The following is a conversation with Avi Loeb, an astrophysicist, astronomer and cosmologist at Harvard. He has authored over 800 papers and written eight books, including his latest called Extraterrestrial The First Sign of Intelligent Life Beyond Earth. It'll be released in a couple of weeks ago. Preorder it now to show support for what I think is truly an important book and that it serves as a strong example of a scientist being both rigorous and open-Minded about the question of intelligent alien civilizations in our universe.

Quick mention of our sponsors. Zero fasting app for intermittent fasting element electrolyte drink, sun basket meal delivery service and pessimist's archive history podcast. So the choices fasting app, fasting fuel, fast breaking delicious meals and the history podcast that has very little to do with fasting. Choose wisely, my friends, and if you wish, click the sponsored links below to get a discount to support this podcast. As a side note, let me say a bit more about why Avi's work is so exciting to me and I think to a lot of people.

In 2017, a strange interstellar object now named a more and more fantasy was detected traveling through our solar system.

Based on the evidence we have, it has strange characteristics which made it not like any asteroid, a comet that we've seen before. IVI was one of the only world class scientists who fearlessly suggested that we should be open minded about whether it is naturally made or in fact is an artifact of an intelligent alien civilization. In fact, he suggested that the more likely explanation, given the evidence, is the latter hypothesis. But we also talk about a lot of fascinating mysteries in our universe, including black holes, dark matter, the Big Bang and close the speed of light space travel.

The theme throughout is that in scientific pursuits, the weird things, the anomalies, the idea is that right now are considered taboo, should not be ignored, afford to have a chance at finding the next big breakthrough, the next big paradigm shift. And also, if we are to inspire the world with a power and beauty of science. If you enjoy this thing, subscribe on YouTube, review and have a podcast, follow on Spotify, support on your own or connect with me on Twitter and Friedemann as usual.

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Anyway, subscribe to listen to pessimist's archive website pessimist's that. Go look in the description please, to make sure that the spelling is right or just click the link. I highly recommend this podcast. And now here's my conversation with Avi Loeb. In the introduction to your new book, Extraterrestrial, you write, this book confronts one of the universe's most profound questions Are we alone? Over time, this question has been framed in different ways. Is life here on Earth the only life in the universe?

Are humans, the only sentient intelligence in the vastness of space and time? A better, more precise framing of this question would be this. Throughout the expanse of space and over the lifetime of the universe, are there now or have ever been other sentient civilizations that, like ours, explore the stars and left evidence of their efforts. So let me ask, are we alone?

That's an excellent question.

For me, the answer is sort of clear because I start from the principle of modesty. You know, if we believe that we are alone and special and unique, that shows arrogance. My daughters, when they were infants, they tended to think that they are special, unique, and then they went out to the street and realized that other kids are very much like them. And and then they developed a sense of a better perspective about themselves. And I think the only reason that we are still thinking that we are special is because we have such well enough to find others that might even be better than us.

And, you know, I say that because I look at the newspaper every morning and I see that we do foolish things.

We are not necessarily the most intelligent ones. And if you think about it, if you open a recipe book, you see that out of the same ingredients, you can make very different cakes depending on how you put them together and how you hit them up. And what is the chance that by taking the soup of chemicals that existed on Earth and cooking it one way to get our life, that you got the best cake possible, I mean, we are probably not the sharpest cookie in the jar.

And my question is, I mean, it's pretty obvious to me that we are probably not alone because half of all the sun like stars we know now is astronomers. Half of the sun like stars from the Kepler satellite data have a planet the size of the Earth, roughly at the same distance that the earth is from the sun. And that means that they can have liquid water on their surface and the chemistry of life as we know it. So if you roll the dice billions of times just within the Milky Way galaxy and then you have tens of billions of galaxies like it within the observable volume of the universe, it would be extremely arrogant to think that we are special.

I would think that we are sort of middle of the road, typical forms of life, and that's why nobody pays attention to us.

You know, if you go down the street on a sidewalk and you see in and you don't pay attention or especially respect to that and you just continue to walk. And so I think that we are sort of average, not very interesting, not exciting. So nobody cares about us. We tend to think that we are special, but that's a sign of immaturity and we're very early on in our development.

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

And so if you imagine that a civilization like ours existed around a typical sun like star by now, if they survived, they could be a billion years old. And then imagine a billion years technology. It would look like magic to us, you know, an approximation to God. We wouldn't be able to understand it. And so, in my view, we should be humble. And by the way, we should probably just listen and not speak because there is a risk, right.

If if you are inferior, there is a risk if you speak too loudly and something bad may happen to you.

You mentioned we should be humble also in the sense with the analogy to ants that they might be better than us. So there's a kind of scale there we're talking about in the in the question, you mentioned the word sentient. So sentience or maybe the more basic formulation of that is consciousness. Do you think? Do you think that this thing within us humans, in terms of the typical life form of consciousness is the essential element that permeates other if there's other alien civilizations out there that they have something like consciousness as well?

Or is this I guess I'm asking, can you try to untangle the word sentient? Yeah.

So that's that's a good question. I think what is most abundant, depending on how long it survives.

So if you look at us as an example, we are now we do have conscious and we do have technology, but the technologies that we are developing are also means for our own destruction.

As we can tell, you know, we can change the climate if we are not careful enough, we can go into nuclear wars. So we are developing means for our own destruction through self-inflicted wounds.

And it might well be that creatures like us are not long lived, that the crocodiles on other planets live for billions of years.

They don't destroy themselves. They live naturally. And so if you look around, the most common thing would be dumb animals that live for a long time, you know, not those that have conscious. But in terms of changing the environment, I think since I mean, humans develop tools, they develop the ability to construct technologies that would. Lift us from this planet that we were born in, and that's something animals without a conscious consciousness cannot really do.

And and so in terms of looking for things that are new, that went beyond the circumstances that were born into. I would think that even if they are short lived, these are the creatures that made the biggest difference to their environment and we can search for them, you know, even if they are short lived and most of the civilizations are dead by now.

Yeah, even if that's the case, it's sad to think about, by the way.

Well, but if you look on Earth that, you know, a lot of cultures that exist throughout time and are dead by now, the Mayan culture was very sophisticated, died, but we can find evidence for it and learn about it just by archaeology, digging into the ground, looking and so we can do the same thing in space. Yes.

Look for dead civilizations and perhaps we can learn a lesson why they died and behave better so that we will not share the same fate.

So I think, you know, there is a lesson to be learned from the sky. And by the way, I should also say, if we find that the technology that we have not dreamed of, that we can import to Earth, that may be a better strategy for making a fortune than going to Silicon Valley or going to Wall Street, because you learn you make a jump start into something of the future.

So that's one way to do the leap, is actually to find, to literally discover versus come up with the idea in our own limited human capacity, the cognitive capacity, which would look like it would feel like cheating in an exam where you look over the shoulder of a student next to you.

Yeah, but it's not good on an exam, but it is good when you're coming up with technology that could change the fabric of human civilization. But there is, you know, in my neck of the woods of artificial intelligence, there's a lot of trajectories one can imagine of creating very powerful beings. The technology that's essentially, you know, you can call superintelligence that could achieve space exploration, all those kinds of things without consciousness. Right. Without something that to us humans looks like consciousness.

And there, you know, there is a sad feeling. I have that consciousness, too, in terms of us being humble is a thing we humans take too seriously, that it's we think it's special just because we have it. But it could be a thing that's actually holding us back and some kind of way will be.

So it will be, I should say, something about A.I. because I do think it offers a very important step into the future. If you look at the Old Testament, the Bible, there is this story about Norks arc that you might know about.

Yes. Nor knew about a great flood that is about to endanger or life on Earth. So he decided to build an ark.

And the Bible actually talks about specifically what the size of this ark was, what the dimensions were.

Turns out it was quite similar to one more that we will discuss in a few minutes.

But at any event, he built this ark and he put animals on it so that they were saved from the Great Flood.

Now you can think about doing the same on Earth because there are risks for future catastrophes.

You know, we could have the self-inflicted wounds that we were talking about, like nuclear war, changing the climate, or there could be an asteroid impacting us just like the dinosaurs died. You know, the the dinosaurs didn't have science astronomy. They couldn't have a warning system. But there was this big stone, big rock approach there. It must have been a beautiful sight. Yeah. Just when it was approaching, got very big and then smashed them.

OK, kill them so you could have a catastrophe like that.

Or in a billion years the sun will basically boil off all the oceans on earth and and currently all our eggs in one basket. But we can spread them. It's sort of like the printing press. If you think about it. The revolution that Gutenberg brought is there were very few copies of the Bible at the time, and each of them was precious because it was handwritten. But once the printing press produced multiple copies, you know, if something bad happened to one of the copies, it wasn't a catastrophe.

You know, it wasn't a disaster because you had many more copies that. And so if we have copies of life here on Earth elsewhere, then we avoid the risk of it being eliminated by a single point breakdown, catastrophe. So the question is, can we build Norks spaceship that will carry life as we know now, you might think we have to put elephants and whales and birds on a big spaceship, but that's not true because all you need to know is the DNA making the genetic making of these animals put it on a computer system that has a class A 3D printer so that this CubeSat, which is rather small.

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

Yeah, and it doesn't have to be exact copies of the humans. It can just contain some basic elements of life and then have enough life on board that it could. Reproduce the process of evolution on another place. Right. So, I mean, that also makes you sad, of course, because you confront the mortality of your own little precious consciousness and all your own memories and knowledge and all that stuff. But who cares?

I mean, we are not supposed to care about mine, right? And you care about yours. No, no, I actually don't. You know, I look at the big if you are an astronomer, one thing that you learn from the universe is to be modest because you are not so significant.

I mean, think about it. All these in-person kinks that concord the piece of land on earth. And we're extremely proud. You know, you see these images of kings and emperors that, you know, usually are alpha males and they stand strong and they are very proud of themselves. But if you think about it, there are 10 to the power, 20 planets like the Earth in the observable volume of the universe.

And this view of conquering a piece of land and even conquering all of earth is just like an ant hugging a single grain of sand on the landscape of a huge beach.

That's not very impressive. So you can't be arrogant if you see the big picture. You have to be humble. You know, also, we are short lived, you know, within a hundred years. That's it. Right. So what does it teach you? First, to be humble, modest. You never have significant powers relative to the big scheme of things.

And second, you should appreciate every day that you live. Yes.

And learn about the world. Humble and still grateful.

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

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

Right. So this is the first object that was spotted close to Earth from outside the solar system, and it was found on October 19th, 2017. And at that time, it was receding away from us. And at first, astronomers thought it must be a piece of rock, you know, just like all the asteroids and comets that we have seen from within the solar system. And it just came from another star. I should say that the actual discovery of this object was surprising to me because a decade earlier I wrote the first paper together with Ed Turner in more more remarking that try to predict whether the same telescope that was serving the SkyPan stars from Hawaii would find anything from interstellar space, given what we know about the solar system.

So if you assume that other planetary systems have similar abundance of rocks and you just calculate how many should be ejected into interstellar space, the conclusion is no, we shouldn't find anything with porn stars.

To me, I apologize, probably reveal my stupidity. But it was surprising to me that so few interstellar objects from outside of the solar system have ever been detected or not.

None has been.

You do well, maybe talk about it that there has been one or two rocks since then?

Well, since then there was one called the Borisov. It was discovered by an amateur Russian astronomer, Gennady Borisovna. And that one looked like a comet. Yeah, and just like a comet from within the solar system.

But this is a really important point. Sorry to interrupt your show that it's unlikely that Iraq from another solar system would arrive to ours. Right.

And so the actual detection of this one was surprising by itself to me. Yes. And then but then so at first they thought maybe it's a comet or an asteroid. But then it looked it didn't look like anything we've seen before. Borisov did look like a comet. So people asked me afterwards and said, you know, doesn't it convince you that if Borisov looks like a comet, doesn't convince you that more and more is also natural?

And I said, you know, when I went on the first date with my wife, she looked special to me.

Yes. And since then, I met many women that didn't change my opinion. My especially you know, that's not an argument anyway. So why did why did the A more and more look weird?

Let me explain. So first of all, astronomers monitored the amount of light sunlight that it reflects and it was tumbling, spinning every eight hours. And as it was spinning the brightness that we saw from that direction, we couldn't resolve it because it's tiny, it's about 100 meters, a few hundred feet size of a football field. And we cannot from Earth with existing telescopes, we cannot resolve it. The only way to actually get a photograph of it is to send the camera close to it.

And that was not possible at the time that more and more was discovered because it was already moving away from us faster than any rocket. We can send it sort of like a guest that appeared for dinner. And then by the time we realized that it's weird, the guest is already out the front door into the dark street. Yeah, what we would like to find is an object like it approaching us, because then you can send the camera irrespective of how fast it moves.

And if we were to find it in July 2017, that would have been possible because it was approaching us at that time.

Actually, I was visiting Mount Kalakala in Maui, Hawaii, with my family for vacation at that time in July 2007. But nobody knew at the observatory that there were more and more is very close.

Sad to think about that. We had the opportunity that time. Yes. To send up a camera.

