whatever, I mean, broadly thinking because we tend to think other alien civilizations would be very human-like. But if we think of alien civilizations out there as basically generators of black holes, however they do it because they get stars. Um, do you think there's a lot of them in our particular universe out there in our universe? Well, okay, let me ask. Okay, this is great. Let me ask a very generic question, and then let's see how you answer it, which is, uh, how many alien civilizations are out there if the hypothesis that I just described is on the right track? Yes, it would mean that the parameters of our universe have been selected so that intelligent civilizations will occur in sufficient numbers so that the if they reach something like supreme technological maturity, let's define that as the ability to produce black holes, then that's not a highly improbable event. It doesn't need to happen often because as I just described, if one, if you get one of them in a galaxy, you're gonna make more black holes than the stars in that galaxy.

but there's also not a super strong motivation. Well, it's not obvious that you need them to be ubiquitous throughout the galaxy, right? So, one of the things that I try to emphasize in that paper is that given this idea of how our parameters might have been selected, it's clear that it's a series of trade-offs, right? If you make... I mean, in order for intelligent life of our variety or anything resembling us to occur, you need a bunch of stuff. You need stars. So, that's right back to Smolin's roots of this idea, but you also need water to have certain properties. You need things like the rocky planets like the Earth to be within the habitable zone, all these things that you start talking about in the field of astrobiology, trying to understand life in the universe. But you can't overemphasize. You can't tune the parameters so precisely to maximize the number of stars or to give water exactly the properties, or to make rocky planets like Earth the...

most numerous you have to compromise on all these things and so i think the way to test this idea is to look at what parameters are necessary for for each of these different subsystems and i've laid out a few that i think are promising there there could be countless others and see how changing the parameters makes it more or less likely that stars would form and have long lifetimes or that or that rocky planets in the habitable zone are likely to form all these different things so we can test how how much these things are in a tug of war with each other and the prediction would be that we kind of sit at this central point where if you if you move the parameters too much stars aren't stable or life doesn't form or technology's infeasible because cause life alone at least the kind of life that we know of cannot make black holes we don't have this well i'm speaking for myself you're a very fit strong person but it might be possible for you but not for me to compress matter so we need these

technologies. But we don't know. We have not been able to quantify yet how um finely adjusted the parameters would need to be in order for silicon to have the properties it does. Okay, this is not directly speaking to what you're saying. You're getting to the Fermi paradox, which is where are they? Where are the life forms out there? How numerous are they, that sort of thing? What I'm trying to argue is that if this framework is on the right track, a potentially correct explanation for our existence. We do. It doesn't necessarily predict that intelligent civilizations are just everywhere because even if you just get one of them in a galaxy, which is quite rare, it could be enough to dramatically uh increase the fecundity of the universe as a whole. Yeah. And I wonder once you start generating the offspring for universes black holes, how that has effect on the what kind of effect does it have on the other uh candidates civilizations within that universe. Maybe it has a destructive aspect or there could be some arguments about once you

have a lot of offspring that that just quickly accelerates to where the other ones can't even catch up. It could, but I guess if you want me to put my chips on the table or whatever, I think I come down more on the side that intelligent life civilizations are rare. Um, I guess I follow Max Tegmark here, and also there's a lot of papers coming out recently in the field of astrobiology that are seeming to say, All right, you just work through the numbers on some modified Drake equation or something like that, and it looks like it's not improbable. You shouldn't be surprised that an intelligent species has arisen in our galaxy, but if you think there's one the next solar system over, it's highly improbable. So I can see that the number, the probability of finding a civilization in a galaxy, maybe it's most likely that you're gonna find one to a hundred or something. But okay, now it's really important to put a

time window on that i think because does that mean in the entire lifetime of the galaxy before it it um so for in our case before we run into andromeda um i think it's highly probable i shouldn't say i think it's tempting to believe that it's highly probable that in that entire lifetime of your galaxy you're going to get at least one intelligent species maybe thousands or something like that but it's also i think a little bit naive to think that they're going to coincide in time and we'll be able to observe them and also if you look at the span of uh life on earth the earth earth history it was surprising to me to kind of look at the amount of time well first of all the the short amount of time there's no life it's surprising life sprang up pretty quickly it's cellular single cell but that was that's the point i'm trying to make is like so much with what of life on earth was just like single cell organisms like most of it most of

