Avi Loeb: Aliens, Black Holes, and the Mystery of the Oumuamua | Lex Fridman Podcast #154

1. 0:00 – 2:31

   Introduction

   1. LFLex Fridman0:00

      The following is a conversation with Avi Loeb, an astrophysicist, astronomer, and cosmologist at Harvard. He has authored over 800 papers and written eight books, including his latest called Extraterrestrial: The First Sign of Intelligent Life Beyond Earth. It'll be released in a couple of weeks, so go pre-order it now to show support for what I think is truly an important book in that it serves as a strong example of a scientist being both rigorous and open-minded about the question of intelligent alien civilizations in our universe. Quick mention of our sponsors: Zero Fasting app for intermittent fasting, LMNT electrolyte drink, Sunbasket meal delivery service, and Pessimists Archive history podcast. So the choice is a fasting app, fasting fuel, fast-breaking delicious meals, and a history podcast that has very little (laughs) to do with fasting. Choose wisely, my friends. And if you wish, click the sponsor links below to get a discount and to support this podcast. As a side note, let me say a bit more about why Avi's work is so exciting to me and I think to a lot of people. In 2017, a strange interstellar object, now named Oumuamua, (laughs) it's fun to say, was detected traveling through our solar system. Based on the evidence we have, it has strange characteristics which made it not like any asteroid or comet that we've seen before. Avi was one of the only world-class scientists who fearlessly suggested that we should be open-minded about whether it is naturally made or, in fact, is an artifact of an intelligent alien civilization. In fact, he suggested that the more likely explanation, given the evidence, is the latter hypothesis. But we also talk about a lot of fascinating mysteries in our universe, including black holes, dark matter, the Big Bang, and close-to-speed-of-light space travel. The theme throughout is that in scientific pursuits, the weird things, the anomalies, the ideas that right now are considered taboo should not be ignored if we're to have a chance at finding the next big breakthrough, the next big paradigm shift, and also if we are to inspire the world with the power and beauty of science. If you enjoy this thing, subscribe on YouTube, review it on Apple Podcasts, follow on Spotify, support on Patreon, or connect with me on Twitter @lexfriedman. And now, here's my conversation with Avi Loeb.

2. 2:31 – 6:46

   Are we alone in the universe?

   1. LFLex Fridman2:31

      In the introduction to your new book, Extraterrestrial, you write, "This book confronts one of the universe's most profound questions: Are we alone?" Over time, this question has been framed in different ways. Is life here on Earth the only life in the universe? Are humans the only sentient intelligence in the vastness of space and time? A better, more precise framing of this question would be this. Throughout the expanse of space and over the lifetime of the universe, are there now or have ever been other sentient civilizations that, like ours, explored the stars and left evidence of their efforts? So let me ask, are we alone?

   2. ALAvi Loeb3:13

      That's an excellent question. Uh, for me, the answer is sort of clear, because, uh, I start from the principle of modesty.

   3. LFLex Fridman3:22

      (laughs)

   4. ALAvi Loeb3:22

      Um, you know, if we believe that we are alone and special and unique, that shows arrogance. My daughters, when they were infants, they tended to think that they are special, unique, and then they went out to the street and realized that other kids are very much like them, and- and then they developed a sense of- a- a better perspective about themselves. And I think the only re- reason that we are still thinking that we are special is because we haven't searched well enough to find others that might even be better than us. Uh, and, um, you know, I say that because I look at the newspaper every morning, and I see that we do foolish things. We are not necessarily the most intelligent ones. And if you think about it, if you open a recipe book, you see that out of the same ingredients, you can make very different cakes, depending on how you put them together and how you heat them up. And, uh, what is the chance that by taking the soup of chemicals that existed on Earth and cooking it one way to get our life that, uh, you got the best cake possible?

   5. LFLex Fridman4:26

      (laughs) Yeah.

   6. ALAvi Loeb4:27

      (laughs) I mean, we are probably not, uh, the sharpest cookie in the jar.

   7. LFLex Fridman4:30

      (laughs)

   8. ALAvi Loeb4:30

      And, uh, my question is, uh, I mean, it's pretty obvious to me that we are probably not alone because half of all the sun-like stars we know now as astronomers, half of the sun-like stars from the Kepler satellite data have a planet, uh, the size of the Earth roughly at the same distance that the Earth is from the sun. And that means that they can have liquid water on their surface and the chemistry of life as we know it. So if you roll the dice billions of times, just within the Milky Way galaxy, and then you have tens of billions of galaxies like it within the observable volume of the universe, it would be extremely arrogant to think that we are special. I would think that we are sort of middle-of-the-road, typical forms of life, and that's why they- nobody pays attention to us, you know?

   9. LFLex Fridman5:19

      (laughs)

   10. ALAvi Loeb5:19

       If you go down the street on a sidewalk and you see an ant, you don't pay attention or special respect to that ant, you just continue to walk, and so I think that we are sort of average, not very interesting, not exciting, so nobody cares about us. We tend to think that we are special, but that's a sign of immaturity.

   11. LFLex Fridman5:38

       And we're very early on in our development.

