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Avi Loeb on 'Oumuamua, Aliens, Space Archeology, Great Filters, and Superstructures
132 Plays3 years ago
Avi Loeb, Professor of Science at Harvard University, joins us to discuss a recent interstellar visitor, if we've already encountered alien technology, and whether we're ultimately alone in the cosmos.
Topics discussed in this episode include:
-Whether 'Oumuamua is alien or natural in origin
-The culture of science and how it affects fruitful inquiry
-Looking for signs of alien life throughout the solar system and beyond
-Alien artefacts and galactic treaties
-How humanity should handle a potential first contact with extraterrestrials
-The relationship between what is true and what is good
You can find the page for this podcast here: https://futureoflife.org/2021/07/09/avi-loeb-on-oumuamua-aliens-space-archeology-great-filters-and-superstructures/
Apply for the Podcast Producer position here: https://futureoflife.org/job-postings/
Check out the video version of the episode here: https://www.youtube.com/watch?v=qcxJ8QZQkwE&ab_channel=FutureofLifeInstitute
See our second interview with Avi here: https://soundcloud.com/futureoflife/avi-loeb-on-ufos-and-if-theyre-alien-in-origin
Have any feedback about the podcast? You can share your thoughts here: www.surveymonkey.com/r/DRBFZCT
Timestamps:
0:00 Intro
3:28 What is 'Oumuamua's wager?
11:29 The properties of 'Oumuamua and how they lend credence to the theory of it being artificial in origin
17:23 Theories of 'Oumuamua being natural in origin
21:42 Why was the smooth acceleration of 'Oumuamua significant?
23:35 What are comets and asteroids?
28:30 What we know about Oort clouds and how 'Oumuamua relates to what we expect of Oort clouds
33:40 Could there be exotic objects in Oort clouds that would account for 'Oumuamua
38:08 What is your credence that 'Oumuamua is alien in origin?
44:50 Bayesian reasoning and 'Oumuamua
46:34 How do UFO reports and sightings affect your perspective of 'Oumuamua?
54:35 Might alien artefacts be more common than we expect?
58:48 The Drake equation
1:01:50 Where are the most likely great filters?
1:11:22 Difficulties in scientific culture and how they affect fruitful inquiry
1:27:03 The cosmic endowment, traveling to galactic clusters, and galactic treaties
1:31:34 Why don't we find evidence of alien superstructures?
1:36:36 Looking for the bio and techno signatures of alien life
1:40:27 Do alien civilizations converge on beneficence?
1:43:05 Is there a necessary relationship between what is true and good?
1:47:02 Is morality evidence based knowledge?
1:48:18 Axiomatic based knowledge and testing moral systems
1:54:08 International governance and making contact with alien life
1:55:59 The need for an elite scientific body to advise on global catastrophic and existential risk
1:59:57 What are the most fundamental questions?
This podcast is possible because of the support of listeners like you. If you found this conversation to be meaningful or valuable, consider supporting it directly by donating at futureoflife.org/donate. Contributions like yours make these conversations possible.
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Transcript
Introduction to Oumuamua and Extraterrestrial Life
00:00:02
Speaker
Welcome to the Future of Life Institute podcast. I'm Lucas Perry. Today's episode is with Avi Loeb and in it we explore a Moa Moa, an interstellar object that passed through our solar system and which is argued by Avi to potentially be alien in origin.
00:00:19
Speaker
We explore how common extraterrestrial life might be, how to search for it through the space archaeology of bio and techno signatures they might create. We
Podcast Content and Government UFO Report
00:00:29
Speaker
also get into great filters and how making first contact with alien life would change human civilization.
00:00:35
Speaker
This conversation marks the beginning of the continuous uploading of video content for all of our podcast episodes. For every new interview that we release, you'll also be able to watch a video version of that episode on our YouTube channel. You can search for Future of Life Institute on YouTube to find our channel or check the link in the description of this podcast to go directly to the video version of this episode.
00:01:00
Speaker
There is also bonus content to this episode, which has been released separately on both our audio and visual feeds. After our initial interview, the US government released a report on UFOs, otherwise now known as UAPs, titled Preliminary Assessment, Unidentified Aerial Phenomena.
00:01:18
Speaker
Given the release of this report and the relevance of UFOs to Amoamoa, both in terms of the culture of science surrounding UFOs and their potential relation to alien life, I sat down to interview Avi for a second time to explore his thoughts on the report as well as his assessment of unidentified aerial phenomena.
00:01:38
Speaker
You can find this bonus content wherever you might be listening. We're also pleased to announce a new opportunity to join this podcast and help make existential risk outreach content. We're currently looking to hire a podcast producer to work on the editing, production, publishing, and analytics tracking of the audio and visual content of this podcast. You would be working directly with me and the FLI outreach team
00:02:02
Speaker
to help produce, grow, and evolve this podcast. If you're interested in applying, head over to the careers tab on the futureoflife.org homepage or follow the link in the description. The application deadline is July 31st with rolling applications accepted thereafter until the role is filled. If you have any questions, feel free to reach out to socialmedia at futureoflife.org.
Avi Loeb's Background and Book Discussion
00:02:24
Speaker
Professor Loeb received a PhD in plasma physics at the age of 24 from the Hebrew University of Jerusalem and was subsequently a long-term member at the Institute for Advanced Study in Princeton, where he started to work in theoretical astrophysics. In 1993, he moved to Harvard University where he was tenured three years later. He is now the Frank B. Baer Jr. Professor of Science and is a former chair of the Harvard Astronomy Department.
00:02:51
Speaker
He also holds a visiting professorship at the Weizmann Institute of Science and a Sackler senior professorship by special appointment in the School of Physics and Astronomy at Tel Aviv University. Loeb has authored nearly 700 research articles and four books, the most recent of which is Extraterrestrial, the first sign of intelligent life beyond Earth. This conversation is centrally focused on the contents of this work. And with that, I'm happy to present this interview with Avi Loeb.
Analysis of Oumuamua's Characteristics
00:03:28
Speaker
to start things off here, I'm curious if you could explain what Oumuamua's wager is and what does it mean for humanity in our future? Oumuamua was the first interstellar object that was spotted near Earth. And by interstellar, I mean an object that came from outside the solar system. We knew that because it moved too fast to be bound to the sun. It's just like finding an object in your backyard from the street.
00:03:55
Speaker
and saves you the need to go to the street and find out what's going on out there. In particular, from my perspective, it allows us to figure out if the street has neighbors, if we are the smartest kid on the block, because this object
00:04:10
Speaker
looked unusual, didn't look like any rock that we have seen before in the solar system. It exhibited a very extreme shape because it changed the amount of reflected sunlight by a factor of 10 as it was tumbling every eight hours. It also didn't have a cometary tail. There was no gas or dust around it.
00:04:29
Speaker
yet it showed an excess push away from the sun. And the only possible interpretation that came to my mind was a reflection of sunlight. And for that, the object had to be very thin, sort of like a sail, but being pushed by sunlight rather than by the wind, as you often find on a boat. And the nature doesn't make sails. So in a scientific paper, we propose that maybe it's artificial in origin,
00:04:54
Speaker
And since then, in September 2020, there was another object found that was pushed away from the sun by reflecting sunlight. And without a cometary tail, it was discovered by the same telescope in Hawaii, Pan-STARRS, and was given the name 2020SO. And then the astronomers realized, actually, it's a rocket booster that we launched in 1966 in a lunar landing mission.
00:05:19
Speaker
And we know that this object had very thin walls, and that's why it had a lot of area for its mass, and it could be pushed by reflecting sunlight. And we definitely know that it was artificial in origin, and that's why it didn't show cometary tail, because we produced it. The question is, who produced Oumuamua?
Scientific Critique and Exploration Advocacy
00:05:38
Speaker
And my point is,
00:05:40
Speaker
that just like Les Pascal, the philosopher, argued that, you know, we cannot ignore the question of whether God exists because Pascal was a mathematician and he said, okay, logically there are two possibilities, either God exists or not, and we can't ignore the possibility that God exists because the implications are huge.
00:05:59
Speaker
And so my argument is very similar. The possibility that Oumuamua is a technological relic carries such great consequences for humanity that we should not ignore it. Many of my colleagues in academia dismiss that possibility. They say, we need extraordinary evidence before we even engage in such a discussion. And my point is, requiring extraordinary evidence is a way of brushing it aside.
00:06:28
Speaker
sort of a self-fulfilling prophecy if you're not funding research that looks for additional evidence. It's sort of like stepping on the grass and claiming the grass doesn't grow because, for example, to the day gravitational waves required an investment of 1.1 billion dollars by the National Science Foundation, we would never discover gravitational waves unless we invested that amount
00:06:52
Speaker
to search for dark matter. We invested hundreds of millions of dollars so far. We didn't find what the dark matter is. It's a search in the dark. But without the investment of funds, we will never find. So on the one hand, the scientific community puts almost no funding towards the search for technological relics. And at the same time argues all the evidence is not sufficiently extraordinary for us to consider that possibility in the first place. And I think that's a sign of arrogance.
00:07:21
Speaker
It's a very presumptuous statement to say we are unique and special. There is nothing like us in the universe. I think a much more reasonable down to earth kind of approach is a modest approach, basically saying, look, the conditions on earth are reproducing.
Probability and Discovery of Intelligent Life
00:07:39
Speaker
in tens of billions of planets within the Milky Way galaxy alone. We know that from the Kepler satellite, about half of the Sun-like stars have a planet the size of the Earth, roughly at the same separation. And that means that not only we are not in the center of the universe, like Aristotle argued, we are also, what we find in our backyard is not
00:08:00
Speaker
privileged. There are lots of Sun Earth systems out there. And if you arrange for similar circumstances, you might as well get similar outcomes. And actually, most of the stars formed billions of years before the Sun. And so that, to me, indicates that there could have been a lot of technological civilization like ours that launched equipment into space, just like we launched the Voyager 1, Voyager 2 New Horizons. And we just need to look for it. Even if these civilizations are dead,
00:08:30
Speaker
you know, we can do space archaeology. And what I mean by that is when I go to the kitchen and I find an ant, I get alarmed because there must be many more ants out there. So we found a mua mua. To me, it means that there must be many more out there and weird objects that do not look like a comet or an asteroid that we have seen before within the solar system.
00:08:52
Speaker
And we should search for them. For example, in a couple of years, there would be the Vera Rubin Observatory that would be much more sensitive than the Panstar's telescope and could find one such Oumuamua-like object every month. So when we find one that approaches us and we have an alert of a year or so, we can send a spacecraft equipped with a camera that will take a close-up photograph of that object and
00:09:17
Speaker
Perhaps even land on it, just like OSIRIS-REx landed on the asteroid Bennu recently and collected a sample from it. Because, you know, they say a picture is worth a thousand words. In my case, a picture is worth 66,000 words, the number of words in my book.
00:09:35
Speaker
If we had a photograph, I wouldn't need to write the book.
Summarizing Oumuamua's Mysteries
00:09:38
Speaker
It would be obvious whether it's a rock or an artificial object. And if it is artificial and we land on it, it can read off the label made on planet X and even import the technology that we find there to Earth. And if it's a technology representing our future, let's say a million years into our future, it will save us a lot of time. It will give us a technological leap and it could be worth a lot of money.
00:10:04
Speaker
So that's an excellent overview. I think of a really good chunk of the conversation, right? So there's this first part of an interstellar object called the MoMAO entering the solar system in 2017. And then there are lots of parameters about and properties of this object, which are not easily or readily explainable.
