Will We Ever Become An Interstellar Civilisation? - Avi Loeb

1. 0:00 – 7:49

   Was Our Universe Created By Aliens?

   1. CWChris Williamson0:00

      What do you think is the chance that our universe was created by aliens in a lab?

   2. ALAvi Loeb0:06

      It's a possibility. We don't understand how the Big Bang, uh, came to exist, uh, and, uh, it's really troubling that there was a beginning in time, uh, and it's, um, uh, in, uh, in a way it shows the shortcoming of Einstein's Theory of, um, General Relativity which, um, has singularities, and the Big Bang is one of them. It's this, it's a time singularity. If we go back in time, there was a point in time (laughs) when, um, the space and time, um, uh, you know, had the very extreme, uh, conditions, and, and, and we can't go beyond that point. Uh, and, um, clearly the reason for that is that there is no, um, quantum mechanical theory of gravity that is predictive. And th- you know, for the past few decades, there were attempts to, uh, put these two theories together, of general relativity and quantum mechanics, and (laughs) I must say that, uh, despite the, the, uh, claims made by string theorists, they don't make any predictions about the Big Bang. They don't even make predictions about what happens inside a black hole. So as far as I'm concerned, you know, if you're a plumber, and I ask you, "Can you fix my toilet?" And you say, "No, that's too difficult." Then I ask you, "Okay, so can you fix, uh, um, my, my faucet?" And you say, "No, that's also too difficult," uh, and then you tell me, "But actually, in the Metaverse, you know, I'm a real plumber," that doesn't buy much from me. I, I would say, "You're not a bl- a real plumber." Um, so claiming that the, you're working on the unification of quantum mechanics and gravity and, and you have succ- some partial success doesn't count if you can't solve the main problems that face us, and one of them is how the Big Bang started. And I can imagine an advanced technological civilization that has these two theories unified, because they had more than a century of physics to work on, and, uh, if so, they might engineer their knowledge into creating a baby universe in the lab. And of course, our ba- our universe could've been the result of a lab, uh, experiment, and in that case it's just like humans, you know, that babies grow up to become adults and they have their own babies and so forth. So you can have a universe inside of which the, you know, it gives rise to technological civilizations that give birth to new baby universes, and, and it goes forever this way. So that's one possibility, and I consider it as possible.

   3. CWChris Williamson2:36

      I suppose this would nicely fold in the fine-tuning argument as well. Why is the cosmological constant just so, so delicately balanced along with gravity, along with the strong and weak, et cetera, et cetera?

   4. ALAvi Loeb2:49

      Well, I think it stems from the fact that, uh, a very advanced technological civilization is a good approximation to God. And of course, some people believe that God created the universe, and I'm just saying it could've been a technological civilization that unified quantum mechanics and gravity. And then, uh, the fine-tuning is also argued, "Oh, well, there was a design here, that some numbers worked out so that we exist, and these numbers were designed by some divine entity." Well, you know, here I say again, uh, whatever we see around us, including life, could've been created by an advanced technological civilization, and the only way to find out... I mean, the difference from religion is that I'm talking about something that can be tested experimentally. I- if we find evidence for such a civilization, we will know their capabilities, I mean, at some point. Once we visit their home, uh, we can see what they are up to. Or, we might see gadgets that are so advanced that, you know, we won't be able to understand them. But, and, and they would be considered as miracles, just the way Moses, you know, in the Old Testament, the Bible, Moses saw the burning bush, and that was a miracle that convinced Moses that God exists. Well, if I was around Moses at the time, I would use infrared cameras that we are using right now in, in the Galileo Project that I'm leading, and I could advise Mor- Moses about the, the surface temperature of the burning bush, the amount of energy emitted per time, and I could assess very clearly whether, uh, the burning bush is a natural phenomena or some creation of a superhuman entity, uh, so that, uh, he would, you know, have more or less awe from this, uh, phenomenon, and perhaps, uh, decide whether he believes, uh, in, in God or not. But what I am saying is, if a cave dweller came to New York City right now, the cave dweller would be at awe, and would think that everything around must be a miracle. Th- and that's what Moses felt.

   5. CWChris Williamson4:54

      You've talked, uh, about a number of, uh, super advanced civilizations. Talk to me about the different ways to classify civilizations and their respective usefulness.

   6. ALAvi Loeb5:04

      Right, so Kardashev, uh, eh, eh, Russian astronomer, he, um, classified civilizations based on the amount of energy that they are harvesting. Uh, so right now, uh, we are using up a, a small fraction of the energy from the sun, uh, that, uh, eh, is, uh, intercepted by Earth, and you can imagine, uh, like Freeman Dyson did, the, surrounding the star with, uh, some mega structure that would harvest all the energy coming out of the star. That's the next step, and, uh, Kardashev even imagined harvesting all the energy from all the stars within our Milky Way galaxy. And that would be... And of course, one can even think farther than that, um, using all the energy that the universe, the observable universe creates. Um, but, um-That is, uh, (laughs) uh, rather difficult engineering-wise, and also I don't think it's the right scale. Uh, you know, it's not, it's not just size that matters, let's put it that way, in terms of energy. It's really what you do with it and how you change your environment. And, um, so obviously, animals, they adapt to their environment, uh, whatever it is, and as humans, we started changing the environment. Climate change, uh, we created the, uh, atomic bomb, uh, as illustrated in the r- recent film, uh, Oppenheimer. You know, that was a major event because, uh, previously, uh, you know, uh, uh, nuclear energy was visible to us in stars but was never, uh, used. Uh, and, and once we started using it, of course it changed history, changed politics, changed society. Um, and so the fact that we are able to change nature, as of now, is quite remarkable. And, um, you know, we're making substitutes to, uh, biological, uh, entities like humans, uh, the human brain. Instead we have the, uh, artificial intelligence that could potentially surpass our abilities, mental abilities, intellectual abilities. But, uh, uh, one can eventually imagine us, uh, changing environments, uh, on a bigger scale, and obviously the larger scale would be to create a baby universe, uh, in the laboratory. So I, uh, think that it's, uh, uh, much more appropriate to evaluate the ab- abilities of, or, or to gauge the, uh, technological abilities of a civilization by the way that it changes, uh, everything around it, uh, ending up with creating new universes.

   7. CWChris Williamson7:48

      What

2. 7:49 – 21:14

   Avi’s Thoughts on the Recent Alien & UFO Rumours

   1. CWChris Williamson7:49

      do you make of the last few years, and specifically the last few months, of alien rumors? What's, what, what do you think is going on?