   12. ALAvi Loeb5:40

       Yes, that's another thing that... We have our technology only for 100 years, and it's evolving exponentially right now on a three-year time scale. So imagine what would happen in 100 years, in 1,000 years, in a million years, or in a billion years. Now, the sun is actually relatively late in the star formation history of the universe. Most of the sun-like stars formed earlier.And some of them already died, you know, became white dwarfs.

   13. LFLex Fridman6:07

       Yeah.

   14. ALAvi Loeb6:07

       And so, um, if you imagine that a civilization like ours existed around a typical sun-like star, by now, if they survived, they could be a billion years old. And then imagine a billion-year technology. It would look like magic to us.

   15. LFLex Fridman6:24

       Mm-hmm.

   16. ALAvi Loeb6:24

       It... You know, an approximation to God. We wouldn't be able to understand it. Uh, and so t- in my view, we should be humble. And by the way, we should probably just listen and not speak-

   17. LFLex Fridman6:35

       (laughs)

   18. ALAvi Loeb6:36

       ... because (laughs) there is a risk, right? If- if- if you are inferior, there is a risk. If you speak too loudly, uh, something bad may happen

3. 6:46 – 11:23

   Consciousness

   1. ALAvi Loeb6:46

      to you.

   2. LFLex Fridman6:46

      Y- you mentioned, uh, we should be humble also in the sense, with the analogy to ants, that, uh, they might be better than us. So there's a kinda scale that we're talking about, and in the- in the question, you mentioned the word sentient. So sentience or maybe the more basic formulation of that is consciousness.

   3. ALAvi Loeb7:08

      Mm-hmm.

   4. LFLex Fridman7:09

      Do you think, um... Do you think that this thing within us humans, in terms of the typical life form of consciousness, is the essential element that permeates other... If- if there's other alien civilizations out there, that they have something like consciousness as well? Or is this... I guess I'm asking, can you try to untangle the word sentient?

   5. ALAvi Loeb7:33

      Yeah, so that's- that's a good question. Uh, I think what is most abundant, depending on how long it survives, so if you look at us, as an example, uh, we are now... We do have conscious, and we do have technology. But the technologies that we are developing are also means for our own destruction-

   6. LFLex Fridman7:54

      Yes. Yes.

   7. ALAvi Loeb7:55

      ... as we can tell. You know, we can change the climate if we are not careful enough. Uh, we can go into nuclear wars. So we are developing means for our own destruction through self-inflicted wounds, and it might well be that creatures like us are not long-lived.

   8. LFLex Fridman8:13

      Mm-hmm.

   9. ALAvi Loeb8:14

      That, uh, crocodiles on other planets live for billions of years. They don't destroy themselves. They live naturally. And so if you look around, the most common thing would be dumb animals that live for long times, you know, not those that have conscious. But in terms of changing the environment, I think since, I mean, humans developed tools, they've had- develop, uh, the ability to construct technologies that would lift us from this planet that we were born in, and that's something animals without a conscious- consciousness cannot really do. And- and so I... You know, in terms of, uh, looking for things that are un- you- that- that went beyond the circumstances they were born into, I would think that even if they are short-lived, these are the creatures that made the biggest difference to their environment, and we can search for them. You know, even if they are short-lived, and most of the civilizations are dead by now-

   10. LFLex Fridman9:16

       Yeah.

   11. ALAvi Loeb9:17

       ... even if that's the case-

   12. LFLex Fridman9:18

       That's sad to think about, by the way.

   13. ALAvi Loeb9:19

       Well, but if you look on Earth-

   14. LFLex Fridman9:21

       (laughs) .

   15. ALAvi Loeb9:22

       ... that, you know-

   16. LFLex Fridman9:22

       Yeah, that's true as well.

   17. ALAvi Loeb9:22

       ... there are lots of cultures that existed throughout time, and they are dead by now. The Mayan culture was very sophisticated, died, but we can find evidence for it and learn about it just by archeology-

   18. LFLex Fridman9:33

       Yeah.

   19. ALAvi Loeb9:33

       ... digging into the ground, looking, and so we can do the same thing in space.

   20. LFLex Fridman9:37

       Yes.

   21. ALAvi Loeb9:38

       Look for dead civilizations, and, uh, perhaps we can learn a lesson, why they died, and behave better so that we will not share the same fate. So I think, you know, there is a lesson to be learned from the sky. And by the way, I should also say, if we find a technology that we have not dreamed of that we can import to Earth, that may be a better strategy for making a fortune than going to Silicon Valley or going to Wall Street-

   22. LFLex Fridman10:06

       (laughs) Yeah.

   23. ALAvi Loeb10:07

       ... because you lea- you- you make a jump start-

   24. LFLex Fridman10:10

       Yeah.

   25. ALAvi Loeb10:11

       ... into something of the future.

   26. LFLex Fridman10:12

       So that's one way to do the leap is actually to find, to literally discover versus come up with the idea, uh, in our own limited human capacity, like, uh, co- cognitive capacity.

   27. ALAvi Loeb10:23

       It would look li- it- it would feel like cheating in an exam where you look-

   28. LFLex Fridman10:26

       (laughs)

   29. ALAvi Loeb10:26

       ... over the shoulder of the student next to you.