00:10:26
Speaker
as an asteroid or as a comet. Some of these things that we'll discuss are, for example, like its rotation, its brightness variation, its size, its shape, how it was accelerating on its way out. And then the noticing of this object is happening in a scientific context, which has some sense of arrogance of not being fully open to exploring hypotheses that seem a bit too weird or too far out there. Like people are much more
00:10:54
Speaker
comfortable trying to explain it as some kind of like loose aggregate of like a cosmic dust bunny or other things which don't really fit or match the evidence and so then you argue that if we look into this with epistemic humility then if we follow the evidence it takes us to having a reasonable amount of credence that this is actually artificial in origin rather than something natural and then that brings up questions of
00:11:20
Speaker
other kinds of life and the Drake equation and what it is that we might find in the universe and how to conduct space archaeology. So to start off, I'm curious if you could explain a bit more of these particular properties that Omoa had and why it is that a natural origin isn't convincing to you.
Challenges to Natural Origin Theories
00:11:43
Speaker
Right. I basically followed the evidence. I didn't have any agenda. And in fact, I worked on the early universe and the black holes throughout most of my career. And then came along this object and was quite unusual. A decade earlier, I predicted how many rocks from other stars should we expect to find. And that was the first paper predicting that. And we predicted that the Pan-Star's telescope that discovered Oumuwa
00:12:13
Speaker
We'll not find anything. And the mere detection of Oumuamua was a surprise by all the magnitude, I should say. And it is still a surprise, given what we know about the solar system, the number of rocks that the solar system produced. But nevertheless, that was the first unusual fact. But it still allowed for Oumuamua to be a rock. And then it didn't show any cometary tail. And the Spitzer Space Telescope put very tight limits.
00:12:40
Speaker
on any carbon-based molecules in its vicinity or any dust particles. And it was definitely clear that it's not a comet, because if you wanted to explain the excess push that it exhibited away from the sun through cometary evaporation, you needed about 10% of the mass of this object to be evaporated.
00:13:01
Speaker
And that's a lot of mass. We would have seen it. The object size is of order the size of a football field, the 100 to 200 meters. And we would see such evaporation easily. So that implied that it's not a comet.
00:13:16
Speaker
And then if it's not the rocket effect that is pushing it through evaporation, the question arose as to what actually triggers that push and the suggestion that we made in the paper is that it's the reflection of sunlight. And for that to be effective, you needed the object to be very thin.
00:13:34
Speaker
The other aspect of the object that was unusual is that as it was tumbling every eight hours, the amount of sunlight reflected from it changed by a factor of 10. And that implied that the object has an extreme shape, most likely pancake shape, flat.
00:13:51
Speaker
not cigar-shaped. The depiction of the object as a cigar was based on the fact that projected on the sky as it was tumbling, the area that it showed us changed by a factor of 10. So then, of course, if you look at the piece of paper tumbling in the wind and you look at it when it's sideways, it does look like a cigar.
00:14:10
Speaker
but intrinsically it's flat. And that is at the 90% confidence when trying to model the amount of light reflected from it as it was tumbling. The conclusion was at the 90% confidence that it should be pancake shaped flat, which again is unusual. You don't get such objects very often in the context of rocks. And the most that we have seen before was of the order of a factor of
00:14:34
Speaker
three in length versus width. And then came the fact that it originated from a special frame of reference called the local standard of rest, which is sort of like the local parking lot of the Milky Way galaxy. If you think about it, the stars are moving relative to each other in the vicinity of the sun, just like cars moving relative to each other in the center of a town.
00:14:57
Speaker
And then there is a parking lot that you can get to when you average over the motions of all the stars in the vicinity of the sun. And that is called the local standard of rest. And Oumuamua originated at rest in that frame. And that's very unusual because only one in 500 stars is so much at rest in that frame as Oumuamua was. So first it tells you it didn't originate from any of the nearby stars.
00:15:23
Speaker
also not likely from any of the faraway stars because they are moving even faster relative to us if they are far away because of the rotation around the center of the Milky Way galaxy. So it was not a natural result to get a very small likelihood to have an object that is
00:15:41
Speaker
so rare but then it was sort of like a beauty sitting at rest on the surface of the ocean and the sun bumped into it like a giant ship and the question is if it's artificial in origin why would it originate from that frame and one possibility is that
00:15:58
Speaker
It's a member of objects on a grid that's for navigation purposes. If you want to know your coordinates as you're navigating an interstellar space, you find your location relative to this grid. And obviously, you want those objects to be stationary, to be at rest.
00:16:17
Speaker
relative to the local frame of the galaxy. And another possibility is that it's a member of relay stations for communication. So to save on the power needed for transmission of signals, you may have relay stations like we have on Earth, and it's one of them. We don't know the purpose of this object because we don't have enough data on it. That's why we need to find more of the same.
Critique of Scientific Community's Responses
00:16:40
Speaker
But my basic point is
00:16:43
Speaker
There were six anomalies of this object that I detail in my book, Exo-Terrestrial, and I also wrote about in Scientific American. And these six anomalies make it very unusual. If you assign a probability of 1% to the object having each of these anomalies, when you multiply them, you get a probability of 1 in a trillion, that this object is something that we have seen before. So clearly, it's very different from what we have seen before.
00:17:11
Speaker
Response of the scientific community was to dismiss the artificial origin, and there were some scientists that took the scientific process more seriously and tried to explain the origin of a mumuwa from a natural source. And they suggested four possibilities after my paper came out. And one of them was maybe it's a hydrogen iceberg, a chunk of frozen hydrogen,
00:17:33
Speaker
that we've never seen before, by the way. And then the idea is that when hydrogen evaporates, you don't see the cometary tail because it's transparent. The problem with that idea is that hydrogen evaporates very easily. So we showed in a follow up paper that such a chunk of frozen hydrogen the size of the football field would not survive the journey through interstellar space from its birth site to the solar system.
00:17:58
Speaker
And then there was another suggestion, maybe it's a nitrogen iceberg that was chipped off the surface of a planet like Pluto. And then we showed in a follow-up paper that, in fact, you need more mass in heavy elements than you find in all the stars in the Milky Way galaxy, by orders of magnitude more
00:18:19
Speaker
just to have a large enough population of nitrogen-icy objects in space to explain the discovery of a moo-mooa. And the reason is that there is a very thin layer of nitrogen, solid nitrogen on the surface of Pluto,
00:18:35
Speaker
And that makes a small fraction of the mass budget of the solar system. And so you just cannot imagine making enough chunks. Even if you rip off all the nitrogen on the surface of exoplutors, it just doesn't work out, this scenario. And then there was a suggestion, maybe it's a dust bunny, as you mentioned, a cloud of dust particles very loosely bound, and it needs to be 100 times less dense than air.
00:19:02
Speaker
so that when reflecting sunlight it will be pushed like a feather and the problem with that idea is that such a cloud would get heated by hundreds of degrees when it gets close to the sun and they would not maintain its integrity so that also has a problem and the final suggestion was maybe it's a fragment a shrapnel
00:19:21
Speaker
from a bigger object that passed close to a star. And the problem with that is the chance of passing close to a star is very small. Most objects do not. So why should we see the first interstellar object is belonging to that category? And the second is when you tidally disrupt a big object when passing through near a star, the fragments usually get elongated and not pancake-shaped. You get often a cigar-shaped object.
00:19:47
Speaker
So all of these suggestions have major flaws. And my argument was simple. If it's nothing like we have seen before, we better live on the table, the possibility that it's artificial, and then take a photograph of future objects that appear as weird as this one. So you mentioned the local standard of rest, which is the average velocity of our local group of stars. Is that right?
00:20:10
Speaker
Yes. Well, it's the frame that you get to after you average over the motions of all the stars relative to the Sun, yes. Okay. So, Oumuamua was at the local standard of rest until the Sun's gravitation pulled it in. Is that right?
00:20:26
Speaker
Well, no. So the way to think of it, it was sitting at rest in that frame and just like a buoy on the surface of the ocean. And then the sun happened to bump into it. The sun simply intercepted it along the path. And as a result, gave it a kick, just like a ship gives a kick to a buoy. The sun acted on it through its gravitational force primarily. And then in addition, there was this excess push, which was a smaller fraction of the gravitational force, just a fraction of a percent.
00:20:56
Speaker
Right, and that's the sun pushing on it through its suspected large surface area and structure. In addition to gravity, there was an extra force acting on it, which was a small correction to the force of gravity, the order of 10% percent. But it was detected at very high significance because we monitored the motion of Umuamua. And to explain this force, given that there was no cometary evaporation,
00:21:21
Speaker
you needed a thin object. Then, as I said, there was another thin object discovered in September 2020 called 2020SO that also exhibited an excess push by reflecting sunlight. So it doesn't mean necessarily that Oumuamua was a light sail. It just means that it had a large area for its mass.
Oumuamua's Movement and Origin Theories
00:21:42
Speaker
Can you explain why the smooth acceleration of Oumuamua is significant?
00:21:48
Speaker
Yeah, so what we detected is an excess acceleration away from the sun that declines inversely with distance squared in a smooth fashion. And first of all, the inverse square law is indicative of a force that acts on the surface of the object. And the reflection of sunlight is exactly giving you that. And the fact that it's smooth cannot be easily mimicked
00:22:16
Speaker
by cometary evaporation because often you have jets. These are spots on the surface of a comet from where the evaporation takes off and that introduces jitter as the object tumbles there is a jitter introduced to its motion because of the localized nature of these jets that are pushing it.
00:22:34
Speaker
You can think of the jets as the jets in a plane that push the airplane forward by ejecting gas backwards. But in the case of a comet, the comet is also tumbling and spinning. And so that introduces some jitter because the jets are exposed to sunlight, a different phases of the spin of the object.
00:22:53
Speaker
And moreover, beyond a certain distance, water does not sublimate, does not evaporate anymore. You have water ice on the surface and beyond a certain distance, it doesn't get heated enough to evaporate. So the push that you get from cometary evaporation
00:23:11
Speaker
has a sharp cutoff beyond a certain distance. And that was not observed. In the case of a Muamua, there was a smooth push that didn't really cut off, didn't show an abrupt change at the distance where water ice would stop evaporating. And so that again is consistent with the reflection of sunlight being the origin of the excess push. Can you explain the difference between comets and asteroids?
00:23:39
Speaker
Yeah, so we're talking about the bricks that were left over from the construction project of the solar system. So the way that the planets form is that first you make a star, like the sun, and you make it from a cloud of gas that condenses and collapses under
00:24:02
Speaker
the influence of its self gravity, its own gravitational force contracts it and it cools and makes a star in the middle. But some of the gas has rotation around the center. And so when you make a star like the sun, a small fraction of the gas of the order of a few percent or so remains in a leftover disk.
00:24:24
Speaker
around the star that was just formed. And that debris of gas in the disk is the birthplace of the planets. And that disk of gas that is left over from the formation process of the Sun, of course, includes hydrogen and helium, the main elements from which the Sun is made, but also includes heavy elements.
00:24:44
Speaker
And they condense in the mid-plane of the disk and make dust particles that stick to each other get bigger and bigger over time. And they make the so-called planetesimals. These are the building blocks, the bricks, that come together in making planets like the Earth or the core of Jupiter that accreted also hydrogen and helium around the central rocky region.
00:25:10
Speaker
So the idea is that you have all these bricks that just like Lego pieces make up the planets and some of them get scattered during the formation process of the planets and they remain as rocks in the outer solar system. So the solar system actually extends a thousand times farther than the location of the most distant planet in a region called the Oort cloud that extends to a hundred thousand
00:25:36
Speaker
times the Earth-Sun separation. And that is a huge volume. It goes halfway to the nearest star. So in fact, if you imagine each star having an ore cloud of these bricks, these building blocks that were scattered out of the construction process of the planets around the star, then these ore clouds are touching each other, just like densely packed billiard balls. So just imagine a spherical region of planetesimas, these rocks. And so comets
00:26:04
Speaker
are those rocks that are covered with water ice. So since they are so far away from the sun, the ice freezes, the water freezes on their surface. But some of them have orbits that bring them very close to the sun. So when they get close to the sun, the water ice evaporates.
