Nathalie Cabrol: Search for Alien Life | Lex Fridman Podcast #348

1. 0:00 – 1:08

   Introduction

   1. NCNathalie Cabrol0:00

      "My friend is telling me that the volcano seems to be starting to erupt. If that volcano goes off, we have nowhere to go." That got my attention. So, if you say scared, I would say that I got the realization that what that meant. I went cold for, like, a fraction of a second. But that meant that just my adrenaline started to kick in. And it was a very, very strange experience because now you have tunnel vision. It's about survival.

   2. LFLex Fridman0:30

      The following is a conversation with Nathalie Cabrol, an astrobiologist and scientist at the SETI Institute, directing the Carl Sagan Center for the Study of Life in the Universe. She explores some of the harshest places on Earth, including free diving in volcanic lakes, all in the pursuit of understanding living organisms beyond Earth. For this, she holds the woman's world record for diving at altitude, both scuba and free diving. She's amazing. This is the Lex Fridman Podcast. To support it, please check out our sponsors in the description. And now, dear friends, here's Nathalie Cabrol.

2. 1:08 – 5:46

   Working in extreme environments

   1. LFLex Fridman1:08

      You are the director of the Carl Sagan Center For Research at the SETI Institute. SETI, of course, stands for Search for ExtraTerrestrial Intelligence. One of the things you do as part of that is travel to some of Earth's most extreme and dangerous environments in search of organisms that live in conditions analogous to those on Mars. First, let me ask what the job posting for the work you do looks like. Is it like Shackleton's ad in, uh, 1900 that said people wanted for hazardous journey to the South Pole?

   2. NCNathalie Cabrol1:39

      (laughs)

   3. LFLex Fridman1:39

      Small wages, bitter cold, long months of complete darkness, constant danger? And also, where do I apply?

   4. NCNathalie Cabrol1:45

      (laughs) That's funny because there was not really a job application. In fact, when you're a scientist, you have questions in your mind and you have hypothesis, and you start to list the kind of thing you need to answer. Um (laughs) , and then when you, you see the kind of thing you have to answer, then you kind of know the places where you need to go to do that. As far as science is concerned, started with analyzing data from the Mars missions. And, uh, I had written a PhD about water on Mars, first looking at, uh, channels and the history evolution of, of water. Uh, but then during my postdoc, I started to look where that water was ponding. Interestingly enough, everybody was about channels and water and whether catastrophic or whatnot, or seepage. But when you are talking about ponding water like lakes or ocean, people were starting waving their arms a little bit. So, it was a little bit of a happy battle, interestingly enough. Yeah. But that got us on track with my husband. Uh, we were working together and, uh, we started developing the idea, the concept of lakes in impact craters. So, why in impact craters? Just because the Viking, uh, mission at the time, which is what we were working with, uh, the resolution and the topography were so poor that there was really no way of telling where you had a real low in the topography. The only thing you knew was a hole in the ground was an impact crater. So, when you saw valleys.

   5. LFLex Fridman3:24

      What was the Viking mission?

   6. NCNathalie Cabrol3:25

      The Viking mission landed on Mars in 1976 and, uh, there were two landers and two orbiters. So, they were really, uh, our first feet on the ground on Mars. But they were lander, they were not moving, they were not going up.

   7. LFLex Fridman3:39

      And that was the data you were looking at?

   8. NCNathalie Cabrol3:41

      It was already in the '90s, but we didn't have yet the Mars Global Surveyor and whatnot. We still work for 20 years, we worked on that. I did my master and my PhD thesis on Viking missions.

   9. LFLex Fridman3:53

      You mentioned that the places you go to are defined by the questions you want to ask. Let's just step back. What questions have always tugged at your heart?

   10. NCNathalie Cabrol4:03

       Well, that's the thing. That's why I was looking at those images and saw some lakes, and then came time where we started talking about sending landers and, and rovers on Mars and looking maybe at the possibility that Mars was habitable and lakes are particularly good places to look for those questions. So, this is how it all ties up.

   11. LFLex Fridman4:28

       So, you were always curious about life out there?

   12. NCNathalie Cabrol4:30

       I have been always curious about life in the universe and about questions on how we got to be here. And, and the bigger question now with 25 years more in, you know, i- i- in that business, um, it's more about understanding the origin and nature of life rather than whether there is life or not on Mars. I mean, this was really for me, a stepping stone to bigger questions. But they were definitely important because they helped me frame the, my way of thinking about those question. And so looking at Mars and lakes, understanding what the conditions were 3.5 billion years ago or close to 4 billion years ago, then I knew the type of environment I needed to explore here on Earth as analogous to be able to understand what type of life still survives in those environment. And what kind of instrument and what kind of resolution do I need to actually detect it. So, this is how the whole thing started, and it started with a small grant, literally 40K. It was a discretionary fund, and this is how I got started in my, in my career.

   13. LFLex Fridman5:41

       And so many of these questions you can answer by looking at life in extreme conditions here

3. 5:46 – 13:52

   Water and life on Mars

   1. LFLex Fridman5:46

      on Earth. But let's, let's step back, uh, a little bit and look at Mars and lakes on Mars. Just going back to your PhD and before and maybe today, what do we understand about life on Mars?What do we understand about lakes on Mars? Is there water on Mars? What do we understand about the conditions from 4 billion years ago on Mars?

   2. NCNathalie Cabrol6:08

      Well, we- we've come a long way. Remember from, from the Viking where we had no resolutio... Well, we had a little bit more resolution with, than with Mariner.

   3. LFLex Fridman6:16

      What did you think at that time? Sorry to interrupt.

   4. NCNathalie Cabrol6:17

      It was-

   5. LFLex Fridman6:18

      Just, just take us back to that mindset.

   6. NCNathalie Cabrol6:19

      It, it was really the exploration, like, the, your first look at a planet. You have to remember that the first mission that successfully snapped some pictures of Mars was Mariner 4. And then, everybody at that time was still under the spell of, you know, H. Wells and, and the idea that Mars looked, with telescope, so similar to the Earth. Polar caps, we could see them with a telescope and we knew it had season. The actual tilt is pretty much the same as the one for Earth. So, when Mariner 4 left, everybody pre- not everybody, but a lot of people thought that we would see crystal cities and domes and stuff.

   7. LFLex Fridman7:06

      (laughs)

   8. NCNathalie Cabrol7:06

      That another civilization might have evolved in parallel to us in the source system. And, of course, when the first images came back and Mars looked, with that kind of resolution it had, uh, like the moon-

   9. LFLex Fridman7:19

      Yeah.