   2. ALAvi Loeb7:58

      Well, um, (laughs) I should take responsibility for part of the discussion here, because, um, uh, about a couple of years ago, I created the Galileo Project, uh, along with, uh, a colleague of mine, Frank Laukien, and, um, that, that was the result of, uh, my previous book, uh, Extraterrestrial, where, uh, I discussed the first, uh, reported interstellar object, uh, Oumuamua, that was discovered by a telescope in Hawaii, and, uh, means, uh, the- this word means, uh, scout in the Hawaiian language. And at first everyone thought it's a rock from another star, but then it had anomalies. It didn't look like familiar rocks, and it was flat in its shape, uh, had an extreme, uh, shape, and moreover, it was pushed away from the sun by, uh, some mysterious force without, uh, showing any cometary evaporation that could give it the rocket effect. So altogether, it looked weird, and I suggested maybe it's pushed by reflecting sunlight, and actually three years later, there was an object discovered by the same telescope in Hawaii that was pushed by reflecting sunlight. It ended up being a rocket booster, uh, that was launched by NASA in 1966, uh, given the name 2020 SO. Um, and so, um, uh, as a result of my book, um, uh, um, a lot of people came to the porch of my home, including some multi-billionaires, and they provided me with funds, uh, to, uh, establish the Galileo Project a month after the Director of National Intelligence talked about unidentified anomalous phenomena, objects in the sky that the government doesn't understand. And I actually met Avril Haines, that, the Director of National Intelligence, and about a half a year later at the Washington National Cathedral, and when we were in the green room, uh, I said, "Uh, you delivered this report, um, and you have a bachelor's degree in physics from the University of Chicago. What do you make, uh, of these objects that are not identified?" And she said, "I don't know," and I believe her. I think the government is simply puzzled, doesn't know, and I'm here to help them figure it out with the Galileo Project. We have a, uh, functioning observatory at Harvard University, and we are planning to make copies of it and place them in different locations, and we are basically observing the sky 24/7, uh, using infrared, optical, radio, and audio, uh, sensors, and then, um, analyzing the data with, um, machine learning, artificial intelligence to differentiate between, uh, birds, natural objects, uh, or balloons, drones, airplanes, human-made objects, and we are just checking if there's anything else. Uh, but as part of the Galileo Project, um, we also have other branches. Uh, one is to find more objects like Oumuamua that passed, uh, away from Earth and never came very close, um, and, uh, also to look for, um, interstellar meteors. These are objects that came from outside the solar system and, uh, collide with Earth. And, um, I discovered the, the first such object from 2014, uh, together with my student, uh, Amir Siraj, um, and, uh, the government confirmed this discovery, and I led an expedition, uh, uh, about, um, a month and a half ago going to the Pacific Ocean to the site of this meteor, and, uh, we did find some materials that we are analyzing now, and we can talk more about it. So that's my approach using the scientific method, uh, to answer a question that I'm curious about, that the public is curious about, and that the government is curious about. So I think, uh, it's really inappropriate for scientists to shy away from it, to ridicule the subject, because, uh, science should serve humanity.... and, uh, not just by building, uh, nuclear bombs or nuclear reactors, but also by figuring out whether we have a neighbor. That's a fundamental question that will change our future. And, um, we can use the tools of science to address this question, not by waiting for a phone call, uh, the way we did for seven years, uh, waiting for a radio signal to be transmitted in our direction. That's what SETI was all about, and surprisingly, the SETI people are not open-minded. I mean, they're really, uh, upset that, uh, this line of research of looking for objects is being taken, that I'm promoting it. I'm not sure why. Uh, uh, you know, I came from a, a culture of cosmology where, for example, the nature of most of the matter in the universe is not known. It's called dark matter. 83% of the matter in the universe was never seen in the solar system. And so, in that culture, if you suggest a, a, a possible explanation to these puzzling data about matter that we don't know its nature, then, uh, people, uh, u- encourage that because then you can have experiments that test that hypothesis. It's g- it's part of doing science. However, people that, uh, worked in the context of SETI for many years looking for radio signals are upset that there is another method which is looking for objects in our backyard to check if there is a tennis ball that the neighbor may have been th- throw... that the neighbor th- threw in our direction. Um, and I don't understand that. I, I also don't understand those people who worked on stones in the sky for decades, so they're experts on meteor- meteorites that, that are made of stone or, or, um, uh, iron at, at the very best, iron meteorites. Uh, they basically argue that anything in the sky must be stone, and, um, (laughs) what I say to that is that this represents the Stone Age of science. Uh, you can't learn something new if you think that everything in the sky must be stone. It, it, it got to a point where the US government reports data, and they confirmed it in a letter to NASA about this meteor that I described from 2014, uh, and, you know, they, uh, checked the data, and they wrote a, an official letter to NASA saying, "Yes, indeed, as Avi Loeb argues, this is, uh, of interstellar origin at the 99.999%." And yet, a year later, astronomers argue, no, the government data is wrong, uh, by a factor of three because otherwise, we can't fit the data with a stone. And I say you will never learn about something new this way. Um, we know that, for example, there is matter in the universe that is not stones. It's called dark matter. We haven't seen it. Why not be open-minded? I mean, um, y- uh, obviously they feel threatened by notions that, you know, something else might be out there.

   3. CWChris Williamson14:58

      Why, why stone? We, we have... There are many, many-

   4. ALAvi Loeb15:02

      (laughs)

   5. CWChris Williamson15:02

      ... different elements. We know that in the heart of every star, that all of these are created. I, I, I don't understand what it threatens for the current scientific establishment if it wasn't stone. Why have they hitched themselves to this particular stone-shaped wagon?

   6. ALAvi Loeb15:20

      Oh, it's very simple, because if you say that the government data is wrong by a factor of three, that this object was moving three times slower than claimed... And by the way, I should say this is the same government agency, the US Space Command, that is monitoring the sky not for meteors. They're monitoring it for ballistic missiles, and if they would make a mistake by a factor of three, they could tell the US president that there is a missile heading towards Mexico where it's actually headed towards Washington, DC. I just think it's completely irresponsible of astronomers to argue that the main agency that is funded as much as NASA, or more actually, the US Space Command, can make a mistake by a factor of three after they wrote a, a letter to NASA saying this is of interstellar origin. And, uh, moreover, the data originated from satellites, whereas the astronomers say, "Oh, it probably came from a radar," but it was publicly shared that it came from a satellite. So, you, you know, it's actually quite, um, insulting to say that to a, a government agency that went beyond their day job to confirm, uh, the identity of a meteor just for the benefit of pure science. And another way to look at it is I went there, to their site in the Pacific Ocean, and amazingly, I found molten droplets from this object concentrated along the meteor path that they talked about, the government talked about. So I sleep better at night because I know that, uh, if there are ballistic missiles ever launched towards the US, they would figure it out, whereas my colleagues would argue, "No, they can get it wrong all the time." So then, you know, what, what happens to these tens of billions of dollars per year that are going in their direction? Like, they're completely fooling themselves if the astronomers know that this, this object must be stone. So the point is, the, the argument is that it's a factor of three slower, therefore it was actually not from outside the solar system, and only then can the data be fitted with a model for a stone, because these are the most common rocks that come from the sky. They are asteroids that belong to the solar system, and they are the most common things. You know, there is only one-

   7. CWChris Williamson17:43

      I, I still don't under-

   8. ALAvi Loeb17:44

      Yeah?

   9. CWChris Williamson17:44

      ... I, I still don't understand why they're so bothered about it being stone. Why?