00:26:24
Speaker
and creates a cloud of gas, water vapor, and some dust that was embedded in this rock that creates this appearance of a cometary tail. So what you see is the object is moving, and then its surface layers get heated up by absorbing sunlight. And the gas and dust evaporate and create this hello around the object.
00:26:50
Speaker
and a tail that always points away from the sun because it's calmed by the solar wind, the wind coming from the sun. And so you end up with a cometary tail. That's what a comet is. Now, some rocks remain closer to the sun and are not covered with ice whatsoever. So they're just bare rocks. And when they get close to the sun,
00:27:15
Speaker
You know, there is no ice that evaporates from them. These are called asteroids. And they are just rock without any ice on the surface. And so we see those as well. There is actually a region where asteroids, it's called the main belt of asteroids.
00:27:32
Speaker
We don't know what the origin of that is. It could be a planet that was disintegrated or it could be a region that didn't quite make a planet and you ended up with fragments floating there. But at any event, there are asteroids, bare rocks without ice on them because they were close enough to the sun that the ice evaporated and we don't have the water there.
00:27:55
Speaker
And then these objects are also seen in the vicinity of the Earth. Every now and then, these are called asteroids. And we see basically two populations. Now, Oumuamua was not a comet because we haven't seen a cometary tail around it. And it wasn't an asteroid because there was this excess push. If you have a piece of rock, it will not be pushed much by reflecting sunlight.
Exploration and Discovery Imperatives
00:28:18
Speaker
because its area is not big enough relative to its mass. So it gets a push, but it's too small for it to exhibit it in its trajectory.
00:28:29
Speaker
Right, so can you also explain how much we know about the composition of Oort clouds, and specifically the shape and size of the kinds of objects there, and how Oumuamua relates to our expectation of what exists in the Oort cloud of different stars?
00:28:50
Speaker
Yeah, so the one thing that I should point up front is when scientists that try to attend to the anomalies of a Muamua suggest that it's a hydrogen iceberg or a nitrogen iceberg. By the way, that notion gathered popularity in the mainstream. People said, oh, they had a sigh of relief. We can explain this object
00:29:13
Speaker
with something we know. But the truth is, it's not something we know. We've never seen a nitrogen iceberg that was chipped off Pluto in our solar system. The Oar Cloud does not have nitrogen icebergs that we witnessed.
00:29:29
Speaker
So claiming that Oumuamua, the first interstellar object, is a nitrogen iceberg or a hydrogen iceberg implies that there are nurseries out there around other stars or in molecular clouds that are completely different than the solar system in the sense that
00:29:49
Speaker
they produce most of the interstellar objects because Uemu was the first one we discovered. So they produce a large fraction of the interstellar object, yet they are completely different from the solar system. It's just like going to the hospital and seeing a baby
00:30:06
Speaker
that looks completely different than any child you have seen before at your home, you know, from any child you had. And it implies that the birthplace of that child was quite different, but yet that child appears to be the first one you see. So, you know, that's
00:30:24
Speaker
to me, an important signal from nature that you have to rethink what the meaning of this discovery is. And the other message is we will learn something new no matter what. So we need to get more data on the next object that belongs to this family, because even if it's a naturally produced object, it will teach us about environments that produce objects
00:30:48
Speaker
that are quite different from the ones we find in the solar system. And that means that we miss something about nature. And even if it's natural in origin, we learn something really new in the process of gathering this data. So we should not dismiss this object and say business as usual.
00:31:08
Speaker
We don't have to worry about it. Rather, we should attempt to collect as much data as possible on the next weird object that comes along. I should say there was a second interstellar object discovered by an amateur astronomer from Russia called Gennady Borisov, and it was given the name Boriso. It was discovered in 2019. That one looked just like a comet, and I was asked,
00:31:33
Speaker
Does that convince you that the mua mua was also natural because this one looks exactly like the comments we have seen?
00:31:40
Speaker
And I replied, you know, when you go along the beach, and most of the time you see rocks and suddenly you see a plastic bottle, and after that you see rocks, the fact that you found rocks afterwards doesn't make the plastic bottle a rock. Each object has to be considered on its own merit, and therefore it makes a mumu even more unusual.
00:32:06
Speaker
and the fact that we see Borisov as a natural comet. So in terms of the objects that come from the Oort cloud, our own Oort cloud, there is a size distribution that there are objects that
00:32:18
Speaker
are much smaller than umuamua and objects that are much bigger and of course the bigger objects are more rare and then roughly speaking there is equal amount of mass per logarithmic size bin so there are many more small objects and most of them we can't see because umuamua was
00:32:40
Speaker
roughly at the limit of our sensitivity with pan stars. And that means that objects much smaller than the size of a football field cannot be noticed within a distance comparable to the distance to the sun. The sun acts as a lamppost that illuminates the darkness around us. And so an object is detected when it reflects enough sunlight for us to detect.
00:33:05
Speaker
with our telescopes and so small objects do not reflect enough sunlight and we will notice them but I calculated that in fact if there are probes moving very fast through the solar system let's say the fraction of the speed of light that were sent by some alien civilizations
00:33:26
Speaker
We could detect the emission from them, the infrared emission from them with the James Webb Space Telescope. They would move very fast across our sky, so we just need to be ready to detect them. Do you think that given our limited knowledge of Oort clouds that there are perhaps exotic objects or rare objects which we haven't encountered yet but that are natural in origin that may account for a MoMA?
00:33:55
Speaker
Of course, there could be, as I mentioned, the people suggested the hydrogen iceberg and nitrogen iceberg, dust bunny. These were suggestions that were already made, and each of them has its own challenges. And it could be something else, of course. And the way to find out, that's the way science operates. Science is guided by evidence, by collecting data.
00:34:19
Speaker
The way science should be done is you leave all possibilities on the table and then you collect enough data to rule out all but one interpretation that looks most plausible. And so my argument is we should leave the artificial origin possibility on the table because all the other possibilities that were contemplated
00:34:39
Speaker
invoke something that we've never seen before. So we cannot argue based on speculations that it's something that we've never seen before. We cannot argue that proves the point that it's not artificial. So it's a very simple point that I'm making and I'm arguing for collecting more data. I mean, I would be happy to be proven wrong that it's not artificial in origin.
00:35:01
Speaker
and then move on. The point is that science is not done by having a prejudice, knowing the answer in advance. It's done by collecting data. And the mistake that was made by the philosophers during Galileo's time is not to look through his telescope and argue that they know that the sun moves around the earth. And that only maintained their ignorance. The reality doesn't care whether we ignore it. The earth continued to move around the sun. If we have neighbors,
00:35:30
Speaker
They exist out there and it doesn't really matter whether we shut down the curtains on our windows and claim, no, we are unique and special and there is nobody out there on the street. The fact that we say that, we can get a lot of likes on Twitter saying that, and we can ridicule anyone that argues differently, but that would not change the fact whether we have neighbors or not.
00:35:56
Speaker
That's an empirical fact. And in order for us to improve our knowledge of reality, I'm talking about reality, not about philosophical arguments, just figuring out whether we have neighbors, whether we are the smartest kid on the block.
00:36:12
Speaker
within the realm of science. And finding out the answer to this question is not a matter of debate. It's a matter of collecting evidence. But of course, if you are not willing to find wonderful things, you will never discover them.
Public Interest and Scientific Obligation
00:36:27
Speaker
So my point is we should consider this possibility as real, as very plausible, as mainstream activity, just like the search for dark matter or the search for gravitational waves. You know, we exist. There are many planets out there just like the Earth. Therefore, we should search for things like us that existed or exist on them.
00:36:50
Speaker
That's a very simple assumption to make and argument to make. And to me, it sounds like this should be a mainstream activity. But then I realized that my colleagues do not agree. And I failed to understand this missile because it's a subject of great interest to the public and the public fund science. So if you go back a thousand years, there were people saying the human body has a soul and therefore anatomy should be forbidden.
00:37:18
Speaker
So imagine if scientists would say, oh, this is a controversial subject. The human body could have a soul. We don't want to deal with that because some people are claiming that we should not operate the human body. Where would modern medicine be? My argument is if science has the tool to address a subject of great interest to the public, we have an obligation to address it and clear it up.
00:37:40
Speaker
Let's do it bravely with open eyes. And by the way, there is an added bonus. If the public cares about it, there will be funding for it. So how is it possible that the scientific community ridicules this subject, brushes it aside, claims we don't want to entertain this unless we have extraordinary evidence, yet fails to fund at a very substantial level the search for that extraordinary evidence? How is that possible in the 21st century?
00:38:09
Speaker
Given the evidence and data that we do have, what is your credence that Oumuamua is alien in origin? Well, I have no certainty in that possibility, but I say it's a possibility that should be put left on the table with at least as high likelihood as a nitrogen iceberg or a hydrogen iceberg or a dustbun.
00:38:32
Speaker
That's what I consider as the competing interpretations. I don't consider statements like it's always rocks, it's never aliens as valid scientific statements because they remind me of the possibility, you know, if you were to present a cell phone to a caveman and the caveman is used to playing with rocks all of his life, the caveman would argue that the cell phone is just a shiny rock.
00:38:59
Speaker
And just basing your assertions on past experience is no different than what the philosophers were arguing. We don't want to look through Galileo's telescope because we know that the sun moves around the Earth. So, you know, this mistake was made over and over again throughout human history. I would expect modern scientists
00:39:18
Speaker
to be more open-minded, to thinking outside the box, to entertain possibilities that are straightforward. And what I find is the strange thing is not so much that there is conservatism regarding this subject, but at the same time, in theoretical particle physics, you have whole communities of hundreds of people entertaining ideas that have no experimental verification, no experimental tests,
00:39:44
Speaker
in the foreseeable future whatsoever. Ideas like the stream theory landscape, or the multiverse, or some people argue we live in a simulation, or other people talk about supersymmetry. And awards were given to people doing mathematical gymnastics. And these studies are part of the mainstream. And I ask myself, how is it possible that this is considered part of the mainstream? And the search for technological signatures, not.
00:40:14
Speaker
And my answer is that these ideas provide a sandbox for people to demonstrate that they're smart, that they're clever. And a lot of the culture in academia is about that. It's not about understanding nature. It's more about showing that you're smart.
00:40:31
Speaker
and getting honors and awards. And that's unfortunate because physics and science is a dialogue with nature. It's a learning experience. We're supposed to listen to nature, and the best way to listen to nature is to look at anomalies, things that do not quite line up with what we expected. And by the way, whether Oumuamua is artificial or not,
00:40:52
Speaker
That doesn't require very fancy math. It's a very simple fact that any person can understand. I mean, nature is under no obligation to reveal its most exciting secrets without fancy math. It doesn't need to be sophisticated. Aristotle had this idea of the spheres surrounding us, that we are at the center of the universe and there are these beautiful spheres around us. That was a very sophisticated
00:41:18
Speaker
idea that many people liked because it flattered their ego to be at the center of the universe. And it also had this very clever arrangement, but it was wrong. So who cares how sophisticated an idea is? Who cares if the math is extremely complicated? I mean, of course, it demonstrates that you are smart if you're able to maneuver through these complicated mathematical gymnastics. But that doesn't mean that it's reflecting reality. And my point is,
00:41:46
Speaker
we better pay attention to anomalies that nature gives us than to promoting our image. Right. So it seems like there's this interesting difference between the extent to which the scientific community is willing to entertain Oumuamua as being artificial in origin. Whereas at the same time, there is a ton of theories that at least at the moment are unfalsifiable. Yet here we have a theory that is simple, matches the data and can be falsified.