   10. NCNathalie Cabrol7:19

       ... it was a huge disappointment. Then Mariner 9, uh, came, and that changed everything. There i- there was a little bit of drama because Mars started the, one of the biggest dust storm it ever experienced. And so, for three months, we had an orbiter circling around Mars and not seeing anything. But then when the dust cleared, all of a sudden, we started discovering volcanoes, valleys, ancient channels, dune fields, polar caps. And see, when I'm talking to you, I don't need to invent any words to describe Mars. And although the myth of extraterrestrial civilization on Mars was gone, all of a sudden, the imagination of the scientists started to pick up because right away we were seeing something that was familiar, that we could describe. So, right away, Viking would put on the fast track. And the idea was, so Mars looks so much like Earth could have been, although it's arid and there is little atmosphere, et cetera. Could there be life? And of course, behind this, at the time, there were people like, uh, Klein and Sagan, Carl Sagan, uh, just, you know, um, thinking about how can we test the idea of biology, of life on Mars. So, this is what Viking did. But of course, at the time when the two landers arrived on Mars, we didn't have the context of the geology of the environment. We didn't have much data at all. So, the data that Viking sent back was very confusing. Some people still think today that we discovered life on Mars, uh, at the time, because some of the experiment turned out to show a strange signal.

   11. LFLex Fridman9:13

       Mm-hmm.

   12. NCNathalie Cabrol9:14

       But most of the community think that it can be explained by a chemical reaction that we see today. So, it was so confusing that NASA decided to say, "Okay, if we want to be serious about looking for life on Mars, we have to understand the environment because life and environment co-evolve." So, as cause or effect, a planet is going to give you the physical chemical environment for life to happen. These are the boundaries. But once life is here, it's going to change everything. Uh, one of the, um, biggest impact of life was to inject oxygen into the atmosphere of the Earth three, uh, two bar- billion years ago. And that changed everything, including our signature in space. So, there is this co-evolution. So, if you want to understand one, you have to remove the other from the equation. There's kind of a two unknown, uh, equation.

   13. LFLex Fridman10:06

       So, even though oxygen changes our signature today, what if all life on Earth died and now we fast-forward a billion years, what would be the traces left? I- so, the question I'm trying to ask is, if life had existed on Mars, what would be the signs we would look for?

   14. NCNathalie Cabrol10:26

       That's a very good question. The thing is that if you draw the parallel with Earth, it took 82% of Earth history, uh, geological history, to go from very simple life, microbial life, to complexity. And when I'm saying complexity, I'm not even talking about us. I'm talking about animals. So, Mars is smaller, lost its magnetic field very fast, and lost its atmosphere very fast. Life also appeared on Earth very fast. So, the condition being quite similar at that time between the Earth and Mars. Let's assume for a moment that life appeared on Mars. It would have been simple life when conditions started to degrade, which was less than a billion year after the planet had formed. So, everything at the surface would have disappeared except maybe for morphological traces of the interaction between life and its environment. So, on Earth, the best example are what we call stromatolites. These are rock formation that are built by microbes. So, we know that. We, we, we know how to recognize them. You could have chemical traces as well. There is some interesting question marks right now about carbon isotopes, uh, at Gale, uh, Crater, because we found an abundance of, uh, C12, which normally is used by life on Earth, but it can produce, be produced by other things. So, it's not that it's a real bio-signature in itself. But it's intriguing. We have now the C12 and we have methane. But, uh, going back...It's a time on Mars, 3.5 billion years ago, where you have lots of destructions, where you have lots of impact cratering, et cetera. So, but we still have very old rocks that are, that survived from that time. So, these are good, uh, good places. That's why we're sending the rovers in those places. Ancient lakes and impact craters and, and places where you have very old rocks.

   15. LFLex Fridman12:27

       So, when you say ancient lakes and impact craters, the simple question. So, impact crater is a crater created by a giant rock hitting the planet?

   16. NCNathalie Cabrol12:36

       Yes, a big rock that can be metal or rock, or it can be a comet as well. Mostly ice.

   17. LFLex Fridman12:42

       So, is that good for life or bad for life? (laughs)

   18. NCNathalie Cabrol12:45

       Both.

   19. LFLex Fridman12:45

       For creating life and-

   20. NCNathalie Cabrol12:46

       Both.

   21. LFLex Fridman12:47

       ... and destroying life.

   22. NCNathalie Cabrol12:47

       Both. It's actually both. Um, interestingly enough, the building blocks of life, the bricks, the stuff we are made of, carbon, hydrogen, oxygen, and nitrogen, and phosphorus, they were included on our planet. They were built in just because our planet is made of these kind of rocks, asteroids and comets coming together by what we call accretion. So, they were built in. When an asteroid comes, there is a lot of destruction going on, but at the same time, those rocks, they bring with them those bricks of life and they create lots of energy. And if the environment around is favorable, you might possibly be, have some seeding going on. That's one of the aspect of what we call panspermia, uh, which is the fact that comets and asteroids have the building blocks of life embedded in them. In that given favorable condition, they might be able to seed planets. This is a theory.

4. 13:52 – 31:21

   Origin of life

   1. NCNathalie Cabrol13:52

   2. LFLex Fridman13:52

      What percent of you, when you're looking up at the stars and wondering about this stuff, thinks that panspermia has, is what happened on Mars or, or on Earth? Which is the building blocks of life came from elsewhere?

   3. NCNathalie Cabrol14:07

      Well, but, uh, you know, that's the thing. Panspermia is a vector, potential vector, which means that it actually distributes the stuff of life left and right, but it doesn't explain the origin of life.

   4. LFLex Fridman14:19

      Right.

   5. NCNathalie Cabrol14:19

      It does, it's not the environment itself. It just promotes maybe, and we still have to prove this, but what we know is that the stuff we are made of is very abundant all over the place, including in interstellar, uh, medium. So, it's all over. It's all over. The idea is that maybe it just waits to have the proper environment, and we know what it needs here on Earth. It needs water. It needs energy, shelter, uh, and nutrients.