But don't worry. I mean, there would be more. There will be more because, you know, I operate by the Copernican principle, which says we don't live at a special place and we don't live at the special time. And that means, you know, if we survey the sky for a few years and we had sensitivity to this region between us and the sun, and we found this object with punsters, you know, there should be many more that we will find in the future with surveys that might be even better.

Yes. And actually, in three years time scale, that would be the so-called Ellis Usted. That's a survey of the Vera Rubin Observatory that would be much more sensitive and could potentially find and more and more like object every month. OK, so I'm just waiting for that. And the main reason for me to alert everyone to the unusual properties of a moomaw is with the hope that next time around, when we see something that is unusual, we would take a photograph.

What we would get as much evidence as possible, because science is based on evidence, not on prejudice. And we will get back to that theme.

So, anyway, let me let me point out what. Properties, actually, yes, they are engaged in nature. All right, other things, so the light, the amount of light sunlight that was reflected from it was changing over eight hours by a factor of ten, meaning that the area of this object, even though we can't resolve in the area on the sky that reflects sunlight, was bigger by a factor of 10 in some phases as it was tumbling around than in other phases.

So even if you take a piece of paper that is razor thin, you know, there is a very small likelihood that it's exactly eggcorn and getting a factor of 10, changing the area that you see on the sky is huge. It's much more than any it means that the object has an unusual geometry. It's at least a factor of a few more than any of the comets or asteroids that we have seen before.

You mentioned reflectivity. So it's not just the geometry, but the properties of the surface of that thing.

Well, or now if you assume the reflectivity is the same, OK, then it's just geometry. If you assume the reflectivity may change, yes, then it could be a combination of the area that you see and the reflectivity because different directions may reflect differently. But the point is that it's very extreme. Yes. And actually the best fit to the light curve that we saw was of a flat object. Unlike all the cartoons that you have seen of a cigar shaped, a flat object at the 90 percent confidence gives a better model for the way that the light varied.

And it's like flat meaning. Like a pancake. Like a pancake. Exactly.

And so that's the very first unusual property. But to me, it was not unusual enough to think that it might be artificial. It was not significant enough then. There was no cometary tail, no dust, no gas around. This object in the Spitzer Space Telescope really search very deeply for carbon based molecules. There was nothing. So it's definitely not a comet the way people expected it to be.

Can you maybe briefly mention what properties of Comet that you're referring to usually has? Right.

So a comet is a rock that has some water ice on the surface. So you can think of it as an icy rock. Actually, comets were discovered a long time ago, but the first model that was developed for them was by Fred Whipple, who was at Harvard. And I think the legend goes that he got the idea from walking through Harvard Square and seeing during a winter day and seeing these icy rocks, you know, and saw a comet is icy.

Asteroid is it's just the rock is just a rock.

Yeah. So when you have ice on the surface, when the rock gets close to the sun, the sunlight warms it up and the ice sublimates evaporates.

Because the one thing about ice water ice is it doesn't become liquid. If you warm it up in vacuum without an external pressure, it just goes straight into gas. And that's what you see is the tail of a comet. The only way to get liquid water is to have an atmosphere like on Earth that has an external pressure. Only then you get liquid. And that's why it's essential to have an atmosphere to a planet in order to have liquid water and the chemistry of life.

So if you look at Mars, Mars lost its atmosphere and therefore no liquid water on the surface anymore. I mean, there may have been early, and that's what the perseverence survey, the perseverence mission will try to find out whether it had liquid water, whether there was life perhaps on it at the time. But at some point it lost its atmosphere and then the liquid water was gone.

So the only reason that we can live on Earth is because of the atmosphere. But a comet is in vacuum pretty much.

And when it gets warmed up on the surface, the water becomes the water, ice becomes gas, and then you see this cometary tail behind it. In addition to water, there is that there are all kinds of carbon based molecules of dust that comes off the surface and those are detectable.

So it's easy to detect. It's very prominent. You see these cometary tails that look very prominent because they reflect sunlight and you can see them. In fact, it's sometimes difficult to see the nucleus of the comet because it's surrounded and shrouded with. And in this case, there was no trace of anything. Now you might say, OK, it's not. So that's what the community said, OK, it's not no problem. It's still a rock. You know, it's not a comet, but it's just a rock rock, you know?

OK, no problem then. And that's. The thing that convinced me to write about it, and then in June 2018, significantly later, there was a report that, in fact, the object. Exhibited an excess push in addition to the force of gravity, so the son acts on it by gravity, but then there was an extra push on this object that was figured out from the orbit that you can trace. And the question was, what is this excess push?

So for comets, you get the rocket effect when you evaporate gas, you know, just like a jet engine on an airplane, you're a jet engine is very simple. You throw the gas back and it pushes the airplane forward. That's all that's happened. So in a case of a comet, you throw gas in the direction of the sun because it's and then you get a push. OK, so in the case of comets, you can get a push.

But that was cometary tail.

So then people said, oh, wait a second. Is it an asteroid? No, but it behaves like a comet, but it doesn't look like a comet. So what? Well, forget about it. Business as usual.

So that's what I mean by a non gravitational gravitational acceleration. So that's interesting. So like the primary force acting on something like just a rock, like an asteroid would be like you can predict a trajectory based on gravity, based on gravity. And so here there's detected movement that's not cannot be accounted for by the gravity.

If it was a comet, you would need about a tenth of the mass of this comet, the weight of this comet to be evaporated in order to give it.

And there is no sign of that. No sign, 10 percent of the mass evaporating. It's huge. Think about it. The 100 meter size object losing 10 percent of its mass. You can't miss that. And so that's super weird. It's super weird.

What is there good in your mind and possible explanations for? You know, so I operated just like Sherlock Holmes. I said, OK, what are the possibilities? And the only thing I could think so I ruled out everything else and I said it must be the sunlight reflected off it. OK, so the sunlight reflects off the surface and gives it a push, just like you get a push on a sail on a boat, you know, from the wind reflecting off it.

Now, in order for this to be effective, it turns out the object needs to be extremely thin. Mm hmm. It turns out it needs to be less than a millimetre thick. Nature does not produce such things.

So but we produce it because it's called the technology of light sail. So we are for space exploration. We are exploring this technology because it has the benefit of not needing to carry the fuel with the spacecraft.

So you don't have the fuel, you just have it and you just have a sail and it's being pushed either by sunlight or by a laser beam or whatever. So perhaps this is the light side.

So this is actually the same technology with the starship project. Yes. So many people afterwards say, OK, you work on this project. You imagine, you know, it's a pretty good explanation, right? Obviously, my imagination is limited by what I know. So, yes, I you know, I would not deny that, you know, working online sales expanded my ability to imagine this possibility. Yes, but let me offer another interesting anecdote.

In September this year, 2010, I mean, yes, 2020. Yes, there was another object found and it was given the name 20-20 Old by the Minor Planet Center. You know, this is an organization actually in Cambridge, Massachusetts, that gives names to objects, astronomical objects found in the solar system. And they gave it that name 20, 20 years ago because, you know, it looked like an object in the solar system and it moved in an orbit that is similar to the orbit of the Earth, but not the same.

Exactly. And therefore, it was bound to the Sun. But it also exhibited a deviation from what you expect based on gravity. So the astronomers that found it extrapolated back in time and found that in 1966 it intercepted the Earth and then they realized they went to the history books and they realized, oh, there was a mission called Lunar Surveyor, Lunar Lander Surveyor two that had a rocket booster. It was a failed mission, but there was a rocket booster that was kicked into space.

And presumably this is the rocket booster that we are seeing now. This rocket booster was sufficiently hollow and thin for us to recognize that it's pushed by satellite. So here is my point. We can tell from the orbit of an object, obviously, this object didn't have any cometary tail. It was artificially made. We know that it was made by us and it did deviate from an orbit of Iraq. So just by seeing something that doesn't have cometary tail and deviates from an orbit shaped by gravity.

We can tell that it's artificial in the case of a more and more, it couldn't have been sent by humans because it just passed near us for a few months. We know exactly what we were doing it those that at that time. And also it was moving faster than any object that we can launch. And so obviously, it came from outside the solar system. And the question is, who produced it? Now, I should say that when I walk on vacation on the beach, I often see natural objects like seashells that are beautiful.

And I look at them and and every now and then I stumble on a plastic bottle. And that was artificially produced.

And my point is that maybe a more and more was a message in a bottle, and we should say this is simply another window into searching for artifacts from other civilizations.

Where do you think it could have come from and. If it's so OK from a scientific perspective, the narrow minded view will probably talk about throughout is, you know, you kind of want to stick to the things that are naturally originating objects like asteroids and comets. OK, that's the space of possible hypotheses. And then if we expand beyond that, you start to think, OK, these are artificially constructed. And like you just said, it could be by humans, it could be by by whatever that means by some kind of extraterrestrial alien civilizations.

If if it's the alien civilization variety. What is this object then that we're looking at an excellent question and let me lay out, I mean, we don't have enough evidence to tell if we had a photograph, perhaps we would have more information. But there is one other peculiar fact about more and more. Well, other than it was very shiny that I didn't mention, you know, we didn't detect any heat from it. And that implies that it's rather small and shiny.

But the other peculiar fact is that it was it came from a very special frame of reference.

So it's sort of like finding a car in a parking lot, in a public parking lot that, you know, you can't really tell where it came from.

So there is this frame of reference where you average over the motions of all the stars in the neighborhood of the sun.

So you find the so-called local standard of rest of the galaxy. And that's a frame of reference that is obtained by averaging the random motions of all the stars. And the sun is moving relative to that frame at some speed.

But this object was addressed in that frame and only one in 500 stars is so much at rest in that frame. And that's why I was saying it's like a parking lot.

It was parked there and we bumped into it. So the relative speed between the solar system and this object is just because we are moving.

It was sitting still. Now you ask yourself, why is it so unusual in that context? You know why? Because if it was expelled from another planetary system, most likely it will carry the speed of the host star that it came from because it was the most loosely bound.

Objects are in the periphery of the planetary system and they move very slowly relative to the star. And so they carry the when they are ripped apart from the planetary system, most of the objects will have the residual motion of the star rough relative to the star.

But this one was addressed in the law because now one thing I can think of is if there is a grid of road posts, like for navigation system so that you can find your way in the local frame. Yeah, then that would be one percent.

These are like little sensors of this. Fascinating think.

So there could be I mean, not necessarily literally a grid, but just even the in some definition of evenly spread out set of objects like these that are just out there, a lot of them.

Another possibility is that these are relay stations, you know, for communication.

You might think in order to communicate, you need a huge beacon, a very powerful beacon. But it's not true because even on Earth, you know, we have these relay stations. So you have a not so powerful beacon. So it can be heard only out to a limited distance. But then you relay the message. Yes. And it could be one of those. Now, after it collided with the solar system, of course, it got a kick.

So it's just like a billiard ball. You know, we gave it a kick by colliding with.

But most of them are not colliding with stars.

And so that's one possibility. OK, and there should be no lots of them if that's the case.

The other possibility is that it is a probe, you know, that was sent in the direction of the habitable region around the sun to find out if there is life.

Now, it takes tens of thousands of years for such a probe to traverse the solar system from the outer edge of the Oort Cloud all the way to where we are. And, you know, it's a long journey. So when you started the journey from the edge of the solar system to get to us now, you know, we were rather primitive back then. You know, we we still didn't have any technology. There was no reason to visit.

You know, there was grass around and so forth.

But, you know, maybe it is a problem. Uh, so you said ten thousand years as fast as it takes that long. Tens of thousands. Tens of thousands of. Yeah, yeah.

And the other thing I should say is, you know, it could be just and an outer layer of something else, like, you know, something that was ripped apart, like a surface of an instrument that was.

And you can have lots of these pieces, you know, if something breaks, lots of these pieces spread out like space junk and it could be just space junk from an X-ray, from an alien civilization.

Yes.

So it's I can tell you about space junk. Let me guess what what do you mean by space junk?

So I think, you know, you might ask, why aren't they looking for us? One possibility is that we are not interesting, like we were talking about any other possibility.

You know, if there are millions or billions of years into their technological development, they created their own their own habitat.

Their own cocoon where. They feel comfortable, they have everything they need, and it's risky for them to establish communication with each other so they have their own cocoon and they close off, they don't care about anything else.

Now, in that case, you might say, oh, so how can we find about them if they are closed off? The answer is they still have to deposit trash. Right. That that is something from the law of thermodynamics. There must be some production of trash.

And, you know, we can still find about them.

Just like investigative journalists going through the trash cans of celebrities in Hollywood. You know, you can learn about the private lives of those celebrities by looking at.

It's fascinating to think, you know, if we are the ants in this picture, if we if this thing is a water bottle or if it's like a smartphone, like where where on the spectrum of possible objects of speak, because there's a lot of interesting trash like where how interesting is this trash?

Imagine a caveman seeing a cell phone.

The cavemen would think since the caveman played with rocks all of his life, he would say it's the rock, just like my fellow astronomers said. Yes, right, exactly. That is brilliantly put. Actually, as a scientist, do you hope it's a water bottle or a smartphone?

Because I hope it's even more than a smartphone. I hope that it's something that is really sophisticated. Then, yes, I'm the opposite. I feel like I hope it's a water bottle because at least we have a hope with our current set of skills to understand it. Yeah, a caveman has no way of understanding the smartphone. It's like it will be like I feel like a caveman has more to learn from the plastic water bottle than they do from the smartphone.