it was like boring bacteria type of stuff. Well, bacteria are fascinating, but I take your point. No, I get it. I mean no offense to them. This kind of speaking from the perspective of your paper of something that's able to generate technology as we kind of understand it, that's a very short moment in time relative to that full history of life on Earth. And maybe our universe is just saturated with bacteria like humans, right? Uh, but not the special extra AGI super humans. Those are very rare. And once those spring up, everything just goes to like, it accelerates very quickly. Yeah, it's, it's. We just don't have enough data to really say, but I find this whole subject extremely engaging. I mean, there's this concept, I think it's called the Rare Earth Hypothesis, which is that basically stating that okay, microbes were here right away after the Hadean era where we were being bombarded, well, after, yeah, bombarded by comets, asteroids, things like that, and also after the moon formed. So once things settled down,

little bit. In a few hundred million years, you have microbes everywhere and it could have been, we don't know exactly when, it could have been remarkably brief. That took so. It does indicate that, okay, life forms relatively easily. I think that alone is sort of a check on the scale for the argument that the parameters that allow even microbial life to form are not just a fluke. But anyway, that aside, yes, then there was this long dormant period. Not dormant, things were happening, but um, important things were happening for some two and a half billion years or something after um, the metabolic process that releases oxygen was developed. Then, basically, the planet is just sitting there getting more and more oxygenated, more and more oxygenated, until it's enough that you can build these large complex organisms. And so, the Rare Earth hypothesis would argue that the microbes are common in everywhere in any planet that's like roughly in the habitable zone and has some water on. It's probably going to have those. But then getting to this Cambrian explosion.

that happened some between five and 600 million years ago. That's rare, you know, and I buy that. I think that is rare. So if you say how much life is in our galaxy, I think that's probably the right answer is that microbes are everywhere. Cambrian explosion is extremely rare. And then but the Cambrian explosion kind of went like that where, um, within a couple tens or 100 million years, all of these body plans came into existence. And basically, all of the body plans that are now in existence on the planet were formed in that brief window. And we've just been shuffling around since then. So then what what caused humans to pop out of that? I mean, that could be another extremely rare threshold that a planet roughly in the habitable zone with water is not guaranteed to cross, you know? To me, it's fascinating for being humble like that. Humans cannot possibly be the most amazing thing that's such if you look at the entirety of the system that lease mola and you

paint that cannot possibly be the most amazing thing. That process generates so like if you look at the evolution. What's the equivalent in the cosmological evolution and its selection for technology? The equivalent of the human eye or the human brain. Universes that are able to do some like they don't need the damn stars. They're able to just do some incredible generation of complexity fast on sk like much more than if you think about it's like most of our universe is pretty freaking boring. There's not much going on there's a few rocks flying around and there's some like apes that are just like um doing podcasts on some weird planet. It just seems very inefficient if you think about like the amazing thing. The human eye the visual cortex can do the the the brain the nervous everything that makes us more powerful than single-cell organisms like if there's an equivalent of that for universes. They're like the richness of physics that could be uh they could be expressed through a

particular set of parameters. Like, I mean that, like for me, I'm, uh, so from a computer science perspective, a huge fan of cellular automata, which is a nice, sort of pretty visual way to illustrate how different laws can result in, uh, drastically different levels of complexity. So like, it's like, yeah, okay, so we're all like celebrating, Look, our little cellular automata is able to generate pretty triangles and squares, and therefore we achieve general intelligence. And then there'll be like some badass Chuck Norris type, like, uh, universal Turing machine type of cellular automata. They're able to generate other cellular automata that does any arbitrary level of computation off the bat. It's like those have to then exist, and then we're just like, this, we're just, we'll be forgotten. Is this the story? This is, uh, this podcast just entertains a few other apes for, for a few months. Well, I, I'm kind of surprised to hear your cynicism. No, I'm very, I, I usually think of you as