   10. ALAvi Loeb17:48

       Well, that- that's, uh, 95% of the rocks that fall from the sky, you know, are made of stone, okay? And, uh, 5% are made of iron. They are called iron meteorites. So, so they say we have a model that fits a lot of data on these rocks.... okay? And we can fit the government data, if the government was wrong by a factor three in its speed, then we can fit it with a stony me- meteorite. That's what they say. And I say, "Well, actually, I respect the government data. I respect data, okay?" I- I'm- I'm not trying to be arrogant and say, "Oh, the data must be wrong if my model doesn't fit it." I say, "I respect the data because they checked it. And because I respect the data, this object could not have been a rock." Now, think about Voyager, um, colliding with an exoplanet, uh, billions of years from now. We launched five probes to interstellar space over the past, uh, five decades, and one of them is Voyager, and it could collide with another planet, and then it would appear as a meteor if the planet looks like the Earth, and, uh, it has an atmosphere, and oceans, and so forth. And- and of- obviously there, you would have those astronomers saying, "Oh, no, no. The measurement was wrong. It's actually a rock," but, uh, whoever respects the data would say, "No, it must be tougher than the rocks because it survived, and it was moving faster." By the way, this meteor moved faster than 95% of all the stars in the vicinity of the sun relative to the local frame of the Milky Way galaxy, and moreover, it must have been tougher than all the rocks that were cataloged by NASA over the past decade, 272 of them. And that's the way that Voyager would appear. That's why I thought it's a possibility, and they say, "No, it's not a possibility." I say, "Okay, well, you write this paper now after I came back from the site, and I have the spherules in my hands. You tell me they are s- uh, stones, but I actually checked their composition (laughs) on the ship at the time that this paper was published," and- and approved for publication, by the way. It's not just the writers, the authors. It's actually whoever reviewed it wanted it to appear at the time that I'm coming back. And when I'm coming back, I'm coming with materials from this object, and I check them on the ship using an x-ray fluorescence analyzer, and I find that they are mostly made of iron, so obviously not a stone. Uh, and then there are other elements in- in the composition that I- I cannot mention because we are now writing the paper on these findings. So what I'm saying is, there are some scientists who declare that they are representing science when they're actually violating, uh, the- the way science is done, which is follow the evidence. So when the evidence doesn't fit what they expect, they would argue the data must be wrong, but then I respect the data, go there, collect materials from the path of the meteor, bring back the materials already knowing that it's mostly iron, and they publish a paper exactly the same time saying, "No, it's stone." And what can I say? I have respect for- for the US government for figuring it out because now I sleep better at night and I'm not so worried about ballistic missiles, but these astronomers must be really worried.

   11. CWChris Williamson21:08

       Serious ructions, serious drama going on in the astronomy world.

   12. ALAvi Loeb21:12

       (laughs)

   13. CWChris Williamson21:12

       Okay, so

3. 21:14 – 32:01

   How Avi Knew that He had Found Interstellar Objects

   1. CWChris Williamson21:14

      you go to this site. You find these spherules, these tiny, tiny little balls. You get to bring them back. You say that they have got a very high iron content along with some other stuff that we can't talk about. How do you know that these little, tiny little balls are interstellar objects? How do you know that they're not just something that's-

   2. ALAvi Loeb21:33

      Oh.

   3. CWChris Williamson21:33

      ... been naturally created terrestrially here on Earth?

   4. ALAvi Loeb21:36

      Well, that's what the paper will address, but then I- I can tell you how in principle it can be shown. Uh, before that, I just wanted to mention, uh, you know, after the sixth day of the expedition, we found mostly, I mean, we had a sled with magnets on it that collected mostly volcanic ash, and I wrote 43 diary reports that were read by millions all over the world and were translated to Spanish. People were inspired to see how science is done. So the public appreciates that. Um, and then, um, on the sixth day, I basically said, "Where are the spherules?" 'Cause I expected molten droplets to come off the surface of the object when it was exposed to the immense heat from the fireball that it created as it moved through air, and there- there were f- a few percent of the Hiroshima atomic bomb energy released into 500 kilograms, so obviously there should have been some molten droplets. And I wrote a- an essay saying, "Where are they? We- we haven't found them yet." And just to demonstrate to you that when I don't find something I expect, I say that, okay? (laughs) I- uh, I'm straightforward. I don't manipulate people. In the case of Oumuamua, we didn't have enough data to reach firm conclusions, but I said, "Maybe it's of artificial origin. It's a possibility we should leave on the table." That was the entire debate, whether we should leave it on the table or not. Here, I decide to take matters to my hand and go and collect the material so I can figure it out. And, uh, when the geologist of the team, uh, came, uh, a day later after I wrote this essay, came down the stairs from the analysis room and said, "Avi..." I was the chief scientist of the mission. He said, "Avi, we found a spherule." I immediately rushed up and, uh, looked at the microscope and it was obvious you could see this, uh, uh, spherical marble, you know, that, um, uh, looked very distinct from the background, less than a millimeter in size. And I basically hugged the person next to me who found it first, and I said, "You don't understand how happy it makes me, you know? Uh, I'm so happy." It was something we... You know, it was very challenging to find millimeter-size particles across a region that is 10 kilometers in size where the ocean depth is two kilometers, and finding it with a sled that is just a meter in width...... that has magnets on it. It's, it's an, uh, a remarkable achievement. Now, to your question. So then, I knew immediately we will find more because I'm familiar with what happens in the kitchen. I wash dishes every day. (laughs) That was the agreement with my wife. That's my duty at home. And when I see an ant, I get alarmed because I realize there must be many more ants out there. So when I saw the first spherule, I said, "Now we will find a lot." Uh, and indeed within hours, we found, uh, more. And over the, uh, uh, uh, 26 lines that we surveyed, uh, through, um, this region of 10 kilometers in size, we, uh, found, uh, 50. Uh, and, um, then when we came back, I have, uh, a summer intern. Um, and, uh, she aspires to become a, a science journalist, but at some point she said that... Her name is Sophie Bergson. She said that, "If I can be of help, let me know." And I arranged for her tweezers and microscope so she can go over the materials once again. And because the, the ship was rocky and we just didn't have enough time to go carefully, and so she went over the materials and found 650 of them. So now we have more than 700 spherules, and that's amazing. And then we could do statistics. So to answer your question, first thing is, we looked at the distribution of spherules relative to the expected path of the meteor, and there is a clear enhancement along the path of the meteor relative to the background. Okay? So that's point number one. Point number two, we can now take those spherules, each of them is a milligram roughly, and analyze them, uh, using a mass spectrometer to try to figure out their composition, and that includes two aspects. One is elements from the periodic table. We can ask, is the abundance of elements similar to solar system materials? And just to remind you, the solar system formed out of a cloud of gas that was enriched by an exploding star nearby, a supernova, and it gave it roughly the same abundance of heavy elements. And, um, so, you know, the solar system when, when it was made was roughly of the same composition. And in fact, there are some, uh, elements that have very precise, uh, values, uh, in their abundances. And, uh, what we can do is check whether the, the, the spherules have the same abundances along the meteor path. And then, of course, when we deviate from the meteor path, go far away, they should have the solar system abundances. And, uh, that's something we can check, and we are already checking. We already have some data. I cannot speak about it. (laughs) Uh, and then the second thing we can do, and we already did, is check isotopes, radioactive isotopes. These are elements that have a, a finite lifespan. Um, you can think of them as, um, uh, time bombs. They, they exist for a, a, a period of time, and they have a half-life, and you can use them as clocks. Uh, they decay into daughter products, and you can compare the abundance of these parent, uh, uh, uh, is- uh, isotopes to the daughter products and figure out, uh, the age of the material. Again, we can compare it to the age of the solar system. So, there is a very simple and straightforward way of telling apart any material you find compare, uh, uh, uh, relative to the solar system. And of course, until now, uh, all the rocks that fell from the sky were from the solar system, you know, because the... this is the first identified interstellar meteor. It's the first one where we knew that it's interstellar, came from outside the solar system because of its high speed. It was mov- uh, you know, we translated the speed near the Earth to the speed that it had far away, and it was moving at 60 kilometers per second outside of the solar system. It was r- uh, faster than nearby stars, 95% of them, outside the solar system. So, it was really fast. And if it were to collide with Earth head-on as the Earth moves around the sun, it would've had a relative speed of 90 kilometers per second. However, it came from behind the Earth, so it had only 45 kilometers per second. So anyway, um, when such an object passes through Earth, uh, through the atmosphere of Earth, uh, it loses some, um, elements, um, uh, and that is called fractionation. And just by examining the spherules, you can also distinguish between materials that came from Earth itself, geological activity, and materials that came through the air at a high speed because evaporation, um, uh, removes some of those and, um, some of the elements. And, and so what I'm saying is that there are signatures of both a meteor passing through the atmosphere, and moreover, a signature of materials associated with that meteor, uh, uh, that came from outside the solar system. Because I- if it came from far away, it was exposed to a different supernova, a different exploding star, and different, different, uh, abundances of elements.