But suppose we figure it out if we if we, for example, come close to it and learn what it's made of.

And I guess the smartphone is full of like thousands of different technologies that we could probably pick out.

Do you have a sense of where a hypothesis of where is the cocoon that it might have come from?

You know, because the OK, so first of all, you know, the solar system, the outermost edge of the solar system is called the Oort Cloud. It's a cloud of. I see rocks of different sizes that were left over from the formation of the solar system. Yes.

And it's thought to be roughly a ball or a sphere and it's half way the extent of it is roughly halfway to the nearest star.

OK, so you can imagine each planetary system basically touching the Oort cloud of those stars that are near us or touching each other.

Space is full of these billiard balls that are very densely packed. Yes. And what that means is any object that you see, irrespective whether it came from the local standard.

So we said that this object is special because it came from a local standard of rest.

But even if it didn't, you would never be able to trace where it came from because all these other clouds overlap. So if you take some direction in the sky, you will cross as many stars as you have in that direction, like there is no way to tell which all it came from.

So, yes, I didn't realize how densely packed everything was from the perspective of the cloud. And that's really interesting. So, yeah, it could be it could be nearby. Could be very far away.

Yeah. We have no clue.

You said Cocoon and you kind of paint I think in the book.

I read a lot of your articles too on Scientific American, which are brilliant. Some kind of mixing things up in my head a little bit.

But there's what is that cocoon look like? What is a civilization that's able to harness the power of multiple suns, for example, look like when you imagined possible civilizations that are a million years more advanced than us? What do you think that actually looks like?

I think it's very different than we can imagine. By the way, I should start from the point that even biological life, you know, just without technology getting into the game, could look like something we have never seen before. Take, for example, the nearest star, which is Proxima Centauri. It's four and a quarter light years away. So they will know about the results of the 2006 elections only next month in February. Twenty twenty one. It's very far away.

But if you think about it, you know, this this star is a dwarf star and it's much cooler than it's twice as cold as the sun and it emits mostly infrared radiation. So if there are any creatures on the planet close to it, that is habitable. Mm hmm. Which is called Proxima B, there is a planet in the habitable zone in the zone, just at the right distance where in principle, liquid water can be on the surface.

If there are any animals there, they have infrared eyes because our eyes was designed to be sensitive to where most of the sunlight is in the visible range. But Proxima Santarem is mostly infrared, so you know, the nearest to see each other in the nearest star system.

These animals would be quite strange. They would have eyes that detectors of infrared very different from ours. Moreover, this planet, Proxima B faces the star always with the same side, so it has a permanent deeside and a permanent night side.

And obviously the creatures that would evolve on the permanent day side, which is much warmer, would be quite different than those on the permanent night side. Between them, there would be a permanent Sunset Strip. And my daughter said that that's the best opportunity for high value real estate because you will see the sunset. Throughout your life, right, if the sun never sets on this on this trip, so, you know, these worlds are out of our imagination, just even the individual creatures, the sensor suite that they're operating with might be very different, very different.

So I think when we see something like that, we would be shocked not to speak about seeing technology now. So I. I don't even dare to imagine, you know. And I think, you know, obviously we can bury our head in the sand and say it's never aliens, like many of my colleagues say. And it's a self-fulfilling prophecy. If you if you never look, you will never find if you are not ready to find wonderful things, you will never discover them.

And the other thing I would like to say is reality doesn't care whether you ignore it or not. You can ignore reality, but it's still there. Yes. So we can all agree based on Twitter that aliens don't exist, that human mewe was a rock. And we can all agree.

And you will get a lot of likes. They have a big crowd of supporters and everyone will be happy and give each other awards and honors and so forth. But Moomaw might still be an alien artifact.

Who cares what humans agree on? Yeah, there is a reality out there and we have to be modest enough to recognize that we should make our statements based on evidence. Science is not about ourselves. It's not about glorifying our image. It's not about getting Hoeness prizes. You know, a lot of the scientific a lot of the academic activity is geared towards creating your echo chamber where you have students, postdocs repeating your mantras so that your voice is heard loudly so that you can get more hoeness prizes recognition.

That's not the purpose of science. The purpose is to figure out what nature is right. And in the process of doing that, it's a learning experience. You make mistakes. You Einstein made three mistakes at the end of his career. He argued that in the 1930s he argued that black holes don't exist, gravitational waves don't exist, and quantum mechanics doesn't have spooky action at a distance. And all three turned out to be wrong. OK, so the point is that if you work at the frontier of then you make mistakes.

It's inevitable because you can tell what is true or not, and avoiding making mistakes in order to preserve your image makes you extremely boring. OK, you will get a prize, but you will be a boring scientist because you will keep repeating things we already know. If you want to make progress, if you want to innovate, you have to take risks and you have to look at the evidence. It's a dialogue with nature. You don't know the truth in advance.

You let nature tell you, educate you, and then you realize that what you thought before is incorrect. And a lot of my colleagues prefer to be in a state where they have a monologue. You know, if you look at these people that work on string theory, yes, they have a monologue, they know what. And in fact, their monologue is centered on a.. The theater space, which we don't live in now. You know, it's to me, it's just like the Olympics.

You know, you define a hundred meters and you say whoever runs this 100 meters is the best athlete, the fastest, you know, and it's completely arbitrary. You could have decided it would be 50 meters, 20 meters. Who cares?

You just measure the ability of people this way. So you define a.. The space as a space where you do your mathematical gymnastics and then you find who can do it the best and you give jobs based on that. You give prizes.

But as we said before, you know, nature doesn't care about, you know, the prizes that you give to each other. It cares. You know, it has its own reality and we should figure it out. And it's not about us. The scientific activity is about figuring out nature. And sometimes we may be wrong. Our image will not be preserved. But it's that's the fun. You know, I kids explore the world out of curiosity.

And I always want to maintain my childhood curiosity. And I don't care about the labels that I have.

In fact, having tenure is is exactly the opportunity to behave like a child because you can make mistakes.

Yeah.

And I was asked by the Harvard Gazette, the the Pravda of Harvard, what what is the one thing that you would like to change about the world? Yes.

And I said I would like my colleagues to behave more like kids. Yeah. That's the one thing I would like them to do because something bad happens to these kids.

When they become tenured professors, they start to worry about their ego and about themselves more than about the purpose of science, which is curiosity driven figuring.

Out from evidence, evidence is the key. So when an object shows anomalies like Momoa, what's the problem discussing whether it's artificial or not? So there was actually there was a mainstream paper in Nature published saying it must be natural. That's it.

It's unusual, but it must be natural, period. And then at the same time that those means some other mainstream scientists try to explain the properties.

Yes. And they came up with interpretations like it's a dust bunny, you know, the kind that you find in a household, a collection of dust particles pushed by sunlight.

Something we have never seen before or it's a hydrogen iceberg, it actually evaporates like a hydrogen is transparent. You don't see it. And that's why we don't see the commentary again. We have never seen something like that.

In both cases, the objects would not survive the long journey.

We discussed it in a paper that they wrote afterwards. But my point is those that try to explain the unusual properties went into great length at discussing things that we have never seen before.

OK, so even when you think about the natural origin, you have to come up with scenarios that are things that were never seen before. And by the way, they look less plausible to me personally. But my point is, if we discussed things that were never seen before, right, why not discuss why not contemplate an artificial origin? What's the problem? Why do people have this push back? And, you know, I worked on dark matter and we don't know what most of the matter in the universe is.

It's called dark matter. It's just an acronym because we have no clue. We simply don't know. So it could be all kinds of particles. And over the years, people suggested weakly interacting, massive particles, axons, all kinds of particles and experiments were made. They cost hundreds of millions of dollars. They put upper limits constraints that ruled out many of the possibilities that were proposed as natural. Initially, the mainstream community regarded it as a mainstream activity to search the nature of the dark matter.

And nobody complained that it's speculative to consider weakly interacting massive particle. Now I asked you, why is it speculative to consider extraterrestrial technologies?

We have a proof that it exists here on Earth. Yes. We also know that the conditions of of of Earth are reproduced in billions of systems throughout the Milky Way galaxy. So what's more conservative than to say if you arrange for similar conditions, you get the same outcome? How can you imagine this to be special? It's not speculative at all. And nevertheless, it's regarded the periphery. And at the same time, you have physics. Is theoretical physics working on extra dimensions, supersymmetry, super string theory, the multiverse.

Maybe we live in a simulation.

All of these ideas that have no grounding in reality, some of which sound to me like, you know, just like what someone would say science fiction, basically, because you have no way to test it, uh, you know, through experiments and experiments really are key.

It's not just the nuance. You say, OK, forget about the experiment, as some philosophers try to say, you know, if there is a consensus, what's the problem? The point is it's key. Then that's what it's key to have feedback from reality. You know, you can think that you have a billion dollar or that you are more rich than, you know, Elon Musk.

That's fine. You can feel very happy about it. You can talk about it with your friends. And all of you will be happy and think about what you can do with the money. Then you go to an ATM machine and you make an experiment. You check how much money you have in your checking account. And if it turns out that, you know, you don't have much, you can you can materialize your dreams. OK, so you realize you have a reality check.

And my point is, without experiments giving you a reality check, without the ATM machine showing you whether your ideas are bankrupt or not, without putting skin in the game and by skin in the game, I mean, don't just talk about theoretical ideas, make them testable. If you don't make them testable, they are worthless. That just like theology, that is not testable. By the way, theology has some tests.

Let me give you three examples. Yes. It turns out that my book already inspired the Ph.D. student at Harvard in the English department to pursue a Ph.D. in that direction, and she invited me to the the exam a couple of months ago. And in the exam, one of the examiners, the professor, asked her. Do you know why Giordano Bruno was burned at the stake and she said no?

I think it's because he was an obnoxious guy and irritated a lot of people.

Yes, which is true. But the professor said, no, it's because Giordano Bruno said that other stars are just like the sun. And they could have a planet like the earth around them. That could host life. And that was offensive to the church, why was it offensive? Because there is the possibility that this life sinned, OK? And if that life sinned on planets around other stars, it should have been saved by Christ. And then you need multiple copies of Christ, and that's unacceptable.

How can you have duplicates of Christ? And so they burned the guy.

It was about that. OK, I'm just like loading this all in, because that's kind of brilliant. So he was actually already into this, not just about the stars anticipating that there could be other life forms, like why if the star if there's other stars, why would it be special? Why would ask to be special? He was making the right argument and he would just follow that all along to say, like there should be other earth, like places should be on the line and then just copies of Christ.

Yes. So that was offensive. So I said I said to that. I said to the professor, I said, great. You know, I wanted to introduce some scientific tone to the discussion. And I said, this is great, because now you basically laid the foundation for an experimental test of this theology. What is the test? We now know that other stars like The Sun and we know they have planets like the Earth around them. So suppose we find life there and we figure out that they sinned.

Then we asked them, did you witness Christ? And if they say no, it means that this this theology is ruled out. So there is an experimental test for this test.

Number one, another experimental test, you know, in the Bible, you know, in the Old Testament, Abraham.

Was her the voice, the voice of God to sacrifice. His son, right, only son, and that's what the story says now suppose Abraham, my name, by the way, had a voice memo up on his cell phone. Yes, he could have pressed this up and recorded The Voice of God, and that would have been experimental evidence that God exists. Right. Fortunately, he didn't. But it's an experimental test. Right? There is a third example I should tell, and that is Elie Wiesel attributed this story to Martin Buber.

But it's not clear whether it's true or not. At an event, the story goes that Martin Buber know he was a philosopher and he said, you know, the Christians argue that Jesus, you know, the Messiah arrived already and will come back again in the future. The Jews argue the Messiah never came and will arrive in the future. So he said, why argue? Both sides agree that the Messiah will arrive in the future. When the Messiah arrives, we can ask whether he or she came before, visited us and then figure it out on one side.

So again, experimental test of theology. Yes. So even theology, if it puts.

A skin in the game, you know, if it makes a prediction, could be tested, right? So why can't string theory test themselves or why can't, you know, even cosmic inflation? That's another model that, you know, one of the inventors from MIT, Alan Guth, argues that it's not falsifiable. I my point is a theory that cannot be falsified is not helpful because it means that you can't make progress. You cannot improve your understanding of nature.

The only way for us to learn about nature is by making hypotheses that are testable, doing the experiments and learning whether we are correct or not.

So be and coupled that with accuracy and open mindedness, that allows us to explore all kinds of possible hypotheses, but always the pursuit of those.

The scientific rigor around those hypotheses is ultimately get evidence.

Knowledge is of what nature is should be a dialogue with nature. Yes. Rather than a monologue. Beautifully put. Can we talk a little bit about the Drake equation, another framework from which to have this kind of discussion about possible civilizations out there? So let me ask within the context of the Drake equation or maybe bigger, how many alien civilizations do you think are out there?

Well, it's hard to tell because the Drake Equation is, again, quantifying our ignorance. It's just a set of factors.

The only one that we know are actually true that we know quite well is the rate of star formation in the Milky Way galaxy, which we measured by now, and the frequency of planets like the Earth around stars.

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

We can look for artifacts that they left behind, even even if they are dead.

