of all, you never know down the line what's going to happen. And secondly, if it's not, if you don't choose what you're most passionate about and

You're not going to be, you know, not only it won't be happy, but you probably won't be as good in something else either. So if you choose a career path that you think is safer, well, it's all right to choose it later, but your whole life doesn't depend upon what you study at school. That's the one time when you can do what you really care about. And all the skills you might learn in astronomy or physics or anything else or history or anything else will later on be useful to you in whatever field you. Well, that's for sure. And I remember thinking just what you said. I want to enjoy a few more years in school before I flunk out.

But also, I knew that I was lucky with the education I'd already had. This is what you were saying. I did have math. I had taken several years of math at the college level, UCLA. I took, you know, many years of physics. I took some chemistry. I had some computer programming skills. You know, I learned Fortran on my own, but it was not, you know, it's not that big a deal,

like how to write an if statement or a, you know, how to write an equation down and solve for X. So, you know, it turns out in the world, if you know English and you know a little bit of math and maybe a little science, you're good to go. You can live a life that way and have a creative life and a life where you pay the bills. Okay, well, you moved to Santa Cruz, which was known for its, which, you can live. which had a very strong astronomy group and a reasonable physics group too. And I think we've talked about this once, but we must have met, or at least we must have been in the same room many times,

because the last year of my PhD, I did my PhD at MIT, but my supervisor moved to Santa Cruz for that last year of my PhD. And I was, and actually I taught a class with George Sand and a really interesting Matthew Sand. sorry, Matthew Sands, who was a fascinating and interesting teacher, who was, who helped write the Feynman books. And, and, and I sat through, yeah, remember him? And, and I sat through many colloquia. I, I didn't, I didn't sit through as many, you know, there weren't separate astronomy ones. I guess there was a physics colloquia. There may have been, I didn't, I began to

venture. It was a time in my life when I began to learn more about astronomy. So I heard those things, but we must have been in the same building at the same time, because you got, you got your PhD at the same time as I did. And there was just one building that had both astronomy and physics. That's interesting. Well, so there we go. We never knew we'd cross paths. For me, I spent one term there, basically, January on. No, no, I guess I was no, the whole year. The whole I could be here, because I went there in September. I remember, and that's when I, and I had to fly back for an interview for the Harvard job. And Santa Cruz for me was a revelation.

It was very different than anywhere I lived in Cambridge and in Boston. But you went from there and you got a, you know, I was happy to move to where I did, but you got a nice fellowship at the Carnegie Institute, which is Mount Wilson, right? That's right. And then you experienced a career issue. And I think that I didn't, I wasn't aware of that. But I think that's really important that you. not only had it, but how you reacted to it. So maybe you want to talk about that a little bit.

Well, I think what you might be referring to is when I got to the Carnegie Institution, I felt like I was surrounded by brilliant astrophysicists, and I knew I wasn't. And I kind of felt like it was a mistake that I had gotten the Carnegie Fellowship in the first place. And indeed, my PhD thesis topic, which was to measure the Zayman effect in stellar spectra, was floundering. It had run its course. And I was desperate to find some other type of research to do for my remaining year and a half. And I couldn't think of a good project. And I got more and more depressed. And it was pretty serious. I remember waking up in the morning. And I felt so terrible I couldn't get out of bed. I just lay there thinking, I feel sick. And my head was hurting. And, I remember asking myself, knowing that I was sort of inadequate in this world of Carnegie Institution with Caltech next door, I started wondering, you know, whether I was actually suicidal. And I remember asking myself that. Am I going to commit suicide? Because what will my parents think? What will my friends think if I can't succeed as a scientist?

And I was lucky the health plan they had allowed me to go see a psychotherapist. And I went, it was a Kaiser downtown Los Angeles. And, you know, for, I don't know, four or five months, I went every week. And, and, you know, in brief, the guy I saw, I was lucky. He basically, you know, pulled me out of the depths. And he said, look, you know, you've got to have a little more self-esteem and you've got to somehow enjoy the ride and whatever happens happens, but you know, you've got to find some pleasure in whatever it is you're doing. And, you know, you may end up opening a new chapter

later on. And that allowed me to at least survive. Oh, yeah, that's, you know, that's fascinating. Again, you know, there are hard periods of, and this is probably worthwhile for students to to know. I mean, there are hard periods in life. It depends. I mean, graduate school itself can be a very difficult time. I know it was for me in some ways the feeling of, especially if you come, I went to a small school in Canada and suddenly I was doing my PhD at MIT, and it was a question of whether, you know, whether I could compete and whether I was good enough. And then, and then the misery of sort of working on, working as a graduate student. And as I remember someone's saying, there's light at the end of the tunnel, you know, after you get your PhD. But then when your PhD, you have to then sell

yourself and do something. And it's hard. You have a limited amount of time. And it's a very stressful period for people. It's stressful. Yeah. I, you know, I had a, I mean, I wasn't in that situation, but I remember, I guess you have, you have two choices. You either have the imposter syndrome or Dunning Krueger's syndrome. And it's better to have the imposter syndrome, namely to feel like you, hey, maybe I shouldn't be here than to not recognize at least. your own inadequacies in some ways. And yeah, I remember at Harvard, suddenly for me it was like I was in the same environment.

I was at MIT and I moved down the street to Harvard. And I'd take it on most of my classes at Harvard. But suddenly when I got this fancy fellowship, this Harvard Junior Fellowship, suddenly everyone knew who I was at Harvard. And I was the same person as when I've been a graduate student. But suddenly I felt like, you know, suddenly they know who I am and I'm supposed to be well.

But I haven't done anything. And I really, for about six months, I had a really difficult time working because I thought, well, I just, I shouldn't be here. And then, you know, then I just said, okay, I'll just work. And you, you recovered from that with the assistance, of course, of some good help, which is important. But I was reading, and again, I don't believe everything I read, but that, that is, you said to someone in the shower or something that you really decided, hey, if I'm going to fail, I want to do

something spectacular. I want to fail spectacularly rather than not, you know, just doing stuff. And that, that choice, I think, is a remarkable one. So maybe you want to go go into it. Well, yeah, it was a little different than that. I do remember very clearly standing in the shower one morning, you know, barely able to get out of bed. The water from the showers falling over me. And I was very depressed. And I thought, I have got to pull myself out of this. I'm obviously going to fail as a scientist, okay, that's a given. But I still have a year and a half left on this Carnegie Fellowship. So what am I going to do? And I thought, well, great, if I'm going to fail, I might as will try to answer a question that is so meaningful to humanity and to me as well that at least

I'll go out trying to do something that has a human component to it, not just sort of the physics, dry scientific aspects. And I realized with the water still falling over me that I wanted to know if there were any other habitable worlds out there and if any of those worlds might in fact be inhabited. And I remembered then something that was a failure of mine back in Santa Cruz, which was my advisor, George Herbig, asked me to measure Doppler shifts in stars. And the brief version of the story is I failed at that, too. I tried to measure the Doppler shifts. And I came back to him with the results.

And he said, Jeff, your errors are about three kilometers per second. Why are your errors so large? And I didn't know. And he didn't know, which was more impressive. But I didn't know. And it stuck with me. How can you make a measurement and not know what your uncertainty is? And there in the shower, I realized, okay, if I can,

measure Doppler shifts more precisely, I can detect the wobble of a star as it's yanked on gravitationally by any planets, but I have to measure Doppler shifts more precisely. And so I thought, okay, I'm going to spend the rest of my time as a postdoc trying to measure Doppler ships precisely enough to maybe detect the largest types of planets or brown dwarfs. Okay, this is great. So you decided this was a scientific question. And again, again, I mean, this fundamental question, are we alone in a sense? Yeah. Which, which Sagan, of course, it was had asked as well.

And everyone's asked at some point in their life. Yeah. And it's really bold, but it's not going to be. But the fact that you were saying, you know, it was going to be clear that it was not going to be easy. So it was not going to be the type of thing that could be done a year and a half, but you're already chalked off your career. So you said, okay, doesn't matter.

