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Episode Transcript

My guest today, Avi Loeb, is a professor in and the former chair of Harvard’s astronomy department. He’s had an extraordinary academic career, but that’s not why he’s been making headlines. He’s in the news because of his claims that he has uncovered evidence of interstellar objects opening the door to the possibility that we’ve already been visited by intelligent alien life.

LOEB: I’m not making a wild conjecture here. I’m just saying what we see in the solar system — imagine it being the case in hundreds of millions of other planets that have conditions similar to the earth, making us not unique and special. Just believe in the mediocracy of the existence of technological civilizations. That’s all! 

Welcome to People I (Mostly) Admire, with Steve Levitt.

I’ve spent a great deal of time studying Avi’s claims, and I have to say, it’s not at all obvious to me where the truth lies. He’s gotten a ton of media coverage, but most of these interviews, they only last a few minutes. And these are complicated issues that can’t adequately be addressed in soundbites. The podcast format — it provides us a luxury of time. And I’m hoping we can dive into the science behind the radical claims he’s making.

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LEVITT: You have an incredible resume: physics Ph.D. at the age of 24; you then spent five years at Princeton’s Institute for Advanced Studies, which is perhaps the best place in the world to be a young scientist; tenured at Harvard; chairman of the astronomy department. You’re the founding director of Harvard’s Black Hole Initiative. You’ve got many hundreds of peer-reviewed papers. It’s far more than that, but the point is it’s clearly incredibly impressive stuff.

LOEB: Well, I don’t see it that way. I’m just a curious farm boy. That’s what defines me. I was born on a farm very much attached to nature. I used to drive a tractor to the hills of the village every weekend and read philosophy books because I was intrigued by the fundamental questions about our existence. And that’s in the realm of philosophy, and I really wanted to pursue that. But of course, I was a farm boy. I had to do farm work. And then circumstances brought me to science. I was born in Israel and there is obligatory military service, and I was recruited to a special program that allowed me to pursue a Ph.D. in physics and mathematics that I received at the age of 24. And that was the closest thing I could do, given the constraints, to philosophy. And then I was offered fellowship at the Institute for Advanced Study at Princeton under the condition that I’ll switch to astrophysics. I said, “Okay, I cannot turn it down even though my true love is philosophy.” And so I went there and it was very difficult, competitive environment. I really didn’t know much about the universe. And then there was an opportunity for a faculty position at Harvard University, and I applied without much expectations. And then they offered me the job after the top candidate declined it, so I was their second choice. About a decade later, I became the chair of the Astronomy Department — the longest serving chair for nine years, three terms. And I also was the founding director of the Black Hole Initiative at Harvard, which is a center that brings together philosophers, scientists, and mathematicians to discuss black holes. And the first image of a black hole was derived in the conference room of that center. Even though it was an arranged marriage, I’m actually married to my true love because in astrophysics there are very fundamental questions, existential questions, that we can address using the scientific method. But my upbringing makes me very different than my colleagues in the sense that I’m curious about the big questions — the most important questions. And to me, the most important question is: “Do we have a partner? Is there someone out there in interstellar space that perhaps is smarter than we are; that we can learn from?” That to me is a very important question because it’ll change the future of humanity. And so I’m very happy at what I’m doing, but I’m fundamentally a farm boy, and I’m really curious about the world. I remember being very frustrated at dinners when I would ask a difficult question and the adults in the room would dismiss it or pretend that they know the answer. It was obvious to me that they don’t know what they’re talking about. And I said to myself, “Maybe by becoming a scientist, I can figure out the answers myself.” And the strange thing is: I became a scientist, and I still have the same feeling of people around me pretending to know things that they don’t actually know.

LEVITT: So you have this amazing resume and in spite of that, there sure are a lot of people who seem to think you’re crazy, no? Does that bother you at all?

LOEB: The principle of science that a lot of scientists miss is that we should be guided by evidence. We should be seeking evidence. That’s the way for us to learn something new. It’s not by showing off. It’s not by doing intellectual gymnastics. We should surrender. We should be humble, modest, and accept whatever nature teaches us. And that means not only waiting for the evidence to fall into our lap — people say, “Extraordinary claims require extraordinary evidence.” The truth is they’re not seeking any evidence. So they maintain their view. It’s just like the people for a thousand years, since Aristotle, thought that we are at the center of the universe. Nobody was seeking any evidence for that. It was obvious that we should be important. And it was obvious to the church because the church wanted to use that as a political tool to tell humans, “God is looking over your shoulder. You’re the center of attention.” And then Galileo came and Copernicus came and said, “Look at the evidence. Perhaps the earth is moving around the sun.” The reaction was, “Let’s put Galileo in house arrest so nobody would listen.” Today he would’ve been canceled on social media. The whole point about being guided by evidence is you adapt to the reality that surrounds us and that allows you to cope with it. If you are refusing to accept evidence, then you might win for a little while. You might suppress people who argue otherwise, but it doesn’t change reality.