You can look for industrial pollution in the atmosphere. So why do I bring this up again to show you the conservatism of the mainstream in astronomy? And by the way, I have leadership positions. I was chair of the astronomy department for nine years, the longest serving chair at Harvard, and I'm the chair of the board on Physics and Astronomy of the National Academies Primary and board. And, you know, I'm director of two centers at Harvard and so forth.

So I do represent the community in various ways.

But at the same time, you know, I'm a little bit disappointed by the conservatism that people have. And so let me give you an illustration of that. So the astronomy community actually is going right now through the process of defining its goals for the next decade. And there are proposals for telescopes that would cost billions of dollars and whose goal is to find evidence for oxygen in the atmosphere of planets around other stars with the idea that this would be a marker, a signature of life.

Now, the problem with that is Earth didn't have much oxygen in its atmosphere for the first two billion years.

Roughly half of, you know, half of its life didn't have much oxygen, but it had life. It had microbial life. It's not it's not clear yet as of yet what the origin is for the rise in the oxygen level after two billion years, about two point four billion years ago.

But we know that a planet can have life without oxygen in the atmosphere because Earth did it. The second problem with this approach is that you can have oxygen from natural processes. You can break water molecules and make oxygen. Right. So even if you find it, it will never tell you that for sure. Life exists there. And so even with these billions of dollars, the mainstream community will never be confident.

But whether there is life there now, how can it be confident?

There is actually a way if instead of looking with the same instruments, if you look for molecules that indicate industrial pollution, for example, CFC that are produced by refrigerating systems or industries here on Earth, that the ozone layer, you know, you can search for that.

And I wrote a paper five years ago suggesting that now what's the problem? You can just tell NASA, I want to build this telescope to search for oxygen, but also for industrial pollution. Nobody would say that because it sounds like. You know, on the periphery of the field and I ask you why was hilarious, because that's exactly I mean, be is quite brilliant. I mean it because there's a really strong signal. And if life if there is alien civilizations out there, then they're probably going to be many of them and they're probably going to be more advanced than us.

And they're probably going to have something like industrial pollution, which would be a much stronger signal than some basic gas, which could have a lot of different explanations. So like somebody like oxygen or I mean, I don't you know, we could talk about signs of life on Venus and so on.

But like, if you want a strong signal, it would be all of our garbage is not the position you have to understand. We think of pollution as the problem. But on a planet that was too cold, for example, to have a comfortable life on it, you can imagine terraforming it and putting a blanket of polluting gases such that it will be warmer and that would be a positive change.

So if an industrial or technological civilization wants to terraform a planet that otherwise is too cold for them, they will do it.

So what's the problem of defining it as a search goal, using the same technologies? The problem is that there is a taboo. We are not supposed to discuss extraterrestrial intelligence. There is no funding for this subject, not much.

Very little and young people because of the bullying on Twitter and all, all the social media and elsewhere, young people with talent that are curious about this. These questions do not enter this field of study. And obviously, if you step on the grass, it will never grow. Right. So if you don't give funding, obviously, you know, the mainstream community says, look, nothing was discovered so far. Obviously, nothing would be discovered if talented people go to other never you never search for it well enough.

You will never find anything. I mean, look at gravitational wave astrophysics. It's a completely new window into the universe pioneered by Ray Weiss at MIT.

And at first it was ridiculed. And thanks to some administrators at the National Science Foundation, it received funding despite the fact that the mainstream of the astronomy community was very resistant yes to it.

And now it's considered a frontier. So all these people that I remember as a postdoc, young post, these people that bash this field, said bad things about, you know, said nothing will come out of it. Now they say, oh, yeah, of course, you know, the Nobel Prize was given to the you know, to the lack of collaboration. Of course, now they're they're supportive of it.

But my point is, if if if you suppress innovation early on, there are lots of missed opportunities. The discovery of exoplanets is one example. You know, in 1952, there was an astronomer called the named the Auto Struve, and he wrote a paper saying, why don't we search for Jupiter like planets close to their host star? Because if they are close enough, they would move the star back and forth and we can detect the signal, Miss.

OK, and so astronomers on time allocation committees of telescopes for 40 years argued this is not possible because we know why Jupiter resides so far from the sun.

You cannot have Jupiter so close because there is this region where ice forms far from the sun and beyond that region is where Jupiter like planets, can form. There was a theory behind it which ended up being wrong by not by today's standards.

But anyway, they did not give time on telescopes to search for such systems until the first system was discovered four decades after this paper and the Nobel Prize was awarded to that just a couple of years ago.

And you ask yourself, OK, so, you know, science still made progress. What's the problem? The problem is that this baby came out barely, you know, and there was a delay of four decades. So the progress was delayed. And I wonder how many babies were not born because of this resistance. So there must be ideas that are as good as this one that were suppressed because they were bullied, because people ridiculed them. That we're actually good ideas and these are missed opportunities, babies that were never born.

Yes.

And, you know, I'm willing to push this frontier of the search for technologies or technological signatures of other civilization because, you know, when I was young, I was in the military in Israel. It's obligatory to serve. And there was this saying that, you know, one of the soldiers sometimes has to put his body on the barbed wire so that others can go through.

And I'm willing to suffer the pain so that, you know, younger people in the future will be able to speak freely about the possibility that some of the anomalies we find in the sky are due to technological signatures.

And it's quite obvious. This is why I like the folks in artificial intelligence space. Elon Musk and a few others speak about this and they look at the long arc. They say, like what? You know, this kind of you know, you can call it like first principles thinking or you can call anything.

It really is like if we just zumar from our current bickering and our current, like, discussions and what science is doing and look at the long arc of the trajectory we're headed at, which questions are obviously fundamental to science and it should be asked and which is the space of hypotheses we should be exploring.

And like exoplanets is a really good example of one that was like an obvious one. I recently talked to Sarah Seager and it was very taboo. She was starting out to work on an exoplanet and that was even in the 90s. And like it's obvious, should not be a taboo subject to me. I mean, I'm probably Egnar, but to me, exoplanets seems like it's ridiculous that I would ever be a taboo subject. To not fund, to not explore has very.

But even for her, it's now taboo to say. Like what you know, to to look for industrial pollution. Right, right. I find that ridiculous if you want to take the next step. It's ridiculous for another reason. Yes. Not because of just the scientific benefits that we might have by exploring it, but because the public cares about these questions.

Yes. And the public funds science. So how dare the scientists shy away from addressing these questions if they have the technology to do it?

It's like saying I don't want to look through Galileo's telescope. It's exactly the same. You have the technology to explore this question, to find evidence, and you shy away from it. You might ask, why do people shy away from it? Yes, and perhaps it's because of the fact that there is science fiction. I'm not a fan of science fiction because it has an element to it that violates the laws of physics in many of the books and the films.

And I cannot enjoy these things when I see the laws of physics violated.

But who cares that, you know, the fact that there is science fiction? I mean, if you have the scientific methodology to address the same subject, I don't care that other people, you know, spoke nonsense about this subject or said things that make no sense. Who cares? You do your scientific work just like you explore the dark matter. You explore the possibility that Momoa is an artifact. You just look for evidence and try to deduce what what it means.

And I have no problem with doing that. To me, it sounds like any other scientific question that we have and given the public's interest, we have an obligation to do that. By the way, science to me is not an occupation of the elite. It doesn't allow me to feel superior to other humans that are unable to understand the math. To me, it's a it's a way of life. You know, if there is a problem in the fosset or in the pipe at home, I try to figure out what the problem is.

And with a plumber, we figure it out and, you know, we look at the clues and the same thing in science.

You know, you look at the evidence, you try to figure out what it means. It's common sense in a way, and then it shouldn't be regarded as something removed from the public.

It should be a reflection of the public's interest. And I think it's actually a crime to resist the public. If the public says, I care about this and you say, no, no, no, that's not sophisticated enough for me. I want to do intellectual gymnastics on a.. The sitter space.

To me, that's a crime. Yes, I 100 percent agree. So it's hilarious that the very.

Not hilarious, it's sad that people who are trained in the scientific community to have the tools to explore this world, to be children, to be the most effective at being children, are the ones that resist being children the most.

But there is a large number of people that embrace the childlike wonder about the world and may not necessarily have the tools to do it. That's the more general public.

And so, you know, I wonder if I could ask you and talk to you a little bit about, you know, UFO sightings, that there's people, you know, quote unquote, believers, you know, there's hundreds of thousands of UFO sightings.

And, you know, I've, you know, consumed some of the things that people have said about it. And one thing I really like about it is how excited they are by the possibility, by it's almost like this childlike wonder about the world out there. They're not it's not a fear. It's an excitement.

Do you think because we're talking about this possibly extraterrestrial object that visited that flew by Earth, do you think it's possible that out of those hundreds of thousands of UFO sightings. One is an actual one or some number is an actual sighting of a non-human, some alien technology, and there we're not we did not. We're too close minded. To to look and to see, I think, to answer this question, we need better evidence. My starting point, as I said, out of modesty, is that we are not particularly interesting.

And therefore, I would agree I would be hard pressed to imagine that someone wants to really spy on us. So I would think, you know, as a starting point that we don't deserve attention and we shouldn't expect someone. But who knows?

Now, the problem that I have with UFO sighting reports is that, you know, 50 years ago there were some reports of fuzzy images, you know, sorta like things are by now our technologies are much better. Our cameras are much more sensitive. These fuzzy images should have turned into crisp, clear images of things that we are confident about, and they haven't turned that way. It's always on the borderline of believability. And because of that, I believe that it might be most likely artifacts of our instruments or some natural phenomena that we are unable to understand.

Now, of course, the reason you need you must examine those. If, for example, pilots report about them or the military finds evidence for them, is because it may pose a national security threat. If another country has technologies that we don't know about and they're spying on us, we need to know about it.

And therefore, we should examine everything that looks unusual. But to associate it with an alien life is a little too far for me until we have evidence that stands up to the level of scientific credence that we are 100 percent sure that, you know, from multiple detectors and, you know, through a scientific process.

Now, again, if the scientific community shies away from these reports, we will never have that. It's like saying I don't want to take photographs of something because I know what it is. Then you will never know what it is.

But I think if some scientist if grunts let's put it this way, funding will be given to scientists to follow on some of these reports and use scientific instruments that are capable of detecting those sightings with much better resolution, with much better information. That would be great because it will clarify the matter. You know, these are not, as you said, you know, hundreds of thousands. These are not once in a lifetime events. So it's possible to take scientific instrumentation and explore, go to the ocean.

Whether, you know, someone reported that there are frequent events that are unusual and check it out, do a scientific experiment. What's the purpose? Why not why only do experiments deep into the ocean and look at the ocean oceanography or do other things? You know, we can do scientific investigation of these sightings and figure out what what they mean.

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

Yeah, we to be humble and acknowledge that we're not that interesting. It's kind of you're making me realize that because it's so taboo that the people that have the equipment, meaning and we're not just talking, everybody has cameras now, but to have a large scale like sensor network that collects data that regularly collects, just like we look at whether we're collecting information. And then we can then access that information when there is reports and like have it not be a taboo thing where there's like millions or billions of dollars funding this effort.

That, by the way, inspires millions of people. This is exactly what you're talking about. It's like is the scientific community is afraid of a topic that inspires millions of people. It's absurd.

But if you put blinders on your eyes, you don't see it. Yeah, right. I should say that we do have meteors that we see.

These are rocks that by chance happen to collide with the Earth.

And they if they are small, they burn up in the atmosphere. But if they're big enough, uh, tens of meters or more, hundreds of meters, the outer layer burns up. But then the core of the object makes it through. And this is our chance of putting our hands around an object if this meteor came from interstellar space. So one path of discovery is to search for interstellar meteors. And with the student of mine, we actually looked through the record and we thought that we found one example of a meteor that was reported that might have come from interstellar space.

And then another approach is, for example, to look at the moon. The moon is different from the earth in the sense that it doesn't have an atmosphere. So objects do not burn up on their way to it, it's sort of like a museum, it collects everything that comes rocks from outer space. And there is no geological activity on the moon. So on Earth, every hundred million years, you know, we could have had computer terminals on Earth.

That could have been a civilization like ours with electronic equipment. Yes. More than 100 million years ago. And it's completely lost. You cannot excavate and find the evidence for it because in archaeological digs, because the earth is being mixed on these timescales and everything that was on the surface more than 100 million years ago is buried deep inside the Earth right now because of geological activity.

Fascinating to think about, by the way. But on the moon, this doesn't happen.

The only thing that happens on the moon is you have objects impacting the moon and they go 10 meters deep. So they produce some dust. But the moon keeps everything.

It's like a museum keeps everything on the surface.

So if we go to the moon, I would highly recommend regarding it as an archaeological site. Yes. And looking for objects that are strange, maybe collected some trash of interstellar space.

If we could just linger on that and the Drake Equation for a little bit, we kind of talked about there's a lot of uncertainty in the parameters and ah, and in the Drake equation itself is very limited.

But I think the parameters are interesting in themselves, even if it's limited, because I think each one is within the reach of science. Right. Did you get the evidence for. I mean, what a few I find really interesting. Interesting. You get your comment on the one with the most variance. I would say from my perspective, is the length that civilizations last. How we define that in the Drake equation is the length of how long you're communicating, just transmitting, just like you said that that might that's a wrong way to think about it, because we can be detecting some other outputted associations, except for just a few, which is defined broadly.