You know, it's not something I can necessarily get to, but it's what I'm going to try and work on. But before we, but you went out, when you went over this, for many people watching this, they will not have the slightest idea what a Doppler shift this. So let's uncompact that a little bit. Yeah. So let's let's let's let's just describe what what why you were one might want to measure doppler ships and what they are. So let's I'll give you a chance to start. Yeah, you know, this is well known to astronomers, but but it's easy to explain. When a star emits light, that star might be coming at you or moving away from you.

and we collect the light from that star. But the light waves get a little compressed if the star is coming at you. And indeed, if the star is going away from you, the light waves get stretched out as the star recedes. Each time it emits a wave crest. We all know this effect in sound. When the race car goes by you, you hear, e-ow. And so that's the dog. Doppler effect in sound, and the same thing happens with light.

So you can determine if a star is coming at you or away from you, and even more excitingly, you can determine if the star sometimes is coming toward you, and then a little later away from you and then toward you and then toward you, as the stars being yanked on gravitationally by any planet. So this is a way and a well-known way to detect unseen orbiting objects around the planet. stars. Had it been used to detect binary stars, stars going around each other? Absolutely, going all the way back to the early 1900s. And there were even papers, indeed, by a guy named W.W. Campbell, I found the paper where he says, you know, currently here, and I think it was around 1908 or 1913 or somewhere in there, he said, clearly if we could measure Doppler shifts more

precisely, we would be able to detect not only small stars orbiting other stars, but we would be able to detect small planets. He actually explicitly said that. So this was a concept known for, you know, 60 years or something prior. And this itself, by the way, not only, so Doppa shifts are that, and it's a different reason for light than sound, but it's the same idea. And we call it a red shift or a blue shift, red being if the star is moving away from you, because the radiation gets stretched out and red is the longer end of the spectrum. And if it goes towards you, blue is a shorter wavelength. And so it gets scrunched up.

So it called blue shifts or red shifts. Those are the terms of astronomy use. But interestingly, within that concept, that it also flies. When kids go to school, they learn the Earth orbits the Sun, if they went to go to a reasonable school, especially since the Copernican Revolution. But of course, it's not true. It's not true. The Earth orbits the Sun, but the Sun's orbit is much smaller than the Earth's orbit.

The point is they orbit each other, and because the Sun is a lot heavier, a million times heavier than the Earth, as the Earth goes around the Sun, the Sun does respond. But this is the point, and this is why I figured what you were doing would never be possible, because the Sun is a million times heavier than the Earth. And therefore, in a sense, its response to the force of gravity of the Earth pulling on it is at least a million times smaller. and therefore the earth goes around the sun the sun is doing a motion but the motion is unbelievably slow and who the heck could do this I mean I think our sun

is the speed of our sun as it moves in its little mini orbit as the earth goes around it is something like am I right it's something like 10 meters per second or 8 meters per second well there's two answers here the earth as it goes around the sun causes the sun to move with a speed

in its little mini orbit, as you called it, by 10 centimeters per second. 10 centimeters per second. Yeah. So in other words, you know, sort of the speed of a caterpillar on a leaf. Yeah, that's right. And so, I mean, that's the reason I would say. You have to measure that speed of a star that's about a thousand light years away to the, you know, to plus or minus 10 centimeters per second.

Ridiculous. And that's, it's ridiculous. And I want to, I want to stress that because that's how bold. the challenge that you decided to face and why, you know, I've talked about this in different contexts. Why as a theorist would have said, no way, I'm going to, no way, I'm not going to try that. I mean, it's just too, it's too difficult. The idea of somehow being able to measure a speed that's much smaller than the speed you can walk of a star far away, but you decided to try and do it. And so, you know, it's worth, it's worth mentioning here for people who are young and thinking of

becoming scientists, it's very helpful to think about challenges in science that seem unreachable to the old folks. But if you have a little bit of a clue about how to do better technically than people did in the past, you can reopen that question. And in my case, I remember telling senior astronomers that I was going to search for planets by measuring Doppler shifts. And they were all embarrassed for me. They literally looked down at their shoes and scuffled their feet.

And there was a little faint smile to try to be polite. But they knew I would fail. And even as recently as, oh, the early 90s, you know, my fellow astronomers would look down at their feet and sort of smile politely. So it was just well known for the whole century of the 1900s that nobody would ever. ever find planets. They just don't have any effect on anything. Okay. And that was, okay, exactly. And I love when conventional wisdom is, is shown to be wrong. And I think you made a point, which is another point I try and stress, and we see in a lot of discussions I've had with scientists, and which is that, and I've said, I've told young experimentalists this as well.

Every time we can open a new window on the universe, we're surprised. So science is, an empirical discipline. I'm a theoretical physicist and sure that gets a lot of attention, you know, all the weird ideas we come up with. But science is an experimental field. It's based on experiment. It's driven by experiment or in this case observation. And if you can find a new technique, use it. It may not, you may not know that, hey, there's no obvious application of this technique. But if history is any guide, if you have a new technique, it's going to be useful somewhere in science. And it's really, it's really, it's really. really is. Right. I'm so envious, I guess. Yeah, exactly what you said. And we're lucky in astronomy. We

ride on the technological advances of the rest of the world. So when the rest of the world invents a new type of camera or a way to form optics, you know, or maybe make larger computers, all of those things allow critical, vital leaps forward in your ability to make the measurements of the universe that simply weren't possible before. Yeah, it's truly amazing. And as I said, it sometimes makes me jealous as a theorist that knowing, you know, the experimentalist who gets a new technique can push it. But, you know, to some extent, the same thing happens, but much less, much less often

in theoretical physics, you know, Einstein's new technique of, you know, learning geometry, which he had to learn are Feynman's development of new techniques. but, you know, a new observation. And that's why one of the reasons why kids have asked me, you know, what's a good field. Well, the one reason is astrophysics is good field is a golden era because it seems every year there are new techniques that come up that you allow you to do things you would never imagine you could have done. Right. 10 years ago and much less 40 years ago. Yeah.

And so you knew, so you started to go back to you now, you started to look at ways to improve your ability to measure. these Doppler shifts from kilometers per second to centimeters per second. And for for people, a centimeter is what, one hundredth of a meter and a kilometer is a thousand meters. So you're talking about an improvement of a factor of a hundred thousand. It's not a factor of two or five or a hundred thousand. And so what did you start doing? Well, there were several steps that, you know, I never foresaw, but they were turned out in the end to be very important. So there I was, of course, course, still as a Carnegie fellow, using the Mount Wilson 100-inch telescope, the venerable telescope that Hubble had used to discover the expansion of the universe. That's a daunting thing, by the way,

to walk by the locker that says Hubble on it. And, you know, what happened was I started using the spectrometer that was there. And I tried hard to trim all of the errors that I thought were causing the trouble and I identified a few and got the errors down to about 200 meters per second, which was already a factor of about 10 better than I had been doing while I was a graduate student. And I ran into a really amazingly brilliant astronomer who hardly anybody knows. His name is Roger Griffin. And he said, oh, you know, Jeff, your problem is that when you guide the telescope and put the star light into the spectrometer, the starlight moves around.

And so you have to prevent that. So he actually gave me yet another clue that it was the motion of the star image that is a problem. You mean naming the fact that the apparent motion due to the, due to jittering of the telescope? Exactly. Yeah. And the Earth's atmosphere, which causes by refraction, causes the star to dart around. And, you know, it's very obvious.

When someone tells you that you think, oh, of course, why didn't I think of that? If the stars moving around, the whole spectrum moves around, so it mimics the Doppler shift. Of course. So I had to figure out a way to get around that. And I'll jump to the next stage, which was really wonderful. And this is a great story in and of itself. There is an obscure astronomer named Bruce Campbell. Nobody's ever heard of him.

he was a postdoc himself. And he and his collaborator, Gordon Walker, invented a new technique to get around this motion of the star. They also realized it. Maybe they talked to Roger Griffin, too. And what they did was in brief fill a glass container with hydrogen fluoride gas. And as the starlight passed through the hydrogen fluoride gas, it, the, the, the light from the star picked up additional absorption at specific wavelengths, i.e. colors, specific wavelengths that indelibly marked the wavelengths right on the spectrum.