LEVITT: So let’s dig into the reasons, the things you believe are so controversial. At the top of that list would be that you believe it’s quite possible we’ve encountered technology built by advanced civilizations outside the solar system. Is that accurate? 

LOEB: Yes. There are two types of interstellar objects that we can think of. One would be space trash — the way our spacecraft would appear once they exit the solar system. In 10,000 years, they will exit from the outskirts of the solar system, the Oort cloud, into interstellar space. And at that point, Voyager one, Voyager two, Pioneer 10, Pioneer 11, and New Horizons will not be functional anymore. They will be our space trash. We send those over the past 50 years. We will send many more in the future, and then they might be faster. But within a million years, a billion years, once they might collide with another planet, they will not be functional anymore. So they would appear as a meteor — a meteorite of some unusual strength because they’re made of stainless steel, some of them, or materials that are tougher than rocks. And, moreover, they might move faster than a typical interstellar object simply because they had propulsion. So that’s what I’m looking for in this meteor from 2014, IM1. I’m trying to check if it belongs to this class.. And then of course, there could be some functional devices that were designed to survive the bombardment of cosmic rays, to survive for the long journey. For example, devices that are equipped with artificial intelligence, so they’re autonomous. They don’t wait for guidance from the sender. You can imagine a civilization that wants to seed the Milky Way galaxy and they could send those functioning devices that become autonomous. And if those devices have 3D printers, if they have artificial intelligence, they will arrive at the planet and make use of the raw materials there to make more of the same. And this is an exponential process if you have self-replicating probes — the way John Von Neumann thought about — about 70 years ago, he came with the idea of self-replicating machines. That was one year before the double-helix structure of D.N.A. was discovered. And he thought about it technologically, and this is quite possible that some civilizations seeded the galaxy with self-replicating probes.

LEVITT: So you mentioned the meteor IM1. This is a project you’re currently involved with; you recently spent some time in a boat in the Pacific Ocean looking for the remains of this meteor. Tell me about IM1 and why it’s so controversial.

LOEB: There was a meteor that was identified by U.S. government sensors back on January 8th, 2014. The data was documented in a catalog by NASA. And then five years later, I was interviewed on the radio about another meteor, and I checked online what is known about meteors. I found this catalog. I asked my undergraduate student, “Why don’t you check the fastest moving meteors to see if they originated from outside the solar system?” Because if they’re fast enough — they’re not bound by gravity to the sun — they may have originated from outside the solar system. So the special thing about this meteor that we identified was that the U.S. government measure its speed and from that we concluded that it must have originated from interstellar space. So it was obviously from outside the solar system. And moreover, it had material strength that was tougher than all the space rocks that were in the catalog — 272 of them. So we submitted a paper for publication. This was the first reported interstellar object. Now, the experts who worked on solar system stones said, “No, we refuse to believe that. We are used to solar system stones. And this may have had bad measurements.” I was frustrated. Three years later, there was an official letter from the U.S. Space Command to NASA saying, “This meteor indeed is of interstellar origin at the 99.999-percent confidence based on our data. We looked at it again and we realized that we can be confident at 99.999 percent.” So then our paper finally was accepted for publication. I initiated an expedition — based on this confirmation — to the Pacific Ocean, where this meteor exploded to find the materials that it was made of, because I wanted to check if it’s a voyager meteor, a spacecraft that, just like our Voyager, that spent millions or billions of years in interstellar space before it collided with a planet like the Earth. That’s a completely reasonable possibility.

LEVITT: This meteorite that you’ve been looking for, even if it’s just interstellar from outside our solar system, but not made by a civilization, even that’s pretty exciting, right?

LOEB: Yeah, that would be the first time that humans put their hands on materials of an object bigger than half a meter that came from outside the solar system; the first time in history. So we actually went there, on a ship called Silver Star, very fittingly, and I had a team of 28 exceptional professionals; people who are the best in the world for ocean expeditions.