   6. LFLex Fridman14:48

      So, you're fundamentally interested in the origin of life and the big leaps that, in evolutionary history, that could be like an origin of something. Origin of eukaryotes, origin of photosynthesis, origin of whatever. I just think if we're a civilization here on Earth and we survive another few hundred years, I think it would be a good idea to take a big gun and just shoot life out there, like a life gun. Basically, try to create panspermia. That's a good backup solution. So, one way is to actually, uh, copy our brains and actual humans, some complex information, and send it out there. Another way to preserve life is just to, like, send the basic building blocks. Send a bunch of bacteria, a bunch of, um, whatever the rugged organisms are on Earth. Just send a bunch of those.

   7. NCNathalie Cabrol15:42

      These are not the building blocks. They, they are actual organism. So, what-

   8. LFLex Fridman15:45

      Right. But isn't that a nice shortcut? Or, or do we wanna... 'cause you said building blocks are everywhere.

   9. NCNathalie Cabrol15:50

      Yeah. The bricks of life, the carbon, nitrogen, et cetera, uh, they, they were, uh, produced by the death of previous stars.

   10. LFLex Fridman15:59

       Okay.

   11. NCNathalie Cabrol15:59

       So, this is how they were produced. And, um, stars like our sun, uh, started to form 10 billion years ago. Uh, that doesn't mean that the, the sun is the only kind of star that produce, you know, uh, life or enables life, but actually was produced 10, uh, 10 billion years ago. Now, what you're talking about is, is a little different. Uh, right now there are many, um, many efforts to do the type of thing you are, uh, talking about, which is to put our DNA on whatever kind of substrate and preserve it in vaults, either in different place on Earth or on the moon. Some people are already thinking about putting DNA o- on the moon. As far as brain is concerned and it's drawing towards transhumanism, which is, um, the enhancement, uh, of who we are through AI and machine learning. Of course, having backups is a good thing. For me, I would say that taking care of our planets and going back to a place where we are in equilibrium with our environment would be also maybe the best backup possible, and let evolution do its things. Right now, we are like teenagers with enough brain to create cool tools, but we don't have enough brain to understand yet the consequences of what we are doing. And right now, we are paying for this. So, uh, the question is whether we are going to be able to move forward and learn from the mistakes we are making to become a mature civilization. You probably heard of the Drake equation. That would be the L at the very end-

   12. LFLex Fridman17:46

       Mm-hmm.

   13. NCNathalie Cabrol17:46

       ... the duration, which-

   14. LFLex Fridman17:48

       The duration of intelligent civilization.

   15. NCNathalie Cabrol17:50

       Exactly. And, and, or at least, uh, the length of time a civilization remains detectable. It can disappear from the radar screen literally for a number of reasons. The first one is...... destroy itself or being destroyed by, uh, external, uh, uh, uh, events. Or it can become so in tune and, uh, with the universe and so advanced that it disappears because it melts, really, in the background and it's not visible anymore. Uh, there are some wild theories out there saying that, uh, civilization might be so advanced that you cannot distinguish them from physical processes. And, uh, that was an example. It doesn't say that this is the case, but some people say, "Imagine that, in fact, all the dark matter that we, we see, or we, we, we theorized about, is, in fact, some sort of a biological, uh, uh, process." So, you can think about a number of things. Personally, I believe that what you talk about, about preserving our information, is, kind of, what life does. We, we need to look at ourselves, uh, as not different of what the little cell that started off was. And this is what tells you not about the origin of life, but in fact, the nature of life, which is a lot more interesting to me. Because-

   16. LFLex Fridman19:15

       I- it is.

   17. NCNathalie Cabrol19:16

       ... the nature of life is really what is going to give you some universal signature to look for it all over the place, and not only around ponds of water, uh, for life as we know it. But the nature of life is telling you that life wants to get the most information possible around its surroundings, and complexity is, in fact, the ability to gather-

   18. LFLex Fridman19:42

       Mm-hmm.

   19. NCNathalie Cabrol19:42

       ... and exchange and preserve the most information possible. And, and so what you're saying is, kind of, preserving the kind of information we have. Um, so in the things that we are doing, as life happened, and I say happened because we don't know what life is. Uh, we have 123 definitions of life and some people are saying we don't have any definition, we only have descriptions of life. And, and that's true. And that's true. So, think about it for two minutes. We are looking for something we don't know it is, but we have a few clues about the nature of life. There are some really good theories. The first one was Schrodinger, right? Uh, in the '40s. Right now, there is a guy named, uh, Jeremy England. It's another biophysical, uh, theory of life. It says, "Life is the inevitable result of thermophysics." This is the best way to beat entropy, to fight entropy. But when you look at what we are doing, if you want to know what the nature of life is, look at our languages. And they can be very different languages, but they all have the same purpose, right? Exchange information, understand... you know, store information, and, and, uh, also whether it is with somebody at the outside-

   20. LFLex Fridman21:03

       Mm-hmm.

   21. NCNathalie Cabrol21:04

       ... or a thought in yourself. That's the same thing the cell was doing. But now when you're looking at life and at the structure of our languages, life started with an atom. So, it's an atom. They got together to create inorganic molecules, then you have complex inorganic molecules, then you get to organic molecules, complex inorgan- uh, organic molecules, and then you have RNA, DNA, et cetera. Look at the structure of our language. We created alphabets, letters. That's your atom. Then we put them together to create syllables, right? Those syllables get together to create words. Words tell you something, but they are nothing without a verb that gives the direction. That's RNA and DNA. And, and then you can put all the complements you want. Our languages are built exactly as life is built. We are repeating patterns. I call this the Mandelbrot universe-

   22. LFLex Fridman22:09

       (laughs) .

   23. NCNathalie Cabrol22:09

       ... and the fractal universe-

   24. LFLex Fridman22:10

       Yes.

   25. NCNathalie Cabrol22:10

       ... because this is exactly what it is. Uh, I, I would say that as much as I do believe to sending probes to explore the universe, I say we should also look inward to find the, uh, uh, the answer to some of the profound question of who we are, what's life, what's the nature of life, because we are expressing life.

   26. LFLex Fridman22:31

       So, searching not for life, but for the nature of life.