   30. LFLex Fridman10:28

       Yeah.
4. 11:23 – 16:01

   Sending digital copies of humans to space

   1. ALAvi Loeb11:23

   2. LFLex Fridman11:23

      So it's-

   3. ALAvi Loeb11:23

      May well be. Uh, I should say something about AI, because I do think it offers a very important, um, uh, step into the future. Uh, if you look at the Old Testament, the Bible, there is this story about Noah's ark that you might-

   4. LFLex Fridman11:39

      Mm-hmm.

   5. ALAvi Loeb11:39

      ... know about.

   6. LFLex Fridman11:39

      Yes.

   7. ALAvi Loeb11:40

      Noah, uh, knew about a great flood that is about to endanger all life on Earth. So he decided to build an ark. And the Bible actually talks about specifically what the- the size of this ark was, what the dimensions were. Turns out it was quite similar to Oumuamua that we will-

   8. LFLex Fridman11:59

      Mm-hmm.

   9. ALAvi Loeb11:59

      ... discuss in a few minutes. But, uh, at any event, he built this ark, and he put animals on it so that they were saved from the great flood. Now, you can think about doing the same on Earth because there are...... risks for future catastrophes.

   10. LFLex Fridman12:16

       Mm-hmm.

   11. ALAvi Loeb12:16

       You know, we could have the self-inflicted wounds that we were talking about, like nuclear war, changing the climate. Or, there could be an asteroid impacting us, just like the dinosaurs died. You know, the- the dinosaurs didn't have science, astronomy. They couldn't have a warning system, but there was this big stone, big rock that approached there.

   12. LFLex Fridman12:35

       (laughs) Yeah.

   13. ALAvi Loeb12:36

       The... It must have been a beautiful sight.

   14. LFLex Fridman12:38

       Yeah.

   15. ALAvi Loeb12:38

       Just when it was approaching, got very big, and then smash them, okay-

   16. LFLex Fridman12:42

       Yeah.

   17. ALAvi Loeb12:42

       ... and kill them. So, um, you could have a catastrophe like that, or in a billion years, the sun will basically boil off all the oceans on earth. And, um, uh, currently all our eggs are in one basket, but we can spread them. It's sort of like, uh, the printing press, if you think about it. The revolution that Gutenberg brought is, there were very few copies of the Bible at the time.

   18. LFLex Fridman13:06

       Mm-hmm.

   19. ALAvi Loeb13:06

       And each of them was precious because it was handwritten. But once the printing press produced multiple copies, you know, if something bad happened to one of the copies, it wasn't a catastrophe. You know, it wasn't disaster, 'cause you had many more copies that...

   20. LFLex Fridman13:20

       Mm-hmm.

   21. ALAvi Loeb13:20

       And so if we have copies of life here on earth elsewhere, then we avoid the risk of it being eliminated by a single-point breakdown, catastrophe. So, the question is, can we build Noach's spaceship that will carry life as we know it? Now, you might think, we have to put elephants and whales and birds on a big-

   22. LFLex Fridman13:44

       Yeah.

   23. ALAvi Loeb13:45

       ... spaceship, but that's not true, because all you need to know is the DNA making, the genetic making of these animals, put it on a computer system that has AI-

   24. LFLex Fridman13:56

       Mm-hmm.

   25. ALAvi Loeb13:56

       ... plus a 3D printer, so that this CubeSat, which is rather small-

   26. LFLex Fridman14:03

       Yeah.

   27. ALAvi Loeb14:03

       ... can go with this information to another planet and use the raw materials there to produce synthetic life. And, uh, that would be a way of producing copies, just like the Gutenberg printing press.

   28. LFLex Fridman14:16

       Yeah. And it doesn't have to be exact copies of the humans. It could just contain some basic elements of life and then have enough life on board that it could, uh, reproduce the process of evolution on another place.

   29. ALAvi Loeb14:31

       Right.

   30. LFLex Fridman14:31

       So, I mean, that also makes you sad, of course, because it, uh, you confront the mortality of your own little precious consciousness and all your own memories and knowledge and all that stuff.
5. 16:01 – 38:04

   Oumuamua

   1. ALAvi Loeb16:01

   2. LFLex Fridman16:01

      Well, let's, uh, talk about, uh, probably the most interesting object I've heard about and also the most fun to pronounce.

   3. ALAvi Loeb16:10

      Oumuamua, yes.

   4. LFLex Fridman16:11

      Oumuamua. Can you tell me the story of, uh, this object and why it may be an important event in human history, and is it possibly a piece of alien technology?

   5. ALAvi Loeb16:23

      Right, so, um, this is the first object that was spotted close to earth from outside the solar system, and it was found in, on October 19th, 2017. And at that time, it was receding away from us. Uh, and at first, astronomers thought it must be a piece of rock, you know, just like all the asteroids and comets that we have seen from within the solar system, and it just came from another star. I should say that the actual discovery of this object was surprising to me because a decade earlier, I wrote the first paper together with Ed Turner and Amaya Mo- Morrow-Martin, that tried to predict whether the same telescope that was surveying the sky, Pan-STARRS from Hawaii-

   6. LFLex Fridman17:09

      Mm-hmm.