So even if the whole spectrum Doppler shifted, or sorry, if the whole spectrum shifted inadvertently, those absorption markers due to the hydrogen fluoride gas marked the true wavelengths of the light. And when I learned about Bruce Campbell's idea, I thought, we've got to do this and we've got to do it better, at least a factor of 10 better than he's doing it. And that's what led me to ask the solar physicists what they should do. And a friend of mine, a solar physicist, Dave Bruning, said to me, we use iodine gas. And so I told my student, Paul Butler, who was absolutely brilliant. I said to Paul, you know, we should think about iodine. And he went off to the library and he checked other molecules and he came back and he said, yep, iodine is the best. So we

developed this whole technique that no one ever heard of of putting iodine gas in a telescope. I mean, it's the craziest thing. But the iodine gas then allowed the starlight to come through and pick up thousands of absorption lines, as we call them, markers in wavelength. and that was the wavelength calibration that allowed us to measure Doppler shifts to within 10 meters a second. Ah, okay. Okay, so that within tens of meters per second. So that, but that idea took time. I mean, the point is, I want to go back, because Paul Butler was your student at San Francisco State University,

which at the time was not a major research since you didn't have a PhD program, right? I went there because I wanted to be a teacher. Yeah, you went exactly. It was a teaching institution. not so much a research institution. So you were cobbling together this kind of effort. And this is the other important thing. This is what year did you go there in 1982, 83 or 84?

Yeah. 84. And you're there for a decade working on these kind of techniques to try and continue to improve it, sort of not quite on the side, but I mean, sort of on the side because it's a teaching institution. I was teaching three classes every semester. Wow. I taught, and I enjoyed the teaching, as I said. I mean, it was a real pleasure.

I taught electricity and magnetism. I taught statistical mechanics. I taught astrophysics labs. And, you know, that's more or less a full-time job. But, of course, I worked evenings. I worked weekends. I wasn't yet married. And so, you know, I had lots of time.

And, you know, Paul is absolutely brilliant. He's still working to this day. He's an incredibly hard worker and very innovative, and he's dedicated to working as hard as he can to get the right answer. But, you know, it worked out. It was a wonderful, like many things, it was fortuitous collaboration of a really good student and a dedicated teacher and a great scientist is working hard.

But was Butler doing a master's degree because there was no Ph.D. He was doing, that's right. He was doing two degrees, a bachelor's degree in chemistry, Ah, that's important because we needed iodine and a master's degree in physics. I see. Well, it's just the fortuitous. And then you continue to work. He must have gone on to do a PhD somewhere else while you were working with him.

He did at Maryland. And Maryland, okay. But your collaboration continued during that period. Oh, absolutely, yeah. Yeah. And so you came upon this new idea, and that allowed you to reduce the uncertainty from 200 meters per second to 10 meters per second. Yeah. Okay. And now 10 meters per second is already interesting, and I already kind of gave it away in a way, because the sun doesn't move with respect to the Earth very much. But the Earth and the Sun aren't all there is in the universe. It could be other things. And so one could work out that maybe, you know, actually, let me ask you this question because I used to know the answer, and I could work it out. But Jupiter is a thousand times the mass of the Earth. And it's pulling the sun, therefore, more strongly than the Earth is, how much does Jupiter make

the sun move? So Jupiter, when it goes around the sun, takes 12 years, but it yanks the sun around at 12 meters per second. Uh-huh. That's a lot more than 10 centimeters per second. So suddenly meters per second. And this was, you know, this was a breakthrough for Paul and me because we knew that our Doppler precision was 10 meters a second. We could tell if a star was a coming or a going at 10 meters a

second. And a Jupiter-like planet around another nearby star would cause that star to move at 12 meters per second. So we would just barely be able to detect Jupiter analogs around other stars. Except, of course, you'd have to have a pretty long career because the other problem is that If you're looking for repetitive motion and the orbit is 12 years, you want to see a bunch of orbits. You've already got two orbits, take 24 years. That's a long time to get data. And you need two orbits because one, one orbit goes by, nobody will believe your results. So the most important ingredient I used to say was not the telescope or the iodine or the computers or the technique.

It was tenure. Yeah, that's right. It was 10 years. the fact that you could, once you had tenure, you could afford to work on a project for 20 years. And I think people don't realize how important that is, is the idea that, you know, you, for some things, you can have a breakthrough right away. Other things require decades of work. And it just depends upon the field.

I don't know if ever, you know, I ever told you a story. I'm sure I've said it to someone else about maybe on this program about Dirac, who was a very, obviously one of the smartest physicists of the. 20th century, but also very laconic and did not talk. And when he went to do a postdoc, I think it was with Boar. And and and and and um, and um, bore asked his supervisors, uh, I think was, I think was that way. Um, back at, I think he did his work at Cambridge, you know, this guy's, he sits in his office. He, you know, he doesn't, he hasn't done anything. And, and, and, and, and then there's some, the, the, the, the supervisor told a

story about this this parrot in a store that's being sold and I won't go to it's a good it's a good joke but basically this guy goes in the store wants to buy a bunch of parrots and there's beautiful parrots are worth five hundred dollars and then there's this ugly parrot sitting in the corner and he says what about that one he goes oh let's not talk about that one and he keeps all the so finally he convinces him what about this parrot does it how many words does it speak oh none no it's not pretty what's it's $500,000. And the guy goes, what? It's not pretty.

It doesn't talk. And the guy goes, yeah, but that pair of thinks. And so I think the point is that, you know, sometimes we, one of the problems of our educational system in his way with the postdoc system is that is that, and happily tenure helps with that. But you've got to get to tenure is the fact that some project problems are so difficult that it takes a long time to make a breakthrough. And unless that's appreciated, it's hard.

and with our published and parish society, it's really difficult. But luckily, you had tenure at this teaching institution, and we're able to say, what the heck, I'm just going to plug away. Exactly. And you plugged away. And for a decade or more, and then there was a race. And then, you know, what happened? Talk to me about 1995 and that period.

People think it was a race, but we all thought we were going to fail. You know, nobody thought we would actually discover planets. My good friend, Gabor Basri, at UC Berkeley, would say to me, you know, look, he was trying to calm me down and temper my probable disappointment. And he would say, you know, surely you realize you're not going to find any planets. And, you know, he was right in a way. You know, it was a long shot. And after decades of people failing to discover planets, why should we be able to do it suddenly out of nowhere? And of course, I would explain to him, we've trimmed our Doppler errors and so on.

But there was still widespread skepticism that planets would ever be discovered. And so it wasn't really erased. There were actually many groups. There was a great group at Harvard, another one at Texas. led by Bill Cochran, a guy named Bob Noyes at the Smithsonian Institution, working on a brilliant, wonderful man. And our little fledgling group at Little San Francisco State.

And I knew of the group in Geneva because I had read the papers by Michel Mayor, and I had met his student, DDA Kolo at a meeting in Garking, Germany. And so, you know, I knew there was interest in measuring Doppler shifts more precisely at these different places. But, you know, we were all just piddling along until 1995. Yeah. And then and then the world changed, not because of a new technique, which you guys had developed, but because of the fact the world was stranger than you thought it was, which is the other wonderful thing about the world. Just hold on, though, because I want to turn off this light to see

if it affects the buzz I'm hearing. And I'll tell Corey to edit this part out. So I'll be right back. Hold on. Sure. It didn't, but it made it cool, it didn't, but it's making it cooler for me. So we'll go back. The buzz might be on my end.