   27. NCNathalie Cabrol22:35

       The nature of life, absolutely. I am more interested in that because the day we understand the nature of life, then we have a universal, um, biosignature. And it doesn't matter whether this life respond to the same kind of biochemical processes as we do. Although it makes sense. I, I told you about the generational aspect of the bricks of life, the stuff we are made of. The sun is part of the youngest generation of stars, and the first two generation of stars didn't produce the kind of, uh, elements we are made of. They were stars that were either, uh, uh, without metal, just made of helium and hydrogen, or poor in metals. So, the stars died off, and stars like the sun were born from those. And this is why we have elements like carbon, hydrogen, uh, oxygen, et cetera now. Um, and, and that's the life we are built on. So, I, I think it's not stupid to be looking for something that looks like us, because right now, in the universe, this is the stuff that's the most abundant. And we see with the exoplanet, uh, with Kepler, with TESS, and, and now with James Webb, we see that there are many, many different type of planets that may be habitable, in the habitable zone of their stars. There are countless stars like the sun, but more interestingly en- enough, there are other type of stars where you do have habitable zone as well, and where the duration of the stars...... sometimes a thousand time more than our sun. So, you can imagine all sorts of things and you can imagine what type of life would be, um, around those stars. Uh, the biochemistry might be quite similar, in fact, and especially for the simple life, because simple life starts really quickly, uh, on earth. So, my take on this is that the universe is full of cyanobacteria, but as far as intelligent life, uh, it takes more time. So, that can take different, you know, aspect.

   28. LFLex Fridman24:49

       So, you think it's possible that the universe is full of bacteria and even those stars that last a thousand times longer than the sun, even, even on the planets that orbit those stars, maybe it's bacteria for billions and billions and billions of years?

   29. NCNathalie Cabrol25:13

       We actually don't know what triggered the evolution to complexity on earth. That's still a big question mark.

   30. LFLex Fridman25:20

       Is that the most impressive invention on earth to you?
5. 31:21 – 34:58

   Complexity

   1. NCNathalie Cabrol31:21

   2. LFLex Fridman31:21

      So, if life is the- the best way to fight entropy, you can imagine that life permeates the entire universe and then the question might change to, like, flavors of ice cream. What are the flavors of complexity that this process, this nature of life leads to? And there we might have bias about what complexity looks like, what beautiful complexity looks like. We'll look at humans that operate a certain physical scale and, uh, time scale, and we think, "This is intelligence."

   3. NCNathalie Cabrol31:56

      We have another problem. We don't know what life is. We don't know what intelligence is and we don't know what consciousness is-

   4. LFLex Fridman32:02

      Yeah.

   5. NCNathalie Cabrol32:02

      ... but we are trying to tackle the big question. Uh-

   6. LFLex Fridman32:04

      But do we know what complexity is also? I mean-

   7. NCNathalie Cabrol32:07

      You don't know. I- I think that we have to be honest and as a scientist-

   8. LFLex Fridman32:11

      Yeah.

   9. NCNathalie Cabrol32:11

      And I'm gonna step back and talk about intelligence. Uh, for me, a bacteria that has survived, like cyanobacteria, that has survived just like us, four billion years in one incarnation or another, and actually they are very similar to the one that they were 3.5 billion years ago. It has some intelligence about its environment. So, for complexity, it might be that we need to take the word literally, which is an assemblage or additional capacity to gather, collect, store information. Maybe this is something like that, or actually use that information to do something with it. Um, but I do completely agree with you when you talk about flavor of ice cream. I think this is exactly it, and I have a basic education about what physics is doing right now. And I look at quantum physics and what it says about the universe and about the connection, about an atom here and an atom here, a foton here and a foton there, and I am starting to put maybe wrongfully two and two together. But in my mind, and of course it's nothing until I can prove it, but in my mind, the universe is co- connected everywhere, in all different places. So, this life connection is something that, as you said, permeate the universe, and the way to find life might be very different than to look for the origins of life. I think it's a good thing to go out there and look for the origin of life somewhere else because it's the manifestation of the nature of life that's all of a sudden becomes apparent, evident to our eye. But what I think would be our greatest achievement is that if we can find that process of life, because at that point, in my mind, the universe all of a sudden is going to illuminate itself with actually its living force, what I can only call a living force. To me, this is what we are looking at, a universe that becomes more and more complex with time, more and more able to gather information, and interestingly enough, why? To understand itself. So, Sagan was right when he was saying, "We are the universe trying to understand itself." And the more we go, the more the universe become alive, maybe intelligent, and maybe also conscious.

   10. LFLex Fridman34:55

       Conscious, self-aware-

   11. NCNathalie Cabrol34:56

       Exactly.

   12. LFLex Fridman34:57

       ... through us.

6. 34:58 – 43:44

   AI

   1. LFLex Fridman34:58

      Uh, it does make me a little bit sad as a human, just watching all the breakthroughs on artificial intelligence side when applied to natural sciences, now more and more to physics, that the creatures that will solve the question of the origin of the nature of life or just the process, the nature of life, will be AI systems. It makes me a bit sad to-

   2. NCNathalie Cabrol35:24

      I don't think so, uh-

   3. LFLex Fridman35:26

      You don't think so?

   4. NCNathalie Cabrol35:26

      ... because a-

   5. LFLex Fridman35:27

      You think humans will?

   6. NCNathalie Cabrol35:27

      ... at- at this point in time, remember who's behind AI. You know, I- I'm not buying in the singularity thing yet. Um, to... AI is not aware. AI is being built by humans. So, um, AI is a tool, an extremely smart tool. As long as we build it and as long as we use it as a tool, it remains a tool and I think there is a lot of brouhaha, uh, and of course science fiction and- and movies. They don't help.

   7. LFLex Fridman35:58

      See, I- I got to push back a little bit. Yes, I agree with you for the most part in terms of brouhaha and s- sci-fi but there is, like in the work of DeepMind, we can look at chess or we can look at protein folding. So, chess is a simple one to first look at. What, uh, AlphaZero, or which is their game-playing engine, was able to discover, and now Stockfish, about chess humbles the best human players. Not just it's better than them. It comes up with ideas that the humans don't understand. And so the AI now is telling you-... uh, even though it's programmed by humans, the AI is saying, like, "Sacrificing a, a pawn here is a good idea. Sacrificing a queen or a bishop here is a good idea." And then you start to kind of intuit as a human why, but you don't deeply understand. And you can say that AI is not conscious, it doesn't deeply understand the way humans do, but there's still a, uh, a wisdom and a depth of knowledge in that chess-playing program (laughs) that humans don't have. And the same with al- AlphaFold, with protein folding. There's a... And now they're applying it to physics through s- simulating nuclear reactions and so on. It feels like there might be a way to understand the nature of life that we can kind of intuit poetically as humans. But the, the true understanding will come from a system that's much more com- computationally sophisticated.