   7. ALAvi Loeb17:10

      ... would find anything from interstellar space given what we know about the solar system. So, if you assume that other planetary systems have similar abundance of rocks and you just calculate how many should be ejected into interstellar space, the conclusion is no, uh, it, we shouldn't find anything with Pan-STARRS.

   8. LFLex Fridman17:30

      To me, I apologize, it's probably revealing my stupidity, but it was surprising to me that so few interstellar objects from outside this whole system have ever been detect-... Or n- none.

   9. ALAvi Loeb17:41

      No, none. Nothing, nothing.

   10. LFLex Fridman17:41

       None has been.

   11. ALAvi Loeb17:42

       Yes.

   12. LFLex Fridman17:42

       You- you do, well, maybe talk about it, that there has been, uh, uh, one or two rocks since then.

   13. ALAvi Loeb17:48

       Well, since then, there was one, uh, called the Borisov.

   14. LFLex Fridman17:52

       Yeah.

   15. ALAvi Loeb17:52

       It was discovered by an amateur Russian astronomer.

   16. LFLex Fridman17:55

       Yeah.

   17. ALAvi Loeb17:55

       Uh, Gennady Borisov. And that one looked like a comet.

   18. LFLex Fridman18:01

       Yep.

   19. ALAvi Loeb18:01

       And, uh, just like a comet from within the solar system.

   20. LFLex Fridman18:05

       But this is a really important point. Sorry to interrupt it.

   21. ALAvi Loeb18:08

       Uh-huh.

   22. LFLex Fridman18:08

       You s- you showed that it's unlikely that a rock from another solar system would arrive to ours.

   23. ALAvi Loeb18:14

       Right.

   24. LFLex Fridman18:14

       Which is an-

   25. ALAvi Loeb18:14

       And so the actual detection of this one was surprising by itself-

   26. LFLex Fridman18:18

       Yes, yes.

   27. ALAvi Loeb18:18

       ... to me.

   28. LFLex Fridman18:19

       Yes.

   29. ALAvi Loeb18:19

       Um, and, um...Eh, but then, so, at first, they thought maybe the c- it's a comet or an asteroid, but then it look- it didn't look like anything we've seen before. Borisov did look like, uh, a comet. So people asked me afterwards and said, "You know, doesn't it convince you, if Borisov looks like a comet, doesn't it convince you that Oumuamua is also natural?"

   30. LFLex Fridman18:42

       Yeah.
6. 38:04 – 42:03

   Alien space junk

   1. ALAvi Loeb38:04

      fir- um, I think, uh, y- you know, you, you might ask, "Why aren't they looking for us?" One possibility is that we are not interesting, like we were talking about-

   2. LFLex Fridman38:12

      Yeah, the ants hypothesis.

   3. ALAvi Loeb38:13

      ... and another possibility, you know, if they are millions of, or billions of years, uh, into their technological development, they created their own ha- their own, uh, habitat, their own cocoon-

   4. LFLex Fridman38:26

      Yeah.

   5. ALAvi Loeb38:27

      ... where they feel comfortable, they have everything they need. And it, it, it's risky for them to establish communication with other-

   6. LFLex Fridman38:34

      Yes.

   7. ALAvi Loeb38:34

      Uh, so they have their own cocoon, and they close off.

   8. LFLex Fridman38:38

      Yes.

   9. ALAvi Loeb38:38

      They don't care about anything else.

   10. LFLex Fridman38:39

       Yes.

   11. ALAvi Loeb38:40

       Now, in that case, you might say, "Oh, so how can we find about them if they are closed off?" The answer is, they still have to deposit trash, right? That's-

   12. LFLex Fridman38:49

       (laughs)

   13. ALAvi Loeb38:49

       That is something from the law of thermodynamics.

   14. LFLex Fridman38:52

       Yes.

   15. ALAvi Loeb38:52

       There must be some production of trash. And, you know, we can still find about them just like investigative journalists going through the trash cans-

   16. LFLex Fridman39:02

       Yeah.

   17. ALAvi Loeb39:02

       ... of, uh, celebrities in Hollywood, you know?

   18. LFLex Fridman39:04

       Yes.

   19. ALAvi Loeb39:04

       You can learn about the private lives of those celebrities by looking at their trash.

   20. LFLex Fridman39:09

       (laughs) It's fascinating to, to think, you know, if, if we are the ants in this picture, if we, if this thing is a water bottle or if it's, like, a smartphone, like, where-

   21. ALAvi Loeb39:19

       (laughs)

   22. LFLex Fridman39:19

       ... where on the spectrum of possible objects of spa- 'cause there's a lot of interesting trash. (laughs)

   23. ALAvi Loeb39:25

       Right. (laughs)

   24. LFLex Fridman39:26

       Right? So, like, where ... How interesting is this trash possibly?

   25. ALAvi Loeb39:29

       But imagine a caveman seeing a cellphone.

   26. LFLex Fridman39:32

       Yeah, uh-

   27. ALAvi Loeb39:32

       The caveman would think ... Since the caveman played with rocks all of his life, he would say, "It's a rock."