   5. CWChris Williamson29:31

      Presumably, this means that it could just be a normal meteor from outside of the solar system. It doesn't necessarily mean that it's an alien artifact, that it's a Voyager probe but from some other star system.

   6. ALAvi Loeb29:45

      Okay, so here we get to the second question. Uh, the second question is, is it technological in origin? How can we address that? Well, imagine (laughs) Voyager entering the Earth's atmosphere at 45 kilometers per second and appearing as a meteor. Just co- uh, given its path, uh, it could happen in a few billion years that it will collide with an Earth-like, uh, planet, okay? And then, uh, imagine the surface...... of this, uh, um, Voyager meteor, uh, m-melted as a result of the friction with the air, uh, and creating spherules. Obviously, their composition, let's say, of stainless steel, would appear different than a rock, okay? And imagine, uh, melting the surface of a computer screen or melting semiconductors. Obviously, you'll have some rare elements that appear at much higher abundance than you find in nature. So, uh, there are ways of telling something technological because you can see some pattern of elements that you wouldn't find, uh, under natural setting, uh, in nature. So, uh, that's the second question that we want to address, and of course, that would be a dramatic, um, realization if true. But even if we just find it to be a rock from another planet far away, uh, near another star very far away, very different from Earth, that is a historic discovery because it's the first time that humans put their hands on the materials from a large object that came from outside the solar system. And we will have confirmation from two directions. One is the speed of the object, which some of my colleagues dismiss and say the government measured it wrong. But completely independently, if we see that the composition of the materials is not solar system material, then, um, you know, that's, uh, obviously, uh, uh, uh, a- an independent piece of evidence telling us that it came from far away. It's interstellar, which happens to be the title of my book, Interstellar. So let's see

4. 32:01 – 43:22

   Promising Methods of Future Interstellar Travel

   1. ALAvi Loeb32:01

      what happens.

   2. CWChris Williamson32:02

      So that's us detecting using, uh, experimental design in order to be able to search for out there and also detect samples of materials that are from different star systems. Let's get onto us, us as humanity. If it's the case that we are on a very long but still ticking down clock to where the ultimate global warming is going to occur when the sun expands, right? Like, global warming is happening regardless of how vehement you disagree with the levels of sea temperature, because over a long enough time, the sun's gonna engulf us all. That means that we need to get off planet eventually. In your opinion, what are some of the most promising ways that we could travel across interstellar distances? What have you- what have you sort of thought about when it comes to this?

   3. ALAvi Loeb32:51

      Right. So first, I should say that irrespective of what we do about our own industrial pollution and global warming that we trigger by our technologies, uh, there will be an inevitable global warming that will basically boil off the oceans. And that will happen in about a billion years because the sun is getting, uh, brighter, and the calculations of the evolution of the sun imply that, uh, there would be, um, uh, uh, boiling of the ocean as a result of, um, uh, uh, the interplay between the Earth's atmosphere and the- and the ground. And, um, so, um, we don't have more than 20% of, uh, the lifespan of Earth, uh, to continue life as we know it, okay? And we will... And, and it's, you know, most of the stars formed billions of years before the sun, and, uh, therefore, stars like the sun with planets like the Earth already went through that, a lot of them, billions of those. And we probably didn't hear the cries for help from those civilizations who decided to stay on the planet. It was the biggest item in the news reports, not so much the, the global warming they make, uh, as a result of the technologies if they happen to overcome that. It was the fact that they, they just sit at a fixed distance from their star, and the furnace is getting hotter. So you have to move out, but you can't bec- if you are stuck to the planet. And perhaps they had some, uh, major exodus in, uh, spacecraft, uh, leaving the planet that we are not aware of. There must have been a lot of tragedies, that's what I'm trying to say, over cosmic history. We just tend to think about stars and say, "Look, these stars evolve in this way and that way based on the physics we know." But we are missing the human perspective of just imagine the star evolving in the way that we expect it to. How many tragedies of other cultures, other technological civilizations happen in the Milky Way galaxy alone? And, um, you know, now there are these, uh, uh, completely, um, desert-like, uh, surfaces of planets that used to have life as we know it, and, um, it's really tragic. We... A- a lot was lost over cosmic history. Now, if you ask me, "What would the future hold?" So actually, frankly, I'm very proud of our technological kids, okay? Which, at this time, are the artificial intelligence systems that we are developing and they're growing in their capabilities exponentially. So it's possible that by the end of this decade, they would surpass, by a large margin, uh, the human brain, okay? And I'm proud of that. I don't see that as a threat because it's not obvious to me that biological creatures like ourselves are any different than, um, the primitive, uh, you know, um, uh, single-cell organisms that were on Earth to start with, and they were replaced by more advanced, uh, entities. And, uh, so perhaps we are just one phase in the evolution, and ultimately, it will be all about the...... artificial intelligence and self-replicating probes that are not biological, okay? We, we of course learn from nature. We are trying to replicate the human brain. We're trying to make, uh, 3D printers that will, uh, produce, uh, three-dimensional objects. We haven't yet produced a self-replicating car. You know, a car, even a car that can repair itself like the human body, uh, that you put a Band-Aid on it after an accident and it will repair itself, we don't have that (laughs) and it will take us a little while. But, um, ultimately, you know, we will get to the point where artificial intelligence carries the torch of intelligence, at least here on Earth. And I believe that it should do so also in space, because when you send a probe to interstellar distances, it, it would take millions to billions of years for it to reach, uh, any destination. And, and that means, uh, thousands of light years away, and any such probe cannot wait for guidance from the senders. It will take thousands of years for a one-way communication signal. And so they need to have their brain if you want them to function when they reach their destination. Obviously, artificial intelligence is a, a better path forward than biological brains, because they're very vulnerable. Biology is very vulnerable to cosmic rays. You know, you can't survive in space for more than a few years exposed to cosmic rays, even if you wear a space suit. Um, and, uh, that's one problem by, uh, in going to Mars that doesn't have an atmosphere. We, we would need to go into caves, into lava tubes, to be protected from cosmic rays. But moreover, human lifespan is very limited, and this would be millions, billions of years. So it's much better to send technological gadgets potentially that would, uh, self-replicate. And that's the way I see it. Uh, now, they will carry, uh, whatever, uh, you know, uh, tasks we provide them with. Maybe we can ask them to replicate what we care about here. So instead of sending what we have here, uh, bio- biology the way we have it, we can perhaps have them seed biology over at great distances by using the raw materials on a planet that appears to be habitable or create whatever we feel like, uh, out there. And to me, that's th- that's the best path forward, sending the type of equipment that can carry, um, the intellectual DNA, the, uh, whatever we care about, um, elsewhere and reproduce it wherever we want it if we want to replicate it so that we have many copies of it. Now, of course, in the solar system, we might, uh, bring people to the moon, to the, to, to Mars, um, and, um, it would be interesting to establish colonies there. But this is, uh, not really going, uh, very far from the sun, and it would not solve the long-term issue of, uh, longevity. Uh, so I do believe in (laughs) technology, uh, leading the way. And of course, if we find that someone else did it already, that would inspire us. That would give us a glimpse at our technological future. That's why, you know, I was, uh, actually, I'm jogging every morning at sunrise, and I did so also on the ship, uh, that was fittingly called Silver Star. And I had a filming crew with me, and you know, there were f- 50 filmmakers and producers and directors that contacted me. They wanted to be on the ship, and I selected one. But the director of that, uh, filming crew, they, he decided to, uh, film me, uh, one morning on the deck of the ship when I was jogging, and he said to me, "Avi, you are running. Uh, are you running away from something or towards something?" And I told him, "I'm running away from some of my colleagues who have very strong opinions without seeking evidence, and I'm running towards a higher intelligence in interstellar space."