How long those civilizations last. Do you have a sense of how long that might last? Like what? What are the great filters that might destroy civilizations that we should be thinking about? What is in what? How can science give us more hints about this topic?

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

Yes, right. You're saying I'm not special. You know, I find conditions here. They exist everywhere. Yes. So if you adopt the Copernican principle, you basically say. Our civilization transmitted radio signals for 100 years, roughly. So probably it would last another hundred or a few hundred, and that's it. Because we don't live at a special time, so that's, you know, well, of course, if we get our act together. And we somehow start to cooperate rather than fighting each other, killing each other, you know, wasting a lot of resources on things that would destroy our planet.

Maybe we can lengthen that period if we get smarter. But. The that the most natural assumption is to say that we will live into the future as much as we lived from the time that we start to develop the means for our own destruction, the technologies we have, which is quite pessimistic, I must say. So several centuries, that's what I would give.

Not unless we get our act, unless we become more intelligent than the newspapers report every day. OK, point number one second. And by the way, this is relevant, I should say, because there was a report about, uh, perhaps the radio signal detected from Proxima Centauri.

What do you make of that signal? Oh, I think it's an Australian guy with a cell phone next to the observatory or something like that because it was the Parkes telescope in Australia.

OK. It's like Australia. Yeah, OK. So it's not a human created noise. Yeah.

Which is always the worry because actually the same observatory, the Parkes Observatory detected a couple of years ago some signal and then they realised that it comes back at lunch lunchtime. Yes.

And they said, OK, what could it be? And then they figured out that it must be the microwave oven in the observatory because someone was opening it before it finished and it was creating this radio signal that they detected with a telescope every lunchtime. So just as a cautionary remark, but the reason I think it's human made without getting to the technical details is because of this very short window by which we were transmitting radio signals out of the lifetime of the earth.

You know, they said one hundred years out of four and a half billion years that the earth existed.

So what's the chance that another civilisation between civilisations of ours is transmitting radio signals? Exactly the time that we are looking with our radio telescopes.

Yeah.

Ten to the minus seven, you know, so and the other the other argument they have that is, is that they detected it in a very narrow band of frequencies.

And that makes it and, you know, it cannot be through natural processes, very narrow band, just like some radio transmissions that we produce.

But if it were to come from the habitable zone, from a transmitter on the surface of Proxima B, this is the planet that orbits Proxima Centauri.

Then I calculated that the frequency would drift through the Doppler effect. You know, just like when you hear a siren on the street, you know, when the car approaches you, it has a different pitch than when it goes away from you.

That's the Doppler effect. And when the planet orbits the star Proxima Centauri, you would see or detect a different frequency when the planet approaches us as compared to when it recedes. So there should be a frequency drift just because of the motion of the planet. And I calculated that it it must be much bigger than than observed. So it cannot just be a transmitter sitting on the planet and sending in our direction a radio signal unless they want to cancel the Doppler effect.

But then they need to know about us because in a different direction it will not be only now direction they can concentrate perfectly.

So there is this direction of Proxima Centauri. But I have a problem imagining a transmitter on the surface of a planet in the habitable zone emitting it.

But my main issue is really with the likelihood, given what we know about ourself.

Right, in terms of the duration of the Copernican principle. Yeah. So nevertheless, this particular signal is likely to be human interference. Perhaps. But do you find a proxima be interesting or the more general question is, do you think we humans will venture out into outside our solar system and potentially colonize other habitable planets?

Actually, I am involved in a project whose goal is to develop the technology that would allow us to leave the solar system and visit the nearest stars. And that is called the Star Shot in 2015 and May 2015, an entrepreneur from Silicon Valley, Yuri Milner, came to my office at Harvard and said, Would you be interested in leading a project that would do that in our lifetime? Because as we discussed before, to traverse those distances, you know, with existing rockets would take tens of thousands of years.

And, you know, that's too long. You know, for example, to get to Proxima Centauri with the kind of spacecraft that we already sent, like New Horizons or Voyager one, Voyager two you need you need to send them when the first humans left Africa.

So they would arrive there now. Yes, and, you know, that's a long time to wait. So you really wanted to do it within our lifetime?

Yes, 10, 20 years. Meaning it has to move at a fraction of the speed of light. So can we send a spacecraft that would be moving at a fraction of the speed of light? And I said, let me look into that for six months. And with my students and postdocs, we arrived to the conclusion that the only technology that can do that is the light cell technology.

Where can you explain it? You basically produce a very powerful laser beam on Earth so you can collect sunlight and with the photovoltaic cells or whatever, and then convert it into, uh, stored energy and then produce a very powerful laser beam that is 100 gigawatt and focus it on a cell in space that is roughly the size of a person, a couple of meters, a few meters that weighs only a gram or a few grams very thin. And through the math, you can show that you can propel such a cell.

If you shine on it for a few minutes, it will traverse the distance that is five times the distance to the moon and it will get to a fifth of the speed of light.

Sounds crazy, but I've talked to a bunch of people and they're like, I know it sounds crazy, but it's actually it will work.

This is one of those is just beautiful.

I mean, this is this is science. And the point is, people didn't get excited about space since the Apollo era.

And it's about time for us to go into space. A couple of months ago, I was asked to participate in a debate organized by IBM and Bloomberg News. And the discussion centered on the question, is the space race between the US and China good for humanity? Oh, interesting.

And all the other debaters were worried about the military threats. Yeah. And I just couldn't understand what they're talking about because military threats come from hovering above the surface of the earth.

Right. And we live on a two dimensional surface. We live on the surface of the earth. But space is not about the third dimension getting far from earth. So if you go to Mars or you go to a star, another star, there is no military threat. What are we talking about? Space is all about, you know, feeling that, you know, we are one civilization, in fact, not fighting each other and just going far and having aspirations for something that goes beyond military threat.

Yeah. So why would we be worried that the space race will lead?

That's actually brilliant. I didn't you know, there's something in our discourse about the space. Race is sometimes made synonymous with like the Cold War or something like that in life or with wars.

But really, yeah, there is a lot of ego tied up in that. I remember. I mean, it's still still to this day, there's a lot of pride that Russians, the Soviet Union was the first to space and there's a lot of pride in the American side that the first on the moon. But yeah, you're exactly right. There's no aggression. There's no wars.

And beyond that, if you think about the global economy right now, there is a commercial interest. That's why Jeff Bezos and Elon Musk are interesting about, you know, Mars. And so there is a commercial interest which is international. It's not it's driven by money, not by by pride. And, you know, nations can sign treaties. First of all, there are lots of treaties that were signed even before the First World War and the Second World War and the World War took place.

So who cares? You know, like humans, treaties do not safeguard anything, you know? But beyond that, even if nations signed treaties about space exploration, you might still find commercial entities that will find a way to get their launches. And, you know, so I think we should rethink space. It has nothing to do with national pride. Once again, nothing to do with our egos. It's about exploration. And the biggest problem, I think, to human in human history is that it is that humans tend to think about egos and about their their own personal image rather than look at the big picture.

You know, we will not be around for long.

We are just occupying a small space right now.

Let's move out of this. You know, the way that Oscar Wilde said I think is the best. He said all of us are in the gutters, but some of us are looking at the stars and the more of us are looking at the stars, the like they are. Where are to to this for this thing, for this little experiment we have going on to last last a while as opposed to end too quickly. I mean, it's not just the.

Our science of being humble, it's about the survival of the human species as being is being humble to me, it's incredibly inspiring. The Stasha project of I mean, there's something magical about being able to go to another habitable planet and take a picture even I mean, within our lifetime.

I mean, that would create the technology to which I could tell you how it was conceived.

So I was at the time. So after six months passed after the visit of your amila, I was usually I go in December, during the winter break, I go to Israel. I used to go to see my family. And, uh, I get a phone call just before the weekend started. I get the phone call. Uh, Uri would like you to present your concept in two weeks at his home. And I said, well, thank you for letting me know because I'm actually out of the door of the hotel to go to a goat farm in the Negev in the southern part of Israel, because my wife wanted to have sort of, uh, to go to a place that is removed from civilization, so to speak.

So we went to that goat farm. And, you know, I need to make the presentation and there was no Internet connectivity except in the office of the goat farm. So the following morning at six am I sit with my back to the office of that goat farm looking at goats that were newly born and they're typing into my laptop. The presentation, you know, the PowerPoint presentation about, you know, our ambitions for visiting the nearest star. Yes.

And that was very surreal to me that, you know, looks like our origins is in many ways this very primitive origins and our dreams of looking at that as being. So that is incredibly inspiring to me. But it's also inspiring of putting humans onto other moons or planets. I still find going to the moon really exciting. I don't know, maybe I'm just a sucker for it, but it's really exciting. And Mars, which is a new place, a new planet, another planet that might have life.

I mean, there's something magical to that or some traces of previous life.

You might think that humans cannot really survive and there are risks by going there. But my point is. You know, we started from Africa and we got to apartment buildings in Manhattan, right? It's a very different environment from the jungles to live in an apartment building, you know, a small cubicle.

And, you know, it took tens of thousands of years. But humans adapted, right. So why couldn't humans also make the leap and adapt to a habitat in space, you know?

Now you can build a platform that would look like an apartment building in the Bronx or somewhere, but have inside of it everything that humans need.

Yes. And just like the space station, but bigger and it will be a platform in space. And the advantage of that is if something bad happens on Earth, you have that complex where humans live and you can also move it back and forth depending on how bright the sun gets, because, you know, within within a billion years, within a billion years, the sun would be too hot and it will boil off all the oceans on Earth. So we cannot stay here for more than a billion years, that's for sure.

Yes.

So that's a billion years from now. I prefer like shorter term deadlines. And so in that's I mean, there's a lot of threats that we're facing currently. Do you find exciting the possibility of, you know, landing on Mars and starting little like building a Manhattan style apartment building on Mars and humans occupying it? Do you think from a scientific and engineering perspective, that's a that's a worthy pursuit?

I think it's worthy.

But the real issue that is often underplayed is the risk to the human body from cosmic rays. These are energetic particles and we are protected from them by the magnetic field around the earth that blocks them. But if you go to Mars, where there is no such magnetic field to block them, then, you know, a significant fraction of the brain cells in your your head will be damaged within a year. And the consequences of that are not clear.

I mean, it's quite possible that humans cannot really survive on the surface. Now, it may mean that we need to dig tunnels, go underground or create some protection. This is something that can be engineered. Yes. And, you know, we can start from the moon and then move to Mars. That would be a natural progression. But it's a big issue that needs to be dealt with. I don't think, you know, it's a showstopper.

I think we can overcome it.

But, you know, just like anything in science and technology, you have to work on it for a while to figure out solutions. And but it's not as rosy as Elon Musk talks about. I mean, you know, Musk can obviously be optimistic. I think eventually it will boil down to figuring out how to cope with this risk, the health risks.

I mean, in defense of optimism, I.

I find that at least a correlation, if not their best friend's optimism and open mindedness is that it's a necessary precondition to talks to do to try crazy things. And in that sense, they're the sense I have about going to Mars. If we use today's logic of what kind of benefits we'll get from that, we're never going to go and make most decisions we make in life. Most decisions we've made as a human species are irrational.

If you just if you look at just today, but if you look at the long arc and the possibilities that it might bring, just like humans left Europe and Europe and and by the way, it was for everybody, but it was a commercial interests that drove that and for trade.

And, you know, it might happen again in this context. You have people like Jeff Bezos and Elon Musk that are commercially driven to go to space.

Yes, but it doesn't mean that what we will ultimately find is not new worlds, you know, that have nothing, you know, have much more to offer than just commercial interests.

And as a side effect, almost, right? Yeah, yeah.

And then that's why I think, you know, we should be open minded and explore. And however, at the same time, because of the reasons you pointed out, I'm not optimistic that we will survive more than a few centuries into the future because people do not think long term. And that means that we will only survive for the short term.

I don't know if you have thoughts about this, but what are the things that worry you the most about from the great perspective of the universe, which is the great filters that destroys intelligent civilizations before our own species here? Like, what are the things that worry the most?

Yeah, the thing the. It worries me the most is that people pay attention to how many likes they have on Twitter. And rather than, you know, basketball coaches tell the team players. Keep your eyes on the ball, not on the audience. The problem is we keep our eyes on the audience most of the time. Yes, let's keep our eyes on the ball. And what does that mean? First of all, in context of science, it means pay attention to the evidence when the evidence looks strange.

Then we should figure it out, you know, I went to a seminar about moyamoya at Harvard and a colleague of mine that is a mainstream conservative. Would never say anything that would deviate from what everyone else is thinking said to me after the seminar.

I wish this object never existed. Now, to me, I mean, I just couldn't hear that. What do you mean?

Nature is whatever it is, you have to pay attention to it. You cannot say I you know, you cannot bury your head in this. I mean, you should bless nature for giving you clues about things that you haven't expected. Yes.

And I think that's the biggest fall that we are looking for, confirmations of things we already know so that we can maintain our pride, that we already knew it and maintain our image, not make mistakes, because we already knew it. Therefore, we expected the right thing.