   28. LFLex Fridman39:37

       Yes.

   29. ALAvi Loeb39:37

       Just like my fellow astronomers said.

   30. LFLex Fridman39:39

       Yes.
7. 42:03 – 59:21

   What do aliens look like?

   1. ALAvi Loeb42:03

      no clue.

   2. LFLex Fridman42:03

      Y- you said cocoon. Uh, and you kind of, uh, uh, paint ... Uh, I think in the book ... Uh, I've read a lot of your articles too on the Scientific American, which are brilliant, so I'm kinda mixing things up in my head a little bit.

   3. ALAvi Loeb42:17

      Go ahead.

   4. LFLex Fridman42:17

      But there's a ... What does that ca- cocoon look like? What does a civilization that's able to harness the power of multiple suns, for example, um, look like? Like, if ... When you imagine possible civilizations that are a million years more advanced than us, what do you think that actually, like, looks like?

   5. ALAvi Loeb42:37

      I think it's very different than we can imagine. Uh, by the way, I should start from the point that even biological...... life, you know, just, uh, without technology getting into the game, uh, could look like something we have never seen before.

   6. LFLex Fridman42:51

      Mm-hmm.

   7. ALAvi Loeb42:52

      Uh, take, for example, the nearest star, which is Proxima Centauri, it's four and a quarter light years away, so they will know about the results of the 2016 elections only next month, in February 2021.

   8. LFLex Fridman43:06

      Yes.

   9. ALAvi Loeb43:06

      Um, it's very far away.

   10. LFLex Fridman43:07

       It's very far away.

   11. ALAvi Loeb43:08

       Um, but, um, if you think about it, um, y- you know, this, this, uh, star is a, is a dwarf star, and, uh, it's much cooler than... I- i- it's, uh, twice as cold as the sun, okay? And it emits mostly infrared radiation.

   12. LFLex Fridman43:26

       Right.

   13. ALAvi Loeb43:26

       So if there are any creatures on, uh, y- the planet close to it that is habitable-

   14. LFLex Fridman43:32

       Mm-hmm.

   15. ALAvi Loeb43:32

       ... which is called Proxima b, there is a planet in the habitable zone, in the zone just at the right distance where, in principle, liquid water can be on the surface.

   16. LFLex Fridman43:41

       Mm-hmm.

   17. ALAvi Loeb43:41

       Uh, if there are any animals there, they have infrared eyes because our eyes was designed to be sensitive to where most of the sunlight is, in the visible range, but Proxima Centauri emits mostly infrared. So, you know, the nearest-

   18. LFLex Fridman43:56

       We would not be able to see each other. (laughs)

   19. ALAvi Loeb43:57

       In the nearest, uh, star system, these animals would be quite strange. They would have eyes that are detectors of infrared-

   20. LFLex Fridman44:05

       Yeah.

   21. ALAvi Loeb44:05

       ... very different from ours. Moreover, this planet, Proxima b, faces the star always with the same side.

   22. LFLex Fridman44:12

       Mm-hmm.

   23. ALAvi Loeb44:12

       So it has a permanent day side and a permanent night side, and, uh, obviously the creatures that would evolve on the permanent day side, which is much warmer, would be quite different than those on the permanent night side. Between them, there would be a permanent sunset strip, and my daughters said that that's the best opportunity for high value real estate, because you will see the sunset throughout your life, right?

   24. LFLex Fridman44:38

       (laughs) Yeah.

   25. ALAvi Loeb44:38

       It ne- the sun never sets-

   26. LFLex Fridman44:40

       Ugh.

   27. ALAvi Loeb44:40

       ... on this, on this trip.

   28. LFLex Fridman44:42

       (laughs)

   29. ALAvi Loeb44:42

       So, you know, these worlds are out of our imagination.

   30. LFLex Fridman44:46

       But just even the individual creatures, the s- their sensor suit that they're operating with might be very different.
8. 59:21 – 1:00:23

   Drake equation

   1. LFLex Fridman59:21

      Can we talk a little bit about the Drake equation-

   2. ALAvi Loeb59:23

      Sure.

   3. LFLex Fridman59:24

      ... another framework f- from which to have this kind of discussion about, uh, possible civilizations out there? So let me ask, within the context of the Drake equation, or maybe bigger, how many alien civilizations do you think are out there?

   4. ALAvi Loeb59:38

      Well, it's hard to tell 'cause the Drake equation is, again, quantifying our ignorance. It's just a set of factors. The only one that we know, or actually two that we know quite well is the rate of star formation in the Milky Way galaxy-

   5. LFLex Fridman59:53

      Mm-hmm.

   6. ALAvi Loeb59:53

      ... which we measured by now, and the frequency of planets like the earth around stars.

   7. LFLex Fridman59:59

      Yes.

   8. ALAvi Loeb1:00:00

      And, uh, at the right distance to have life. But other than that, there are lots of, um, implicit assumptions about all the other factors that will enable us to detect a signal. Now, I should say, the Drake equation has a very limited validity just for signals from civilizations that are transmitting at the time that you are observing them. However,

9. 1:00:23 – 1:12:15

   Industrial polution from aliens

   1. ALAvi Loeb1:00:23

      y- we can do much better than that. We can look for artifacts that they left behind, even-

   2. LFLex Fridman1:00:29

      Right.