It's all right. No worries. Well, now, so the world, as I say, the world turned out to be stranger. That was the other gift. I mean, there's two great gift for scientists, new techniques, and the fact that nature has a greater imagination than we do. And no one, when I, you know, when when I was younger, when thinking about other solar systems, I'm estimating the probability of life, you know, the natural thing is to assume we, and it's,

it's a reasonable assumption is that you're typical, is that your situation is typical. Yeah. So that if you're, so that if you want to, if you want to investigate situation, you haven't seen, to assume if you're looking out into the unknown that, that, that what you're, that you're, that you can base things on your circumstances. And it turns out we're not typical. So talk about that remarkable discovery, which suddenly, which occurred for a bunch of you that taught you that, hey, things aren't what we thought. Well, I'll back up and restate what you said.

There were people who worked on the theory of planet formation. And their job was to determine what planetary systems might be like around other stars. and they used theory, how dust and gas collects gravitationally and coagulates into planets. One of the most famous was by a guy named Alan Boss, and he predicted that Jupiter-like planets would all form at Jupiter-like distances around their stars. And it was a very formal theory with hydrodynamics and gravitational forces and, you know, hydrodynamic waves traveling through the gas. And he predicted that Jupiter's, sure enough, would form so far,

away from the star that they would look a lot like our own Jupiter. Well, with that is the backdrop, of course, Paul Butler and I were tooling along, improving our technique, thinking that the orbital periods would be 10 years or 12 years. That's how long it would take the Jupiters to go around. And one day I got an email in 1995, October 1995, I got an email from a physicist named Phil Morrison. Now, you might know Phil, but nobody... Not the Philip Morrison. The Phil Morrison. And he was on leave at Edinburgh.

And he sent me a nice email. This is again October 95. He sent me a nice email saying, Jeff, I've just gotten a rumor that someone is going to announce the discovery of the first planet ever. It's Michel Mayor giving a talk in Florence, Italy. Do you know anything about this rumor? and I didn't, but I immediately thought to myself, first, here we go again. Another false claim of a planet found like Barnard Star. But my second thought was, wait a minute, I know Michel Mayor.

He's one of the most careful observational astronomers ever. And so if anybody might have it right, it might be Michel Mayer. He gave the talk in Florence. He announced the planet. It was denounced immediately. by most of the astronomical community. They said that he had fooled himself. The star was either pulsating

or maybe it was wobbling in a face-on orbit due to a stellar companion. But it was very lucky what happened. Paul Butler and I had telescope time at the Lick Observatory five days in the future. And just by sheer luck, we had four consecutive nights

on that telescope. And the supposed orbital period of this supposed planet around 51 Pegacy was four days. So here we just happened to have telescope time later in the week

with a string of nights exactly equal to the duration of the supposed orbit of this planet. Of course, we were also lucky it was clear every single night. We got Doppler measurements every night. Paul worked the computer and measured the Doppler shift. And by the end of the four nights,

we saw exactly the wobble, a sign wave in Doppler shift up and down at the end of the four nights. Bang on what the Swiss team, Michel Mayor and Dedi Akalo had said. And I remember to this day, Paul and I drove off the mountain, Mount Hamilton, where we had used the telescope. And we were just silent. We were both astonished and really ecstatic that somehow the first planet had been found and we had been fortunate enough to play a role in confirming it. You know, that's one of the wonderful things that I think about you having come to know you, Jeff, is that generosity of spirit. Remember when I first heard about this, I heard that your first response was ecstasy.

And it wouldn't have been the first response of a lot of people. I think, you know, it takes a big sign. I remember when, of course, when the when the Cosmikwave background was discovered, the people who were really looking for it were, you know, didn't get to see it first. People's and Wilkinson and the leader of it, who's the one of the greatest experimental physicists around who, who's, oh my God, my name, he's gone for a moment. But anyway, but I, you know, and these guys at Bell Labs had accidentally discovered it.

And I remember the leader of that group of Peebles and Wilkinson was, oh, my mind. Oh, he's a great scientist. He's the one that did gravity experiments? Yeah, yeah, yeah, yeah. Yeah, but anyway, it'll come to me again when we're talking. Wasn't he Virginia Trimble's husband? No, no, no, not that guy. No, no, no, no, no.

No, he was a, this was a truly, he was a truly fantastic experimental. Make breakthroughs in a wide variety of things and people don't know who he is and I'd feel bad. Yeah. But anyway, the, he came in and said, hey, guys, we've been scooped. And it was like with a smile and they were gracious about it and they were great scientists. But the fact that you felt ecstatic, I, again, you know, I remember, yeah, I remember in various times my own career, you know, when I'm working at. something and you discover and you're writing a paper you discover someone else has just written it. The feeling is not always ecstasy.

And so I think it's wonderful that you felt wonderfully a part of it. But the point then is that it wasn't as if you could just be observers, literally where you were observers, but not observing the phenomenon elsewhere. Because you developed these techniques, not only could you immediately confirm that, but you became the leaders in discovering new planets. I mean, I think something like 70 of the first hundred planets that were discovered, were discovered by you guys, right? Yeah, that's exactly right. We were lucky because our technique using iodine gas really was fantastic,

and it offered a higher Doppler precision than the Swiss team had. And so, you know, it was kind of a shared joy because we could contribute so many of the next planets confirming the types of orbits, the eccentricities. some of the planets were in close, and of course, that's the strange thing about 51 Pegacy was four-day orbital period, whereas our own Jupiter takes 12 years to go around the sun. You're right, you're right. I passed over that. I was going to get to it.

But the fact that we almost just came upon as a side thing, yeah, the period is four days. Well, that's not surprising. But of course it is. The Earth's period around the sun is a year, and here's a Jupiter object. going around the sun in four days, which means it's far closer to its star than Mercury is. It's unbelievably close.

It defied all the wisdom of what makes a solar system a solar system. And the first calculation I did, which is what anybody would do, is you would ask, is a Jupiter that close to its star stable? Maybe it'll heat up and evaporate away. So you can quickly do that calculation of the thermal equilibrium of the planet and what the, you know the escape velocity from the gravity of the planet. And you can calculate how much of the gas is going to escape every year and how much will be left after a billion years.

And sure enough, the planet is stable. Yeah, it's amazing. Again, it's another thing. If you asked my gut feeling, I would have said such a planet that close would not be stable. The tidal forces would strip it. By the way, I remember the guy's name. It's Bob Dickie, of course. Oh, Bob Dickie.

Yeah. Who's probably one. Dickie Wilson, Peebles and Wilkinson were the ones who were devided. And they were all each one, a truly great scientist. One of the sad things in a way that they passed away. Well, that they didn't get that particular Nobel Prize. Not that it matters, but Dickie was an amazing man. But anyway, so go back to this.

The fact that the fact that another surprise, not only that it was there, but that it could be stable there. And then the question is, how the heck did it get there in the first place? And that originally, and so it's not only, I mean, confirming the assistance of a planet around a star

is one thing, although I think it's fair to say, I know at least from my own experience around that time, that astrophysus is all suspected there were lots of planets around lots of stars. If you make stars on a computer, you get this equation gist, and it fragments,

and generally you're going to expect a solar system, but no one had ever seen it. So just seeing a planet around a star is maybe it's a remarkable observational discovery, but you might not be surprised. But this discovery at the same time revolutionized the thinking about solar systems. It was two things at once.