LEVITT: How deep is the ocean where you’re looking?

LOEB: The ocean was two kilometers deep at that location. And we built a sled with magnets and we placed it on the ocean floor and the sled was connected by a cable to the ship. We were looking for tiny, basically, fragments of a meteorite. Those fragments we expected are less than a millimeter in size because when such a meteor explodes you end up with droplets that rain down on the ocean and eventually sink to the floor of the ocean. So we were looking for those milligram-mass droplets. And the area that we were serving, that the U.S. Department of Defense provided us with, is 10 kilometers on a side. We were able to narrow it, thanks to data from a seismometer in Manus Island. Just think about it: it’s an impossible mission. I was very worried we will not find anything. The truth is, we found it! We found along the meteor path those droplets.

LEVITT: What I found interesting is that in dragging this magnets along the bottom, you did it both where you expected the meteorite to be, and also in a control area of the ocean, where you didn’t, so you would have a comparison, which I think is a really simple, but a really good idea.

LOEB: Yeah. That’s the scientific method. And the next step is, of course, to examine the composition of those spherules, these droplets, using the best instruments in the world. So we are using mass spectrometers in three laboratories at U.C. Berkeley, at Harvard University, and also at the Bruker Corporation in Berlin. I basically identified agnostic experts who are used to studying such materials of spherules. Before I went on this expedition, colleagues of mine approached me and said, “Oh, we don’t think you will find anything. It’s a waste of money. It’s a waste of time. And why would you do that?” And I replied, “I’m not asking you to do anything. I’m doing the heavy lifting. You just sit back and relax. And if I come back with nothing, you tell me that’s what you expected. And by the way, the money that is funding this expedition was not allocated to science to start with. The donor was inspired by the vision that I have and decided to give this money to science. So science benefits, it’s a win-win proposition. I’m just seeking evidence. And then after the expedition ended and I had in my hands those spherules that we found, and we managed to examine them using an X-ray fluorescence analyzer on the ship, we could tell that they’re made mostly of iron. On the day that I’m back with these spherules made mostly of iron, what do I see? I see a scientific paper that was just published the same day in the Astrophysical Journal, and the argument says as follows: The government released this data about this meteor. We are trying to use a model based on stones that we are familiar with in the solar system. The model cannot fit the data. Therefore, the data is wrong. So they say, even though the U.S. Space Command put their reputation on the line — and to remind you, this is an organization who is tasked to provide the President of the United States with a warning about ballistic missiles should it notice any of them. Suppose they make a mistake, the velocities are actually smaller by a factor of three compared to what they measure. They would warn Mexico about a missile that is headed towards Washington D.C. That makes zero sense in my mind. Now, these two astronomers come out and say, “The government must be wrong because our model for space rocks based on stones does not fit it.” Now I call that the stone age of science — the stone age because everything in the sky, according to these experts, must be stones. And you ask yourself, how can we learn anything new?

LEVITT: So let me ask you about the spheres that you’ve just recovered from the ocean. It hasn’t been long, but you’ve been analyzing them. Have you learned anything yet that’s striking? Anything that confirms the hypothesis that these came from outside the solar system?

LOEB: So far we examined maybe about 10 of them. We have a long way to go through most of them. But already I can tell you some very interesting things. Like on the first day when we came back from the expedition, I stopped at U.C. Berkeley, and they had an electron microscope imager — scanning imager. And we looked at one of the spherules that was found along the meteor path, and we looked inside of it. And what we saw is that it’s made just like Russian dolls. It has tiny spheres. They look like eggs, and the smallest eggs have the size of a few hundred atoms. That’s all. And they were probably the droplets that solidified first. And then these marbles — metallic marbles — they were immediately engulfed by a bigger droplet and then that bigger droplet was engulfed by an even bigger droplet. So altogether, you end up with spheres inside spheres. This is something I haven’t seen in the literature, and it’s really beautiful to look at. And then we started doing the analysis of the composition. And in principle, we can figure out the composition in terms of the radioactive isotopes that have a finite lifespan. They have a half-life that varies, so they can serve as clocks.

LEVITT: So you’re saying there’s uranium or something in there as well?