Yes, but science is a learning experience and sometimes you're wrong. And let's learn from those mistakes. And what's the problem about that? Why is why do we have to get, you know, prizes and why do we get to be honored and maintain our image when the actual objective of science is learning about nature?

And like you've talked about anomalies in this case are actually are not things that are unfortunate. And to be ignored are, in fact gifts and should be the focus of science.

Exactly. Because that's the way for us to improve our understanding. If you look at quantum mechanics, nobody dreamed about it and it was revolutionary and we still don't fully understand it. It's a pain for us to figure out.

So why do it? So I understand from the perspective that's holding our science back. Well, why do you have a sense that that's also something that might be a problem for us in terms of the survival of human civilization?

Because when you look at society, it operates by the same principles. There is a people look for affirmation by groups and they, uh, you know, people segregate into herds that think like them, especially these days when social media is so strong you can find your support group. And if you don't look for evidence for what you're saying, you can say crazy things. As long as there are enough people supporting what you say, you can even have your newspapers.

You can have everything to support your view.

And then, you know, bad things will happen to society because we're detaching ourselves from reality and feel detached from reality, all the destructive things that can occur in the real world, whether from nuclear weapons, all the kinds of threats that we're facing, even we're living through a pandemic. The people, you know, are much, much worse. Pandemic can happen. And then we could we did this one politicizing some kind of way and have bickering in the space of Twitter and politics as opposed to there's an actual thing that can destroy the human species.

So the only way for us to maintain to to stay modest. Yes. And learn about what really happens is by looking for evidence. Again, I'm saying it's not about ourself, you know, it's about figuring out what's around us. And if you close yourself by surround yourself with people that are like minded, that refuse to look at the evidence, you can do bad things.

And throughout human history, that's the origin of all the bad things that happen. Yes. And I think it's a key it's a key to be modest and to look at the evidence. And it's not a nuance. Now, you might say, oh, OK, the uneducated person might operate. No, it's the scientific community operates this way. My problem is not with. People that don't have an academic pedigree include everywhere in society on the topic of discovery, of evidence of alien civilizations, which is something you touch on in your book, what that idea would do to societies, to the human psyche and in general, do you think?

And you talk about the have still have trouble pronouncing, but with more and more and more wager, right.

What do you think is can you explain it? And what do you think in general is the effect that such knowledge might have on human civilization? Right.

So Pascal had this wager about God. And by the way, there are interesting connections between theology and the search for extraterrestrial life.

You know, it's possible that, you know, we were planted on this planet by another civilization that we attribute to God powers that are that belong really to technological civilization. But putting that aside, Pascal basically said, you know, let's the two possibilities, either God exists or not.

Right. And if God exists, you know, the consequences are quite significant. And therefore, you know, we should we should consider that possibility differently then equal weight to both positions.

And then, uh, I suggest that we do the same with Momoa or other technological signatures that we keep in mind the consequences and therefore pay more attention to that possibility. Now, some people say extraordinary claims require extraordinary evidence.

My point is that the term extraordinary. Is really subjective, you know, for one person. A black hole is extraordinary for another oh, it's just a consequence of Einstein's theory of gravity. It's nothing extraordinary. The same about the type of dark matter, anything. So we should leave the extraordinary part of that sentence. Just keep evidence. OK, so let's be guided by evidence, and if even if we have extraordinary claims, you know, let's not dismiss them because the evidence is not extraordinary enough, because if we have an image of something and it looks really strange and we say, oh, the image is not sufficiently sharp, therefore we should not even pay attention to this image or not even consider.

I think that's a mistake. Yes, what we should do is say, look, there is some evidence for something unusual. Let's try and build instruments that will give us a better image. And if you just dismiss extraordinary claims because you consider them extraordinary, you avoid discovering things that you haven't expected. And so I believe that along the history of astronomy, there are many missed opportunities.

And I speak about astronomy, but I'm sure in other fields it's also true. I mean, this is my expertise. For example, you know, the Astrophysical Journal, which is the main primary publication in astrophysics.

If you go you go back before the 1980s, there are images that were posted, Industria physical journal of giant arcs, you know, arcs of light surrounding clusters of galaxies.

And you can find it in printed versions of the Astrophysical Journal.

People just ignore. They put the image, they see the arc.

They say, who knows what it is and just ignore it. And then in the 1980s, the subject of gravitational lensing became popular.

And the idea is that you can deflect light by the force of gravity and then you can put the source behind the cluster of galaxies and then you get these arcs.

And actually, Einstein predicted it in 1940 and, you know, so these things. Were expected, but people just had them in the images, didn't pay attention, so I'm sure there are lots of opportunities, sometimes even existing data, you have things that are unusual and exceptional and are not being addressed.

Yeah, you actually, I think of the article, the data is not enough from quite a few years ago with where you talk was, you know, we can go back to the 70s and 80s, but we can go to the Mayan civilization.

Right. The Mayan civilization basically believed in astrology, that you can forecast the outcome of a war based on the position of the planets. Yes. And and they had, you know, astronomers in their culture had the highest social status. There were priests. Yes, there were elevated. And the reason was that they help politicians decide when to go to war because they would tell the politicians, you know, the planets would be in this configuration. It's a better chance for you to win the war.

Yes, go to war.

And in retrospect, they know they collected wonderful data, but misinterpreted it because we now know that the position of Venus or Jupiter or whatever has nothing to do with the outcome of World War One world has nothing to do. And so we can have a prejudice and collect data without actually doing the right thing with it.

That's such a Pisces thing to say.

I looked up what your astrological sign as well. So you mentioned Einstein predicted that black holes don't exist or just or exist in nature don't exist. When Einstein came up with this theory of gravity in 1915, November, 1915, a few months later, another physicist called Schwarzschild, he was the director of the Potsdam Observatory, but he was a patriot, a German patriot. So he went into the First World War fighting for Germany. But while he was at the front, he sent a postcard to Einstein saying, you know, a few months after the theory was developed, saying, actually, I found a solution to your equations and that was the Blackhall solution.

And then he died a few months later and Einstein was a pacifist and he survived. So the lesson from this story is that if you want to work out the consequences of a theory, you can work hostages.

But, um, but the point is that, uh, this solution was known shortly after Einstein came up with his theory.

But but in 1939, Einstein wrote a paper in the Annals of Mathematics saying, even though the solution exists, I don't think it's realized the nature. And his argument was, you imagine a star collapsing. Stars often spin and the spin will prevent them from making a black hole collapsing to a point.

So, I mean, can you maybe one of the many things you you have work on, you're an expert in as black holes.

Can you first say what are black holes? And second, how do we know that they exist?

Right. So black holes are the ultimate prison.

You know, you can check in, but there's never even light cannot escape from them. So there are extreme structures of space and time.

And there is this so-called Schwarzschild radius or the event horizon of a black hole, once you enter into it with a spaceship, you would never be able to tweet back to your friends and tell them. By the way, I asked the students in my class freshman seminar at Harvard, they said, let me give you two possible journeys that you can take.

I said, suppose aliens come to Earth and then suggest that you would border a spaceship. Would you do it?

And the second is, suppose you could board a spaceship that will take you into a black hole. Would you do it? So all of them said to the first question, yes, under one condition, that I'll be able to maintain my social media contacts and report back, share the experience with them.

I couldn't personally.

I have no footprint on social media, which is as a matter of principle. Yeah, my wife asked me when we got married and I hohner that and told Joslyn I need to get married to such and such a woman.

She truly is, especially when she she was wise enough to recognize the risk.

But it saves me time and it also keeps me away from crowds. You know, I don't have the, uh, notion of what a lot of other people think. So I can think of anything except. Yeah, exactly.

But putting so I was surprised to hear that for students, it's extremely important to share experiences. Even if they go on a spaceship with aliens, they still want to brag about it rather than look around and see what's going on.

This is not an option when you go to the black hole is exactly the point.

So for the black hole, they said no, because obviously you can find your death after you get into it.

You the already there is the singularity in the center. So inside the event horizon, we know that all the metal collects at a point. Now, we can't really predict what happens at the singularity because Einstein's theory breaks down and we know why it breaks down because it doesn't have quantum mechanics that talks about small distances.

We don't have a theory that unifies quantum mechanics and gravity so that it will predict what happens in near a singularity. And in fact, you know, I once a couple of years ago, I had the flood in my basement. I mean, uh, and I invited the plumber to come over and figure out. And we found that the sewer was clogged because of tree roots that got into it. And we solved the problem. But then, uh, I thought to myself, well, isn't that what happens to the singularity of a black hole?

Because, uh. The question is, where does the matter go, you know, if you know, in the case of a home, I never thought about it, but the water, all the water that we use goes in, you know, through the sewer to some reservoir somewhere. And the question is what happens inside a black hole? And one possibility is that there is an object in the middle, just like a star, you know, and everything collects there.

And the object has the maximum density that we can imagine, like Planck densities. It's the ultimate density that you can have where gravity is strongest, all the other forces. So you can imagine this object, very dense object at the center that collects all the matter. Another possibility is that there is some tunnel just like this where it takes the matter into another place and we don't know the answer where. But I wrote a Scientific American essay about it and admitting our ignorance.

It's a fascinating question. What happens to the method that goes into black hole? I actually recommend it to some of my colleagues that work on string theory at the closing of a conference.

I'm the founding director of the Black Hole Initiative at Harvard, which brings together astronomers, physicists, philosophers and mathematicians. And we have a conference once a year.

And at the end of one of them, since I'm the director, I had to summarize and I said that I wish we could go on a field trip to a black hole nearby.

And I highly recommend to my colleagues that work on string theory to enter into that black hole because then they can test their theory when they get inside. But one of the string theorists in the audience, Nimar Hamade, immediately raised his voice and said, you have an ulterior motive for sending us into a black hole, which I didn't deny.

But at any event. Yes, that's true.

That's true. Can you say. Why we know that black holes exist, right? So it's an interesting question because black holes were considered a theoretical construct and Einstein even denied their existence in 1939.

But then in the 19th, in the mid 1960s, quasars were discovered.

These are very bright sources of light, 100 times brighter than their host galaxy, which are point like this at the center of galaxies and.

It was immediately suggested by Ed Salpeter in the West and Bierko of the doveish in the East that these are black holes that secrete gas, collect gas from their host galaxy that are being fed with gas. And they shine very brightly because it's the gas falls towards the black holes, just like water running down the the sink. The gas swirls and then rubs against itself and heats up and shines very brightly because it's very hot, close to the black hole. By viscose, by viscosity, it heats up.

And in the case of black holes, it's the turbulence, the turbulent viscosity that causes it to heat up. So we get these very bright sources of light just from black holes that are supposed to be dark. You know, nothing escapes from them, but they create a violent environment where gas moves close to the speed of light and therefore shines very brightly, much more than any other source in the sky. And we can see these quasars all the way to the edge of the universe.

So we have evidence now that when the universe was, you know, about seven percent of its present age, you know, infant. Yes. Already back then, you had Blackhorse of a billion times the mass of the sun, which is quite remarkable. It's like finding giant babies in a nursery, you know, like how can these blackhorse grow so fast?

You know, less than a billion years after the big bang, you already have a billion times the mass of the sun in these black holes. And the answer is, presumably they are very quick processes that build them up.

They they they build quickly, very quickly.

And so we see those black holes. And that was found in the mid 1960s, but in nineteen instore in 2015, exactly 100 hundred years after Einstein came up with his theory of gravity, the like observatory detected gravitational waves.

And these are just ripples in space and time. So according to Einstein's theory, the innovation, the ingenuity of Einstein's theory of gravity that was formulated in November 1915 was to say that space and time are not rigid. You know, they are they respond to matter. So, for example, if you have two black holes and they collide. It's just like a stone being thrown into this on the surface of a pond, they generate waves, disturbances in space and time that propagate out at the speed of light.

These are gravitational waves. They create a space time storm around them and then the waves go all the way through the universe and reach us.

And if you have a sensitive enough detector like Lego, you can detect these waves. And so it was not just the message that we received for the first time gravitational waves, but it was the messenger. So there are two aspects to it.

One is the messenger, which is gravitational wave for the first time were detected directly. And the second was the message, which was a collision of two black holes, because we could see the pattern of the ripples in space and time. And it was fully consistent with the prediction that Schwarcz had made for how black the space time around the black hole is, because when two black holes collide, you can sort of map from the message that you get. You can reconstruct what what really happened.

And it's fully consistent.

And in 2017 and 2020, there's two Nobel Prizes. That's right. That had to do with the black holes. Can you maybe describe in the same mass for whether you already been doing what those Nobel Prizes were given for you? Yeah.

So the 2017 was given for the Lego collaboration for discovering gravitational waves from collisions of black holes and the 2020 Nobel Prize in physics was given for two things. One was theoretical work that was done by Roger Penrose in the 1960s, demonstrating that black holes are inevitable when stars collapse.

And it was mostly mathematical work. And actually, Stephen Hawking also contributed significantly to that frontier. And unfortunately, he is not alive, so he could not be Honold. So Penrose received it on his own and then the two other astronomers received it as well under Agis and Rhinehart Guenzel and they provided conclusive evidence that there is a black hole at the centre of the Milky Way galaxy that weighs about four million times the mass of the sun. And they found the evidence from the motion of stars very close to the black hole.