And it was... Well, let's back up a little bit because I'd like to just offer a slightly different rendering of history. Good. When that discovery was made, very few astronomers believed it. I can tell you many stories, visits to Caltech where astronomers would draw me aside and say,

you know, that 51 Pegacy discovery is not right. And here's what they said. They said, first of all, the so-called planet might have actually been a small star in a face-on orbit, so nearly face-on that the Doppler shift, which only accounts for the motion toward you or away from you, is very small, not because the object orbiting is small, but because the orbit is so face on that the star is hardly wobbling to and fro. So that was a very widely espoused theory for 51 pang. Another theory was that the star itself was pulsating,

getting bigger and smaller, bigger and smaller. So you would see the Doppler shift. We went for two years with many people thinking one or the other of those was the right answer. And indeed, there was an interferometer, so called, on Mount Palomar, that made measurements of 51 peg and saw it wobbling as if it really was a face on orbit. You know, when I learned that, I was sure it was wrong, but I was probably the only person. And I can tell you why I was sure it was wrong. But it just it gave everybody an excuse to say, ah, 51 Pegasies wrong. And I'll tell you one last thing. The papers,

that Michel Mayor and DDA Kolo sent to nature about the discovery of 51 peg was rejected. Yes. The paper was rejected. And I learned about this. I was not the referee. I can tell you. I know who it was. And the referee correctly, I think, or at least consistent with the sociology of the time,

said, look, this is not an adequate defense of the claim that it's a planet. Now, of course, five days later, Paul and I. I went up to the telescope and we saw the same effect. And that doesn't prove that it's a planet. It still could be a face on orbit or pulsation. But at least it gave nature the impetus. So of course, the journalist descended on Paul and me. We showed them our Doppler shift measurements. And nature changed its tune. And they published the paper by the Swiss team, which of course was the correct thing. I remember some, it's a cute little story. Michel Mayor was. panicking because he learned that we had found the wobble effect.

And he called me on the phone from Geneva. And there I was in Berkeley at the time. And he called me up and he said, Jeff, I have a very urgent request for you. Would you please not publish your paper? Nature is refusing to publish the paper. Would you please just not publish the paper until we can publish our paper? And of course, I said, of course, Michelle, no problem. We wouldn't even dream of doing this.

So, you know, it was just a cute moment. And what was interesting, if I don't, if you don't mind my droning a bit, was we went for two years with most of the astronomy community doubting that this was really a planet. And that's science at its best, right? You make an extraordinary claim. We started finding planets. and the community dragged its feet until they got better confirmation. Well, extraordinary claims, and it wasn't Carl Sagan, the first person to say this, but he popularized it.

Extraordinary claims require extraordinary evidence. And so it's not, you know, people may say, oh, scientists are closed-minded, but, but it's reasonable to be skeptical. Most exciting new discoveries are wrong. And if they weren't, we'd be getting one a day, you know, and, and so it's reasonable. But what ultimately caused a sea change? Was it the fact that you discovered 70 of these? You see, one observation can always be anomalous.

You know, one observation could be a system which is accidentally face on. But 70 of them is not likely you're going to get that same accident. What caused that sea change in the community? So there were two breakthroughs. David Black, who doubted the planets, said to me in Houston, I will never believe these are planets until you find at least two of them going around a star. Planets come in groups. Yeah, maybe there was a protoplanetary disk.

But if these are really planets that you think you're finding, there should be two or three or four. Until you find a system, I'm not going to believe these are more like binary stars, where the second star is a puny one. And then, luckily, in 1998, we did. discover a triple planet system around Upsilon Andromedy. It was wonderful. We found one planet, then we found a second, and then a third. We worked with the Harvard team on this. It was great.

And those three planets, I think, offered a lot more assurance that these planets we were finding were at least kin, maybe not close kin, but kin of the planets in our own solar system. The real breakthrough actually occurred in 1999 when we, We finally found one planet that we had been anticipating that orbited the star and crossed in front of the star dimming it. And that cinched it. And that was Greg Henry, by the way, who made that discovery. And Dave Charbonneau made it independently.

When Greg and Dave found that transiting planet, it was HD 209-458, for those of you were interested. I'll never forget it because when we saw, we predicted when the dimming would occur. Imagine you make Doppler measurements. You know the so-called ephemorous. You know when that planet should be in front. And Greg Henry did the photometry, measured the brightness, and the star dimmed exactly when and by the amount that it should have if it was a Jupiter crossing in front. So that removed all doubt. You know, it's interesting.

You know, you just anticipated where I was going to go. next because no no it's great and and that's first of all that's a new technique right you have the technique of the wobble and then you have another technique which I also would have said and not believed I remember I think the first time I thought I probably didn't believe it either because I would have said per shaw you can't measure a star moving at the same speed a sprinter is moving 10 meters per second right then I would say look this puny the planet in front of a star is going to dim it by a little bit but stars are variable and they who would believe that you could do that. And so it's another technique that again, as an outside ignorant theorist,

I would have said, ha, no way. But then, but the fact that it, but again, the fact, I think the point was that not only did it happen, but it happened with a kind of regularity that was exactly what you predicted, I think is the more important aspect. Well, and, you know, again, it's probably worth going back because this is, I hope, inspirational for young scientists, in retrospect, the Doppler shift we measured for some of the planets was so large it could have been done in the 1960s. It's just that nobody expected Jupiter-sized planets that close to the star. And similarly, when a Jupiter goes in front of a star

and blocks some of the starlight, it dims the star by 1%. Okay, 1% is a small number, but it's measurable. So in fact, in the 1960s, people could have discovered planets. You would have had to look at a few thousand stars, but sooner or later, you would have seen one that dimmed due to its planet. Actually, that's probably, well, you know, that's an interesting thing, which probably it's not so much the telescope capabilities as computational capabilities. One of the things that was a big development, which came in the 70s, 80s, 90s, was the ability to look at a thousand stars, not just one star. the ability to do that with the optics and the computer technology. So I think that's an important.

Computers were critical. Yeah, yeah. So it wasn't that, you know, you could have done it by an accident of discovery, but having to look at a thousand stars was simply impossible in the 1960s and 70s. Well, it's a little more than that because I've glossed over this point. But the spectrum, when we spread the light out from the star from blue, green, yellow, and red, all the wavelengths, we actually spread it out. into about 10,000 individual units of wavelength.

And I have to give credit to Steve Vote, who was at UC Santa Cruz, designed and built the spectrometer that we first used at Lick Observatory. So, you know, without Steve Vote building that spectrometer, we never would have, we never would have had a chance. A combination. Well, being the right place at the right time is a large part of science as well. But taking advantage, taking advantage of that moment is sometimes what makes,

one special. Now, so suddenly there's a new technique, which is really neat because now you have two techniques, independent techniques for look for planets. And I think the important thing is, again, a strange observation, it can be strange and usually wrong, but when you predict it, and it's exactly what you predict, it gives you a great deal more confidence that you're not seeing something anomalous. Something I talk about in terms, by the way, in climate change, it's not just that the, temperature Earth is rising.

It's exactly what you predict from fundamental physics. and that gives you great confidence. But now two things. Suddenly, a Jupiter that's orbiting a star is observable, but really what was interest to you when you first had that moment in the shower was not Jupiter's, but the question, well, maybe Jupiter's, because we know so little

about life in the universe that who knows. But like the drunk coming out of a bar, you look where you lost your keys under the lamppost, the simplest thing you look for is Earth-like planet, And that's what everyone, that's, that's where the money is and the, and the, and the, and the, and the, and the, and the, and the, and the, and the, and the, and the, and the, and the, and the, and the, and the, and the, I think to take me through. So, the, lower, lower size, smaller size planets than you could just using doppelish as alone. Is that right? Yeah. So there were. two stages here. One was that the Swiss team led by Michel Mayor and DDA Kolo improved their spectrometer. And I would say by around 2005, 2010, their spectrometer was producing

superior Doppler shift measurements to what we could do. And that's just the truth of it. I can tell you technically what they did and it was brilliant. But it was so good that they started finding Neptune-sized planets and planets that were five times and ten times the mass of the Earth. Okay, they weren't Earth-sized quite, but they weren't Jupiter's either. They were smaller and smaller planets. And we were starting to find them too, but the Swiss team was doing a better job. And it gave us a hint. They wrote a couple of papers about this. It gave us a hint that there might be even smaller planets. And then the second big breakthrough, frankly, was the advent of two space-borne telescopes, one by Europe called Corot, and then the really great one launched by

NASA called Kepler. Kepler was designed to look at something like 100,000 stars in a small region of galaxy and to look at them every night to look for specifically this occlusion, this, this dimming, periodic dimming. And it was the first time that's, you know, a systematic planet finding capability at a statistical level was possible, not just a random luck here or there, but where you could where you could definitively look at large systems and begin to get the statistics of planets. Yeah. Which of course, and like the statistics of many things, they're skewed, right you I remember I give public lectures and I show all the plants that were discovered and you'd see a lot of Jupiter's nearby planets and you'd say well maybe most planets are Jupiter's

nearby their sun but of course you realize there's what called a selection effect it's the looking under the Lampost the easiest ones to find are Jupiter's nearby stars and let's face it in the life the Earth goes around the Sun once a year so even if you could measure that few centimeters per year or the occlusion of the Earth runs on you'd have to measure many years. And so if a system, if a telescope is only up for two or three or four years, you're not going to see systems that have periods of 10 or 20 years. Right. Yeah. And it's worth pointing out that this spaceborne telescope called Kepler funded by NASA was led by one individual. And I only bring this up because it shows again the struggle of science. He wrote multiple proposals.