LOEB: That’s right. There is uranium, there is lead. But some of the lead may be a contamination from the fact that this material sat on the ocean floor for almost a decade. So we have to go beyond the surface, the skin of these spherules. So there is work to be done. We are doing it systematically, rigorously. But you find people who call themselves experts and they express an opinion about these spherules. They don’t have access to those spherules. We didn’t analyze them yet. And yet those people who call themselves scientists have opinions. How can they have an opinion without us going through the analysis rigorously? Let’s use the best instruments in the world and analyze the composition of the spherules that we found in the meteor site. What could be more rigorous than that? After I show them the results, they can express their opinion. That’s okay. But before that, it shows a bias. It shows the fact that they want a particular outcome.

Just before we published this episode, Avi made a formal announcement: The sphericals he found on the ocean floor, the pieces of the meteor IM1 are interstellar in origin. According to the lab results, they were comprised of a pattern of elements beryllium, lanthanum, and uranium, which makes it extremely unlikely that the meteor originated in the solar system. But whether the meteor was geological in nature or created by an advanced civilization still remains to be determined. We’ll be right back with more of my conversation with Harvard astronomer Avi Loeb after this short break.

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LEVITT: So I’ve read your last two books, Extraterrestrial and Interstellar. And what’s interesting is the tone of those books are very different than your tone now. They’re very measured; they’re very scientific. It almost feels to me like your critics have gotten under your skin; they’ve gotten to you. Do you feel like they have?

LOEB: It’s not so much about me. By now my skin is made of titanium. It really doesn’t bother me. But, why am I so passionate about it? Why do I speak like that? The reason is because it suppresses innovation in science. It’s not about me; it’s about the young people who are watching this and they see the senior people, those self-proclaimed experts that are used to modeling rocks made of stone, basically not allowing a conversation on something that is completely reasonable in the eyes of the public. And they see that and they say, “Well, I’m in a vulnerable position. I have to get a job, a faculty job in the future. I have to dance to the tunes of the selection committees. And if these senior people are so upset about Avi Loeb, then I should basically follow the beaten path.” And that is very bad for science because if all the troops are following the beaten path, we will never discover something new. So the damage is far beyond the fate of Avi Loeb. It’s about the fact that innovation is being suppressed. I’m not making a wild conjecture here. I’m just saying what we see in the solar system — imagine it being the case in hundreds of millions of other planets that have conditions similar to the earth, making us not unique and special. Just believe in the mediocracy of the existence of technological civilizations. That’s all! I’m saying, “We exist. We know what we are doing. So just imagine something like that.” Now you are telling me that’s a wild speculation. Is believing in extra dimensions of the multiverse a much more robust speculation? How would you justify an extra dimension? Just because you can’t unify gravity and quantum mechanics in the three dimensions we know, and you say, “Well, if there are extra dimensions, I can do that” — that is not a good enough argument because we don’t see the extra dimensions. That’s a valid thing to work on. But I’m telling you, I’m motivated by something we do see, which is ourselves.

LEVITT: What’s confusing to me is that what you’re doing —retrieving that meteorite and testing to see whether it came from interstellar space — that doesn’t really seem controversial. That seems like common sense. I’d like to talk about something that I think is understandably controversial, and that has to do with Oumuamua. And I would love for you to talk about that object. Just start with the facts and lay out what made Oumuamua such an anomaly and has led to it generating so much scientific interest.

LOEB: It was discovered on October 19th, 2017. And I was intrigued by the discovery because the telescope that found it was Pan-STARRS in Hawaii. The goal of the telescope was to find near-Earth objects that could potentially endanger the earth by colliding with it. And so this object was found as a near-Earth object. It was flagged just because it passed near the earth. And then the observers realized, oh, it actually came from outside the solar system because it’s moving too fast to be bound by the sun. Now, to me, that was very intriguing, because a decade earlier, I already wrote the first paper that tried to forecast how many rocks should we expect from other stars passing through the solar system that should be detected by Pan-STARRS. And we realized that they have to be the size of a football field because otherwise they would not reflect enough sunlight for Pan-STARRS to discover them. And then we asked how many football field-sized objects do you expect to be ejected from planetary systems, taking into account all the stars in the Milky Way galaxy, and we calculated that there will be nothing detected by Pan-STARRS. By orders of magnitude, somewhere between a factor of a hundred to a factor of a hundred million, given the uncertainties, there were fewer than necessary objects for Pan-STARRS to notice even one of them. And yet it found Oumuamua. That was, to me, very intriguing. And then after they found it, they started saying, “Oh, wait a minute. It’s really unusual because the amount of sunlight reflected from it changes by a factor of 10 as it’s tumbling, and that means that the area projected on the sky changes by a factor of 10.” So seeing a variation by a factor of 10 in the surface area is very extreme. Usually, at most, you see a factor of three. And then someone concluded it has to be a most likely flat object. Then someone wrote another paper saying, “Well, wait a minute. This object actually was at rest in the local frame of the galaxy.” It’s sort of like we, the solar system, just bumped into it like a giant ship that bumped into a buoy on the surface of the ocean. So this object was unlikely because only one in 500 stars are so much at rest in that frame as Oumuamua was. And then there was another paper in Nature saying, “Wait a minute, this object shows non-gravitational acceleration. It’s being pushed away from the sun.” So at that point, that was too many anomalies. I said to myself, “Wait a minute, something is wrong here. It’s not a rock. It’s not an asteroid because it’s flat, because it’s being pushed away from the sun. It’s not a comet because nobody’s seeing any traces of gas or dust around it. 