Just like we see the planets moving around the sun. There are stars close to the center of the galaxy and they are orbiting at very high speeds of other thousands of kilometres per second or thousands of miles per second per second. Think about it. Yeah.

Which can only be induced at those distances if there is a four million solar mass object that is extremely compact.

And the only thing that is compatible with the constraints is a black hole.

And they actually made a movie of the motion of these stars around the centre. One of them moves around the center over a decade over timescales that we can monitor. And then it was a breakthrough in a way.

So combining Lego with the detection of a black hole at the center of the Milky Way and in many other galaxies like quasars, you know, now, I would say black hole research is vogue.

You know, it's very much in fashion. You know, we saw it back in 2016 when we established the Black Hole Initiative.

Yes. You kind of saw that there's this excitement about in in breakthroughs and discoveries around black holes, which are probably one of the most fascinating objects in the universe. I mean, it's up there. They're both terrifying and beautiful just and they capture the entirety of the physics that we know about the universe.

I should say the you know, the question is, where is the nearest black hole? Can we visited? And, you know, I wrote a paper with my undergraduate student, Amir Saraj, suggesting that perhaps, you know, there could be if there is one in the solar system, we can detect it because I don't know if you heard, but there is a claim that maybe there is a planet nine in the solar system because we see some anomalies at the outer parts of the solar system.

So some people suggest that maybe there is a planet out there that was not yet detected. So people search for it, didn't find it. It weighs roughly five times the mass of the earth. And we said, OK, maybe you can't find it because it's a black hole.

And that was formed early in the universe. Is that so? So where do you stand?

It could be that the dark matter. There is made of black holes of this mass, you know, we don't know what the dark matter is made of, you could it could be the black holes.

So we said, but there is an experimental way to test it in the way to do it is because is there is the Oort cloud of icy rocks in the outer solar system. And if you imagine a black hole there, um, every now and then a rock will pass close enough to the black hole to be disrupted by the very strong gravity close to the black hole. And that would produce a flare that you can observe. And we calculated how frequently these flares would occur.

And with LSD on the Vera Rubin Observatory, we found that you can actually test this hypothesis as brilliant. And if you don't see flares, then you can put limits on the existence of a black hole in the solar system.

It would be extremely exciting if there was a black a planet nine was a black hole because we could visit it and we can examine it. And it will not be a matter of, you know, an object that is very removed from us. Another thing I should say is it's possible that the black hole affected life on Earth. The black hole at the center of the Milky Way. How do you know that black hole right now is dormant? It's very faint, but we know that it flares when a star like the Sun comes close to it.

The star will be spagetti fight, basically become a stream of gas like a spaghetti. And then the gas would fall into the black hole and there would be a flare. And this process happens once every 10000 years or so. So we expect that, you know, these flares to occur every 10000 years. But we also see evidence for the possibility that gas clouds were disrupted by the black hole because the stars that are close to the black hole are residing in a single or two planes.

And the only way you can get that is if they formed out of a disc of gas, just like the planets in the solar system formed. So there is evidence that gas fell into the black hole and powered possibly a flare. And these flares produce x rays and ultraviolet radiation that could damage life if if the earth was close enough to the center of the galaxy where we are right now, it's not very risky for us. But there is a theoretical argument that says the solar system, the sun was closer to the galactic center early on and then it migrated outwards.

So maybe, maybe in the early stage of the solar system, the conditions, you know, were affected, shaped by these flares of the black hole at the center of the galaxy. And that's why for the first two billion years, there wasn't any oxygen in the atmosphere. Now, who knows? But it's just interesting to think that, you know, from a theoretical concept that Einstein resisted in 1939, it may well be that, you know, black holes have influence on our life and that, you know, it's just like discovering that some, uh, stranger affected your family and in a way, your life.

And, you know, if that happens to be the case, a second Nobel Prize should be given not not for just the discovery of this black hole at the center of the galaxy, but perhaps for the Nobel Prize in chemistry for the effect that it had for the for the for the interplay that resulted in some kind of. Yeah, yeah. The chemical effect by biology, I mean all those kinds of things in terms of the emergence of life and the creation of a habitable environment.

That's so fascinating. And of course, like you said, dark matter like black holes have some say could be the dark matter in principle.

Yes. We don't know what the dark matter is at the moment.

Does it make you sad? So you've had an interaction and perhaps a bit of a friendship with Stephen Hawking. Does it make you sad that he didn't win the Nobel?

Well, altogether, I don't assign great importance to prizes because as you said, you know, Jean-Paul Sartre, who I admired as a teenager because I was interested in philosophy when I grew up on a farm in Israel, you know, I used to collect eggs every afternoon and I would drive the tractor to the hills of our village and just think about philosophy, read philosophy books.

And Jean-Paul Sartre was one of my favorite and he was honored with a Nobel Prize in literature. He was a philosopher, primarily existentialist, and he said, the hell with it. You know, why should they give special attention to this committee of people that get their self-importance from awarding me the prize?

Like what? What's what? Why does that merit my attention? Yes. So he gave up on the Nobel Prize. And, you know, there are two benefits to that one.

That you don't you are not working your entire life in the direction that would satisfy the will of other people, that you work independently. You are not after these homeowners.

Just for the same reason that if you are not living your life for making a profit or money, you can live a more fulfilling life because you are not being swayed by the wind. You know how to make money and so forth.

The second aspect of it is, you know, that very often, you know, these prizes, they they distort the way we do science because instead of people willing to take risks and instead of having announcements only after a group of people converges with a definite result.

You know, the natural progression of science is based on trial and error, reporting some results and perhaps they're wrong, but then other people find perhaps better evidence and then you figure out what's going on. And that's the natural way the science is. You know, it's a learning experience. So if you give the public an image by which scientists are always right, you know, and you know, some of my colleagues say we must do that because otherwise the public will never believe us that global warming is really taking place.

Right. But that's not true because the public would really believe you if you showed the evidence. So the point is, you should be sincere when the evidence is not absolutely clear, all where there are disputes about the interpretation of the evidence, which should show Chaucer, you know, the king is naked, OK? There is no point in pretending that the king is dressed. Yes. Saying that scientists are always right. Scientists are wrong frequently. And the only way to make progress is by evidence giving us the support that we need to make airtight arguments.

So when you say global warming is taking place, if the evidence is fully supportive, there are no holes in the argument, then people will be convinced because you're not trying to fool them when the evidence was not complete.

You also show them that the evidence is not going. And when there's holes, you show that there's holes in it. Here's the methodology we're using to try to close those holes. Exactly.

Let's see why pretend. So if there were not in a world where there were no prizes, no holocaust, we would act like kids.

As they said before, we would really be focusing on the ball and not on the audience.

Yeah, the prizes get in the way and it's so powerful. Do you think in some sense the few people have turned down the prize, made a much more powerful statement? I don't know if you're familiar in the in the in the space of mathematics with the Fields Medal and Google Perlman. Yes.

Turn down the prize is so he I've committed one of the reasons I started this podcast is I I'm going to definitely talk to Putin and go talking to him. And people keep telling me it's impossible.

I, I love hearing that because I'll talk to both anyway.

But do you have a do you have a sense of why he turned down the prize and is that a powerful statement to you?

Well, what I read is that you're talking about the mathematicians, the mathematician.

What I read is that he was disappointed by the response of the community, the mainstream community, the mathematicians, to his earlier work where they dismissed it. They didn't attend to the details and didn't treat him with proper respect because he was not considered. One of them. Yes, and I think that speaks volumes about the current scientific culture, which is, uh, based on groupthink and on social interaction rather than on the merit of the argument and on the evidence in the context of physics and mathematics, there is no empirical base.

You're exploring ideas that are logically consistent. But nevertheless, there is this, uh, groupthink. And I think he was so frustrated with his past experience that he didn't even bother to publish his papers. He just posted them on the archive and in a way saying, you know, I know what what the answer is, go look at it.

And then again, in the long arc of history, his work on archives will be remembered and all the prizes, most of the prizes will be forgotten. So people don't kind of think about is when you look at Roger Penrose, for example, is another fascinating figure. You know, it's possible and I forgive me if, as I'm sure my ignorance, but, you know, he's also did some work on consciousness. He's been one of the only people who spoke about consciousness, which for a longest time and is still arguably outside of the realm of the sciences, is still seen as a taboo subject.

And and he was brave enough to explore it from a physics perspective, from a just the philosophical perspective, but like with the rigor, like proposing different kind of hypotheses of how consciousness might be able to emerge in the brain. And it's possible that that is the thing he's remembered for. If you look a hundred years from now. Right. As opposed to the working of black holes, which fits into the kind of ESP like the fits into what the current scientific community allows to be the space of what is and isn't science.

Yeah, it's really interesting to look at people that are innovators were in some phases of their career.

Their ideas fit into the social structure that is around them, but in other phases it doesn't. And when you look at them, they just operated the same way throughout. And it's it says more about their environment than about them.

We I don't know if you know who Max Tegmark has just recently talked to a friend of mine. I just recently talked to him again. And he I mean, he was a little bit more explicit about saying, you know, being aware, which is something I also recommend, is like being aware where the scientific community stands and doing enough to get, like, move along into your career in your career. And it's the necessary evil, I suppose, if if you are one of those out of the box thinkers that just naturally have this childlike curiosity, which Max definitely is one of them, is sometimes you have to do some stuff that fits and you publish and you get tenure and all those great things.

But the tenure is a great privilege because it allows you to, in principle, explore things that are not accepted by others. And unfortunately, it's not being being taken advantage of by most people. And it's a waste of a very precious resource.

Yeah, absolutely. The space that you kind of touched on that's full of theories and is perhaps detached from appreciation of empirical evidence or a longing for empirical evidence or grounding in empirical evidence, is the theoretical physics community and the interest in unifying the laws of physics and with the theory of everything.

It I'm not sure from which direction to approach this question, but how far away are we from arriving at a theory of everything?

Do you think and how would we how important is it to try to arrive at it at this kind of goal of this beautiful, simple theory that unlocks the the very, you know, fundamental basis of our nature as we know it and, you know.

And how what are the kinds of approaches we need to take to get there? Yeah, so in physics, the biggest challenge is to unify quantum mechanics with gravity. And I believe that once we have experimental evidence for how this happens in nature, in systems that have quantum mechanical effects, but also gravity is important, then the theory will fall into our lap.

OK, but the mistake that is made by the community right now is to come up with the right theory from scratch.

And, you know, Einstein gave the illusion that you can just sit in your office and understand nature. And when he came up with this general theory of relativity.

But, you know, first of all, perhaps he was lucky. But it's not a rule. The rule is that you need evidence to guide you, especially when dealing with quantum mechanics, which is really not intuitive. And so there are two places where the two theories meet. One is black holes and there is a puzzle there. It's called the information paradox. And in principle, you can throw the Encyclopedia Britannica into a black hole.

It's a lot of information and then it will be gone because a black hole carries only three properties or qualities, the mass, the charge and the spin, according to Einstein. But then when Hawking tried to bring in quantum mechanics to the game, he realized that black holes have a temperature and they radiate. This is called hawking radiation. And it was sort of anticipated by. Jacob Lichenstein before him and Hawking wanted to prove Berenstein wrong and then figured this out.

And so what it means is Blackhorse eventually evaporate. And they evaporate into radiation that doesn't carry this information according to Hocking's calculation, and then the question is, according to quantum mechanics, information must be preserved. So where did the information go if a black hole is gone?

And where is the information that was included in the encyclopedia when it went into the black hole? And to that question, we don't have an answer yet. It's one of those puzzles about black holes and it touches on the interplay between quantum mechanics and gravity. Another important question is what happened at the beginning of the universe, what happened before the Big Bang? And by the way, on that, I should say, you know, there are some conjectures, it's in principle, if we figure it out, if we have a theory of quantum gravity, it's possible to imagine that we will figure out how to create the universe in the laboratory by irritating the vacuum.

You might create a baby universe.

And if we do that, it will offer a solution to what happened before the Big Bang. Perhaps the Big Bang emerged from the laboratory of another civilization.

So it's like a baby. Universes are being born out of laboratories and inside the baby universe. You have a civilization that brings to existence a new baby, universal, just like humans, right? We have babies and they make babies. So in principle, that would solve the problem of why there was a big bang and also what happened before the Big Bang. Yes. So we came. Our umbilical cord is connected to a laboratory of a civilization that produced our universe once it figured out quantum gravity.

You know, as as baby big bangs all the way down, big banks all the way up.

So if we collect data about how the universe started, we could potentially test theories of or it can educate us about how to unify quantum mechanics and gravity. If we if we get any information about what happens near the singularity of a black hole, you know, if we if we get a sense of, you know, somehow we learn what happens to this thing, that would educate. So there are places where we can search for evidence. But it's very challenging, I should say.

And my point is, you know, the string theorists decided that they know how to approach the problem, but they don't have a single theory. There is a multitude of theories and it's not tightly constrained. And they cannot make predictions about black holes or about the beginning of the universe. So the moment they say we are at a loss and the way I feel about this concept of the theory of everything, we should wait until we get enough evidence to guide us.

And until then, you know, there are many important problems that we can address.