   3. ALAvi Loeb1:00:29

      ... even if they are dead. You can look for industrial pollution in the atmospheres of planets.

   4. LFLex Fridman1:00:34

      Oh, right.

   5. ALAvi Loeb1:00:35

      Uh, why do I bring this up? Again, to show you the conservatism of the mainstream in astronomy, and by the way, I shouldn't... You know, I have leadership positions. I- I was chair of the astronomy department for nine years, the longest serving chair at Harvard, and I'm the chair of the Board on Physics and Astronomy-

   6. LFLex Fridman1:00:51

      Wow.

   7. ALAvi Loeb1:00:51

      ... of the National Academies. You know, it's the primary, uh, board, um, and, um, you know, I'm director of two centers at Harvard and so forth. So I- I- I do represent the community in- in various ways, but at the same time, you know, I'm a little bit disappointed by the conservatism that people have. And so let me give you an illustration of that. So the astronomy community-... actually is going right now through the process of defining its goals for the next decade. And there are proposals for telescopes that would cost billions of dollars, and whose goal is to find evidence for oxygen-

   8. LFLex Fridman1:01:31

      Mm-hmm.

   9. ALAvi Loeb1:01:31

      ... in the atmosphere of planets around other stars.

   10. LFLex Fridman1:01:34

       Yes.

   11. ALAvi Loeb1:01:34

       With the idea that this would be a marker, a signature of life. Now, the problem with that is Earth didn't have much oxygen in its atmosphere for the first two billion years. Roughly half of, you know, half of its life, it didn't have much oxygen. But it had life, it had microbial life. It's not un- i- it's not clear yet, as of yet, what the origin is for the rise in the oxygen level after two, uh, billion years, about 2.4, uh, billion years ago. But we know that a planet can have life without oxygen in the atmosphere, because Earth did it. The second problem with this approach is that you can have oxygen from natural processes. You can break, uh, water molecules and make oxygen.

   12. LFLex Fridman1:02:22

       Right.

   13. ALAvi Loeb1:02:22

       So even if you find it, it will never tell you that for sure life exists there.

   14. LFLex Fridman1:02:27

       Mm-hmm.

   15. ALAvi Loeb1:02:27

       And so even with these billions of dollars, the mainstream community will never be confident-

   16. LFLex Fridman1:02:34

       Right.

   17. ALAvi Loeb1:02:34

       ... uh, whether there is life there. Now, how can it be confident? There is actually a way. If instead of looking... With the same instruments, if you look for molecules that indicate industrial pollution-

   18. LFLex Fridman1:02:45

       (laughs)

   19. ALAvi Loeb1:02:46

       ... for example, CFCs, you know, that are produced by refrigerating systems or industries here on Earth-

   20. LFLex Fridman1:02:52

       That's brilliant.

   21. ALAvi Loeb1:02:52

       ... that they do the ozone layer.

   22. LFLex Fridman1:02:54

       Mm-hmm.

   23. ALAvi Loeb1:02:54

       You know, you can search for that. And I wrote a paper five years ago suggesting that. Now, what's the problem? You can just tell NASA, "I want to build this telescope to search for oxygen, but also for industrial pollution." Nobody would say that-

   24. LFLex Fridman1:03:09

       Yeah.

   25. ALAvi Loeb1:03:09

       ... because it sounds like, you know, on the periphery of the field. And I ask you, why would-

   26. LFLex Fridman1:03:17

       That's hilarious, 'cause that's exactly... I mean, even just what you're saying-

   27. ALAvi Loeb1:03:21

       That would be a-

   28. LFLex Fridman1:03:21

       ... is quite brilliant. I mean, uh, because it's a really strong signal, and if life, if there's alien civilizations out there, then they're probably going to be many of them, and they're probably going to be more advanced than us, and they're probably going to have something like industrial pollution, which would be a much stronger signal than some basic gas which could have a lot of different explanations. So like-

   29. ALAvi Loeb1:03:44

       Right.

   30. LFLex Fridman1:03:44

       ... (...) like oxygen or, I mean, I don't... I-i-i-it would be, you know, uh, I mean, we could talk about signs of life on Venus and so on. But, like, if you want a strong signal, it will be (laughs) pollution. I love how garbage is-
10. 1:12:15 – 1:20:11

    UFO sightings

    1. LFLex Fridman1:12:15

       So, it's- it's hilarious that the very... Not hilarious, it's sad that s- people who are trained in a scientific community to have the tools to explore this world, to be children, to be the most effective at being children, uh, are the ones that resist being children the- the most. But there is a large number of people that embrace the childlike wonder about the world, and may not necessarily have the tools to do it. That's the- the more general public. And so, you know, I wonder if I could ask you and- and talk to you a little bit about, you know, UFO sightings. That there's people, you know, quote-unquote "believers," you know, there's hundreds of thousands of UFO sightings, and, you know, I've- I've, you know, uh, consumed some of the things that people have said about it, and, uh, one- one thing I really like about it is how excited they are by the possibility, uh, uh, by... It's- it's almost like this childlike wonder about the world out there. They're not... Uh, it's not a fear, it's an excitement.Do you think, 'cause we're talking about, uh, this extraterre- possibly extraterrestrial object that visited, that flew by Earth, do you think it's possible that out of those hundreds of thousands of UFO sightings, one is an actual, one or some number is an actual sighting of a non-human, some alien technology, and that we're not, um, we did not, we're too close-minded to, uh, to look and to see?