LEVITT: So this object flies somewhat past the earth. We don’t get very good data on it because we’re not trying very hard because we haven’t invested a lot in this particular activity of keeping track of things flying around at high speeds. So we get fragmentary data. On dimension after dimension, it doesn’t seem to fit with the typical comets or asteroids that we see. It’s going too fast. It’s got a very strange shape and it’s got no obvious tail. And as it spins around the sun, it doesn’t go in the direction we would expect it to. And so that leads a lot of scientists to spend a lot of time and effort trying to figure out what’s going on — many theories about that, but your theory is very different than everyone else’s. Can you explain it?

LOEB: So in fact, there weren’t many theories to start with. And there was a new postdoc that I received named Shmuel Bialy. And I said, “What is pushing it? Maybe it’s a very thin membrane, which is pushed by reflecting sunlight.” And we checked and the numbers worked out. So we wrote a paper saying, “Maybe it’s a thin membrane, like a sail, which is pushed by light instead of wind.” And we just checked the numbers and it seemed to work. So we submitted it for publication in the Astrophysical Journal Letters, a very prestigious journal, and the paper was accepted for publication within three days. Usually it takes months for papers to get accepted for publication. This one was within three days, and the reviewer of the paper said, “Your idea is an extremely good one because we have evidence that this object is flat.” So he was strengthening the argument. And then the press, the media got a hold of this paper and everyone paid attention to it. And then the mainstream of this astronomy community changed direction. Months later, there was a review paper by all the experts on comets or asteroids, basically saying, “Oh, there is nothing unusual about Oumuamua. Forget about it. It’s a natural object, exclamation mark.” Paper published. But then a few months later, a group of people said, “Wait a minute, it could be natural, but we have to explain why it has non gravitational acceleration.” So they said, “Oh, maybe it’s a hydrogen iceberg where the cometary tail is transparent because it’s made of hydrogen, we can’t see it.” To make a hydrogen iceberg, you cannot do that in a planetary system like the solar system. You have to do it in a molecular cloud, a very different environment. But we showed with a colleague of mine from Korea, Thiem Hoang, that this model is not viable because hydrogen iceberg would evaporate along the way by absorbing starlight. And the authors agreed, so this model is not viable. So then another team came forward and said, “Oh, no. We now think that it was a cloud of dust particles, a dust bunny like you find at home. Except this one was a hundred times less dense than air.” And even though you can push it very easily because it’s so lightweight, so reflection of sunlight can easily move it around. The problem with such an object is when it gets close to the sun, it’ll get heated by hundreds of degrees and will not maintain its integrity. So then another team said — a few months later they said, “Oh, now we got it. It’s actually a nitrogen iceberg. Again, you can’t see the nitrogen and the solid nitrogen came from chipping off the surface of a planet like Pluto.” And we did a calculation with my student and realized there is not enough solid nitrogen in the Milky Way galaxy to account for a large enough population of such chips. So then, most recently, just a few months ago, there was the final suggestion. And by the way, this is more than five years after Oumuamua was discovered. “Now we know it. It’s natural, yes.” And everyone celebrated. “Yeah, now we know it.” And all the major newspapers said “Problem solved.” What is the solution? The solution is a water iceberg — something very common, an iceberg made of water. Except that in interstellar space, the idea is the water will be broken by cosmic rays and will be broken to hydrogen and oxygen, and then when the object comes close to the sun, the hydrogen will evaporate. This paper appeared in Nature Magazine, was featured in all major newspapers. The minute I saw it, I realized something does not work here. I spoke with my colleague in Korea, Thiem Hoang. Within a day, we wrote a paper saying they made a mistake in the energy equation. They just calculated incorrectly the energy balance on the surface of the object. And when you do it correctly, it makes the model not viable. 