00:42:17
Speaker
Right. And the way to falsify it, I mean, is not by chasing Momomoa, because by now it's a million times fainter than it was close to the sun. But then it's by finding more objects that look as weird as it was. You know, this was the first object we identified.
00:42:34
Speaker
There must be many more. If we found this object by serving the sky for a few years, we will definitely find more by serving the sky for a few more years because of the Copernical principle. Copernicus discovered that we are not positioned in a special location, in a privileged location in the universe. We are not at the center of the universe.
00:42:54
Speaker
And you can extend it also not just to space, but also time. And when you make an observation over a few years time, the chance of these few years being special and privileged is small. I mean, most likely it's a typical time and you would find it if you were to look
00:43:10
Speaker
the previous three years or the following three years. That's the Copernican principle, and I very much subscribe to it because, again, the one thing I learned from practicing astronomy over the decades was a sense of modesty. We are not special, we are not unique, we are not located at the center of the universe. We don't have anything, especially in our backyard. The Earth-Sun system is very common. So that's the message that nature gives us.
00:43:37
Speaker
and you know we are born into the world like actors put on a stage and first thing we see is the stage is huge it's 10 to the power 26 times larger than our body and the second thing we see is that the play has been going on
00:43:55
Speaker
for 13.8 billion years since the Big Bang and we just arrived at the end of it. So the play is not about us, we are not the main actors. So let's get a sense of modesty and let's look for other actors that may have been around for longer than we did as a technological civilization
00:44:14
Speaker
maybe they know they have a better sense of what the play is about. So I think it all starts from a sense of modesty and you know my daughters when they were young they were at home and they had the impression that they are the center of the world that they are the smartest because they haven't met anyone else outside
00:44:32
Speaker
the family. And then when we took them to the kindergarten, they got a better sense of reality by meeting others and realizing that they're not necessarily the smartest kid on the block. And so I think our civilization has yet mature. And the best way to do that is by meeting others.
00:44:50
Speaker
So before we move on to meeting others, I'm curious if you're willing to offer like a specific credence. So you said that there are these other natural theories like the dust bunny and the iceberg theories. If we think of this in terms of Bayesian reasoning, what kind of probability would you assign to the alien hypothesis?
00:45:08
Speaker
Well, the point is that these objects that were post-related for a natural origin of a mumu were never seen before. So there is no way of assigning likelihood to something that we've never seen before. And it needs to be the most common object in interstellar space. So what I would say is that we should approach it without a Bayesian prior.
00:45:30
Speaker
Basically, we should leave all of these possibilities on the table and then get as much data as possible on the next object that shows the same qualities as Oumuamua. By these qualities, I mean not having a cometary tail, so not being a comet, and showing an excess push away from the sun. And as I mentioned, there was such an object, 2020SO, but it was produced by us.
00:45:56
Speaker
So we should just look for more objects that come from interstellar space that exhibit these properties and see what the data tells us. It's not a matter of a philosophical debate. That's my point. We just need a close-up photograph and we can easily tell the difference between a rock and an artificial object. And I would argue that
00:46:17
Speaker
anyone on Earth should be convinced when we have such a photograph. So if we can get such a photograph in the next few years, I would be delighted, even if I'm proven wrong, you know, because we will learn something new no matter what.
00:46:34
Speaker
So there's also been a lot of energy in the news around UFO sightings and UFO reports recently.
Impact of UFO Reports on Oumuamua's Perception
00:46:41
Speaker
I'm curious how the current news and status of UFO interest in the United States and the world, how that affects your credence of Umuamua being alien in origin, and if you have any perspective or thoughts on UFOs.
00:46:57
Speaker
Yeah, it's a completely independent set of facts that is underlying the discussion on UFOs. But of course, again, it's the facts, the evidence that we need to pay attention to. I always say, let's keep our eyes on the ball, not on the audience. And because if you look at the audience, the scientists are responding to these UFO reports in exactly the same way as they responded to a more and more. They dismiss it. They ridicule it.
00:47:24
Speaker
And that's unfortunate because the scientists should ask, could we have access to the data? Could we analyze the data? Could we see the full data? Or could we collect new data on these objects so that we can clear up the mystery? I mean, science is about evidence. It's not about prejudice. But instead, the scientists know the answer in advance. They say, oh, these reports are just related to human-made objects. And that's it.
00:47:53
Speaker
Now, let's follow the logic of Sherlock Holmes. Basically, Sherlock Holmes, as I mentioned in my book, Exocerrestrial, made the statement that you put all possibilities on the table and then whatever remains after you sort out all the facts must be the truth.
00:48:10
Speaker
That's the way he operated as a detective. So that's the way we should operate as scientists. And what do we know about the latest UFO report from the Pentagon and intelligence agencies? So far, a few weeks before it's being released, we know from leaks that there is a statement that some of the objects that were found are real.
00:48:35
Speaker
There are not artifacts of the cameras, there are not illusions of the people who saw them, because they were detected by multiple instruments, including infrared cameras, radar systems, optical cameras, and a lot of people from different angles.
00:48:56
Speaker
And when you consider that statement coming from the Pentagon, you have to take it seriously because it's just the tip of the iceberg. The data that will be released to the public presumably is partial because
00:49:11
Speaker
they will never release the high quality data because it will inform other nations of the capabilities, the kind of sensors that the US has in monitoring the sky. So I have no doubt that a lot of data is being hidden for national security reasons because otherwise it will expose the capabilities of these sensors that are being routinely used to monitor the sky.
00:49:40
Speaker
But if people that had access to the full data, and that includes officials such as former president Barack Obama, former CIA director James Woolsey and others that sold the data and they make the case that these objects are real, then these objects may very well be real.
00:50:02
Speaker
Okay? And I take that at face value. Of course, as a scientist, I would like to see the full data or collect new data. There is no difference because science is about reproducibility of results. So if the data is classified, I would much rather place state-of-the-art cameras
00:50:22
Speaker
that you can buy in the commercial sector or scientific instrumentation that we can purchase and just place those in the same locations and record the sky. The sky is not classified. In principle, anyone can collect data about the sky. So I would argue that if all data is classified, we should collect new data that will be open to the public. And it's not a huge investment of funds to have such an experiment.
00:50:51
Speaker
But the point of the matter is that we can infer if the objects are real. And using the scientific method, then let's assume that they are real, like the people that saw the full data claim. So if they are real, then there are three possibilities. Either they were produced, manufactured by other nations, because we certainly know what we are doing, the US.
00:51:14
Speaker
So if they were produced by other nations like China or Russia, then humans have the ability to produce such objects and they cannot exceed the limits of our technology. And if the maneuvering of these objects looked as if they exceed substantially the limits of the technologies we possess, then we would argue it's not made by humans because there is no way
00:51:43
Speaker
that the secret about an advanced technology would be preserved on earth by humans because it has huge benefits commercially, you know, so it would appear in the market, in the commercial sector, because you can sell it for a lot of money, or it would appear in the battlefield if it's being used by
00:52:05
Speaker
other nations and we pretty much know what humans are capable of producing. We are also probably getting intelligence on other nations so we know what are the limits of human technology. I don't think the
00:52:20
Speaker
you know, we can leave that possibility vague. If there is an object behaving in a way that far exceeds what we are able to produce, then that looks quite intriguing. The remaining possibilities are that somehow it's a phenomenon that occurs in the Earth's atmosphere. There is something that happens
00:52:43
Speaker
that we didn't identify before, or that these are objects that came from an extraterrestrial origin. And once again, I make the case that the way to make progress on this is not to appear on Twitter and claim we know the answer in advance and ridicule the other side of the argument. This is not the way by which we make progress, but rather collect
00:53:09
Speaker
better evidence, better clues and figure it out, clear up the fog. You know, it's not a mystery that should be unraveled by philosophical arguments. It's something that you can measure and get data on and reproduce with future experiments.
00:53:29
Speaker
And once we get that, we will have a clear view of what it means. And then that's how mysteries get resolved in science. So I would argue for a scientific experiment that will clear up the fog. And the way that we will not do that is if the scientific community would ridicule these reports.
00:53:51
Speaker
and the public would speculate about the possible interpretations. That's the worst situation you can be in because you're basically living a subject of great interest to the public unresolved. And that's not the right way, again, in the 21st century to treat a subject of interest to the public that obviously reaches the Congress. It's not an eyewitness on the street that says, I saw something unusual.
00:54:19
Speaker
You know, it's military personnel. We have to take it seriously. And we have to get to the bottom of it. So that's the way I look at it. And, you know, it may well be that it's not the extraterrestrial in origin, but I think the key is by finding evidence.
00:54:35
Speaker
So given the age of the universe and the age of our galaxy and the age of our solar system, would you be surprised if there were alien artifacts almost everywhere or in many places, but we were just really bad at finding them? Or those artifacts were really good at hiding?
00:54:55
Speaker
I wouldn't be surprised because, as I said, most of the stars formed billions of years before the sun. And if there were technological civilizations around them, you know, some of many of these stars died by now, and these civilizations may have perished. But if they send equipment, that equipment may operate, especially if it's being operated by artificial intelligence or by
00:55:19
Speaker
things that we haven't invented yet, it may well survive billions of years and get to our environment.
Human Presence and Extraterrestrial Contact
00:55:26
Speaker
Now, one thing you have to realize is when you go in the wilderness and you better be quiet, you better not make a sound and listen because there may be predators out there.
00:55:37
Speaker
Now, we have not been careful in that sense because we have been broadcasting radio waves for more than a century. So these radio signals reached 100 light years by now. And if there is another advanced civilization out there with radio telescopes of the type that we possess, they may already know about us. And then if they use chemical rockets to get back to us,
00:56:03
Speaker
it would take them a million years to traverse a hundred light years. But if they use much faster propulsion, they may be already here. And the question is, are we noticing them? There was this Fermi paradox formulated seven years ago by Enrico Fermi, a famous physicist,
00:56:23
Speaker
who said then, where is everybody? And of course, that's a presumptuous statement because it assumes that we are sufficiently interesting for them to come and visit us. And when I met my wife, she had a lot of friends that were waiting for Prince Charming on a white horse to make them a marriage proposal. And that never happened. And then they compromised. And we as a civilization,
00:56:47
Speaker
you know, would be presumptuous in assuming that we are sufficiently interesting for others to have a party in our backyard. But nevertheless, you know, it could be that it already happened. As you said, then we did notice. One thing to keep in mind is through geological activity, most of the surface of the earth
00:57:07
Speaker
gets mixed with the interior of the Earth over a hundred million years timescale. So it could be that some of the evidence was buried by the geological activity on Earth. And that's why we don't see it. But the moon, for example, is like a museum because it doesn't have geological activity.
00:57:28
Speaker
And also it doesn't have an atmosphere that would burn up an object that is smaller than the size of a person like the Earth's atmosphere does for meteors. So in principle, once we establish a sustainable base on the Moon, you know, we can regard it as an archaeological site.
00:57:46
Speaker
and survey the surface of the moon to look for artifacts that may have landed, may have crashed on it. Maybe we will find a piece of equipment that we never sent that came from somewhere else that crashed on the surface of the moon.
00:58:01
Speaker
So it'd be wonderful if we could pivot into great filters and space archaeology here, but before we do that, you were talking about the Fermi Paradox and whether or not we're sufficiently interesting to merit the attention of other alien civilizations.
00:58:17
Speaker
I wonder if interesting is really the right criteria, because if advanced civilizations converge on some form of ethics or beneficence, then whether or not we're interesting is not perhaps the right criteria for whether or not they would reach out. We have people on Earth who are interested in animal ethics, like how the ants and bees and other animals are doing, so it could be the same case with aliens, right?