His name is Bill Baruchy at NASA Ames Research Center. He wrote multiple proposals to NASA stating that a space-borne telescope would be able to watch the brightness of stars, indeed 100,000 stars, and measure the brightness so precisely that even a tiny Earth-sized planets crossing in front of the star would dim the star by a measurable amount. And what is amusing and, of course, telltale is that despite several proposals being turned down, Bill Baruki continued to write proposals to NASA headquarters, and eventually they said yes. And that led to the Kepler mission and the discovery of now about 4,000 planets, most of which are about the size of the Earth. Yeah, no, it's an amazing. See, again, a sea shift.

sea shift and and it is of course caused a great deal of excitement because you say we now know that earthlike planets are not rare and in fact you with kepler you and a student i think wrote a key paper yeah which won a big prize because you were the am i wrong or the first people to kind of estimate the likelihood of finding earth like planets yeah there were several groups chipping away, but really the key one was by Eric Pettigura, who's brilliant astronomer now. He was my PhD student, and now he's at UCLA as a professor. And Eric, the tour to force, I can't even begin to describe, but it was an amazing tour to force. He simulated the errors, the systematic effects, the selection effects, the sensitivity to Earth-sized planets.

All of that went in, and then he reanalyzed himself personally all of the data. I mean, we're talking about years, four years of data from the Kepler telescope and found all the planets himself with his own code. And then we published a paper with Andrew Howard and myself. And Eric, of course, was first author and, as you say, received a prize for determining what fraction of stars in the night sky have Earth-sized planets in Earth-like orbits so that those planets would be lukewarm, allowing water to be in liquid form? The first, basically, the first, I mean, people had estimated, it's easy to make an estimate,

especially if you don't have any data. But so people had speculated about Earth like planets and how unique we are and all that. was the first time one had data to actually make his statistical analysis that gave you uncertainties and estimates that told you, hey, habitable planets might not be rare. And by habitable, all we mean are all that is traditionally means is, hey, there's water and and a gravity and and and and and gravity that isn't too large, the combination of the two. And that estimate that you guys made, in some sense, laid the basis for much of the excitement that is now what is called the field of astrobiology. Well, and it's worth recapping that, first of all, our Milky Way galaxy in which we live has about

200 billion stars, and our universe as a whole has hundreds of of billions of galaxies, each one of which is roughly like our Milky Way. And what we learned was that something like 10 to 20 percent of those stars have Earth-sized planets in habitable-like orbits. And so if you do the math, 10 percent of 200 billion stars, you quickly see that there's something like tens of billions of lukewarm Earth-sized planets. out there. And by the way, one last news note, we still have never confirmed that there's actually water on those planets. So there's probably water, because let's be fair, hydrogen

atoms and oxygen atoms are among the most common atoms in the universe. They're going to combine to make H2O. Nonetheless, it would be nice to confirm has not yet been done that there are standing lakes and oceans on these so-called earth-like planets. I think you, again, you lead me to where I was going to go in this regard, which is great, because I'm going to make a statement which is going to cause some people to be, you know, to be concerned. I read, astrobiology is a field which has, one could say, more hype and less substance than many other fields.

And by that, I don't mean to want to put down the people are working in it. what I mean is we read about habitable planets and discoveries of potential life. When people talk about the level of our knowledge is so little that to make the claims that are made that are often a trip to astrobiology is, you know, I understand the enthusiasm, but it's not supported by the science. And while there's a great deal of money and attention that's being framed there, one of the examples I just give is hey, the Earth is an Earth-like planet. But for some period of its history, it was frozen solid. It all depends upon the distribution of continents around the Earth, as well as a few other things. So when the Earth's continents were right, so the albedo of the Earth was such, well, the Earth froze over.

And so when people talk about habitable planets and Earth-like planets, where we don't even know that there's water, but even if there is, we don't know if the continents are such that the planet actually has liquid water, there are huge leaps of the imagination and then claims about, well, maybe life has occurred here or there or there or there because in extreme environments maybe it's here or there when we don't yet know the origin of life on earth is a huge leap.

And I think it's really important for people to realize that I just want to moderate. That that hype should be taken with many grains of salt. And, you know, there are, there's a specific example of what you're talking about. I'll mention our earth has some amount of water. Much of it is locked into the mantle of the interior of the earth. We know that there are many oceans worth of water locked into the mantle in hydrated minerals. So you might ask, why do we have oceans on the earth? Well, the answer is we have so much water associated with the earth that not only

does the mantle have water, but some of it leaks up to the surface and puddles into oceans and lakes. Well, that's great. But what if the earth had had a little bit more water? Well, then there'd be so much water, the whole thing would be covered. Look, the continents are only, you know, some tens of thousands of feet high, Mount Everest, you know, 20,000 feet high or so. It wouldn't take very much water to cover the earth. So the earth could either have been formed with too little water, in which case it would all be in the mantle soaked into the sponge of the interior of the earth, or the earth could have been made with too much water, and somehow we're lucky to have continents and oceans. And let's be clear, if the earth only had an ocean covering it and no continents,

it would be difficult to build rockets, computers, electronics. You couldn't even build a violin in water and have it work. Yeah, no, exactly. You could have intelligent dolphins. But, you know, unless they're a product of a hyper-intelligent civilization and they leave the earth and say, thanks for all the fish. Right. You know, yeah, no, it's really important to realize that a water place,

planet. While everyone loves the idea of water, a water planet will not produce, if you're interested in intelligent life, as opposed to microbial life or even animals, which could exist in water. And the right way to say this is technological life. Because as you point out, marine mammals could in fact be even more intelligent, certainly socially more intelligent than we humans. But technology, you know, building mechanical devices, electrical, devices, computing devices, never mind telescopes and rocket chips, really requires dry land. Yeah, absolutely. And, you know, and yeah, it's true. Octopuses or octopi, I guess, is the word, are very intelligent as are as are dolphins. But there's another factor, too. I mean,

one could write science fiction stories about this. And that's the point. I think people should realize a lot of what is claimed to be science right now is science fiction in this area area. it's incredibly important because of their new techniques that we're developing to be on the threshold of discovering the possible existence of life elsewhere, any kind of life elsewhere, which is a great discovery, but take the claims with a grain of salt. But another thing that's relevant, and as I say, if you're going to write a science fiction story,

about intelligent animals or at least some kind of social intelligence in the ocean, is if you've ever been scuba diving, you can't see out there very much. And so it's not so obvious. is that they're aware that there's a universe outside that ocean because of the refraction of light. And so, you know, there are many things. So, and but again, you know, even if you had continents, you have to have been the right distribution to have water.

And you also have to have a, you also have a stuff to have a star that's quiesin and lots of other things. For example, many of the habitable planets are around star, they're discovered because they're close to their stars. And they can only be close to their stars inhabitable because the stars are much less massive. than our sun, and therefore you can be much closer without the water boiling off.

But if you're much closer, you're subject to other aspects of your stars, if there's a flare or some other things that could kill off life. So there's a lot of work in what's called astrobiology about habit of planets that I think people, it's incredibly exciting, the techniques that are developing. But people have to be wary of what they read as they always have. Even, you know, the rare Earth hypothesis, as it's sometimes called, includes some obscure aspects like our moon, which orbiting the Earth stabilizes the spin axis against procession. So how many, you know, Earth-like planets in an Earth-like orbit do not have a fairly massive moon close enough to stabilize the spin axis of that Earth-like planet?