LEVITT: As I listened to you talk, it sounds like you are 100-percent convinced that your hypothesis, while not proven, is the leading hypothesis. And that theory is that Oumuamua was an object created by an advanced civilization that took a very odd shape, the shape of a sail, which you can’t imagine that would arise in any way other than being created. That would seem to be a story that people would like. Human nature likes exciting results. Why do you think there’s so much resistance, both within the scientific community and outside of it? Do you think it’s just because, for way too long, crackpots have been talking about U.F.O.s?

LOEB: That could be part of it. But I think the real answer is that people do like it. People in the public do like it and because they pay attention to it, people in academia shy away from it. Because as I said, when my first paper was submitted for publication, it was immediately accepted. There was no issue with that. So I think the issue is really with the public’s attention. Science can be exciting if you just attend to the public’s interest and if you just follow the scientific method. Of course there are crackpots making all kinds of false statements. Science should not be stopped because of crackpots. You should ignore the crackpots. You should follow the method of science, of seeking evidence and being guided by it. That’s the way by which we will gain new knowledge.

You’re listening to People I (Mostly) Admire with Steve Levitt and his conversation with Harvard astronomer Avi Loeb. After this short break, they’ll return to talk about recent congressional hearings about unidentified anomalous phenomena.

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We’ve been talking so far about Avi Loeb’s own research on alien life. But in recent months, a former Air Force intelligence officer has claimed that the U.S. has been concealing a program for decades that retrieves and reverse engineers U.F.O.s. This became the subject of a recent congressional hearing, and I’m eager to hear Avi’s take.

LEVITT: So today, which is at least a month before we published this episode, there was a hearing at the U.S. House of Representatives about unidentified anomalous phenomena, U.A.P.s, as they’re called. Tell me about the significance of these hearings from your perspective. And what you hope comes out of them. 

LOEB: There were three witnesses that testified under oath about their experiences. So two of them were pilots. One is Ryan Graves and the other one is David Fravor. And they talked about objects that they saw in the sky, which look anomalous. They don’t represent objects that they’re familiar with; they were maneuvering in very unusual ways and just didn’t resemble anything they were familiar with. So they just said that these objects are very intriguing because, first of all, they pose a risk to flight safety. But also, Grave said, these were frequent occurrences. He saw it multiple times. Fravor talked about one incident where, you know, these objects were moving extremely fast. And there were many of them, and they could just make no sense of what they might be. But more amazingly, there was a report by David Grush about his encounter with 40 people who told him that there are programs of recovery and reverse engineering of materials from crash sites of unidentified objects that imply non-human origin. He said the government is in possession of those materials. If these objects have nothing to do with adversaries — they’re not human made — then they have no relevance to national security. If they came from interstellar space, they spent millions or billions of years traveling through space before arriving here, it’s a matter of science, and the government shouldn’t really engage with the scientific study of such materials. This material should be brought to the attention of scientists that will try to figure it out. And the knowledge that is gained from studying it should be shared with all humans because if we do have a neighbor, everyone should know about it. But we don’t necessarily need to wait for the government to tell us what is in interstellar space because the sky is not classified, the oceans are not classified. We can gather that information ourselves as scientists. 

LEVITT: So you work on a project at Harvard that does exactly this. Tell me about the Galileo Project.

LOEB: The Galileo Project was established two years ago and it has three branches. One is to find more objects like Oumuamua and study their nature; collect the evidence that would tell us whether they’re natural, and if so, what origin they have — or whether they are technological in origin. And the second branch is expeditions of the type that I described to go after interstellar meteors and identify what they were made of and whether they had the technological origin. Finally, we built an observatory at Harvard University, which monitors the sky 24/7, all the time, in the infrared, in the optical band, in radio, and in audio. And we are developing a machine-learning software that will identify objects that we see in the sky and put them into categories, whether they’re natural like bugs or birds, whether they’re human-made like balloons or drones or airplanes, or perhaps something from outside of this earth. We are doing a systematic study of the sky that’s very different from the anecdotal reports that were delivered by Fravor and Graves. They just happened to be in a place where they saw something unusual, but in order to calibrate how rare is the thing that they saw, we need a systematic search of the sky with instruments that are well calibrated, that are under our full control. That’s the way science is done. So we built, already, one such observatory at Harvard University, and we are planning to make copies of it in the coming months in other locations and bring clarity into this question of: What’s the nature of unidentified anomalous phenomena?