   4. CWChris Williamson40:14

      Yes. So what you're suggesting is, it seems, it seems like you, you think it would be unlikely for a human or a generation ship of a series of humans to go from Earth to some other star system, like l- let's say Proxima Centauri, Alpha Centauri, et cetera. You think it's much more likely, much more feasible to go artificial intelligence, put it on a ship, maybe have a desktop encoder for bioengineering or something like that. It's got the code, it gets there, it then deploys the code. Uh, I think I, I understand how you could see that as a solution. Uh, I don't think that that's going to satisfy most people's feeling or their desire for-

   5. ALAvi Loeb41:05

      No, no.

   6. CWChris Williamson41:05

      ... human civilization to continue.

   7. ALAvi Loeb41:07

      It will not satisfy most people's desires, but just think about a dandelion flower. Okay? What does a dandelion do? (laughs) It sends off seeds that are carried by the wind, and they carry the DNA of the dandelion flower and establish new flowers. Now you might say, "Oh, that's not satisfactory, because as a dandelion flower, I really want to be out there in other places." But no, that's not what nature... What nature cares about is longevity of information content. And in the case of the dandelion flower, it's not the identity of the single dandelion. Actually, for humans as well, you know, all of us die, right? So w- we have kids that carry our DNA. We gave up on us living forever, or some people didn't give up, but we don't have an option. Okay, let's put it that way. Uh, and what I'm saying is, if you think about it more broadly, it's not so much about yourself as an individual.... uh, it's about maintaining (laughs) longevity of the, what you care about. Uh, and the dandelion flowers, uh, I mean, at least from the point of view of biology, cares about having more dandelion flowers, like, uh, preserving the beauty of the dandelion flower. And therefore, it doesn't have any umbilical cord connecting it to the seeds. You might say, "Oh, if it wanted, it could have been connected to the seeds." No, but that doesn't work very well, because then you need a long wire that goes all the way (laughs) to where the seed lands on the floor. Uh, and only then the dandelion will learn something about what the s- the whereabouts of the seeds. But in the way that nature does it, it just sends the seeds with the wind, and they do their job, and sort of there is some trust in the system. So in the same way that you send a, uh, a spacecraft with AI somewhere and you don't communicate with it because it takes a long time, it's very cumbersome for the, for you to communicate with it, you just trust it. It will do the job. (laughs) And that's the way nature works.

   8. CWChris Williamson43:21

      Do

5. 43:22 – 52:28

   Will Humanity Ever Visit Another Galaxy?

   1. CWChris Williamson43:22

      you think that we will ever physically visit another galaxy, whether that be an AI robot, whether that be a spacecraft that has the seeds of our Noah's ark, spacecraft Noah's ark? Um, obviously we, I'm aware that we're talking about, "Oh my God, we found something from outside of the solar system," and I'm saying, "Why don't we take it one step further and go outside of the galaxy?" But what do you think? Is, is that something that's realistic? Could we get from-

   2. ALAvi Loeb43:49

      Well, uh-

   3. CWChris Williamson43:49

      ... the Milky Way to elsewhere?

   4. ALAvi Loeb43:50

      ... here is a, a fact of life that we need to accept. Uh, that the universe is not just expanding, uh, its expansion is accelerating. And that means that any distant galaxy beyond the local group of galaxies, the ones, uh, surrounding the Milky Way, any galaxy farther away than a few million light years, uh, is running away from us at an ever-increasing speed. And once the universe will age by a factor of 10, all these galaxies will recede away from us faster than the speed of light. So, even if you build the fastest spacecraft that moves at the speed of light, you won't be able to catch up with them. And if you ask me, (laughs) there is only one galaxy outside the Milky Way that we have a chance of getting to. I mean, we could aim to get to more, but that would require propulsion at speeds that are getting close to the speed of light. But the one that we have a good chance of getting to is the one that will collide with the Milky Way and merge with it.

   5. CWChris Williamson44:55

      That's a cheating ... That, I knew you were gonna give that answer, and that's cheating.

   6. ALAvi Loeb44:58

      (laughs)

   7. CWChris Williamson44:58

      Uh, we can't, we can't wait for Andromeda to come to us. That's not the same-

   8. ALAvi Loeb45:04

      Okay.

   9. CWChris Williamson45:04

      ... thing that I meant.

   10. ALAvi Loeb45:05

       So I actually did a calculation and asked, um, suppose you move, uh, uh, you know, at, uh, uh, at a higher speed than chemical rockets, how far can we go? Okay? And if you have a spacecraft that moves 10 times faster, you can go within the so-called Virgo Cluster of galaxies, that's, uh, within a distance of, uh, some, uh, tens of millions of light years. We can do that. Uh, but you need a propulsion scheme that, uh, is 10 to 100 times, uh, faster. 100 times would buy us that, uh, uh ... Otherwise, uh, it's just, um, you know, the, the universe expansion is too rapid. Uh, so I can imagine us getting to other galaxies as long as we can make our propulsion let's say 100 times faster than all the spacecraft that we launched so far. And of course there is a benefit to that, because then we can all settle in a bigger environment. Like, the center of the Virgo Cluster includes the Andro- uh, the galaxy M87, which is a giant elliptical galaxy, and there are many more stars there, uh, than the Milky Way has by a, uh, uh, a factor of about 100. So, um, uh, you know, we will just have a bigger party over there as the rest of the universe recedes away from us. More resources. And actually, I had a correspondence with Freeman Dyson about a decade ago on this subject because, um, um, what I pointed out is that as the universe is ex- uh, accelerating, you know, we will be left in a lonely place. And he said, "Why don't we contact all these other civilizations out there far away and arrange, um, a project of, uh, cosmic engineering where all of us would come together, uh, by moving our stars with us?" And I said, "That's too much work." I mean, we can do much better by just simply going to a cluster of galaxies, like the Virgo Cluster, and finding, uh, you know, hundreds or maybe thousands of times more stars in our environment. Uh, and then instead of us moving stars, we can just go to where the stars are, which are clusters of, a cluster of galaxies nearby. Uh, so, yeah.