00:58:42
Speaker
Right, I completely agree. One thing I should say, well, actually two things. First, you mentioned before the Drake's equation, it doesn't apply to relics, it doesn't apply to objects. The Drake equation talks about the likelihood of detecting radio signals.
00:58:59
Speaker
You know, that has been the method we used over the past 70 years in searching for other civilizations. And I think it's misguided because in order to get a signal, it's just like trying to have a phone conversation. You need the counterpart to be alive.
00:59:14
Speaker
And it's quite possible that most of the civilizations are dead by now. So that's the great filter idea that there is a narrow window of opportunity for us to communicate with them. But on the other hand, they may have sent equipment into space and we can search for it through space archaeology and find relics from civilizations that are not around anymore. Just like we find relics from cultures that existed on the surface of Earth.
00:59:39
Speaker
through archaeological digs. So I think a much more promising approach to find evidence for dead civilizations is looking for objects floating in space. And the calculation of what's the likelihood of finding them is completely different from the Drake equation. It resembles more the calculation of what's the chance that you will stumble across a plastic bottle on the beach or on the surface of the ocean.
01:00:05
Speaker
And you just need to know how many plastic bottles are per unit area on the surface of the ocean. And then you will know what's the likelihood of crossing one of them. And the same is true for relics in space. You just need to know the number of such objects per unit volume. And then you will figure out what's your chance of bumping into one of them. And that's a completely different calculation than the Drake equation, which talks about receiving radio signals. This is one point
01:00:35
Speaker
that should be born. And the other point that I would like to mention is that during our childhood, we always have a sense of adults looking over our shoulders and they're making sure that everything goes well and they often protect us. And then as we become independent and grow up, we encounter reality on our own.
01:01:01
Speaker
there is this longing for a higher power that overlooks our shoulder. And that is provided by the idea of God in religion. But interestingly enough, it's also related to the idea of some unidentified flying objects that are looking over our shoulders because if
01:01:27
Speaker
A UFO was identified to be of extraterrestrial origin. It may imply that there is an adult wiser than we are in the room looking over our shoulder. The question of whether that adult is trying to protect us is still open, remains open. But we can be optimistic.
01:01:51
Speaker
All right, so let's talk a little bit about whether or not there might be adults in the room. So you defined what a great filter was. So when I think of great filters, I think of there being potentially many of them rather than a single great filter. So there's the birth of the universe, and then you need generations of stars to fuse heavier elements. And then there's the number of planets in Goldilocks zones, and then there's
01:02:19
Speaker
abiogenesis or the arising of life on Earth, and then there's moving from single to multicellular life, and then there's intelligent life and civilization, et cetera, right? So it seems like there's a lot of different places where there could be great filters. Could you explain your perspective on where you think the most likely great filters might be?
01:02:39
Speaker
Well, I think it's self-destruction because I was asked by Harvard alumni, how much longer do I expect our civilization to survive? And I said, when you look at your life and you just select a random day throughout your life, what's the chance that it's the first day after you are born? That probability is tens of thousands of times smaller
01:03:02
Speaker
then the probability that the day you select would be during your adulthood because there are tens of thousands of days in the life of an adult. So we existed for about a century as an advanced technological civilization. And you ask yourself, okay, well, if we are in our adulthood, which is the most
01:03:25
Speaker
probable state for us to be in. As I mentioned before, you're just sampling randomly at time and most likely during your adulthood. Then that means that we have only a few more centuries left because the likelihood that we will survive for millions of years is tens of thousands of times smaller. It would imply that we are in the first day of our life and that is unlikely.
01:03:52
Speaker
Now, the one caveat I have to this statement is that the human spirit can defy all odds. So I believe that in principle, if we get our act together, we can be an outlier in the statistical likelihood function.
01:04:09
Speaker
And that's my hope. I'm an optimist. And I hope that we will get our act together. But if we continue to behave the way we are, not to care so much about the climate, you can even see it in world politics nowadays, even when you have administrations that care about climate, they cannot really convince the commercial sector to cooperate. And suppose our civilization is on a path to self-destruction, then we don't have more than a few centuries left.
01:04:37
Speaker
So that is a great filter. And of course there could be many other great filters, but that seems to me as the most serious one. And then you ask yourself, okay, so which civilization is more likely to survive? It's probably the dumber civilization that doesn't create the technologies that destroy it. Like if you have a bunch of crocodiles swimming on the surface of a planet, you know, they will not create an atomic weapon.
01:05:02
Speaker
They would not change the climate so they may survive for billions of years. Who knows? So maybe the most common civilizations are the dumb ones. But one thing to keep in mind is that when you create technological capabilities, you can create equipment that will
01:05:19
Speaker
reproduce itself like phenomenon machines or you can send it to space you can escape from the location that you were born on and so that opens up a whole range of opportunities in space and that's why i say that once a civilization
01:05:36
Speaker
ventures into space, then everything is possible. Then you can fill up space with equipment that reproduces
Advanced Civilizations and Technological Capabilities
01:05:44
Speaker
itself. And there could be a lot of plastic bottles out there. And we don't know. We shouldn't assume anything. We should just search for them. And Oumuamua, as far as I'm concerned, was a wake-up call. And the other thing I would like to say is
01:05:59
Speaker
If I imagine a very advanced civilization that understands how to unify quantum mechanics with gravity, something we don't possess at the moment, there's such a unification scheme that we know works, perhaps they know how to irritate the vacuum and create a baby universe that would lead to more civilization. So it's just like having a baby that can make babies, that can make babies.
01:06:24
Speaker
and you would get many generations as a result of that. This could be an origin of the Big Bang. Maybe the umbilical cord of the Big Bang started in a laboratory. By the way, it would say that intelligence, technological advance is an approximation to God because in the religious stories, God created the universe. We can imagine a technology that would create a baby universe.
01:06:52
Speaker
And then the same is true for life. We don't know if life was seeded, the origins of life was seeded in a laboratory somewhere. And so that remains a possibility. And that's what's so fascinating about the search for intelligent life out there, because it may provide answers to the most fundamental questions we have, like the meaning of life.
01:07:15
Speaker
Would you consider your argument there about human extinction given what we are currently observing? Is that like the doomsday argument?
01:07:22
Speaker
Yeah, well, you can call it the doomsday. I would call it risk assessment. And then I don't think we are statistical systems in the sense that there is no escape from a particular future, because I think that once we recognize the risk in a particular future, we can respond and avoid it. The only question is whether as a civilization we will be intelligent enough.
01:07:48
Speaker
Frankly, I'm worried that we are not intelligent enough. And it may be just like a Darwinian principle where if you're not intelligent enough, you will not survive. And we will never be admitted to the club of intelligent civilizations in the Milky Way galaxy unless we change our behavior. And it's yet to be seen
01:08:09
Speaker
whether we will change our behavior accordingly. And one way to convince people to change their behavior is to find evidence for other civilizations that didn't and perished as a result. That would be a warning for us, a history lesson. Now, one caveat I should mention is we always imagine things like us, you know, and when we go to meet someone, it's a fair assumption to assume that that person has eyes and nose and ears the way we have.
01:08:39
Speaker
And the reason it's a reasonable assumption is because we share the same genetic heritage as the person that we are meeting. But if you think about life on a planet that had no causal contact with Earth, it could be very different. And so calculating the likelihood of self-destruction, the likelihood of life of one form versus another,
01:09:02
Speaker
the likelihood of intelligence. All of these very often assume something similar to us, which may not be the case. I think it might be shocking to us to find the creatures from another planet or technologies from another planet. And so my solution to this ambiguity is to be an observer. Even though I'm a theorist, I would argue, let's be modest. Let's not try to predict things in this context.
01:09:30
Speaker
let's just explore the universe. And the biggest mistake we are making over and over again is to argue about the answer before seeing the evidence. And that's the biggest mistake because it convinces you to be lazy, not to collect more evidence, to say, I know the answer in advance. I don't need to look through the telescope. I don't need to invest funds in searching for this.
01:09:53
Speaker
Even though it's an important question, I know the answer in advance. And that's the biggest mistake we can make as a species. I'm willing to go through all the hardships of arguing something outside the box, of confronting these personal attacks against me, just because it's a question of such great importance to humanity. If that was a minor question about the nature of dark matter,
01:10:17
Speaker
I would not risk anything for that. Who cares? If the dark matter is axions or weakly interacting massive particles, that has very little impact on our daily lives. It's not worth confronting the mainstream on that. By the way, the response would not be so emotional in that case either. But on a subject as important as this one, to the future of humanity, which is the title of your organization, there is no doubt in my mind
01:10:45
Speaker
that it's worth the extra effort. It's worth the hardship bringing people to recognize that such a search for technological relics in space is extremely important for the way we view ourselves in the big scheme of things, our aspirations for space, our notions about religion, and what we might do in response to the knowledge that we acquire will completely change the future of humanity.
01:11:14
Speaker
And on such a question, I'm willing to put my body on the barbed wire. Well, thank you very much for putting your body on the barbed wire. I think you mentioned that there was something in, was it Israeli training where soldiers were taught to put their body on the barbed wire so people can climb over them?
01:11:31
Speaker
Yeah, that was a statement that in the battlefield, very often a soldier is asked to put his body on the barbed wire so that others can pass through. The way I see it historically is you look at Socrates, the ancient Greek philosopher. He advocated for doubting the wisdom of influential politicians at the time and
01:11:54
Speaker
other important figures. And he was blamed for corrupting the youth by dismissing the gods that were valued by the civilians of the city state of Athens at the time. And he was prosecuted and forced to drink poison. Now, if Socrates would have lived today, he would have been counseled on the Athenian social media.
01:12:24
Speaker
That would be the equivalent of poison. And you see another philosopher, Epicorus, that made many true statements, but again was disliked by some religious authorities at the time. And you see, of course, Galileo Galilei that was put in house arrest.
01:12:44
Speaker
Later on, you see Giordano Bruno. He was an obnoxious person that was not liked by a lot of people, but he simply argued that other stars are just like the Sun, and therefore they might have a planet just like the Earth that could have life on it. And
01:13:04
Speaker
The church at the time found it offensive because if there is life that is intelligent out there, then that life may have sinned and then Christ should have saved that life. And then you need billions of copies of Christ to be distributed throughout the galaxy.
01:13:24
Speaker
to visit all these planets. And that makes little sense. That made little sense to the church. And so they burned Giordano Bruno on a stake. And even though nowadays we know that indeed a lot of stars are like the sun, a lot of planets are just like the Earth, at roughly the same separation from their host stars, where life may exist on the surface. So in that sense, he was correct.
01:13:50
Speaker
And obviously, you find many such examples also in modern science over the past century of people advocating for the correct ideas and being dismissed and ridiculed. Just to give you an example, a former chair of the astronomy department at Harvard that preceded me, I chaired astronomy department for nine years. I was the longest serving chair in the history of astronomy department at Harvard. Before me was
01:14:16
Speaker
Cecilia Payne-Kopashkin. And in her PhD thesis, which was the first thesis in astronomy at Harvard, she argued, based on analyzing the spectrum of the sun, that most of the surface of the sun is made of hydrogen. And while defending her PhD thesis,
01:14:34
Speaker
Henry Norris Russell, who was the director of the Princeton University Observatory and authority on stars at that time, dismissed her idea and said, that is ridiculous, because we know that the sun is made of the same elements as the Earth. So there is not much hydrogen on Earth. It cannot be the case that the sun is made mostly of hydrogen. So she took out that conclusion from her PhD
01:15:01
Speaker
And then in the subsequent few years, he redid the analysis, got more data, and wrote an extended paper in the Astrophysical Journal arguing the same, that she was correct.