You start adding all these factors, or I should say multiplying these factors together, and you start worrying that the number of truly habitable planets for long enough for Darwinian evolution to do its thing and produce technological life, it might be that the galaxy is filled with a few dozen of these or a few thousands of these, but not billions. Yeah, I think the point is my attitude has always been, I'm pretty convinced by these factors is that intelligent life is extremely rare, but with 200 billion solar systems, rare can still produce a lot of stuff.

And that's the wonderful thing about science. Yeah, go ahead. Well, you know, it goes back. You probably know Frank Drake yourself. I knew him as well and lovely guy. But people seem to think that there's a lot of content. The Drake equation is a Drake equation. Isn't an equation?

It's just a parameterization of our ignorance. Right. and saying, let's guess how many intelligence civilizations are. And you multiply a whole bunch of probabilities, each of which you know almost nothing about. And you come up anywhere from one or zero to a billion. And I think the point I'm trying to say is it's a field. Remember how I said with just one star, of course,

and in one planet, a lot of possibilities are you need to discover a lot more things. We're in a field. We have zero. We have yet to know anything experiment. fundamentally about these planets. And therefore, we have zero empirical data. And therefore, any claim about the likelihood or not likelihood of habitable life or where it's likely to form is just pure hypothesis right now. And it's a field with lots of, obviously, there's lots of ideas. And I've thought about them. And so have others. And you have and there's lots of new techniques. But right now,

there's no data and with no data probably it deserves a little less hype except for you know every time we discover new what the discovery of new planets which you which you pioneered has been the data that's driving at least the next generation of experiments which may allow us to get some signals for life and maybe we should talk about then what's next

because I know you pioneered you know worrying about the terrestrial planet finder oh before I get there something else I didn't know about you that you're a poet. I did not know that. And I heard something about when Kepler died or something like when that sounded like that,

that you wrote a poem, which I'm not going to read, but I did find it. And so do you often write poetry? I took a very well-known poem and recast it for our beloved Kepler that had died. And what was interesting,

it really did bring tears to my eyes and others, because Kepler was, I think, one of the most profound experiments that humanity's ever done. And interestingly, NASA's engineers brought Kepler back to life. They actually figured out a way to use solar radiation and the pressure to reorient Kepler and overcome its hobbled state. So, you know, the poem was premature. That's all right. Well, the poem can never be premature. Sure, it can just reflect the feelings of the moment. And I'd like to go back, if you wouldn't mind to something, just to touch up your astrobiology rant there.

Okay, sorry. Better me than you, matter I get the hate mail. Exactly. Well, let's look at the positive side here. NASA and ESA are planning missions to Mars to the, the giant moons of Jupiter to tighten the large moon around Saturn and also Enceladus.

Now, these moons are easily explored robotically. You can send a mission up for something like $3 per American. And that means you can go and sample the water that we know is there on all of those bodies I just mentioned. And look for bacteria. So, you know, in terms of the pessimism that you very rightly articulated, there is an experimental solution within our lifetimes, which is to send probes, examine the water literally for microbial life.

And look, in 30 or 40 years, we will have visited all of the objects I just mentioned, Mars, Jupiter's moon, Saturn's moons, a few others. And frankly, we're going to know whether or not the origin of life happened on any of them. That'll be cool. Yeah, no, of course. In fact, I'm a big supporter. I think you misinterpreted it. I'm not pessimistic. I'm optimistic because every time you know nothing, there's a lot to be learned.

So I guess my point to us to point out how little we know. But that, to me, makes it exciting. I just want to point. I'm opposed to hype. but I love the fact that there's a tremendous amount to be learned, and we have the technology, not just in our solar system, but elsewhere. And I want to get to the elsewhere. But you're absolutely right.

There's no doubt that exploring, especially Enceladus and systems, not so much Mars, it seems to me, which of course be fascinating to find evidence for fossilized life or extant life or extinct life. But there, the problem with that system is we know that it's been, you know, that it's been in communication with the Earth. I'd like to see in the oceans of Encelot, Enceladus, which the principle has been separated. And by the way, if you asked me to bet, I would bet you now dollars to donuts that there's microbes there. And I bet you it's an independent genesis of life.

I think life, as far as I can see, if the Earth is any example, evolves about as soon as the laws of chemistry and physics allow it to. But that would be a profound discovery, and I can't wait for it. And by the way, it's going to be done not by astronauts. It's not going to be done, you know, even by Elon Musk or any of the people that get all the press. It's going to be done by robots because, you know, and that's the other thing. I, you know, I get a lot of, you know, I've had fun debates with my friend, Neil DeGrasse Tyson, about this. But the science that, the best science that NASA does is done without astronauts. Because astronauts, although it's exciting and adventurous, most of the money that's spent is spent on keeping them alive, whereas, you know, and robots can go to places that astronauts just can't.

So it's going to, the most exciting work is going to be done there in our solar system, not by astronauts, I would argue, although it would be wonderful adventures, but the science. But then outside our solar system, it's definitely not going to be done by astronauts. It's going to be done by new technologies. And I know that you are one of the early people to be really pushing for the next step beyond Kepler. Because, look, to make it clear, yeah, you can now see planets going in front of stars, but when you can see planets going around in front of stars, if those planets have atmospheres, then the starlight goes through those atmospheres, and in principle, you could look for telltale signs of life.

So maybe you want to go into what's next? Well, there's a very exciting future right at our doorstep to watch nearby stars for the moment when a planet goes in front, as you said, and you watch the starlight pass through the atmosphere of that planet on its way to the earth. And of course, when the light passes through the atmosphere of the planet, some of the light will be absorbed by whatever molecules happen to be in that atmosphere. And some of those molecules might be telltale signs of biological processes. The interpretation will be difficult. But the first step is almost at hand with the launch of the James Webb Space Telescope. And there will be others in the future designed specifically to, to measure the starlight passing through planet atmospheres.

So there will be a great new field of sort of planetary atmosphere spectroscopy, allowing us to do chemical and you might say biological assays of the composition of those planets. And eventually we'll learn a lot. I mean, the point is we have a sample of one right now, the Earth. So we have an idea of what biological signatures you'd have if you were looking at the Earth some far away. but we don't know if those are generic and we may be surprised. But, you know, for example, when I in my young days, when I wrote a book called Adam,

and I probably might even mention there, I would have thought that observation of oxygen and free oxygen in the atmosphere of an earth would be a sign of life because in Earth, there wasn't free oxygen in Earth was created by life on Earth. But then I learned to be by people who know these things better than me. Yeah, that's true, but it's not the only way to get free oxygen. And so you've got to be careful.

time you see these things, you've got to be careful and you'll need a lot of data and we'll learn things. And what we may learn is that the biological signatures are something else. Or maybe the best biological signature will be pollution. We don't know. But we are in yet another golden era and that's why I'm optimistic, not pessimistic, because we will have the tools in our lifetime to not just explore a solar system, but to image at least the atmospheres in one way or another. with spectroscopy, if not visually. And who knows, maybe even with new technological optical systems to actually image some aspects of those systems.

You know, in the next 30 or 40 years, lots of things are possible. And so I know that you've been spearheading that. And, but, you know, I think the, you know, for. It's not me spearheading it. I mean, there are people out there who are the real experts. What I meant, I mean, an early proponent. cheering them on let's put that but at a stage when you had a lot of

of play of influence because of the work you've done on planets you're one of the first people say hey we've got to keep going we can't stop with Kepler and that's very important for significant scientists to provide those kind of that kind of rallying cry and but nevertheless I think it's really important to point out that that that the importance of having made the discoveries that you and Michelle Meyer mayor and and his and his collaborators have done. And I think it's, you know, we want to point out that,

that, um, that you and Michelle happily shared, uh, the Shaw Prize, uh, for the work you did. And I think,

um, and of course, uh, and Michelle and Didier went on to win the Nobel Prize. And many of us thought that you, I still think that it would have been a nice thing for you to be a part of it. And then these prizes are arbitrary. But the significance of it,

I think in the long run is what's important. And as Feyman said, that's much important. The discovery is much more important. And I'm just, I hope every day you feel a sense of awe and wonder at what you were able to have been able to accomplish less far. But now I want to end by going the next stage. You're not satisfied in just because what got you interested in that shower

wasn't just discovering Earth like planets. That was a technology. But what you really wanted to know is, you know, they're technological civilizations. And that's been a question. That's a central question. And are we alone as an intelligent society in the universe? And of course, much as I have written recently and people hate the fact that if we're going to discover that, it's not by going around with spacecraft or expecting them to be coming here and doing neat things.