   11. CWChris Williamson47:20

       Okay. So this, this is, this is kind of the same as cosmic fertile ground, so to speak.

   12. ALAvi Loeb47:25

       Yeah.

   13. CWChris Williamson47:25

       And so y- I know that you mentioned about how, uh, galaxies are moving apart, they're going to move apart at ever, ever-increasing speeds. Is the Virgo Cluster, even though they are distinct individual galaxies, are they sufficiently gravity-bound that that's going to stick together? That's not going-

   14. ALAvi Loeb47:42

       Yes.

   15. CWChris Williamson47:42

       ... to blow apart? Is that right?

   16. ALAvi Loeb47:43

       The Virgo Cluster will stick together, but if we don't go there, uh, it will go-

   17. CWChris Williamson47:48

       It's going to move away too quickly.

   18. ALAvi Loeb47:49

       ... it will move away from us. So what-

   19. CWChris Williamson47:49

       Yeah.

   20. ALAvi Loeb47:49

       ... we need is to go there, and then we'll have, uh, you know, the company of, let's say, 1,000 times more stars than the Milky Way has. So, um, you might imagine a situation where we are not the first to recognize that, that in fact other civilizations decided to do that, and then you have a flow of these spacecraft towards the center of the Virgo Cluster right now because everyone recognizes that they want to be there. So that's like-

   21. CWChris Williamson48:15

       The race to the fertile ground.

   22. ALAvi Loeb48:17

       (laughs) Well, I would call it a cosmic party, where you can celebrate until you exau- until the, the lights, uh, go down. And the lights, uh, the lights will go down, if you ask me, "When would that happen?" That would happen, uh, when the smallest stars will burn up their fuel, which will happen when the universe will age by another factor of almost a thousand. Uh, so in 10 trillion years, um, eh, that's when the tiniest stars will go away, uh, and those are the most common stars. It, eh, so we are fortunate, the nearest star to the sun is actually a dwarf star, Proxima Centauri, and, uh, it would live, um, for trillions of years. You know, the sun will die, uh, at- a- a- at an age of, uh, 1% of that. So, um, so it's 100 times... It will have 100 times longer lifespan. And obviously, if you want to, uh, get the- the light from, uh, a nuclear furnace like this, like a star, then we want to come close to a dwarf star like Proxima Centauri. A- and amazingly, it has a planet in the habitable zone. Uh, but then you might ask, "Why are we close to a star that is not typical? If most of the stars are dwarfs, why do we reside next to the sun?" And there might be a reason for that because these furnaces, the dwarf stars, you know, they're much, uh, fainter because they have less fuel but then they burn it more slowly than the stars like the sun. So in order to keep yourself warm, you need to get closer to them. In the case of Proxima Centauri, you need to get 20 times closer. That's where the habitable zone is. And then when you are so close to a star, you are vulnerable to the eruptions on the star, the flares, and those can remove the atmosphere of habitable planets. So it's prob- possible that, uh, the best place is, uh, being close to, to a star like the sun. But o- obviously, you know, in the future, the sun will not stay around and we would, we could create our own nuclear energy. You know, we can, uh, use a nuclear reactor to provide all of our, uh, energy needs.

   23. CWChris Williamson50:32

       Well, my favorite theory, one of my favorite theories about far-flung future civilizations, uh, i- is the idea that we would wait until you get really close to heat death of the universe, because it's then very, very cold, which means that if you want to run computer systems, they can burn off all of their heat. As a byproduct of that, they can be kept cool, they can run more efficiently. You're now doing simulations within simulations within simulations of you and all of your ancestors, and it's this blissed out, completely perfect world that you want to exist in or whatever artificially, uh, recreated consciousness. You can do that much more easily when the universe is much cooler. So yes, you have a, you have an energy problem because you no longer have as much energy that you have access to, but I've seen a number of theories that talk about a- almost going into hibernation, super advanced civilizations going into hibernation, capturing energy or finding a way to create their own energy for as long as they need to and then switching off or going into standby mode, waiting for the universe to get down to a requisite cool temperature and then switching back on again.

   24. ALAvi Loeb51:38

       Yeah. I mean, this is, um, similar to, um, you know, some, uh, people as they get old, they go on a diet that, um, uh, keeps them more, uh, healthier so they can, uh, live longer. But of course, the best way to prolong, um, the longevity of your DNA is to have a lot of kids that will have more kids that will have more kids, rather than you. Uh, s- and so here I come back to the idea that if we... You know, by that time, it's quite likely that whoever is around will figure out how to make baby universes. And by creating baby universes, you can basically put whatever you want in those babies, uh, in terms of their qualities such that you will know that, uh, life will continue in them.

   25. CWChris Williamson52:27

       Have you

6. 52:28 – 56:18

   Average Length of Existence of Non-Interstellar Civilisations

   1. CWChris Williamson52:28

      thought about how long the average civilization that doesn't become interstellar would exist for? Obviously, we've spoken...

   2. ALAvi Loeb52:39

      Well, that, that depends a lot on how intelligent they are, because if you look at what we do, we spend $2 trillion every year on military budgets. Uh, we are thinking about how to kill other people or how to protect ourselves from being killed. You know, that, that was, uh, true, uh, you know, when we were in the jungle, you know, and had the, to, uh, survive in zero sum games. It's not true anymore. We could have worked together. Uh, instead of conquering small pieces of land and being proud of that, uh, you know, we- we are talking about, um, you know, the, the surface of this rock that we happen to be born on, like, why is that so valuable? Uh, why do we need to feel superior relative to other people just for superficial reasons, like the color of their skin or their ethnic origin? I mean, this is completely ridiculous if you think about it from a perspective of intelligence, yet we spend $2 trillion a year on that. Now, imagine if we were, you know, uh, eh, if we were to find, um, a sign of a cosmic neighbor and we will tell ourself, "Wait a minute, that makes no sense. You know, look at this other civilization, they live much longer. Look at the technologies they developed. Why aren't we, uh, having a different set of priorities?" And, and then we will remember the words of the song by John Lennon who said that, "Imagine all the people living in peace." And we would say, "Oh yeah, that's a good idea. Let's live in peace and let's use..." Then we will have a, uh, a surplus, uh, $2 trillion a year. What can we u- do with it? Uh, we can use it for space exploration. And I did the calculation, I did the math, and, uh, with that budget, we can send a probe to every star in the Milky Way galaxy.... by the end of this century. Billions of probes by the end of this century, sending them. Of course, it will take them time to get there, you know, maybe billions of years, but we can just do that. Now, imagine, uh, uh, an- another civilization who reached this conclusion. They have their own John Lennon. They got their own inspiration. They're more intelligent (laughs) than we are. They're not wasting resources on fighting each other and conquering a small piece of land on this rock that they were born on, okay? They, instead they say, "Let's work together rather than kill each other. Let's not feel superior relative to each other. Let's thrive towards, uh, a better future." So prosperity is recognized as a priority rather than a zero-sum games. And then imagine them sending probes everywhere, and then these probes make their way. And by the way, uh, (laughs) uh, the speed of those probes that we sent so far is at least 10 times smaller than the speed needed to escape from the gravitational pull of the Milky Way galaxy. So if, if others send probes like that, they would keep accumulating in the Milky Way galaxy over cosmic time and over billions of years, so just like plastics in the ocean, and many of those will not be functional anymore. Just imagine, you know, Voyager a billion years from now, it will not be working. It will be just space trash. And just like plastics in the ocean, it's trash, but it keeps accumulating, and the- the same would happen with all these probes. That's what I'm talking about. Let's check our backyard and see if there is a tennis ball thrown by a neighbor.

