David, Carl Carl Sagan, John Batchelor discussed on John Batchelor
I'm John Batchelor. This is the John Batchelor show. My colleague, and friend these many years, David grins, planetary geologist, and Astro biologist and unoften. Once again, David has published a book that summarizes everything we've learned in these last decades since planetary geology became a real thing. Not a speculation. Now, we have planets we have Rovers on the surface of Mars. We're anticipating more on Mars. We're planning for Venus. But when David and I started talking after his first book, it was a treat to speculate. Now, it's here and the new book earth in human hands shaping. Our planet's future puts everything together. The David has learned these last thirty years since he left graduate school. And then everything he learned before graduate school because he was very lucky to grow up with the professor Cornell University his dad who was colleagues with Carl Sagan who is the author the progenitor of our thinking about our planet. As a creature in the midst of other planets and much to discover and much to concern ourselves with so David congratulations yearbook is fun to read. It's a compendium of ANC of anticipation of ambition and anxiety, and I want to begin with the exiled because you hold back, but you get to Saturday soon enough in the course of your telling about how astronomers planetary geologists think about their work, and we come to a list six possibilities of SETI, which is the search for extraterrestrial intelligence in the universe, passive SETI, active SETI, and then it comes to the last one you hold out till the end of the chapter, David what is fair may six and what is the anxiety among the cognoscenti people who understand astronomy, and planetary geology and the amount of world's out there. What is fair may six? Good evening to you. David. Good evening, John. Thank you very much for your comments about the book. And it's it's always a pleasure to talk with you. The Fermi paradox is sort of a short hand way of. That we used to describe their fact this perhaps strange fact that we have not yet detected or heard from any extraterrestrial intelligence now why why would I say that's a strange fact, well that was sort of fair point family being Enrico Fermi, the famous physicist who were so important in Manhattan project. One of the great physicist of the the twentieth, century and key. At Los Alamos, where where he was in fact for the Manhattan project gathered some of his colleagues at lunch one day and started discussing what he called a this paradox that if there is intelligent life out there, then some fraction of the species. Some fraction of the civilizations. Should surely have by now colonized the or visited the entire galaxy. You can sort of look at it as a physics problem and do the math that. Given the the age of the galaxy which is so many billions of years and given how long it would take for a technological civilization to sort of jump from star to star and colonize and keep traveling on even with the immensity of interstellar distances the time works out. So that in fact, if it could be done somebody should have already done it. So if there could be intelligent life. It should be obvious. This was fair miscalculation. And that's what we now. Call the Fermi paradox. Namely, where are they if if we're not alone if life and intelligent life is not unique to earth. Then then it should be obvious. According to these assumptions that fair me made. And that's that's why we call this question the Fermi paradox. And of course, there are a number of possible. Interesting answers that have been discussed including that they're there. But they're just not using. Radio. And we just don't know how to recognize them or they're not interested in talking to somebody primitive like us because they're so advanced there are a number of categories of answers that have been advanced. It's a very interesting and rich topic of conversation, but the one that you're referring to that. I do discuss in my book is the sort of unsettling possibility which I call family answer six that that the galaxy is silent because contact is very dangerous. Because. There's something out there that that that is a threat to to communicating civilizations. And so either they're silence because every young radio communicating civilization has been wiped out by something powerful and dangerous or because the civilizations out there know better than to advertise their positions because they're aware of some of this possibility that it might be danger. And this became a debate in the SETI community early on because there were those who wanted to switch to active SETI in other words to send a message and not just to listen, David because we're going to come back to this. I don't want to go any farther. I just wanted to alert everybody that there is the possibility that the search for life also includes the search for something we don't wanna find. I just want to a park that there because it's a thrilling moment in your book. It was not why you became a planetary geologist. You became a planetary geologist back at Cornell University where your father, Lester, Lester, grins spoon was a teacher of psychiatry, and he was colleagues with Carl Sagan an astronomer, and you from very early on were in this community of thinkers about life here and life on other planets in that transformation from you. And it's in the book in that transformation. Did you know did you understand as a teenager or just before you went off to higher higher education that you were that you were swimming in a privileged group that you are surrounded by not science fiction, but science thinkers, did you understand that? Well, I mean, I guess we're all we all sort of acclimate to the conditions of our youth. And and it seems normal even when it's not the environments we grow up in. So I guess at some point I came to appreciate how unusual it was. And maybe that point was when Carl Carl Sagan started showing up on television because you know, when I was a kid. He was just ankle Carl. He was this this cool guy who was my dad's best friend who was an astronomer who had come around the house and tell us great stories, and, you know, take us to go look through the telescope. And so I that was thrilling to me, but it wasn't thrilling because he was famous guy. It was just throwing because what he was talking about was really interesting to me. But then I guess at some point. And maybe it was you know, when he started showing up on the Johnny Carson show, and then later on cosmos that you realize oh, this is rather extrordinary. Yes. You do. You just start to realize that you're you're quite privileged in that sense. And then you decided to become not only an undergraduate, but a graduate astronomer and you wind up at university of Arizona in the early eighties. And after having grown up with Carl Sagan, your then plunged into an environment informed by Koiper, and by Lovelock who are they David? And what what contribution? Do they make to are thinking about life in the universe? What's your art Koiper is a kind of the father of planetary science? In this country really in in the world. He was a Dutch astronomer go out, then a Dutch American stronger who founded the lunar and planetary institute in Arizona, which at that time was sort of an exotic thing for for astronomers to go out and out there in the desert in Tucson and format institute of planetary studies. But that was because that's where the skies are clear and the big mountains are and their big observatories are down there and planetary science. Then was sort of an aberration. It was it was an offshoot of astronomy. Astronomers weren't really that interested in studying the planet. But then with the advent of the space age in the nineteen sixties and the ability to start sending spacecraft to other planets. There was the need for a new field, and it was sort of a hybrid of astronomy and geology. Using the techniques of earth science to study the other planets because suddenly the Panish weren't just these points of light and telescopes. They were these worlds that we could see up close with spacecraft. And so you needed the techniques of people that think about rocks, and geology and weather system. So so you really needed a hybrid of earth science and space science, and that was the birth of planetary science rod locker who was Lovelock what significance and Lovelock was a British tinkerer inventor maverick chemist who started thinking about extraterrestrial life. And he he was hired by NASA to help think about how to how how they should search for life on Mars with the first Landers and Lovelock came up with an answer that Nassar didn't really like. But then ended up being very profound. He said, you don't really need a Lander to search for life on Mars just look at the atmosphere because life he started studying the way that life interacts with the planet's atmosphere. That led to the guy a hypothesis, this strange notion that life is so deeply part of a planet that it will radically change the atmosphere, which of course, is what life does on earth. And by thinking about how to find life on Mars Lovelock with his colleague colleague, a Lynn Margulis came up with this guy hypothesis which was a profound insight into the role that life place on our home planet. Let's go to the changes that we can calibrate on planet earth and thinking about these are other planets, also David Grenz bone is author of earth and human hands shaping our planet's future. He's a planetary geologist and Ostra biologists and astronomer. I'm John Batchelor. This is the John Batchelor show. This corporate pro Rosenberg here have you considered Mazda. The Japanese premium brand US news and World Report to the two thousand eighteen best brand they build some of those technological SUV's, of course, overs available today. One reason sky, active technology, more power and performance out of their engines, one of the best places to test drive, the Mazda c x five or Mazda.