    2. ALAvi Loeb1:14:04

       I think to answer this question, we need better evidence. Um, my starting point, as I said, out of modesty, is that we are not particularly interesting.

    3. LFLex Fridman1:14:14

       (laughs) Yes.

    4. ALAvi Loeb1:14:15

       And therefore-

    5. LFLex Fridman1:14:16

       I agree with you.

    6. ALAvi Loeb1:14:17

       ... I would be hard-pressed to imagine that someone wants to really spy on us. Uh, so I would think, you know, as a starting point, that we don't deserve attention and we shouldn't expect someone... But who knows? Now, the problem that I have with UFO sighting reports is that, you know, 50 years ago, there were some reports of fuzzy images, you know, saucer-like things. Uh, by now, our technologies are much better. Our cameras are much more sensitive. These fuzzy images should have turned into crisp, clear images-

    7. LFLex Fridman1:14:52

       Yes.

    8. ALAvi Loeb1:14:53

       ... of things that we are confident about, and they haven't turned that way. It always on the borderline of believability. And because of that, I believe that it might be most likely artifacts of our instruments-

    9. LFLex Fridman1:15:05

       Yes.

    10. ALAvi Loeb1:15:05

        ... or some natural phenomena that we are unable to understand.

    11. LFLex Fridman1:15:09

        Yeah, yeah.

    12. ALAvi Loeb1:15:09

        Now, of course, the reason you sh- you need, you must examine those, if, for example, pilots report about them, or, uh, the military finds evidence for them, is because it may pose a national security threat. If another country has technologies that we don't know about, and they're spying on us, we need to know about it, and therefore we should examine everything that looks unusual. But to associate it with an alien life is a little too far for me. Until we have evidence that stands up to the level of scientific credence, you know, that, that we are 100% sure that, you know, from multiple detectors and, you know, through a scientific process. Now, again, if the scientific community shies away from these reports-

    13. LFLex Fridman1:15:58

        Right.

    14. ALAvi Loeb1:15:58

        ... we will never have that. It's like saying, "I don't want to take photographs of something because I know what it is," then you will never know what it is. But I think if, if some scientist, if grants, let's put it this way, if funding will be given to scientists-

    15. LFLex Fridman1:16:12

        Mm-hmm.

    16. ALAvi Loeb1:16:13

        ... to follow on some of these reports and use scientific instruments that are capable of detecting those sightings with much better resolution, with much better-

    17. LFLex Fridman1:16:24

        Yes.

    18. ALAvi Loeb1:16:24

        ... information, that would be great because it will clarify the matter. You know, these are not, as you said, you know, hundreds of thousand. These are not, uh, once-in-a-lifetime events.

    19. LFLex Fridman1:16:34

        Yeah.

    20. ALAvi Loeb1:16:34

        So it's possible to take scientific instrumentation and explore, go to the ocean where the, you know, someone reported that there are frequent, uh, events that are unusual, and check it out.

    21. LFLex Fridman1:16:47

        Yeah.

    22. ALAvi Loeb1:16:47

        Do a scientific experiment. What's the pro- why not, why only do experiments deep into the ocean and look at the oceano- ocean- oceanography or, or do other things? You know, we can do scientific investigation of these sightings and figure out what, what they mean.

    23. LFLex Fridman1:17:02

        Yes.

    24. ALAvi Loeb1:17:02

        Uh, I'm very much in favor of that. Uh, but until we have the evidence, I would be doubtful as to what they actually mean.

    25. LFLex Fridman1:17:09

        Yeah, we'll have to be humble and, uh, and, and acknowledge that we're not that interesting. It's kinda, you're, you're making me realize that because it's so taboo that the people that have the equipment, uh, meaning... And we're not just talking, everybody has cameras now, but to have a large-scale, like, uh, sensor network-

    26. ALAvi Loeb1:17:28

        Right, network.

    27. LFLex Fridman1:17:30

        ... that collects data, that regularly collects, just like we look at the weather.

    28. ALAvi Loeb1:17:33

        Exactly.

    29. LFLex Fridman1:17:33

        We're collecting information, and then we can then access that information when there is reports, and, like, have it not be a taboo thing where there's, like, millions or billions-

    30. ALAvi Loeb1:17:42

        Exactly.
11. 1:20:11 – 1:22:51

    How long will human civilization last?

    1. ALAvi Loeb1:20:11

    2. LFLex Fridman1:20:11

       If we could just linger on the, on the Drake equation for, for a little bit. We kind of talked about, there's a lot of uncertainty in the parameters, and, and our, and, and the Drake equation itself is very limited, but I think the parameters are interesting in themselves, even if it's limited, because I think each one is within the reach of science, right?