01:15:14
Speaker
Interestingly enough, in a visiting committee to the Princeton University Department of Astrophysics, the chair of that department was bragging that Henry Norris Russell discovered that the sun is made mostly of hydrogen. So you can see that history depends pretty much on who tells it. But the point of the matter is that sometimes when you propose an idea that even though it
01:15:39
Speaker
has to be correct because it's based on evidence, it's being dismissed by the authorities. And science is not dictated by authority. In the 1930s, there was a book co-authored by tens of scientists arguing that Einstein's theory of relativity must be wrong. And when Einstein was asked about it, he said, why do we need tens of scientists to prove that my theory is wrong? It's enough to have one author that would explain why the theory is wrong.
01:16:09
Speaker
science is not based on authority, it's based on reasoning and on evidence and there is a lot of bullying going on nowadays and I witness it and throughout my career I've seen a number of ideas that I proposed that were dismissed and ridiculed at first and then they became the interest of
01:16:31
Speaker
mainstream and now there are hundreds of people working on them. That was true for my work on the first stars. I remember that it was dismissed early on. There were people claiming even that there are no stars beyond the Redshift too. And then I worked on imaging black holes. I suggested that there could be a correlation between black hole mass and characteristic velocity dispersion of stars.
01:16:56
Speaker
in the vicinity of those supermassive black holes in the centers of galaxies. I worked on gravitational wave astrophysics long before it was fashionable. And in all of these cases, the interest that I had early on was really cute. I gave a lecture in a winter school in 2013, in January 2013, winter school in Jerusalem on gravitational wave astrophysics. And then one of the other lecturers
01:17:24
Speaker
who still is 20 years younger than I am, stood up and said, why are you wasting the time of these young students on a subject that will not be of importance in their career? And he said that publicly stood up in front of everyone. It's on video.
01:17:40
Speaker
And two and a half years later, the LIGO experiment detected the first gravitational wave signal. Many of these students were still doing their PhD. And this became the hottest frontier in astrophysics in subsequent years. And the Nobel Prize was awarded. So here you have a situation where someone says, why are you giving a lecture on this subject to students? Because it would never be of importance
01:18:05
Speaker
throughout their careers. And two and a half years later, it becomes the hottest topic, the hottest frontier in astrophysics. And it involves a new messenger other than light that was never used before in astrophysics.
01:18:22
Speaker
gravitational waves, ripples in space and time, it opens up a whole new window into the universe. So how is it possible that someone that is 20 times younger than I am stands up, feels that it's completely appropriate for him to stand up in front of all the students and say that? And to me, it illustrates
01:18:42
Speaker
narrow-mindedness. It's not a matter of conservatism. It's a matter of thinking within the box and not allowing to think outside the box. And that, you might say, OK, it's acceptable because there are lots of people suggesting crazy ideas. But at the same time, you have whole communities of theoretical physicists working on very strange ideas that were not verified experimentally. And that is part of the mainstream.
01:19:10
Speaker
And the common thread between these two communities of people is that they both don't pay attention to evidence. They both do not recognize the fact that evidence leads the way. In the case of gravitational waves, it's the fact that we detected the signal. So just wait for LIGO to find the signal and then everything will change.
01:19:32
Speaker
In the case of Oumuamua, we saw some anomalies. Let's pay attention to them. Let's talk about them. And in the case of string theory, it's let's say this should be at the fringes of mainstream because we haven't found evidence that supports the idea of extra dimensions as of yet. So it doesn't deserve to be center stage. But you have these two communities living side to side because both of them feel comfortable not paying attention to evidence.
01:20:00
Speaker
We like to think of science as this really clean, epistemic process of hypothesis generating and creating theories, and then verification and falsification through evidence and data gathering. But the reality is that it's still made up of lots of humans.
01:20:36
Speaker
who have their
01:20:47
Speaker
about. Right. And I was the founding director of the Black Hole Initiative at Harvard University, which brings together physicists, mathematicians, astronomers, and philosophers. And my motivation in creating this center was to bring people from different perspectives
01:21:08
Speaker
so that they will open the minds of other disciplines to possible breakthroughs in the context of black holes. And I think this is key. I think we should be open-minded and we should also fund risky propositions, risky ideas. There should be a certain fraction of the funding that goes in those directions. And even though I founded this black hole initiative in the first annual conference that we had,
01:21:33
Speaker
A philosopher gave a lecture, and at the end of the lecture, the philosopher argued that after speaking to a lot of string theories, he made the statement that if a bunch of physicists agree on something as being true for a decade, then it must be true. Because physics is what physicists decide to do. And I raised my hand. I said, how can you make sense?
01:21:59
Speaker
I would expect philosophers to give us a litmus test of honesty. It's just like the canary in a cave. They should tell us when truth is not being spoken. And I just couldn't understand how a philosopher could make such a thing. I said there are many examples in history where physicists agreed on something and it was completely wrong. And the only way for us to find out is by experimental evidence.
01:22:23
Speaker
Nature is teaching us. It's a learning experience. And we can all agree that we are the wealthiest people in the world. And if we go to an ATM machine, that's equivalent to doing an experiment and testing that idea. Now we can feel happy until we try to cash the money out of the ATM machine. And then we realize that our ideas were wrong. And how do you tell if someone
01:22:49
Speaker
mentions an idea. How do you tell whether it's a Ponzi scheme or not? Bernie Madoff told a lot of people that if they give him their money, he will give them more in return, irrespective of what the stock market will do. Now, that was a beautiful idea. It appealed to a lot of people. They gave him their money. What else can you expect from people that believe a beautiful idea? They made money and gave it to Bernie Madoff because the idea was so beautiful.
01:23:15
Speaker
And he felt great about it. They felt great about it. But when they wanted to cash out, which was the experiment, he couldn't provide them the money. So this idea turned out to be wrong. And it's not just the nuance of science to say, oh, OK, there is an experimental test, but we can give up on this as long as we are happy and we feel very smart.
01:23:38
Speaker
And we completely agree that we should pursue these questions and just do mathematical gymnastics and give each other awards and feel great about life. And in general, just make the general statement that experiments would be great, but we can't do them right now. And therefore let's not even discuss them. Having a culture of this type is unhealthy for science, because how can you tell the difference between the idea of Bernie Madoff and reality?
01:24:04
Speaker
you can feel very happy until you try to cash it out. And if you don't have an experimental test during your life, then you might spend your life as a physicist on an idea that doesn't really describe reality. And that's a risk that as a physicist, I'm not willing to take. I want to spend my life on ideas that I can test
01:24:26
Speaker
And if they are wrong, I learned something new. And by the way, Einstein was wrong three times in the last decade of his career. He argued that black holes don't exist, gravitational waves don't exist, and quantum mechanics doesn't have spooky action at the distance.
01:24:42
Speaker
But that was part of his work at the frontiers of physics. You can be wrong. There's nothing bad about it. When you explore new territories, you don't always know if you're heading in the right direction. As long as you're doing it with dignity and honesty and integrity, and you are just following what is known at the time, it's part of the scientific pursuit. And that's why people should not ridicule others that think outside the box.
01:25:09
Speaker
As long as they're doing it honestly, and as long as the evidence allows for what they are talking about, that should be considered seriously. And I think it's really important for the health of the scientific endeavor because we are missing on opportunities to discover new things. Just to give you an example, in 1952,
01:25:27
Speaker
There was an astronomer named Otto Strueve. They argued that we might find planets close in to a star like the Sun if they have the mass of Jupiter, because if they are close in, if they are hot Jupiters, heated by the Sun, they're getting very close to the Sun.
01:25:43
Speaker
Then they would tag the Sun like star back and forth in a way that we can measure, or they would occult a significant portion of the area of the star so we can see them when they transit the star. So he argued, let's search for those.
01:25:58
Speaker
And for four decades, no time on major facilities was allocated for such a search because astronomers argued, oh, we pretty much understand why Jupiter formed so far away from the sun, and we shouldn't expect hot Jupiters. And then in 1995, a hot Jupiter was discovered, and the Nobel Prize was given for that a couple of years ago. So
01:26:22
Speaker
You might say, okay, that baby was born. Eventually, even though four decades were wasted, eventually we found the whole Jupiter. And that opened up the field of exoplanets. But my argument is that this is a baby that was born. For each baby like that, there must be many babies that were never born, because it's still being argued that it's not worth the effort.
01:26:46
Speaker
to pursue those frontiers. And that's unfortunate because we are missing opportunities to discover new things. If you are not open to discover new things, you will never discover them.
01:26:59
Speaker
I think that's some great wisdom for many different parts of life. One thing that you mentioned earlier that really caught my attention was you were talking about us becoming technologically advanced and that that would unlock replicators and that replicators could explore the universe and fundamentally change it and life in our local galactic cluster. That was also tied into the search for the meaning for life.
01:27:24
Speaker
And a place where I see these two ideas as intersecting is in the idea of the cosmic endowment. The cosmic endowment is this idea of the total amount of matter and energy that an intelligent species has access to after it begins creating replicators.
01:27:41
Speaker
So since the expansion of the universe is accelerating, there's some number of galaxies which exist outside of a volume that we have access to. So there's a limited amount of energy and matter that we can use for whatever the meaning of life is or whatever good is. So what do you think the cosmic endowment should be used for?
01:28:03
Speaker
Right. So I actually had an exchange with Freeman Dyson on this question. When the accelerating universe was discovered, I wrote a paper saying, you know, when the universe ages by a factor of 10, we will be surrounded by vacuum beyond our galaxy and we will not have contact with other civilizations, with resources. And he wrote back to me and said, we should engage in a cosmic engineering project where
01:28:25
Speaker
We propel our star and come together with other civilizations. And by that, we will not be left alone. And I told him, look, this cosmic engineering project is very ambitious. It's not practical. In fact, there are locations where you have much more resources, a thousand times more than in our Milky Way galaxy. These are called clusters of galaxies.
01:28:47
Speaker
And we can migrate to the center of the nearest cluster of galaxies. And in fact, there might be a lot of journeys taken by advanced civilizations towards clusters of galaxies that would avoid the cosmic expansion. So that's my answer of how to prepare for the cold winter that awaits us.
01:29:08
Speaker
where we will be surrounded by vacuum, it's best to go to the nearest cluster of galaxies where the amount of resources is a thousand times larger. In addition to that, you can imagine that in the future we will build the accelerators that bring particles to energies that far exceed the Large Hadron Collider. And the maximum particle energy that we can imagine
01:29:32
Speaker
is so-called the Planck energy scale. And if you imagine developing our accelerator techniques, you can in principle imagine building an accelerator within the solar system that will reach Planck energies. And if you collide particles at these energies,
01:29:51
Speaker
We don't really know the physics of quantum gravity, but you can imagine a situation where you would irritate the vacuum to a level where the vacuum will start burning up because we know the vacuum has some mass density, some energy density that is causing the accelerated expansions, the so-called cosmological constant.
01:30:11
Speaker
And if you bring the vacuum to a zero energy density state, then you have an excess energy that is just like a burning front. It's the energy you get from a propellant that burns. And you get a domain wall that can expand and consume all the vacuum energy along its path.
01:30:31
Speaker
And of course, it moves at the speed of light. So if you were to be on the path of such a domain world, you would not get an advanced warning and it will burn up everything along its path at the speed of light. So I think if we ever meet advanced civilizations that have the capabilities,
01:30:49
Speaker
of building accelerators that reach the Planck scale. We should sign a treaty, a galactic treaty whereby we will never collide particles approaching that energy in order not to risk everyone else from domain walls that would burn them up. And that's just a matter of cosmic responsibility. I think Max Tegmark caused these death bubbles.