   3. CWChris Williamson56:04

      Right. We have... The difficulties that are facing going interstellar pale in insignificance in the different difficulties going intergalactic. I'm kidding.

   4. ALAvi Loeb56:15

      Oh, yeah. But the-

   5. CWChris Williamson56:17

      So talk to me. Can you t-

7. 56:18 – 1:01:54

   What Difficulties Would You Face on an Interstellar Journey?

   1. CWChris Williamson56:18

      just...

   2. ALAvi Loeb56:18

      Yeah.

   3. CWChris Williamson56:18

      One thing that I was really interested by, w- no matter what the spacecraft is, let's say that it was seeded with a, a tabletop bioengineering 3D printer that can recreate human babies in a test tube or something. Can you just talk me through the journey? Pick any star that you want. Pick any star that you think looks like a nice piece of real estate within the Milky Way galaxy. Can you just explain what the major hurdles upon that interstellar journey would consist of? I know we've got the Oort cloud. We've got different things that we need to get through, like what are the, what are the main hurdles that we need to get past?

   4. ALAvi Loeb56:53

      Right. So first, I should say that even biology, we should not dismiss it altogether, because just recently, there were some worms found in the, uh, uh, in s- in the Siberian permafrost, and then, uh, they were frozen. And after they were rejuvenated in the laboratory, they came to life 46,000 years after they became, uh, frozen, 46,000 years. So one can imagine engineering biology perhaps to survive interstellar travel. That, that is something for the future. Um, so we don't yet know if it's possible, but it may be. But then in terms of the timetable, um, so let's imagine the kind of spacecraft we are launching right now because that's what we are doing. I mean, I, of course, am leading a, a, a very ambitious, uh, initiative called Starshot to launch, uh, a spacecraft at the fifth of the speed of light to the nearest star. It will take 20 years, but we are not there yet. The technology is very challenging. So let's, um, imagine chemical rockets of the type that we used, um, and so a chemical rocket just like Voyager 1, Voyager 2, Pioneer 10, Pioneer 11, and New Horizons that are making their way out of the solar system. So these were launched over the past 50 years, okay? So they are still deep inside (laughs) the solar system. The solar system, by the way, the Oort cloud is 100,000 times larger than the Earth-sun separation, okay? So these, uh, spacecraft will exit, will get to the outskirts of the solar system, the edge of the Oort cloud, which is, by the way, halfway to the nearest star, Proxima Centauri. They will get there, uh, within about 10,000, 20,000 years, depending on which spacecraft you are talking about. Um, uh, so we're talking tens of thousands of years, okay? They will not be functional. We may be gone by then. That's another lesson that you can look for packages in your mailbox while the sender is dead. That's the advantage of, uh, of that compared to the method of SETI to look for a phone call, to search for someone sending you a radio signal. It needs to be active. So here, you know, we might be dead by the time our packages leave the solar system, at least the ones that we sent so far. Um, and if we send something much faster in the future, it will overtake those very slow ships that sail through space. (laughs) Um, okay, so after 10,000 years, we leave the solar system. We start making our way into inter... This is truly interstellar space at that point because we cross the midpoint separating us from the nearest star, okay? And then, um, to get to the nearest star, we'll take, uh, s- some more tens of thousands of years because we crossed the midpoint. (laughs) Uh, so, uh, we're talking tens of, uh, maybe 50,000 years to reach the nearest star, and that is roughly the time that elapsed since the first humans left Africa, okay? Just think about it. If we were to send a spacecraft when the first humans left Africa, it would get to the nearest star just now. (laughs) And then, um, then, um, if we continue to, uh, the voyage, uh, through space, how long will it take us to go to the other side of the Milky Way galaxy? That will take us half a billion years. So, um, it sounds long, but it actually...... is not so long because, uh, the time difference between the formation of most stars and the formation of the sun is billions of years. Most stars form billions of years before the sun. So, there was enough time even for chemical rockets to make their way to our doorstep. But that's, um ... and, and at that speed, we can't really exit the solar system as, as you can tell, because the edge of the solar system is, uh, another factor of 10 farther away, and that would make the travel time equal to the age of the universe and-

   5. CWChris Williamson1:01:01

      Oh, you mean the edge ... not the age of the solar system, the edge of the galaxy, you mean?

   6. ALAvi Loeb1:01:06

      Sorry, the ... yeah. The, the time, uh, to cross, uh, the age of the Milky Way galaxy would be longer than the age of the universe.

   7. CWChris Williamson1:01:15

      Yes. Okay.

   8. ALAvi Loeb1:01:16

      Uh, because, uh, it's 10 times bigger than, uh, the Milky Way disc that I was alluding to before, going to a star on the other side of the Milky Way galaxy. So there is the entire halo of dark matter of the Milky Way which is 10 times bigger, or ev- even more, 20 times bigger, than the extent of the disc of stars that are at the s- near the center of the Milky Way galaxy. So actually, g- (laughs) if you think of galaxies, there is the luminous part which is sort of like a light bulb in the middle, but then there is this big structure that is invisible to us of dark matter that is 20 times bigger.

8. 1:01:54 – 1:08:00

   How to Reach the Nearest Star at 1/5 Speed of Light

   1. CWChris Williamson1:01:54

      What is your proposed pro- propulsion mechanism to get to the, the nearest, closest star at one-fifth the speed of light?

   2. ALAvi Loeb1:02:05

      Oh, that is using a light sail. Basically, a very thin membrane. Uh, that's the concept of the Starshot project. Uh, if this, uh, membrane weighs, um, uh, about a gram, if it has the size of a person, roughly, and it's being, uh, pushed by a very powerful laser, a 100-gigawatt laser for a few minutes, it would reach a fifth of the speed of light. And you can put, uh ... in this light sail, you can put, uh, uh, some electronic, uh, um, uh, infrastructure that, that, uh, could record w- um ... for example, take a photograph when it comes close to the, uh planet near Proxima Centauri and also transmit the signal to us. Uh, that is not so much of a challenge. The, the big challenge is generating this photon engine, the radiation that, uh, uh, associated with a laser such that you have a beam of light focused on the sail and pushing it. Uh, the sail itself can be made of materials that we already know and that it could be sufficiently tough. Um, uh, the main challenge is, uh, getting, uh, it, uh, to maintain a stable ride on the light beam with a very powerful laser, and then communicating whatever it finds, uh, near the planet around Proxima Centauri. And I should say that it takes a few minutes to get it to a fifth of the speed of light, then it continues the travel like a bullet towards the destination. That will take 20 years at the fifth of the speed of light. So, it's two minutes of, uh, very fast, uh, acceleration and then, uh, a coasting over 20 years before it gets to the destination.