So I've argued that what we see is UAPs are definitely not aliens, much to some people's, the way to do it is to listen or look. And you've been involved for a long time now in what we call SETI and what we call SETI or what you can call SETI, to search for extraterrestrial intelligence. And that's developed a lot too. So that's occupied the most recent phase of your career. And I wanted to spend a little while talking about that, too. Well, I'm very appreciative of several dozen astronomers around the world

who are using radio telescopes to listen, if you will, to use that term generically, listen for radio waves from advanced civilizations. There's a wonderful group called Breakthrough Listen that has a whole team funded by Yuri Milner, and they're working very hard to use the world's largest radio telescopes to detect signals, radio wave signals from other civilizations. It's a very reasonable thing to do, and it's the best, maybe the best we can do. There are other ways to detect. Let me stop there for a second,

because I know you're looking at the other technologies, and I want to discuss them. Radios get the most play in the media. And again, in my book about Star Trek from 1993, I spent a lot of time, the early stages of SETI were talking about, but trying to moderate enthusiasm by pointing out that how hard it is, that even if intelligent civilizations are out there, the universe is a pretty big place and so is the galaxy.

And it's not only, and as I like to say, now I have guides, but I used to say I, you know, when I got cable TV, I immediately gave up watching TV because suddenly I couldn't find what I wanted to find anyway. There were so many channels. And that was just for 200 channels. But in the universe, you have an infinite number of frequencies. And, you know, one can give arguments for why it's really, really tough. So that even if intelligent civilizations out there, you shouldn't expect the absence of hearing

anything to be, you know, absence of evidence as Sagan went. said is not evidence of absence. And that's a clear example. It's a really tough business. And I, my own bet is that even if intelligent civilizations exist, I'd still give small odds that will know about it. But, but what you've been, so radio is one way to look for it. And there's been a lot of, you know, work and, you know, listening for I love Lucy from, from, or whatever, from the distant galaxy or distant stars is one way. But you've been looking at other techniques, which I find fascinating. So I, since they don't get a lot of play, I want to talk about them. Well, as you pointed out, the radio waves are just one part of the so-called

electromagnetic spectrum, which includes infrared, optical visible light, ultraviolet light, x-rays, gamma rays, and frankly, any of those are reasonable parts of the spectrum of light that advanced civilizations may use. And I can even argue. you that it's the higher frequencies like optical and ultraviolet and x-rays that have some advantages in terms of keeping privacy, being able to send individual photons on or off that give you bits like ones and zeros on a computer. But in any case, what I've been involved with is searching visible light, the light that your human eye is sensitive to, for laser beams because some people have pointed out that our galaxy, our Milky Way galaxy,

may have a galactic internet and you can't string Ethernet cables between the stars or from a star to a spacecraft or a spacecraft to a colony and so on. Instead of fiber, you would use laser beams. And so we might be able to eavesdrop on the galactic internet by catching one of those beams as it travels from a colony to a spacecraft and the earth happens to be in between. So my group has been using telescopes, visible light telescopes, to look at different stars, different parts of the galaxy, even within our solar system, for laser beams. And we haven't found any. Yeah, but again, it's a tough, not finding it is not in evidence. But one thing that I think is interesting and a recent development that you've been involved in, which is a little complicated,

but not too complicated, is the fact that, yeah, you know, if it laser beam, you have to be able to detect the signal and it has to be in your direction. But things like the sun are natural lenses or what I call gravitational lenses, which is an area that fascinating me and I've worked on as a theorist. But the fact is that because gravity bends light, objects like the sun can magnify other objects behind them. And as you pointed out in a recent publication, I think, you can imagine the sun acting as a gravitational lens. So in one of your searches, I think you once talked about not having seen a signal

that might come from kilowatt lasers or something like that. But if you happen to use the sun as a magnifier, you could detect a 100 watt laser on a star. How far away? How far away? The nearest star is Alpha Centauri and Proxima Centauri. And yeah, if you use the sun as a gravitational lens, the light from those stars can be lensed by the sun very close within our solar system.

And so we're pointing our telescopes at those focal points, hoping that some advanced civilization has put its probes there using the sun as a gravitational lens. And maybe we can eavesdrop on the communication that the probe is involved in. Yeah, it's a long shot, but why not? I think it's amazing to use these. Again, it's a new tech. And you never know what you're going to see unless you listen or look. And if it doesn't break the bank, why not look? That was always my attitude about SETI.

If it doesn't break the bank, it's a long shot. I wouldn't bet on it. But why not? And if it's a billionaire that funds it even better. Yeah. And so I just find that this romantic search, which has really been going on for much of your career that's driven you and for which you made major discoveries and pushed things forward.

to be a lovely example of the quest, the inexhaustible curiosity of humans, and what you can do if you keep trying. And I hope what our discussion has also showed is something not just the incredible humility, which I know is not false humility in your case, but the generosity of spirit towards your colleagues, which I hope has come across,

because it's what I've come to know from, beginning to know you as an individual and as a friend, that generosity of spirit is so pleasing. And it's one of the things that in my mind makes you such a, not just such a wonderful scientist, but such a wonderful human being. And I hope that's come across here. Well, that's awfully generous of you. All I can say is we should all feel lucky.

I think we should feel lucky. We live in this era when we can ask these questions. questions and make use of the resources here on the earth to try to answer these questions. It's amazing that, you know, it was only a half a million years ago that we were clambering out of the East African Savannah. And here we are now with space-borne telescopes trying to answer questions ironically about the origins of other technological beings, which in effect is a very technological. an effort to answer a question about our own roots. Where did we come from?

And we may get the answer ironically by looking to the stars. In fact, that's a wonderfully poetic way to put this because this is an Origins Project Foundation podcast. And it is to me remarkable that, and maybe not that remarkable, that the way we may learn about our own origins, which really what it comes down to, where did we come from?

How do we get here? We'll come from looking at the heavens and not at the earth. why? Because we're one example and it's really hard to know. Although I actually think we're coming very close to discovering the chemical processes that it may have led to the development of self-replicating living systems. I actually think that's an area where there's been a lot of developments and I've been following it and we'll talk about in this podcast. But surely by looking out and seeing what the universe has to offer, if life is ubiquitous,

then we'll learn a lot more by seeing lots of things. kinds of life, about the kind of variety of life, whether there's a unique chemistry of life. We'll learn a lot more about ourselves by looking up there. And I think that's one of the reasons to continue to look out there. When people say, why should we, why should we fund these things? We should be thinking about ourselves in Earth. If we want to understand ourselves and our place in the universe, we have to look out of the universe and see it. And it's nice to have people like you who've been looking out at the universe and with their tools going boldly where no one has gone before. So thanks, Jeff, for, and for all you've done and for the wonderful discussions here.

And again, your ability to, and your interest and enthusiasm to explain this to people. It's been a pleasure to talk. Thank you, Lawrence, for your very generous interview. This has been a wonderful time. Thanks. I hope you enjoyed today's conversation. This podcast is produced by the Origins Project Foundation, a non-profit organization. whose goal is to enrich your perspective of your place in the cosmos by providing access to the people who are driving the future of society in the 21st century and to the ideas that are changing our understanding of ourselves and our world.

To learn more, please visit Originsproject Foundation.org.