   8. NCNathalie Cabrol37:29

      Again, you know, I would push back and... And my turn, because I still think that human give themself ability to do that by building that tool. So, the idea that the tool... You know, we're, we're, we're, we are getting into the, the Kardashev scale and, and, and the dark forest and all of these things. We can see the world this way. Uh, at this point in time, for me, I still see a great tool. Now, uh, whether the sci-fi scenario is going to, you know, uh, happen, et cetera, I still think that we are far away from, from this. But if that tool is capable of giving me a new perspective, uh, it's just that, uh, we are starting to jump into a deeper, uh, cognition of, of what the universe is, whether it's through our brain or through a different way of gathering information. Remember, this is what we do.

   9. LFLex Fridman38:29

      Yeah. Humans are able to actually build tools and then, like, integrate them into their way of thinking. Maybe another generation has to be born that is raised with those tools, but we seem to, like, take for granted all the cool technologies you integrate into your way of thinking. A lot of people that are growing up now, their mind is integrated with the internet. Y- you basically reconfigure the way you memorize things. You no longer have to memorize a lot of facts because you can look them up really quickly.

   10. NCNathalie Cabrol39:00

       Yeah.

   11. LFLex Fridman39:01

       And, and, so, like, uh, so you, uh, reallocate a lot of resources for, uh, thinking versus memory of just strict facts, so that kind of stuff. And we integrate all of that.

   12. NCNathalie Cabrol39:13

       Yeah. And, and, uh, you know, there, I would completely agree with you. In fact, I wrote about this, again, uh, um, in, in, in this new book that's coming out.

   13. LFLex Fridman39:22

       When is the book coming out?

   14. NCNathalie Cabrol39:23

       In January. It's, it will be in French, actually, uh, to start with.

   15. LFLex Fridman39:26

       You wrote it in French?

   16. NCNathalie Cabrol39:28

       Actually, I wrote it first in English-

   17. LFLex Fridman39:29

       Yes.

   18. NCNathalie Cabrol39:30

       ... uh, and I translated it into French. So, the, the English version is already, uh, pretty much ready to go, uh, if we find a publisher in, uh, in the US. But anyways, um, the point, uh, being here, that I looked at this as, uh, our relationship with technology as a complete change. To me, this is the singularity more than anything else, which is the co-evolution of human with technology, not anymore with their environment. Why we are messing up the environment right now, why we don't respond to pandemic the way we should, because we are disconnected to the environment we are taking our information from and we were adapting from. Right now, exactly as you said, we take the information from the web, from the phones, et cetera. We have no filter over that information. Before, you were out in the environment, the information you get is the one the planet is sending you. Now this information is coming from different way. You have no way of knowing an information is correct or not.

   19. LFLex Fridman40:32

       Yeah, I gotta push back on that.

   20. NCNathalie Cabrol40:33

       No, you look-

   21. LFLex Fridman40:34

       Oh, okay. Go ahead. No, I-

   22. NCNathalie Cabrol40:34

       You look at this as an ecosystem and it explains-

   23. LFLex Fridman40:37

       Yes.

   24. NCNathalie Cabrol40:37

       ... a lot of our behavior.

   25. LFLex Fridman40:38

       See, I like, though, you said teenagers. So, we... The technology, I think, when we move past the teenager stage, enriches our ability to sense the earth, to understand what's going on with the environment. It's just that we're very... So, it's not that technology disconnects us from the environment. It gives us more tools with which to understand what's going on with the environment.

   26. NCNathalie Cabrol41:01

       That's true for the people who are building the tools and know how to use it.

   27. LFLex Fridman41:05

       Sure.

   28. NCNathalie Cabrol41:05

       Take those tools now, put them in the general public with no filter, which is happening with social media, which is happening with a lot of things, and you see the disaster this is creating.

   29. LFLex Fridman41:16

       It's not the disaster.

   30. NCNathalie Cabrol41:17

       It is.
7. 43:44 – 51:26

   Extinction

   1. NCNathalie Cabrol43:44

   2. LFLex Fridman43:44

      I draw a lot of optimism from the similar things that happened many decades ago when nuclear weapons were developed. Boy, was that, at the time, even more terrifying. You just now created weapons that could destroy the entirety of life on Earth. Or not entirety, but a lot of it, and we somehow found a balance. And that the threat constantly is out there, and that threat has been made more visceral in recent times, um, because the war in Ukraine. But we find a balance somehow. So, I have a thread of optimism for human civilization that we, that we figure it out. We're clever teenagers, I think.

   3. NCNathalie Cabrol44:29

      We are clever teenagers. There is definitely a thread of optimism, but I think it's thin. It's thin because something that has changed as well is the mentality of, of humans. Um, although the threat was terrifying when, uh, nuclear weapons were, were created, um, there was a sense of limits you were willing to push in the threats. Um, there were... there was a sense of decency, of moral values. It was not perfect, but it was at least a time where people could come together from very different perspective and agree that something was more important than destroying everything.

   4. LFLex Fridman45:22

      But that's so hilarious you say that. Yes, you're talking about a small slither of humans, which is the scientist in the Manhattan Project, perhaps.

   5. NCNathalie Cabrol45:31

      No, absolutely not.

   6. LFLex Fridman45:32

      That was also the time when over 100 million people were tortured or murdered-

   7. NCNathalie Cabrol45:37

      No, no, I agree with that.

   8. LFLex Fridman45:39

      ... in China and Europe.

   9. NCNathalie Cabrol45:40

      Absolutely, absolutely. I'm not talking about scientists here. Actually, I'm talking about politicians. We've gone beyond that point now. This is what I'm worried about. I mean, torture, et cetera, unfortunately, well, we are apes. Exactly what you said.

   10. LFLex Fridman45:57

       (laughs)

   11. NCNathalie Cabrol45:57

       So, I think that, you know, there is a lot to be-

   12. LFLex Fridman45:59

       Yeah.

   13. NCNathalie Cabrol45:59

       Uh, not, not, not to blame grandpa for that-

   14. LFLex Fridman46:02

       Yeah.

   15. NCNathalie Cabrol46:02

       ... but because we can always get better. Um-

   16. LFLex Fridman46:04

       Grandpa was a wild man.

   17. NCNathalie Cabrol46:06

       (laughs)

   18. LFLex Fridman46:07

       Yes.

   19. NCNathalie Cabrol46:08

       But we have to improve a lot on that side before we can claim that we are a, a mature civilization.

   20. LFLex Fridman46:13

       When you, um, just 'cause you mentioned the magic, uh, when you look out there, perhaps this is not a scientific question but-

   21. NCNathalie Cabrol46:21

       You don't have to be scientific all the time.