LEVITT: It seems like your interest in these questions is partly scientific curiosity, but also something deeper…if we knew of the existence of other advanced life forms… that you Avi hope it might change how humanity perceives itself, maybe lead us to collectively act in more thoughtful and responsible ways. Am I right about that?

LOEB: Definitely. When you go out and find a partner in real life, it changes your life because, first of all, you get some feedback about your actions. You put them in perspective. We are very much occupied with destructive activity on earth. We don’t care so much about the health of our planet. We fight each other in wars that make very little sense. All of us earthlings are in the same boat. Why don’t we work together? Try to figure out from the big picture what we should do. And that, to me, implies two things. One, that we should work together. We should help each other rather than fight each other. The second, a sense of modesty because we came to this cosmic play — at first we thought we’re at the center of the stage. Then we realized, no, we are not at the center of the stage. We’re not at the center of the universe. And then we realized, oh, actually, humans, homo sapiens, arrived just a few million years ago to Earth. That’s just one part in 10,000 of the age of the universe. So we arrived to the cosmic play at the end of the play. We are not at the center of the stage. And so the conclusion is the play is not about us. And if we want to figure out what the cosmic play is all about, we should seek other actors and they might advise us about the bigger picture. It will change our perspective.

LEVITT: We’ve talked a bit about Galileo today. There are parallels between what you’re doing and what he did. History looks fondly on Galileo, but he spent the last decade of his life under house arrest for what he found. If you find smoking gun evidence of intelligent extraterrestrial life, do you think you’ll be treated more kindly than Galileo was?

LOEB: Well, so Galileo removed the self-importance of people in terms of our location. He saw moons moving around Jupiter and said, “Okay, well, if we were at the center, they would move around us, and they don’t, okay?” So that was a very simple proposition, made a lot of sense, and he was right. And now, of course, the church admits that, but back then he was put in house arrest. Now, what I’m trying to do is bring a sense of modesty of similar proportion or even bigger proportion to our existence, which is that Albert Einstein was not the smartest scientist. Whoever lived since the Big Bang 13.8 billion years ago, there must have been smarter scientists on other planets, which had similar conditions to those on earth. And they may have preceded us by billions of years with enough time to send packages to our doorstep. Now, in the past we were looking for radio signals. It’s just like waiting for a phone call. You need the caller to be active when you are waiting. But it’s possible that the phone calls came when we were not around ’cause we just arrived in the last few million years. And most of the calls may have been billions of years ago, so they are billions of light years away. A different approach, which is the one that I’m advocating, is going out to your mailbox and perhaps you will find a package from a sender that is not alive anymore. You don’t need the sender to be active when you’re looking at the package.

I sure hope Avi’s right, and I hope one day that he finds definitive evidence of intelligent alien life. Personally, I think it would be so exciting to be witness to one of the all-time greatest scientific discoveries. I’m curious, though, to hear what you think: Is Avi Loeb a modern day Galileo? Or maybe just a dreamer? If you’re inspired to share your opinion, send us a quick email at That’s And just write in the subject heading either Galileo or Dreamer, depending on what you think. And I’m eager to analyze the emails we receive, so if you’re willing to include your age and gender as well, that would be great.

LEVITT: And now’s the time where we take a listener question, and as always, I’m joined by my producer, Morgan.

LEVEY: Hi, Steve. So, some of the listeners sent us an article in The New York Times called, “In California, a Math Problem: Does Data Science = Algebra II?” The gist of the article is that starting in 2020, California’s public universities began accepting students who had taken data science in high school instead of Algebra 2. But that decision has recently been revoked by the State Board of Education. Now, you’re a huge proponent of data science, and you’re part of a group called Data Science for Everyone, and someone from that group is even quoted in the article. What is your reaction to California’s decision?