    3. ALAvi Loeb1:20:31

       Right.

    4. LFLex Fridman1:20:32

       To get-

    5. ALAvi Loeb1:20:32

       Yes.

    6. LFLex Fridman1:20:32

       ... the evidence for it. Uh, I mean, one, a few I find really interesting, it'd be int- interesting to get your comment on. Uh, so the one with the most variance, I, I would say, from my perspective, is the length that civilizations last, however you define that. In the Drake equation, it's the length of how long you're communicating.

    7. ALAvi Loeb1:20:52

       Yeah, transmitting.

    8. LFLex Fridman1:20:52

       Just like transmitting. Just like you said, that, that might w- that's a wrong way to think about it, because we can be detecting some other outputs of the civilizations

    9. NANarrator1:21:00

       Right.

    10. LFLex Fridman1:21:01

        ... etc. But just, if we just define broadly how long those civilizations last, do you have a sense of, uh, how long they might last? Like, what, what are the great filters that might destroy civilizations-

    11. ALAvi Loeb1:21:14

        Yes.

    12. LFLex Fridman1:21:14

        ... that we should be thinking about? What, uh-

    13. ALAvi Loeb1:21:17

        Yeah.

    14. LFLex Fridman1:21:17

        ... is, and, and what it, how can science give us more hints on this topic?

    15. ALAvi Loeb1:21:21

        Right. So, uh, I, as I mentioned before, operate by the Copernican principle, meaning that, you know, we are not special. We don't live in a special place, and not in a special time. And by the way, it's just modesty encapsulated in scientific terms.

    16. LFLex Fridman1:21:38

        Yes.

    17. ALAvi Loeb1:21:38

        Right? You're saying, "I'm not special. You know, I find conditions here, they exist everywhere."

    18. LFLex Fridman1:21:44

        Yes.

    19. ALAvi Loeb1:21:44

        So if you adopt the Copernican principle, you basically say, "Our civilization transmitted radio signals for 100 years, roughly, so probably it would last another 100 or few 100, and that's it, because we don't live at a special time."

    20. LFLex Fridman1:22:02

        Oh.

    21. ALAvi Loeb1:22:02

        (laughs) So that's, you know... Well, of course, if we get our act together, and we somehow start to cooperate rather than fighting each other, killing each other, you know, wasting a lot of resources on things that would destroy our planet, maybe we can lengthen that period, if we get smarter. But the, the, the most natural assumption is to say that we would live into the future as much as we lived from the time that we start to develop the means for our own destruction-

    22. LFLex Fridman1:22:36

        Mm-hmm.

    23. ALAvi Loeb1:22:36

        ... the technologies we have, which is quite pessimistic, I must say.

    24. LFLex Fridman1:22:39

        (laughs)

    25. ALAvi Loeb1:22:39

        So several centuries, that's what I would give, not, unless we get our act... Unless we become more intelligent than the newspapers report every day, okay?

    26. LFLex Fridman1:22:49

        (laughs)

    27. ALAvi Loeb1:22:49

        Point number one. Second,

12. 1:22:51 – 1:26:12

    Radio signal from Proxima Centauri

    1. ALAvi Loeb1:22:51

       and, and by the way, this is relevant, I should say, because there was a report about, uh, perhaps a radio signal detected from Proxima-

    2. LFLex Fridman1:22:59

       Yes.

    3. ALAvi Loeb1:22:59

       ... Centauri.

    4. LFLex Fridman1:23:00

       What do you make of that signal?

    5. ALAvi Loeb1:23:01

       Oh, I think it's some Australian guy with a cellphone next to the observatory, or something like that.

    6. LFLex Fridman1:23:06

       (laughs)

    7. ALAvi Loeb1:23:06

       (laughs) Because, uh, it was the Parkes telescope in Australia.

    8. LFLex Fridman1:23:09

       Okay.

    9. ALAvi Loeb1:23:10

       Uh, but-

    10. LFLex Fridman1:23:10

        I was like, "Why an Australian guy?" Yeah, okay. So it's no- human-created noise. (laughs)

    11. ALAvi Loeb1:23:14

        Yeah, which is always the worry.

    12. LFLex Fridman1:23:16

        Yes.

    13. ALAvi Loeb1:23:16

        Because actually, the same observatory, the Parkes Observatory, uh, detected a couple of years ago some signal, and then they realized that it comes back at lunch- lunchtime.

    14. LFLex Fridman1:23:28

        Yes. (laughs)

    15. ALAvi Loeb1:23:28

        And they said, "Okay, what could it be?" And then they figured out that it must be the microwave oven in the observatory, because someone was opening it before it finished, and it was creating this radio signal that they detected with a telescope every lunchtime. Uh, so just-

    16. LFLex Fridman1:23:44

        That's fascinating.

    17. ALAvi Loeb1:23:44

        ... a cautionary remark.

    18. LFLex Fridman1:23:46

        Yeah.

    19. ALAvi Loeb1:23:46

        But the reason I think it's human-made, without getting to the de- technical details, is because of this very short window by which we were transmitting radio signals out of the lifetime of the earth.

Episode duration: 2:43:50