   22. LFLex Fridman46:23

       Yeah, well, that's... (laughs) you said magic, so there's a-

   23. NCNathalie Cabrol46:26

       Yeah.

   24. LFLex Fridman46:26

       There's a magic to magic that is in part scientific and in part, I don't know, whatever. Whatever fills us with awe-

   25. NCNathalie Cabrol46:32

       Yeah.

   26. LFLex Fridman46:32

       ... as humans when we look up at the stars. Do you think the universe is full of life or not? Like, you know, when you're sitting drinking some wine, looking up at the stars and, and wondering as a human, uh, do you think we're alone or do you think it's... life is everywhere?

   27. NCNathalie Cabrol46:53

       I am going to make such an unmagical response to that. My response is, that's the scientific response-

   28. LFLex Fridman47:02

       Yeah.

   29. NCNathalie Cabrol47:02

       ... that if we are alone, then the universe is a statistical absurdity.

   30. LFLex Fridman47:08

       (laughs) Yeah.
8. 51:26 – 1:05:09

   Fermi Paradox

   1. NCNathalie Cabrol51:26

   2. LFLex Fridman51:26

      Everything I've seen from life, it seems obvious that there's life everywhere out there. In fact, maybe I don't understand the jump from bacteria enough, but it seems obvious that there's intelligent civilizations out there. Now, I don't know what intelligence, how to define intelligence, but there's beautiful complexity. Like when you look at a... I, I've looked at enough cellular automata, which is a very primitive mathematical construction that when you run, complexity emerges. I've looked at that enough to know that it just seems like there's complexity everywhere out there, so I... That's why I'm deeply puzzled by the, the Fermi paradox. It makes no sense to me. Uh, I mean, uh, there have trivial answers to it. Why haven't aliens at scale not shown up? I, I think the, the, the two possible options for me is either we're too dumb to see it. They're already here. They've been talking to us through processes we just don't understand, like, like w- what we experience as, uh, life here on Earth is actually... They're everywhere. Conscious... Aliens could be consciousness. That when we feel love for e- one another, that could be aliens. When we, I don't know, or feel fear or whatever, that could be aliens.

   3. NCNathalie Cabrol52:46

      I, I have to agree with you. None of this is scientifically provable right now. We talked a little bit a- already about that. But I would say that I do not adhere to the Fermi paradox because it's very anthropomorphic. It's, you know-

   4. LFLex Fridman53:04

      Sure.

   5. NCNathalie Cabrol53:04

      ... it's an interesting exercise. Let's put it that way. But it's a typical example of seeing the universe through our own eyes, and, uh, this is where the limitation is. Understanding what's going on with complexity, as you said, and looking at the biophysical model and theories for the nature of life. I would agree that probably this extraterrestrial message is all around us. We're not yet capable of picking it up.

   6. LFLex Fridman53:37

      But I think unfortunately, even though that makes me sad, the way to pick it up is by studying life here on Earth, doing some of the science you're doing, better understand the nature of life until you realize, uh, holy crap, the thing I was looking for all along has been, has been here all along, right under our nose.

   7. NCNathalie Cabrol53:55

      Well, you know, a, a good example of that... And it doesn't need to be, um, an extraterrestrial civilization. Look at something that I really... You know, whether or not it's real, I don't care because in terms of intellectual exercise, I think it's fantastic. Look at the shadow biosphere. The idea that life didn't appear only once on Earth but there were many different pathways of it. And today, we know when we study the tree of life that led to us, from LUCA to us, and the shadow biosphere is telling us that there is or there are other pathways that came up at the time where life originated, but they are so different that we cannot recognize them as being living and we cannot pick them up in our test because our test are being built to recognize life as we know it. And for me, again, I don't know if this theory... will be verified or it would be discredited. But what I like about it is that it forces me to think on how do I look for life? I don't know. So, that starts here on our planet. Not even with little green men. Uh, it starts with very simple life that be- can be so different that it might be just right in front of our nose and we don't see it.

   8. LFLex Fridman55:38

      So, that's probably starts with the scientific humility of-

   9. NCNathalie Cabrol55:42

      Always.

   10. LFLex Fridman55:44

       ... realizing that we might be too biased in our understanding of what is the phenomena we're trying to study.

   11. NCNathalie Cabrol55:50

       Yeah, I don't like the term biased because it involves some moral connotation that, you know-

   12. LFLex Fridman55:55

       Sure. I'm using it in a traditional sense.

   13. NCNathalie Cabrol55:55

       But I understand the bias in t- in terms of scientific-

   14. LFLex Fridman55:59

       Yes.

   15. NCNathalie Cabrol55:59

       ... uh, pathway, intellectual framework. Definitely.

   16. LFLex Fridman56:02

       What do you think about the UFO sightings? So, the widespread experiences that people have in seeing different phenomena that they, sort of, that are mysterious-

   17. NCNathalie Cabrol56:16

       Mm-hmm.

   18. LFLex Fridman56:16

       ... that people project ideas about whether it's aliens or not, but they can't explain it and there's pictures and data and the government is involved in releasing footage and all that kind of stuff.

   19. NCNathalie Cabrol56:28

       Mm-hmm.

   20. LFLex Fridman56:28

       And that seems to captivate the public-

   21. NCNathalie Cabrol56:30

       It always-

   22. LFLex Fridman56:30

       ... imagination.

   23. NCNathalie Cabrol56:31

       ... it, it always do. I mean, you know, there are a number of things that, uh, captivate people, especially children actually, dinosaurs and aliens.

   24. LFLex Fridman56:39

       I'm still a child.

   25. NCNathalie Cabrol56:40

       Yeah. We are also child at heart. And, um, so about UFOs, I am a scientist and I'm a citizen, so, I'm gonna tell you a couple of things. First, uh, I don't mind talking about that at all because I think, as a scientist, this is extremely interesting 'cause the thing I don't know, I want to learn about it. This is more knowledge. So, we all know the statistics about UFOs, 95% of them are just natural phenomenon or things that are being misinterpreted. We know that. Uh, then you have the 2% that might be secret programs by whatever government, uh, it's out there. Another percent, say, is about natural phenomenon that we don't know about yet, that we cannot explain. And then there is this tiny percentage that don't fall into all these categories or thing. And I think that the rep- the report about the UAPs falls into the same kind of s- uh, scheme, except that now they have at least some patterns of speed of other things, uh, that were in the report. Today, we don't know if these sightings are part of military program or actual UFOs. Um, I always run into that question because, of course, as the director of The Carl Sagan Center at the SETI Institute, I receive a number of emails about the subject. People are actually-

   26. LFLex Fridman58:06

       Oh, okay.