01:31:17
Speaker
Yeah, I mean, these are domain walls that, of course, we have no evidence for, but could be triggered by collisions at the
Life Exploration and Technosignatures
01:31:26
Speaker
Planck scale. And a matter of cosmic responsibility is not to generate these domain walls artificially.
01:31:32
Speaker
So let's pivot into looking for life and space archaeology, which is a cool term that you've created, and looking for them through biosignatures and technosignatures. One place that I'm curious to start here is, since we were just talking about replicators, why is it that we don't find evidence of
01:31:51
Speaker
replicators or large-scale superstructures in other galaxies or in our own galaxy. For example, like a galaxy where half of it has been turned into Dyson spheres, and so it's half illuminated.
01:32:08
Speaker
Right. I mean, presumably such things do not exist. It's actually very difficult to imagine an engineering project that will construct a Dyson sphere. And I think it's much more prudent for an advanced civilization to build small pieces of equipment that go through the vast space in between stars. And that is actually very difficult for us to detect with existing instrumentation.
01:32:35
Speaker
Even a spacecraft as big as a football field would be noticed only when it passes within the Earth's orbit around the sun. That's the only region where pan stars detected objects the size of a mua mua from the reflected sunlight.
01:32:52
Speaker
So we will notice such objects when there are farther than the Earth is from the sun. And the distance to the nearest star is hundreds of thousands of times bigger than that. So most of space could be filled with things passing through it that are not visible to us. A spacecraft the size of a football field is huge. We cannot imagine something much bigger than that. And so I would argue that there could be a lot of things floating through space.
01:33:22
Speaker
Also, as of now, our telescopes were not monitoring for objects that move very fast, a fraction of the speed of light. Obviously, if astronomers saw something moving across the sky so fast, they would dismiss it. They would say it makes no sense. We are looking for asteroids or comets that are moving at a percent of a percent of the speed of light, 10 to the minus 4 of the speed of light.
01:33:47
Speaker
Part of it is our inability to consider possibilities that may exist out there, but most of the fact that we haven't yet detected a lot of these objects is a lack of sensitivity. We can't really see these things when they're far away, unless there are major megastructures, as you pointed out, but I think such engineering projects are unlikely.
01:34:11
Speaker
I'm curious why you feel that engineering projects like that are unlikely. One of the most interesting things you can do is computation. Computation seems like it has something to do with creating consciousness and consciousness seems like it is the bedrock of value given that all value arises in conscious experience.
01:34:30
Speaker
I would imagine using the energy of suns to enable vast amounts of computation is one of the most interesting things that a civilization can do. The objects that they might send out to other solar systems would be at a nanoscale. You send out nanoscale replicators.
01:34:49
Speaker
So they would be even smaller than football fields or smaller than Oumuamua. And then those would begin Dyson sphere engineering projects, right? And so with artificial super intelligence and billions and billions of years to go in the universe, in some sense it feels like we're in the early universe. It feels curious to me why superstructures would be unlikely. I'm not sure I totally understand that.
01:35:12
Speaker
If you think about what the star is, a star is just a nuclear reactor that is bound by gravity. And that doesn't seem to be the optimal system for us to use. It's better to build an artificial nuclear reactor that is not bound by gravity, like a nuclear engine.
01:35:34
Speaker
We're trying to do that. It's not easy to build a fusion reactor on Earth, but we do have a fission reactor. If I were to think about using nuclear energy, I would say it's much better to use artificially made nuclear engines than to use the energy produced by a giant nuclear reactor that nature produced in particular locations.
01:35:58
Speaker
Then you can carry your engine with you. You are always close to it. You can harness all of its energy. And you don't need to put a huge structure around the star, which brings in a lot of engineering difficulties or challenges. So I would be leaning in the direction of having a lot of small systems.
01:36:21
Speaker
sent out rather than a giant system that covers the star. But once again, I would argue that, you know, we should look at the evidence. And there are constraints on Dyson spheres that imply that they're not very common. I should say a couple of weeks ago, I wrote this paper with an undergraduate student in Stanford, Eliza Tabour, that considers
01:36:45
Speaker
the possibility of detecting artificial lights on the night side of Proxima b, the habitable planet around the nearest star, Proxima Centauri, using the James Webb Space Telescope. And we showed that one can put very interesting limits on the level of artificial illumination on the dark side
01:37:04
Speaker
of that planet if there are any city lights out there. And the other technological signatures that one can look for are, for example, industrial pollution in the atmosphere of planet. I wrote a paper about that six years ago. You can look for reflectance that indicates photovoltaic cells on the day side of a planet, which is quite different than the reflectance of rock. It has a spectral edge. You can look for light beams that sweep across the sky. You see them as a flash of light.
01:37:34
Speaker
For example, the light beam used for propulsion, they're using light sails. If you imagine another planetary system where cargoes are being delivered from an Earth-like planet to a Mars-like planet using light sails, the beam of light could cross our line of sight and we could see it as a flash of light. And we can have even correlated with the two planets passing along our line of sight.
01:37:59
Speaker
And so that would give us confidence that indeed it's a light sail traveling between those two planets that we are witnessing. And I wrote a paper about that in 2016. So there are all kinds of technological signatures we can search for, but we need to search for it and we need to put funds towards this.
01:38:17
Speaker
Right, so we have both biosignatures and technosignatures. In terms of biosignatures, you've proposed looking in the clouds of brown dwarfs and green dwarfs. There's looking around our own solar system through looking at the elements in, for example, the atmosphere of Venus. There was phosphine, which we thought could not exist except through biological pathways. And so it's hypothesized that maybe there's some kind of life in the atmosphere of
01:38:43
Speaker
Venus, they're searching other planets for elements that can't exist without life. And then in terms of technosignatures, they're searching for radio waves, which you've talked about, SETI's primary way of looking for life, but it potentially needing a refresh, where it is, for example, looking for artificial light or the remnants of industry. And you've also proposed increasing the threshold of sensitivities for developing imaging that is increasingly sensitive, because Oumuamua was basically
01:39:13
Speaker
Was it at the limit of our telescope's capacity? It was roughly. I mean, it was at the level of sensitivity that allows us a definite detection, but we can't see objects that are much smaller than that or reflect much less light than Omaha did.
Ethics and Morality in Contacting Aliens
01:39:31
Speaker
Yeah, so I should say that all of these both biological signatures and technological signatures are being reviewed in a textbook that I wrote together with my former postdoc, Manasvi Lingam, that is coming out to be published on the 29th of June, 2021. It's more than 1,000 pages long. It's 1,061 pages long, and it has an overview.
01:39:59
Speaker
of the current scientific knowledge we have and expectations we have for biological signatures and technological signatures. The title of the book is Life in the Cosmos, and it's to be published by Harvard University Press. It is meant to be a textbook for scientific research as a follow up on my popular level book, extraterrestrial.
01:40:24
Speaker
So, pivoting a bit here, do you feel that, and we mentioned this a little bit earlier when we were talking about the difference between aliens being interested in us or compelled to reach out to us because of ethical concerns, do you think that advanced alien civilizations can converge on ethics and beneficence?
01:40:41
Speaker
And that's an interesting question. It really depends on their value system. And it also depends on Darwinian selection. The question is what kind of civilizations will be most abundant? If you look at human history very often, the more aggressive, less ethical cultures survive because they were able to destroy the others. So it's not just a matter of
01:41:06
Speaker
which values appear to be more noble, it's the question of which set of values leads to survival in the long run and domination in the long run. And without knowing the full spectrum of possibilities, we can't really assess that. So once again, I would say the smart thing for us to do is be careful. I mean, not transmit too much to the outside world until we figure out if we have neighbors, you know, there was this joke when
01:41:34
Speaker
I Love Lucy was replayed again and again that we might get a message from another planet saying, if you keep replaying reruns of I Love Lucy, we will invade you.
01:41:48
Speaker
I think it's important for us to be careful and figure out first whether there are smarter kids on the block. But having said that, if we ever establish contact or if you find equipment in our neighborhood, the question is what to do. It's a policy question, how to respond to that.
01:42:09
Speaker
And it really depends on the nature of what we find. How much more advanced is the equipment that we uncover? What were the intentions of those who produced it and sent it? These are fundamental questions that will guide our policy and our behavior. And until we find conclusive evidence, we should wait until that moment.
01:42:32
Speaker
So to push back a little bit on the Darwinian argument, right, that's of course a factor where we have this kind of game theoretic expression of genes, the selfish gene trying to propagate itself through generations and that leading to behaviors and how the human being is conditioned by evolution in that way. There's also the sense that over time humanity has become increasingly moral.
01:42:54
Speaker
We're of course doing plenty of things right now that are wrong, but morality seems to be improving over time. And so this leads to a question where, for example, do you think that there is a relationship, a necessary relationship between what is true and what is good? So you need to know more and more true facts in order to, for example, spread throughout the universe.
01:43:16
Speaker
And so if there's a necessary relationship between what is true and what is good, there would be a convergence then also on what is good as truth continues to progress.
01:43:26
Speaker
Yeah, I was asked in a forum when I joked about the fact that I'm seeking intelligence in space in the sky because I don't find it often here on Earth. A member of the audience chuckled and asked me, how do you define an intelligent civilization? And the way I define it is by the guiding principles of science, which is
01:43:50
Speaker
sharing or cooperation on evidence-based knowledge. And the word cooperation is extremely important. I believe that intelligence is marked by cooperation, not by fighting each other because that's
01:44:09
Speaker
a sink for our energy, for our resources that doesn't do any good. So promoting a better future for ourselves through cooperation is a trademark of intelligence. It's also the guiding principle of science. The second component of these guiding principles is evidence-based
01:44:31
Speaker
knowledge. And the way I view science is as an infinite sum game. In economics, you have a zero sum game where if someone makes a profit, another person loses. In science, when we increase the level of knowledge we have, everyone benefits.
01:44:49
Speaker
When a vaccine was developed for COVID-19, everyone on Earth benefited from it. And so science aims to increase the territory of this island of knowledge that we have in the ocean of ignorance that surrounds it. It should be evidence-based, not based on our prejudice.
01:45:09
Speaker
So that's what I hope the future of humanity is. It will be coincident with the guiding principles of science, meaning people will cooperate with each other, nations will cooperate with each other, and try to share evidence-based knowledge. Rather than what's the alternative? The alternative is what we are doing right now, fighting each other, trying to feel superior relative to each other.
01:45:38
Speaker
If you look at human history, you find racism, you find attempts to feel supremacy or elitism or, you know, all kinds of phenomena that stem from a desire to feel superior relative to other people. And that's ridiculous in the big scheme of things, because, you know, we are such an unimportant player in the cosmic stage that we should all feel modest
01:46:06
Speaker
not try to feel superior relative to each other because any advantage that we have relative to each other is really minuscule in the big scheme of things. The color of the skin is completely meaningless. Who cares what the color of the skin is? What significance could that have for the qualities of a person? Yet, a lot of human history is shaped around that. This is not the intelligent way for us to behave as a species.
01:46:34
Speaker
we should focus on the guiding principles of science, which are cooperation and sharing of evidence-based knowledge rather than ridiculing each other, rather than trying to feel superior relative to each other, rather than fighting each other. Let's work together towards a better future and demonstrate that we are intelligent so that we will acquire a place in the club of intelligent species in the Milky Way galaxy.