LEVITT: Let me just start by saying the people on both sides are smart, well-intentioned people. They care deeply about math and its teaching. Now, that being said, I think this fundamentally isn’t really a debate about data science. It’s a debate about equity — how best to achieve equity, and at what cost when it comes to rigor. That’s really — like, this is being phrased in terms of data science, but when you dig deeper, it’s really about something different. So at the heart of this is that a group of people just rewrote the California math framework, and these are people who have a deep belief in the importance of equity. They acknowledge that there are big racial gaps in math achievement in our current system, and they have the hope that data science as an alternative pathway could lead to greater equity. On the other side, there’s a fear by mathematicians that if equity is a primary justification for pushing data science, then there’s a real risk that the version of data science that will be taught will be so watered down that, in the end, if you push minorities towards that track, it could actually be an obstacle to their achievement in life because they won’t be well prepared for a STEM career. So that’s what I see the debates about.

LEVEY: So where do you lie on this debate in terms of equity and rigor?

LEVITT: So let me say first about equity, my own opinion: I just don’t think that data science is going to be very effective in achieving equity. Data science is not that vehicle. I’ve been approached by lots of different schools to launch data science programs. And these are the most elite high schools in the U.S. Data science is hard to teach. The current math teachers don’t have the skills. I believe that at least in the short and the medium run, it’s much more likely that the high-achieving schools are going to do a much better job of teaching data science than the current low-achieving schools. So I actually think, personally, that this equity play just isn’t going to work.

LEVEY: Okay, so what about rigor?

LEVITT: Whether or not the existing data science courses that are being offered at K-12 are rigorous, let me say this: You can teach a data science course at the K-12 level, which is far more difficult than any Algebra 2 class you would ever get; that brings in more skills in terms of judgment and creativity and thoughtfulness, but still has as much hard math as you want. So whether or not the existing courses are rigorous enough is an open question, but I don’t think anybody could argue that, by its nature, data science isn’t as rigorous as the other math topics that are being taught. That’s just a mistake. Anyone who believes that has never tried to do data science. It’s hard to do data science well.

LEVEY: Are there any other dimensions that you think are important in this debate?

LEVITT: Absolutely. The most important dimension, and the one that isn’t being talked about, is that it is completely idiotic not to teach kids data science because data science is ruling the world more and more every day. Eight of the 10 fastest growing jobs in America are based on data science. If you look at what kids in college and university are taking, the movement towards data science is enormous. At my own university, the University of Chicago, they’ve had to hire 25 extra data science faculty to meet the demand of the students. So, look, the thing is, the kids understand it. The kids know where the future is, and they’re trying to get data science. And honestly, I think this is a case where the adults just have to try not to screw it up, and that’s exactly what’s going on. By making debates political about equity and rigor, it’s missing the main point, which is: kids deserve the chance to learn data science, and we have to figure out how to give it to them.

LEVEY: So this article is really about whether data science is a worthwhile course to replace Algebra 2 with. And it sounds like what you’re saying is, regardless of that debate, data science should be taught in high schools across the country. 

LEVITT: I don’t care how we put data science into the curriculum. I don’t care whether it’s replacing Algebra 2 or doing something else. The fact is that in 20 years, data science is going to be part of every K-12 program. So, look, California can fight about the specifics of it, but if they don’t get back on the data science bandwagon, they’re going to fall behind.

LEVEY: Thank you to everyone who sent us the New York Times article. If you have a question or comment for us, our email is PIMA@freakonomics. com. That’s It’s an acronym for our show. We read every email that’s sent and we look forward to reading yours.

In two weeks, we’ll be back with a brand new episode featuring Thomas Curran. He’s a psychologist who studies perfectionism. And his view is that perfectionism is a far more damaging trait than people realize.

CURRAN: Perfectionism is a lot deeper than just having high standards. It’s really a way of existing; it’s a feeling of deficit, of not being perfect enough. 

As always, thanks for listening and we’ll see you back in two weeks.

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People I (Mostly) Admire is part of the Freakonomics Radio Network, which also includes Freakonomics Radio, No Stupid Questions, and The Economics of Everyday Things. All our shows are produced by Stitcher and Renbud Radio. This episode was produced by Morgan Levey, with help from Lyric Bowditch, and mixed by Jasmin Klinger. Our theme music was composed by Luis Guerra. We can be reached at, that’s Thanks for listening.

LOEB: Hello?

LEVITT: Can you hear me, Avi?

LOEB: Are you there?

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  • Avi Loeb, professor of astronomy at Harvard University, founding director of the Black Hole Initiative, and head of the Galileo Project.



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