   27. NCNathalie Cabrol58:07

       ... confused about what the SETI Institute is. We are not studying UFOs. Uh, we are studying... we are actually looking for messages. The way I put it, you know, usually is that we are studying extraterrestrial in their natural habitat.

   28. LFLex Fridman58:21

       (laughs) Yes.

   29. NCNathalie Cabrol58:22

       And, and the UFO people are trying to understand whether they invaded our aerial space.

   30. LFLex Fridman58:28

       Yes.
9. 1:05:09 – 1:07:59

   SETI research

   1. NCNathalie Cabrol1:05:09

   2. LFLex Fridman1:05:09

      So, SETI, in terms of both signatures and signals, is a pretty active field?

   3. NCNathalie Cabrol1:05:14

      So, it, it's getting better. Right now, uh, it's getting better. Uh, but remember that the SETI Institute is not only about the search for extraterrestrial intelligence. This is the root of, uh, the historical root of the institute, but it's about 10% of what we do. In fact, we are searching for life in the universe from the origins of life to extraterrestrial intelligence. So, 90% of everything else is exoplanet. Uh, for instance, we have a good chunk of the Kepler team that is actually, uh, with, uh, the SETI Institute, and they are working with TESS right now. Some already have some time on the James Webb. We have astrobiologists. We have astronomers.

   4. LFLex Fridman1:05:55

      And those are looking for data, for signals, for planets out there outside of our solar system.

   5. NCNathalie Cabrol1:06:02

      Go to an- yeah, go to analog places to try and understand the type of life that survive in planetary-type environments. I mean, people are always surprised when I tell them, "You know, whatever flies in the solar system has flown or will be flying, we're involved." So, this is not something that pops in everybody's mind when they are thinking about the, the SETI Institute because we started off as the search for extraterrestrial intelligence. But the institute has really bloomed into, uh, the search for life along the Drake equation, all the terms of the Drake equation.

   6. LFLex Fridman1:06:39

      Just to clarify, 'cause by the way, you're saying a bunch of terms. Sometimes it's good to return to the basics. When you're saying whatever has flown, SETI is a part of the things that have flown-

   7. NCNathalie Cabrol1:06:52

      Yeah.

   8. LFLex Fridman1:06:52

      ... so we... 'Cause we're using "we" elusive sometimes to say "we humans" and sometimes "we SETI."

   9. NCNathalie Cabrol1:06:57

      Yeah.

   10. LFLex Fridman1:06:57

       So, the... SETI is, is really broadly involved-

   11. NCNathalie Cabrol1:07:00

       Oh, yeah.

   12. LFLex Fridman1:07:00

       ... in a lot of the fingertips reaching out there towards the stars.

   13. NCNathalie Cabrol1:07:03

       Think about Mars, involved in lending site selection, in instrument that are actually on board, some of the mission in science teams, for instance. Uh, Cassini, uh, New Horizon, also missions that will be coming, it's...... the search for life, we do this all across the Drake Equation. So, SETI is part of it and it's, uh, our root, and it's expanding a little bit right now. We hope it will continue to expand. So, this is, this is a good time, uh, for the institute. And it also, uh, in my mind, was the very first astrobiology institute because we have this multi-discipli-, uh, disciplinary approach where I can bring many of these scientists from different domains and disciplines to think about a question. And as you know, discoveries happen at the nexus of disciplines. And, uh, it's really a privilege when, when you are in an institute like that.

10. 1:07:59 – 1:27:17

    Diving in volcanic lakes

    1. NCNathalie Cabrol1:07:59

    2. LFLex Fridman1:07:59

       You've dived in volcanic lakes at high altitudes to study the creatures within. Can you tell me the technical, the fun, the human story of that effort?

    3. NCNathalie Cabrol1:08:10

       The, the image that is associated with a scientist is the person with the white coat in the lab. In fact, um, a number of us at the institute are athletes doing extreme s-, what would be considered extreme stuff. Uh, uh, and that, I mean, it's fun. Uh, it's a little dangerous too. But, uh, it's to get data and more knowledge. So, there are so many stories. I don't even know where-

    4. LFLex Fridman1:08:35

       What was the first time you did a dangerous thing with a volcano? (laughs)

    5. NCNathalie Cabrol1:08:40

       Oh. So, the, the, the first one associated to, uh, the search for life understanding was in 2002, uh, where I started climbing those high volcanoes in the Andes that are 20,000-footers. The view out there is just beautiful.

    6. LFLex Fridman1:08:57

       (laughs) Okay. You got... (laughs) I... y- you're so hilarious at spending almost no time on some epic things. I, I love this. Okay. What... Uh, the, the volca- okay. How tall are these volcanoes? What are you doing with a volcano? What's required to prepare for that?

    7. NCNathalie Cabrol1:09:12

       (laughs)

    8. LFLex Fridman1:09:12

       What does a mission look, like that look like? I mean, how do you... I mean, that is true that this is science embodied. It's like athletics and it's science. And you're studying the extreme conditions of life on Earth, extreme beauty of life on Earth-

    9. NCNathalie Cabrol1:09:26

       Yeah.

    10. LFLex Fridman1:09:26

        ... in those conditions. So, what, what, what was, what was the... What, what are we talking about with this volcano? What, how big is it?

    11. NCNathalie Cabrol1:09:32

        So, remember when we were talking about how do I understand how I search for life on Mars? This is how it started for me. And then I looked at environment, in my head started, you know, going through all the environments on Earth that would be good analogs. And then you only have a few. And the Andes, in that case, are some of the best in the world just because of the aridity, uh, of the place. And the higher you go, the least atmosphere you have, the more UV radiation you have. And the Andes are volcanic, hydrothermal, plus you have the climate change that's coming, you have evaporation. It's a picture of Mars 3.5 billion years ago. And so now you are actually entering a time machine-

    12. LFLex Fridman1:10:19

        Yeah.

    13. NCNathalie Cabrol1:10:19

        ... basically. So, um, remember I'm a diver. And the first time I got, in 2002, to the places, uh, we wanted to, uh, explore, all of a sudden I was standing at 14,000 foot looking at 20,000 feet and saying, "Okay. (laughs) Well, I need to get up there." (laughs)

    14. LFLex Fridman1:10:43

        Were you scared?