   3. CWChris Williamson1:03:51

      That's crazy.

   4. ALAvi Loeb1:03:52

      So you need a lot of patience. That's all I'm saying.

   5. CWChris Williamson1:03:54

      Well, you need a little bit of patience. You need a lot more accuracy, I think.

   6. ALAvi Loeb1:03:57

      Right.

   7. CWChris Williamson1:03:57

      That's the main, that's the main thing. Yeah, so one other thing that I was thinking about, it seems to me it's probably disheartening to hear that, you know, there isn't going to be a human, or it seems unlikely in your estimation that a human will go to some other system, that it's, it's likely to be seeded by whatever, whatever. That-

   8. ALAvi Loeb1:04:16

      Well, I, I would not rule it out, by the way. Uh, if you go through the numbers, if we develop this technology of light sails and you get to the extreme of using all the energy intercepted by Earth from, uh, sunlight, you know, uh, and you use all that energy to create a very powerful radio beam that is pushing a sail, a, a giant sail this time, it could propel humans at an acceleration of one G for about a year. Uh, and if you accelerate it at one G for one year, you can reach the speed of light.

   9. CWChris Williamson1:04:59

      Wow.

   10. ALAvi Loeb1:04:59

       And, um, that is possible in principle, and we would not feel any different than being on Earth because gravity gives us an acceleration of one G on the surface of Earth. So if you board a spacecraft that is accelerated, accelerating at one G, it would feel just like being on the surface of Earth. And, uh, the only issue is how to build such the infrastructure necessary to use all the power coming from the sun on Earth towards creating a giant radio beam that pushes on a light sail. But in principle, I did the calculation. It's possible.

   11. CWChris Williamson1:05:35

       Is there not a second problem, which is how do you slow down?

   12. ALAvi Loeb1:05:38

       Oh, for that you need (laughs) a similar beam on the other end. But if you just, uh, get to the speed ... By the way, if you board such a ship and you continue accelerating at one G for 20 years, you can cross the entire universe while the universe is aging, but because of time dilation, according to Einstein's special theory of relativity, you can do it in your lifetime. So, the only, uh, problem there is that you need a huge amount of power to k- keep accelerating for 20 years at one G, but-

   13. CWChris Williamson1:06:12

       But I thought-

   14. ALAvi Loeb1:06:13

       ... the point is-

   15. CWChris Williamson1:06:13

       ... you couldn't go quicker than the speed of light.

   16. ALAvi Loeb1:06:15

       You cannot ... Well, according to what we know in physics, we cannot go faster than light, but you don't need to. You just need to go very close to the speed of light, and then time is ticking more slowly in your spacecraft than it is in elsewhere. So the universe, you know, will age by billions of years while you are aging just by a decade.... and, uh, because you are getting so close to the speed of light. Of course, there are lots of practical problems, how to get enough power to propel you at 1 G for such a long period of time, and also when you're moving so fast, any particle of dust or any, uh, material that you collide with will generate a huge explosion on your ship.

   17. CWChris Williamson1:06:58

       Yeah, very good. I saw a visual representation, a computer simulation of what it would be like to approach the speed of light from the front deck of a ship, and all manner of weird stuff starts happening. The way that, that light moves past you and doesn't, um, i- it's very, very bizarre.

   18. ALAvi Loeb1:07:17

       By the way, that is the best way to maintain longevity. When the universe ages by billions of years, you are just aging by decades, and-

   19. CWChris Williamson1:07:24

       Just move fast, move faster.

   20. ALAvi Loeb1:07:26

       ... uh, yeah, just move fast. And of course, then, uh, if you have a similar system, uh, elsewhere, you can slow down. The, the problem is you need someone else to build it. Um, so, um, uh, otherwise you will just move at that speed for a very long time (laughs) . Um, of course, this is, you know, this is science. Uh, we are not, um... I mean, there are practical problems, but it's all allowed by the laws of physics. I don't like science fiction because it violates the laws of physics, the, the storyline, very often.

   21. CWChris Williamson1:07:58

       Avi Loeb, ladies and gentlemen.

9. 1:08:00 – 1:10:55

   Where to Find Avi

   1. CWChris Williamson1:08:00

      Avi, I really appreciate your work. I'm very excited to see what you come up with on this new paper, what you can reveal to the world once you've finally got your work done and, and got it past everything. And I'm interested to see what other groups of people and colleagues you can piss off as you continue to (laughs) -

   2. ALAvi Loeb1:08:16

      (laughs) .

   3. CWChris Williamson1:08:16

      ... to do your research. Where should people go if they want to keep up to date with all of this stuff that you're talking about, and publishing, and all the rest of it?

   4. ALAvi Loeb1:08:22

      Yeah. Uh, f- I just wanted to comment on what you said, the footnote, that, uh, you know, we know that we are not at the center of the universe, and we also know that humans came to exist only over the past few million years. So if you come to a play, a cosmic play in this case, you are not at the center of the stage, and you're coming at the end of the play, the play is not about you. And, uh, the best way to find out what it's about is to look for other actors and ask them. So that's what I'm trying (laughs) to do. Um, in terms of, uh, my writings, I have essays on medium.com. Uh, you can just type, uh, Avi Loeb at medium.com where you can find updates about my research. Also, I have a website on, uh, at Harvard University that you can go to, the professional website, where you can see some links to papers and videos and interviews and other things. And, um, I have no footprint whatsoever on social media, uh, because, uh, you know, I just realized that if you want, um, an, uh, an airplane to fly faster, you reduce the friction with air. You reduce its cross-sectional area. So I reduce my friction to the best of my ability with other people who may criticize me, w- may want to slow me down. I simply don't have any footprint on social media. Another, uh, metaphor (laughs) that I should mention in this context, there is the metaphor of the crow and the eagle. So, the crow is the only bird that can sit on the eagle's back and peck at the eagle's neck. And there are photographs of, uh, crows on the backs of eagles. But the eagles do not waste any energy or effort pushing the crows away. Uh, what they do is, uh, rise to greater heights where the oxygen level is low and the crows just drop off their back. To me, the l- the, the greatest height is to do my science in the best possible way by collecting evidence, material evidence, and studying it and reaching my conclusions based on what the evidence shows. And, uh, once I get to those heights, all the crows that are currently pecking (laughs) at my neck will drop off.

   5. CWChris Williamson1:10:42

      What a mic drop. Avi, I really appreciate you. Thank you, mate. If you enjoyed that episode, then press here for a selection of the best clips from the podcast over the last few weeks, and don't forget to subscribe.

Episode duration: 1:10:56