You know, why? Why bang our head against the wall on a problem for which we have no guidance?

Right. We don't have a good dance partner in terms of evidence. There's not. I mean, it would be interesting, just like I said. I mean, the lab is one place to create universes or black holes, but it would be fascinating if there is indeed a black hole in our solar system that you can interact with. So the problem with the origin of the universe is all you can do is collect data about it. Right. You can't interact with it.

Well, you can, for example, detect gravitational waves that emerged from that. And, you know, there is an effort to do that and that could potentially tell us something. But then, yeah, it's a challenge and that's why we're stuck. So I should say, despite what physicists portray, that, you know, we live through an exceptional growth in our understanding of the universe.

We're actually pretty much stuck. I would say, because we don't know the nature of the dark matter, most of the matter in the universe, we don't know what it is and we don't know how the universe started. We don't know what happens in this in the interior of a black hole, because you've thought it quite a bit about dark matter as well.

Do you have any kind of hypothesis, interesting hypothesis where you mentioned a few about what is dark matter and what are the possible paths that we could take to unlock the mystery of dark? What is dark matter?

Yeah, so what we need is some anomalies that would hint at what the nature of the dark matter is or to detect it in the laboratory. There are lots of laboratory experiments searching, but it's like searching for a needle in a haystack because there are so many possibilities for the type of particle that it may be.

But maybe at some point, you know, we'll find either a particle or black hole, dark matter or something else.

But it also may be sorry to interrupt to comment about what is dark matter, like what is just the name we're assigned to what?

So most of the community believes that it's a particle. That we haven't yet detected, it doesn't interact with light, so it's dark, but the question is, what does it interact with and how can we find it?

And for many years, physicists were guided by the idea that it's some extension of the standard model of particle physics. But then they said, oh, we will find some clues from the Large Hadron Collider about its nature. Or maybe it's related to supersymmetry, which is a new symmetry that we haven't found any evidence for. In both cases, the Large Hadron Collider did not give us any clues, and other people search for specific types of particles in the laboratory and didn't find any.

A couple of years ago, actually, around the time that I worked on more and more, I also worked on the possibility that the dark matter particles may have a small electric charge, which is a speculation, but nobody complained about it.

And, you know, it was published and I regard it more as this of a speculation than the artificial origin of a Moomaw. And then to me, I applied, as far as I'm concerned, apply the same scientific tools. In both cases. There is an anomaly that led me to that discussion, which has to do with the hydrogen being called in the early universe more than we expected. So we suggest that maybe the dark matter particles have some small charge, but then you deal with anomalies by exploring possibilities.

That's the only way to do it.

And then collecting more data to check those and searching for technological signatures is the same as any other part of our scientific endeavor.

We make hypotheses and we collect data, and I don't see any reason for having a taboo on this subject in your childlike, open minded excitement and approach to science here, I think to anyone listening to this truly inspiring I mean, the question I think is useful to ask is by way of advice for young people. A lot of young people listen to this, whether from all over the world and teenagers, undergraduate students, even graduate students, even like even young faculty, even older faculty, they're all young at heart, like it's really hard to have advice for.

Let's focus on the traditionally defined sort of young folks that kind of graduate. You have advice to give to young people like that today about life, maybe in general, maybe a life of curiosity in the sciences. Definitely.

Well, first, I should confess that I enjoy working with young people much more than with senior people. And the reason is they don't carry a baggage of prejudice. Yes, they are not so self-centered. They're open to exploration. My advice I mean, one of the lessons that took me a while to learn, and I should say I lost important opportunities as a result of that so that I would regard it as a mistake on my behalf was to believe experts, quote unquote.

So on a number of occasions, I would come up with an original idea and then suggested to an expert, someone that works in the same field for a while, and the expert would dismiss it most of the time because it's new and was not explored, not because of the merit.

And then what happened to me several times is that someone else would listen to the conversation or would hear me suggesting it and I would give up because the experts said no and then that someone else would develop it so that it becomes the hottest thing in this field.

And it happened once. It happened to me multiple times. I then realized the hell with the experts.

They don't know that. They are just repeating that, yes, they don't think creatively. They are being threatened by innovation. OK, and then it's the natural reaction of someone that cares about their ego more than about the matter that we are discussing. And so I said I would not I don't care how many likes I have on Twitter. I don't care whether the experts say one thing or another. I will basically exercise my judgment. Yes. And do the best they can.

You know, turns out that I'm wrong. I made a mistake. You know, that's part of the of the scientific endeavor.

And it took me a while to recognize that. And it was a lot of wasted opportunities to the young people. I would recommend don't listen to experts carve your own path.

Now, of course you will be wrong. Should learn from experience just like kids do. But do it yourself. Your father died in 2017. Your mother died in twenty nineteen. Do you miss them very much? Is there a memory? That fond memory that stands out or maybe more, have you learned from them? From my mother, I mean, she was very much my inspiration for pursuing intellectual work because. She studied at the university and then because of the Second World War, after the Second World War, she she was born in Bulgaria.

They immigrated to to Israel and the and she left university to work on a farm.

And the later in life, when all the kids left home, she went back to the university and finished the food. But she planted in me the intellectual curiosity and valuing, learning or acquiring knowledge as a very important element in life.

And and my love with philosophy came from attending classes that she took at the university when I was a teenager.

I was fortunate to go to some of these and they inspired me later on. And I'm very different than my colleagues, as you can tell, because my upbringing was quite different. And the only reason I'm doing physics or astrophysics is because of circumstances.

I at age 18, I was asked to serve in the military and, uh, the only way for me to pursue intellectual work was to work on physics because that was the closest to philosophy. And I was good at physics. So they admitted me to an elite program called Talpiot that allowed me to finish my Ph.D. at age 24 and to actually propose the first international project that was funded by the Star Wars initiative for Ronald Regan.

And that brought me brought me to the US to visit Washington, D.C., where we were funded from.

And then on one of the visits, I went to, uh, the Institute for Advanced Study at Princeton and the Met John Baycol that later offered me a five year fellowship there under the condition that I'll switch to astrophysics, at which point I said, OK, I cannot give up on this opportunity. I'll do it. Switch to astrophysics.

It felt like a forced marriage, kind of arranged marriages. And then I was offered the position at Harvard because nobody wanted that they first elected someone else and that someone said, I don't want to become a junior faculty at the Harvard Astronomy Department because the chance for being promoted are very small. So he took another job and then I was second in line. They gave it to me.

I didn't care much because I could go back to the farm any day, you know, and after three years, I was tenured. Yeah. And eventually, a decade later became the chair of this department and served for nine years as the chair of the astronomy department at Harvard.

But at that point, it became clear to me that I'm actually married to the love of my life, even though it was an arranged marriage.

The many philosophical questions in astrophysics that we can address. But I'm still very different than my colleagues, you know, that we're focusing on technical skills in getting to this job.

So my mother was really, uh, extremely instrumental in planting the seeds of stop thinking about the big picture in me.

Then my father, he was you know, he was working in the farm and we didn't speak much because we sort of understood each other without speaking. But what he gave me is a sense of, uh, you know, that it's more important to do things than to talk about them.

I love the they the I mean, my apologies, but Amitay, mind in hand, I love that there is that the root of philosophy that you gain from your mom and the hand that action is all that ultimately in the end matters from your dad, that it's really powerful.

If we could take a small detour into our philosophy, is there by chance any books, authors, whether philosophical or not, you mentioned Sucher that stand out to you. There were formative and some small or big that perhaps you would recommend to others, maybe when you were very young or maybe later on in life?

Well, actually, yeah, I you know, I read the number of existentialists that. Appealed to me because there were authentic, you know, Sator, you know, he declined the Nobel Prizes we discussed, but he also was mocking people that pretend to be something better than they are.

You know, he was living an authentic life that is sincere. And that's what appealed to me. And the album to me was another French philosopher that advocated existentialism. You know, that really appealed to me as probably my favorite existentialist, Cummo.

Yeah. And he died at a young age in an accident of fortune.

And then, you know, people like Nietzsche that, um, uh, you know, broke conventions.

And I noticed that the Nicha is still extremely popular. You know, that's quite surprising. He appeals to the young people of today and the people that it's the children.

It's the childlike wonder about the world. And he was unapologetic. You know, it's like most philosophers have a very strict adherence to terminology into the practices. Academic philosophers and nature was full of contradictions.

And and you just I mean, he was just this big kid with opinions and thought deeply about this world. And people are really attracted. And surprisingly, there's not enough people like that throughout history of philosophy. And that's why I think is still drawn to him.

Yeah, to me.

What stands out is his statement that the best way to corrupt the mind of young people is to tell them that they should agree with the common view, you know, and the you know, it goes back to the thread that went through our discussion.

Yes. You've you've kind of suggested that we ought to be humble about our very own existence and that our existence lasts only a short time.

We talked about you losing your father and your mother. Do you think about your own mortality?

Are you afraid of death?

I'm not afraid. You know what, Epicurus, actually, because course was a very wise person. Uh. Uh, according to Lucretius, of course, didn't leave anything in writing, but, uh, he said that he's never afraid of death because as long as he's around, death is not around. And when death will be around, he will not be around. So he will never meet death.

So why should you be worried about something you will never meet? You know, and it's an interesting philosophy of life. You know, you shouldn't be afraid of something that you will never encounter.

Right. But there's a finiteness to this experience where we live every day.

And I think of her being honest with every day as if it's going to last forever. We often kind of don't contemplate the fact that it ends you kind of plans and goals and you have this possibilities. You have a kind of lingering thought, especially as you get older and older and older, that this is especially when you lose friends. Right. And then you start to realize, you know, it doesn't. But I don't know if you really are cognizant of that.

I mean, because but you have to be careful not to be depressed by it because otherwise you lose the vitality. Right.

So I think the most important thing to draw from from knowing that you are short lived is a sense of appreciation that your alive that's the first thing, but more importantly, a sense of modesty, because how can anyone be arrogant?

If they kept at the same time this notion that they are short lived, I mean, you cannot be arrogant because anything that you advocate for, you know, you will not be around to do that in a hundred years. So people would just forget and move on, you know, and if you keep that in mind, you know, the scissors in ancient Rome, they they had the person next to them telling them, don't forget that you're immortal.

You know, there was a person with that duty because the scissors thought that they are all powerful, you know, and they had for a good reason someone they hired to whisper in their ear, forget that you're mortal.

Yeah, well, you're somebody one of the most respected, famous scientists in the world, sitting on a farm, gazing up at the stars. So you seem like an appropriate person to ask the completely inappropriate question of what do you think is the meaning of it all? What's the meaning of life?

That's an excellent question. And if we ever find an alien that we can converse with, I would like to answer this. I would like to ask for an answer to this question because, um, would they have a different opinion, you think?

Well, they might be wiser because they go around for a while, but I'm afraid they will. They will be silent. I'm afraid they will not have a good answer.

And I think, um, it's it's the process that you should get satisfied by the process of learning you should enjoy. OK, so it's not so much that there is a meaning.

In fact, there is.

As far as I can tell, things just exist, you know, um, and it's, um, yeah, I think it's inappropriate for us to assign meaning for our existence because, you know, we as a civilization, we will eventually perish and nothing will be, you know, just another planet on which life died, you know, and if you look at the big scheme of things, who cares?

Who cares? And how can we assign significance to what we are doing, you know? So if you said the meaning of life is this, well, it will not be around in a billion years.

So what you know, it cannot be the meaning of life because like, you know, nothing will be around.

So I think we should just enjoy the process. And, you know, it's like many other things in life.

You enjoy good food, OK? And you can enjoy learning.

Why?

Because it makes you, uh, appreciate better where, you know, the environment that you live in.

And sometimes people think religion, for example, is in conflict with science. Spirituality. That's not true. If you see a watch and you look at it from the outside. You know, you might say, oh, that's interesting, but then if you start to open it up and learn about how it works, you appreciate it more. So science is the way to learn about how the world works.

And it's not in conflict to the meaning that you assign to all of this, but it helps you appreciate the world better. So, in fact, I would think that the religious person should promote science because it gives you a better appreciation of what's around you.

You know, it's like, you know, if you buy in a grocery, buy something, you know, a bunch of fruits that are packed together.

And you can see from the outside exactly what kind of fruits are inside. But if you open it up and study, you appreciate better the merchandise that you get. Right? So you pay the same amount of money, but at least you know what's inside. So why don't we figure out what the word is about? You know, what the universe content, what is the dark matter?

It will help us appreciate, you know, the bigger picture and then you can assign your own flavor to what it means.

You know, I think I'm truly grateful that a person like you exists at the center of the scientific community gives me faith and hope about this this big journey that we call science. So thank you for writing the book you wrote recently. You have many other books and articles that I think people should definitely read. And thank you for wasting all this time with me as a truly and I thank you.

So it's not a waste at all. And thank you for having me. I learned a lot from your questions and your remarks. Thank you. Thank you. Thanks for listening to this conversation with Avi Loeb and thank you to our sponsors, zero fasting app for intermittent fasting element, electrolyte drink, sun basket meal delivery service and pessimist's archive history podcast. So the choice is the fasting app, fasting for your fast breaking delicious meals and a history podcast that has very little, as far as I know, to do with fasting.

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Thank you for listening and hope to see you next time.