    15. NCNathalie Cabrol1:10:44

        No. No, because we are prepared. And the only thing I didn't know is if I was going to be able to make it to the top because now you're dealing with high altitude. You can deal with high altitude sickness. You can deal with a number of things. And for God's sake, these are volcanoes and they are dormant. They are not extinct. (laughs) Um, that can buy, to bite us a, a couple of times.

    16. LFLex Fridman1:11:04

        What was your preparation for that kind of... I mean, this is-

    17. NCNathalie Cabrol1:11:07

        There is a lot of, uh, you know, hiking and trekking at high altitude around here, but not so high because we don't have anything closer to, uh, those, uh, elevations, uh, around here in the US. Um, but, uh, in, in volcanic environment, climbing volcanoes here, we have plenty of those. Diving as well. I am a free diver. So, this is where it's going to be hilarious because I started with a completely irrational fear of pressurized vessels that comes from an incident in my childhood. And so I became a free diver to avoid having to carry oxygen tanks on my back.

    18. LFLex Fridman1:11:44

        Free diving is diving without-

    19. NCNathalie Cabrol1:11:46

        Without anything.

    20. LFLex Fridman1:11:47

        Yeah.

    21. NCNathalie Cabrol1:11:47

        Just your lungs, right?

    22. LFLex Fridman1:11:49

        That, that was, that started from childhood?

    23. NCNathalie Cabrol1:11:51

        Yeah. No. It was to the point where when I s-, I saw a pressurized vessel like a methane tanks or anything, I would be, you know, going around and puts a lot of distance between me and that tank.

    24. LFLex Fridman1:12:04

        Yes.

    25. NCNathalie Cabrol1:12:05

        So, I was not going to carry any oxygen tank. Um, and, and the first time I actually dived at the summit of that lake was free diving.

    26. LFLex Fridman1:12:14

        Okay.

    27. NCNathalie Cabrol1:12:14

        People look at me like I'm nuts. Well, maybe I am a little bit.

    28. LFLex Fridman1:12:18

        The people that work with you as well? I mean, that, that kind of seems kind of nuts.

    29. NCNathalie Cabrol1:12:21

        No. Uh, we knew what-

    30. LFLex Fridman1:12:23

        It's a, it's a risk.
11. 1:27:17 – 1:37:58

    Surviving an earthquake on a volcano

    1. NCNathalie Cabrol1:27:18

       We had a magnitude 7.8 earthquake-

    2. LFLex Fridman1:27:20

       Pfft.

    3. NCNathalie Cabrol1:27:21

       ... hitting one day when we are 50 meters away from the summit.

    4. LFLex Fridman1:27:25

       So, you can't obviously plan for that?

    5. NCNathalie Cabrol1:27:27

       No, you can't. And that's the acts of God, you know. Uh, working with NASA, uh, a- although I am, uh, the director of the SETI Institute, I, uh, my grants are coming from NASA. So, I'm a NASA contractor. And every time we go to those environments, we have to go through the rigorous process of training with NASA and checking all the boxes for safety. So, they are training and training and training us. And I have to thank them because a lot of those trainings are the things that are in your brain when these kind of things happen, you know how to react and you are not freaking out. But in all of the things they are training us for, you have the green risk, the yellow risk, and the red risk. So, the green risks are basically the don't be stupid and don't do the kind of thing you wouldn't be doing at home. Like it's jumping, you know, on rocks that are not stable, you can tweak your ankle, you know. And then you have other risk, like high altitude sickness, how you prepare for that, how you recognize that. These are the yellow risk. And then the red risk. The red risks are what they call the acts of Gods, the kind of thing that they can happen, you know there is nothing you can do about it and then you accept that when you do that. So, those are volcanic eruptions when you're in this kind of environment, earthquakes and everything that... And avalanches, for instance.

    6. LFLex Fridman1:28:47

       So, you're in this giant mountain and it's shaking?

    7. NCNathalie Cabrol1:28:51

       No, it's not shaking. That's the interesting part of it. Um, there was a whole background of things that happened that day when we, we started off, but we got to 50 meters, uh, from the summit and I have part of my logistics team that is at the foot of the mountain. And being so close to the summit, we have to go under a overhang of lava. So, it's just like we are just under this big vault, uh, of lava and it's actually beautiful. Uh, if you want something beautiful is the Altiplano seen from 20,000 feet. It's just absolutely stunning.

    8. LFLex Fridman1:29:26

       What's the colors? What are we looking at?

    9. NCNathalie Cabrol1:29:27

       The colors are that of early earth, which means primordial earth. It's ochers, yellows, oranges, browns, uh, with a dark blue sky. And so you are just, you know, it's a time machine. You are just out there and you're climbing 42-degree slopes. So, all of a sudden, uh, I'm right next behind the guide, uh, and the guide has been with us, it's family, you know, we've been together for 10 years and he's starting to do that. I don't discuss, uh, when, uh, Macario do that, you know, I, I listen and I ask the team to do the same thing. We are maybe half a dozen. And then I went to talk to him and say, "What's going on?" He's on the radio. And then he, uh, gives me the radio and talking to my logistic chief officer who was at the bottom and he said, "We're having a tremendous earthquake." Uh, he was saying that the, uh, actually the ground was waving it was so bad. And he was freaking out because he said, "Everything is avalanching and I'm very puzzled because we are in a very dangerous part of the volcano, nothing's happening." I turn around and then this is when I realize there is dust absolutely everywhere. Everything that I saw two minutes before, it's gone, just disappear into a wall of dust. But nothing's happening where we are and, uh, our, our friends down, uh, they were freaking out because they were seeing everything avalanching and especially the other side of the mountain we were on was avalanching.

    10. LFLex Fridman1:30:59

        So, they have no visuals of the

    11. NCNathalie Cabrol1:31:38

        ... and, uh, this is what- why we came for. So, we just had a 7.8 earthquake and what do you think they do? But, of course, they do the science they came to- to do. So, the only thing is that I couldn't because, uh, my radio was only working when I was on the rim of the crater. But I had a- a little assistant with me, uh, uh, a- a young, uh, Bolivian teenager, who had been shadowing me for, uh, three weeks so he knew exactly what to do. And he said, "Nathalie, don't... No problem, give me your bag. I'll do the sampling for you." So, I was monitoring, uh, the situation and, um-

Episode duration: 2:06:24