01:47:02
Speaker
Do you see morality as evidence-based knowledge? I think morality, if you listen to Kant, it's the logical thing to do if you consider a principle such that it will promote the better good of everyone around you. You're basically taking into consideration others and shaping your behavior so that if other people follow the same principles, we will be in a better
01:47:29
Speaker
world. And that to me is a sign of recognizing evidence because the evidence is that you don't live alone. If you are to live alone, if you are the only person on earth, morality loses significance. Not only that
01:47:44
Speaker
There is nobody else for you to consider morality relative to. That's not the issue. The issue is that it's irrelevant. You don't need to consider morality because you're the only person. You can do whatever you want. It has no effect on other people, therefore morality is not relevant. You can do whatever you want. But given the fact that you look at the evidence and you realize that you're not alone, that's evidence, you shape your behavior based on that evidence.
01:48:13
Speaker
And I do think that's evidence-based knowledge, definitely. How do you see axiomatic based knowledge? So for example, axioms of morality and mathematics that build these structures. They're also axioms, for example, of science, like this value of communication and evidence-based reasoning. And axioms and morality are, for example, might be that value and disvalue are innate and intrinsically experienced in consciousness.
01:48:40
Speaker
And then there are axioms and mathematics which motivate and structure that field. So we've talked a lot about science and evidence-based reasoning, but what about knowledge in the philosophical territory which is almost a priori true, like things which we rest fields upon? How do you see that?
01:48:56
Speaker
I do believe that there is room for humanities of the future. The way that philosophy was handled in past centuries should be updated. And let me illustrate that with an example related to your question. Basically, suppose we want to decide about the principles of morality. The way to do that is you can construct a simulation.
01:49:19
Speaker
that includes a lot of people. So in principle, if you include all the ingredients that make people behave one way or another, you know, it doesn't need to be rational reasoning. You can include this some randomness or some other elements that shape human behavior based on their environment. You can include that in the simulation. So let's just imagine a simulation where you put individual people
01:49:42
Speaker
And the way you have an algorithm for the way that they respond to their environment doesn't need to be by rational reasoning. It could be emotional. It could be any other way that you find appropriate. And you have the building blocks. Each of them is a person. And you introduce the randomness that is in the population. And then you run the simulation and you see what happens. OK, so this is just like trying to produce human history artificially.
01:50:09
Speaker
And then you introduce principles for the behavior of people, guiding principles, just like moral principles. So first you let people behave in a completely crazy way, like anything they want, and you will get chaos as the outcome of the simulation. But if you introduce principles of morality, you can see the outcomes that will come out of it. So
01:50:33
Speaker
What I would say is, in principle, in the future, if we have a sophisticated enough computer algorithm to describe behavior of people based on our understanding of how people behave, if we get a better sense of how people behave and respond to their environment, we can design the optimal code by which people should behave such that we will end up in a stable society
01:50:56
Speaker
that is intelligent, that follows the kind of principles I mentioned before, that is older, orderly, and that benefits everyone for a better future. And that's one way of approaching it. And obviously in the past, philosophers could not approach it this way because they didn't have the computer capabilities that we currently have. You can imagine artificial intelligence addressing this task in principle.
01:51:22
Speaker
Right, so you can set moral principles and moral parameters for a system and then evolve the system, right? But the criteria for evaluating the success or not of that system, and those are more like moral axioms. So as a scientist, I'm curious about how you approach, for example, moral axioms that you use for evaluating the evolution of a particular moral system.
01:51:43
Speaker
So my criterion, the one that I think that guides me is maintaining the longevity of the human species. So whatever will keep us for the longest amount of time, of course, bearing in mind that the physical conditions will change on Earth. So within a billion years, the sun will boil off all the oceans on Earth. But let's leave that aside. Let's just ask, suppose you put the people in a box and let them generation after generation.
01:52:12
Speaker
let them follow some principles, what would be the ideal principles to maintain the stability of society and the longevity of the human species. That's what will guide me. I think survival is really the key for maintaining your ideas. That's the precondition, right? So in nature, things that are transient, they go away, they don't survive, and they lose their value.
01:52:35
Speaker
So they have less value. I mean, obviously in the short term, they could have more value, but I care about the long term. And I define the principles based on how long they would allow us to survive. Would you add expected value to that calculation? So it's not just time, but it's actually like the expected reward or expected value over time, right? Because some futures are worse than others. And so maybe we wouldn't want to just have longevity.
01:53:01
Speaker
Yeah, there is the issue of being happy and pleased with the environment that you live in and that could be factored in. But I think the primary principle would be survival because within any population you always will find a fraction of the components that are
01:53:19
Speaker
happy. And it partly depends on the circumstances that they live in, but partly on the way they accept those circumstances. You can live in the barrel and be happy. You can be in a mansion and be unhappy. So it's complicated as to what makes you happy. And I would put that as a secondary condition. I would worry more about social structures that maintain longevity.
01:53:44
Speaker
All right. So on humanity's longevity, we're basically beginning to become technologically advanced. We're facing existential risks in the 21st century from artificial intelligence and nuclear weapons and synthetic biology. And there's UFOs and there's Moa Moa and a lot of really interesting crazy things are going on.
01:54:07
Speaker
I'm curious if you could touch on the challenge of humanity's response and the need for international governance for potentially communicating and encountering alien life.
01:54:17
Speaker
Well, I do think it's extremely important for us to recognize that we belong to the same species. So all the confrontations we often have in politics between nations, they should play a lesser role in guiding our behavior. Cooperation on the global scale, international cooperation, is extremely important.
01:54:39
Speaker
And let me give an example from recent history. There was a virus that came from Wuhan, China. And if the scientists were allowed to gather all the information of how this virus came and what the characteristics of this virus are, then the vaccine would have been developed earlier and it could have saved the lives of many people. So
01:55:01
Speaker
I would say in the global world that we live in today, many of our problems are global, and therefore we should cooperate on the solutions. And that argues against putting borders in our knowledge, trying again to gain superiority of one nation relative to another, but instead
Global Risks and International Cooperation
01:55:23
Speaker
help each other towards a better future and you know it's really the science that provides the glue that that can bind us internationally and I realize you know I'm trying to be realist that it may not happen every anytime soon that people recognize the value of science as the international glue
01:55:44
Speaker
But I hope that eventually we will realize that this is the only path that will bring us to survival, to a better future if we act based on cooperation on evidence-based knowledge.
01:55:59
Speaker
So in 2020, you have an article where you advocate for creating an elite scientific body to advise on global catastrophes. In the Future of Life Institute, we're interested in reducing the risks of existential risks, so ways in which technology can be misused or lead to accidents which lead to the extinction of life on Earth. Could you comment on your perspective on the need for an elite scientific body to advise on existential risk and global catastrophic risk?
01:56:28
Speaker
Well, we noticed that during the pandemic, we were not really prepared, especially in the Western world, because the last major pandemic of this magnitude, the place a century ago, and nobody around today in politics or otherwise was around back then. And as a result, we were not ready. We were not prepared. And I think it's prudent to have an organization that will cultivate cooperation
01:56:55
Speaker
globally, and you know, it could be established by the United Nations, it could be a different body. But once again, it's important for us to plan ahead and avoid catastrophes that could be more damaging than COVID-19. And if you prevent them, it would more than overpay for the investment of funds.
01:57:16
Speaker
Just to give you another example, solar storms. If there was a current event about 150 years ago, it was a big eruption on the sun that brought energetic particles to Earth. Back in the mid-19th century,
01:57:35
Speaker
There wasn't much technological infrastructure, but if the same event would have happened today, it would cost trillions of dollars to the world economy because it would damage power grids and satellites, communication, and so forth, and it would be extremely expensive. So it's important for us to plan ahead. There was, about seven years ago, there was a plume of hot gas that was ejected by the sun, and it just missed
01:58:03
Speaker
the earth and we should be ready for that and build infrastructure that would protect us for such a catastrophe and there are many more so one can go through the risks and some of them are bigger than others some of them are rarer than others.
01:58:18
Speaker
Of course, one of them is the risk from an asteroid hitting the Earth, and the Congress tasked NASA to find all asteroids, all rocks, bigger than the size of Oumuamua, about 140 meters. They wanted NASA to find the 90% of all of those that could potentially intercept Earth and collide with Earth.
01:58:39
Speaker
And the Pan-Star's telescope that we started from, that discovered the Muamua, was funded for finding such near-Earth objects. And the Vera Rubin Observatory will most likely fulfill two-thirds of the congressional task and find 60% of all the near-Earth asteroids bigger than 140 meters. And that shows that the human brain
01:59:05
Speaker
is actually much more useful for survival than the body of a dinosaur because the dinosaurs had huge bodies. And 66 million years ago, you know, they were very proud of themselves. They dominated their environment. They ate grass and were happy. And then from the sky came this giant rock the size of Manhattan Island. And when it hit the ground, they tarnished their ego trip abruptly.
01:59:31
Speaker
And so just to show you that the human brain, even though it's much smaller than the dinosaur body, is much more precious for protecting us because we can design telescopes that would alert us to incoming objects. And that's a catastrophe that obviously we can protect ourselves against by shifting the trajectories of objects heading our way.
01:59:57
Speaker
As a final question, I'm curious, what are the most fundamental questions to you in life and what motivates and excites you from moment to moment as a human being on earth? I've read or heard that you were really interested in existentialism as a kid. So yeah, what are the most foundational or important questions to you?
02:00:17
Speaker
Well, the fundamental issue is that we live for a finite time, a short time. And the question is, what's the meaning of our existence, you see? Because very often we forget that this trip that is very exciting that we're having and could be very stimulating and intriguing is finite. And when I realized that, when both my parents passed away over the past three years, I came to the realization that I don't
02:00:47
Speaker
give a damn of what other people think. Let's focus on the substance. Let's keep our eyes on the ball, not on the audience. And then it was the focusing of my attention to the important things in life that we should appreciate.
02:01:06
Speaker
And then there is this fundamental question of why is life worth living? What are we living life for? And what is the meaning of our life? And, you know, that's it may well be that there is no meaning that we just go through this interesting trip. We are spectators of the universe.
02:01:24
Speaker
And we should enjoy the play while it lasts. But that again argues that we should be modest and behave like spectators rather than trying to shape our immediate environment and feel a sense of deep arrogance as a result of that. That was the view of the dinosaurs before the rock hit them.
02:01:45
Speaker
So in a way, what gives me a sense of meaning for life is just looking at the universe and learning from it. I don't really care about my colleagues. Every morning I jog at 5 AM, I develop this routine during the pandemic, and I enjoy the company of birds, ducks, wild turkeys, and rabbits. And I really enjoy nature left to its own much more than people because
02:02:14
Speaker
There is something true in looking at me. Every morning I see something different. I see today I saw a red bird. I saw the sunrise was completely different than yesterday. So every day you can learn new things and you just need to pay attention, not to feel that you know everything. It's not about us. It's about what is going on around us that we should pay attention to. And once we behave more like kids,
02:02:42
Speaker
appreciating things around us and learning from them, then we would feel happier. And I was asked by the Harvard Gazette, what is the one thing I would like to change about the world?
Conclusion: Meaningful Existence and Curiosity
02:02:52
Speaker
And I said, I would like my colleagues to behave more like kids, basically not being driven by promoting their image, but rather
02:03:00
Speaker
willing to make mistakes, putting skin in the game, and learning regarding life as a learning experience. We might be wrong sometimes, but we are doing our best to figure out when we are wrong.
02:03:14
Speaker
All right, Avi, thank you very much for inspiring this childlike curiosity in science, for also helping to improve the cultural and epistemic situation in science, and also for your work on a Moa Moa and everything to do with extraterrestrials in astronomy. So thank you very much for coming on the podcast. Thanks for having me. I had a great time.
02:03:40
Speaker
Thanks for joining us. If you found this podcast interesting or useful, consider sharing it on social media with friends and subscribing on your preferred podcasting platform. We'll be back again soon with another episode in the FLI podcast.