like a one who celebrates humanity in all its forms and things like that. And I, I guess I just, I don't, I see it the way you just described. I mean, okay, if we've been here for 13.7 billion years and you're saying, gosh, that's a long time, let's get on with the show already, some other universe could have kicked our butt by now. But that's putting a characteristic. I mean, why is 13.7 billion a long time? I mean, compared to, compared to what, I guess. So when I look at our universe, I see this extraordinary hierarchy that has developed over that time. So at the beginning, it was a chaotic mess of, you know, some plasma and nothing interesting going on there. And it even for the first stars to form, that a lot of really interesting, uh, evolutionary processes had to occur. By evolutionary in that sense, I just mean, um, taking place over extended periods of time and structures are forming. Then, and then it took that first generation of stars in order to

produce the metals that then can more efficiently produce another generation of stars. We're only the third generation of stars so we might still be pretty quick to the game here. So, but I don't think I don't okay so then so then you have these stars. Now you have solar systems on those solar systems. You have um rocky worlds. You have gas giants like all this complexity. And then you start getting life and the complexity that's evolved through the evolutionary process in life forms is just it's not a letdown to me just no no. And there's some of it is like some some of the planets is like icy it's like different flavors of ice cream. They're icy but there might be water under yeah all kinds of life forms with some volcanoes right all kinds of weird stuff no no. I I don't uh I think it's beautiful. I think our life is beautiful and I think it was uh designed that by by design the scarcity of the whole thing. I think mortality as terrifying as

it is fundamental to the whole reason we enjoy everything. No, I think it's beautiful. I just think that all of us, um, conscious beings in the grand scheme of basically every at every scale will be completely forgotten. Well, that's true. I think everything is transient and that would go back to maybe something more like Lao Tzu, the Dao De Jing or something where it's like, yes, there is nothing but change, there is nothing but emergence and dissolve and that that's it. But I just in this picture of this hierarchy that's developed, I don't mean to say that now it gets to us and that's the pinnacle. In fact, I think at a high level, the story I'm trying to tease out in my research is about, okay, well, so then what's the next level of hierarchy? And if, in, if it's okay, we're, we're kind of pretty smart. I mean, talking about people like Lee Smolin, Alan Guth, Max Tegmark. Okay, we're really smart, talking about me. Okay, we're kinda, we can find our way to the grocery store.

or whatever, but sometimes, but what's next, you know? I mean, what if, what if there's another level of hierarchy that grows on top of us that is even more profoundly capable? And I mean, we've talked a lot about superconducting sensors. Imagine these, uh, cognitive systems far more capable than us residing somewhere else in the solar system, off of the surface of the earth where it's much darker, much colder, much more naturally suited to them. And they have these sensors that can detect single photons of light, uh, from radio waves out to all across the spectrum to gamma rays and just see the whole universe. And they just live in space with these massive, um, collection optics. So that they, what, what do they do? They just look out and experience that vast array of what's being developed. And if you're such a system, presumably you would do some things for fun. And it, the kind of fun thing I would do, somebody who likes video games, is I would create and maintain and observe something like earth.

and uh so in some sense we're like all what players on on a stage for this uh superconducting um cold computing system out there. I mean all of this is fascinating to think the fact that you're actually designing systems here on earth that are trying to push this technological at the very cutting edge and also thinking about how does the like the evolution of physical laws lead us to the way we are. It's fascinating that that coupling is fascinating. It's like the ultimate rigorous application of philosophy to the rigorous application of engineering. So i um jeff you're one of the most fascinating. I'm I'm so glad I did not know much about you except through your work and I'm so glad we got this um chance to talk. You're one of the best explainers of exceptionally difficult concepts um and you're also the speaking of like fractal. You're able to function intellectually at all levels of the stack which which I deeply appreciate. This was really fun. You're a

great educator, great scientist. It's an honor that you spend your valuable time with me. It's an honor that you would spend your time with me as well. Thanks, Jeff.

Our universe is full of superintelligent alien civilizations | Jeffrey Shainline and Lex Fridman

Clips from the Lex Fridman podcast. Visit the main channel for full conversations and other videos.