Did our Universe evolve?

00:00:00
Speaker 1: Hi, it's Jorge and Daniel here. And this holiday season, if you're looking for a gift for yourself, for a friend, or for your your family, why not get him the Gift of Answers about the Universe. To check out our new book Frequently Asked Questions about the Universe, you can find details at Universe f a Q dot com. Thanks for supporting the podcast. Happy holidays everyone, Hey or hey? Do you think that our universe is well suited to us? I don't know. I mean, some of it seems so staggeringly beautiful to our eyes, you know, like stars, the galaxies, even like the drama of the black holes. That's true, it's definitely something we can appreciate, but also sometimes seems like the universe is kind of alien to us. I think the universe is here first, so technically we are the eighteen Yeah, but you know, sometimes the way that it works is so bizarre and so strange that I wonder if we're ever going to understand it, if our minds are suited to it, maybe that's what makes it especially suited to us. What do you mean? You know, it's like the perfect puzzle to keep us entertained. For attorney it's like that toy you put in front of a toddler. Why you need to get some work done. It's like the TV for human toddlers. Maybe Steve Jobs created the universe. Hi, I'm poor Hammad, cartoonists and the creator of PhD comics. Hi I'm Daniel. I'm a particle physicist, and I'm constantly amazed at the strangeness and the bonkers nous of the universe that we live in. Do you think the universe is bonkers? Like it is bonkers or it was made bonkers or made by a bonkers I won't speak to the mind of the creator if one exists, but it does continue to astound me how strange and how weird the univer is, and the fact that it is weird, that it seems strange, that it's counter to our expectations because we are part of the universe, So why doesn't it feel intuitive to us? Well, you know what I always say, if your expectations are not being met, maybe you should change your expectations, Daniel, I should try the Scandinavian approach. Just expect to be disappointed all the time and then be pleased when you're not, or expect to be surprised. You know, it's only weird because you think it's weird because it doesn't mean but really, really, the universe was here first, so that's true. Maybe the universe thinks we're weird. We are kind of bonkers after all. Welcome to our bonkers podcast. Daniel and Jorge Explain the Universe, a production of I Heart Radio in which we have no idea what the universe thinks of us, but we do dive deep into what human minds think about the universe, the questions we have about the way it works. At the tiniest scale of frothing buzzing quantum particles to the very biggest scale of galaxy formations and the entire fate of the universe. We question the very nature of reality, peel it back to see what's going on underneath, and we explain all of it to you, at least as far as we understand. Yeah, because it is a pretty big universe, and there's a lot that seems very puzzling and perplexing to us. It's, you know, wonderful and amazing and beautiful it seems sometimes but also a little bit terrifying and powerful and sometimes even dangerous. It sometimes seems amazing that we even live here. You know, we could have been wiped out by a supernova nearby, or could be that with small changes in the nature of the particles, we couldn't have had the chemistry we need for life to happen. Sometimes it seems like a lot of things had to go just right for us to evolve and to survive. Yeah, and if we hadn't been here, who would be asking these questions? Daniel, That's the main question. Probably some better looking, smarter version of us. If that's yeah, impossible, but we just disproved that theory or improbable at least. But yeah, it is a pretty amazing universe. And sometimes you have to wonder, like, how did it come to be like that? And how coming it came to be? And we are here and we are looking at it and wondering how it works. That's right, and that is one of the deepest questions in physics. We are often asking how do things work? What's going on with these particles? But underlying that there is a question standing in the wings waiting for an answer, and that question really is why this universe? Why is the universe of this one and not some other one? Could it have been a different universe, or is this the only possible way for universe to exist? What does it mean that we ended up in this universe? Well, for thankful that we are in this universe, I guess, or that this universe is here for us. But to understand these questions sometimes you kind of have to look outside of physics to think about the new ways in which you might answer these types of queries. That's right, And when we look to biology, for example, we find a very compelling and very powerful, very broadly useful argument for understanding why creatures exist and have certain traits. When we look at, for example, the beaks of birds and ask like, why do they have that shape? We get the answer when we look at the nuts they eat or they bug that they have to pick up. They seem to be very well suited to their environment and for a reason. Yeah, So to be on the podcast really asking the question is the universe the result of natural selection? All right? We're asking some big questions. Did they hear? I know that's sort of mind blowing to imagine, Like the universe is a bird on an island somewhere picking on bugs. I thought we were the birds, aren't we the birds. I think we might be the bugs and or the nuts, like the nuts are we're wondering how some some things are are suited to eat us. No, we are the birds, and when physics is the nuts and we're trying to crack it open. Oh boy, I'm getting lost in these analogies here. I know I'm driving you nuts, But it is a fun idea to wonder if the universe could have been other ways, and if the universe that we ended up when is this way because of some sort of process that guides the formation of universes to end up at one that sort of works. WHOA you mean like the evolution of universe is multiple universes over countless time, somehow changing and evolving. Yeah, that's the idea. We have talked about multiverses and many times on this podcast. But this is sort of like a different take. Instead of imagining the universe is actually many universes all sort of rolled up into one grand idea, this is like maybe our universe is in competition with other universes on some sort of like meta universe playing field. WHOA like an African savannah but for universes. And then there's some kind of predator, some universe predator, some universe eating. I think I saw that on an episode of the new show Look what can eat an entire universe? Exactly right, and so maybe Marvel got it right. As usual, they can do no wrong. Well, this is a kind of a mind bogging question, big ideas here, and so we were wondering how many people out there had thought about the universe as evolving and or as being the result of something like natural select. So Daniel went out there as usual and ask people on the internet what they thought of this question. That's right, and so thank you to everybody who's willing to entertain my crazy questions without the opportunity to think about it or to prepare. If you'd like to participate for a future episode, we would love to hear your voice on the podcast. Just to write us an email, no special equipment required. Shoot us an email two questions at Daniel and Jorge dot com. So think about it for a second. If someone asked you what is cosmological natural selection? What would come to mind in your brain? Here's what people had to say. I'm gonna say those bodies orbiting around a star that have the most stable gravitational orbits last the longest. Every star for itself, may the strongest in the universe survive and the weakest universal objects becomes space test well, I guess planet stars, gallessies, etcetera. Survival of the fittest would apply to another star is more likely to pass on positive traits. Does that have an influence on the next generation stars. Maybe it's a theory that explains why there are no medium sized black holes by using an analogy from evolution. Maybe there were some conditions in the environment that made them go extinct, while the supermassive black holes with you today lived on and appropriated. Assuming that's the thing they can do, all right. Nobody said in African Savannah with the universes, nobody talked about something eating universes. It's a pretty crazy idea to encapsulate in just three words, cosmological natural selection. So we didn't give them a whole lot to go on. It seems like people didn't trigger something big in their heads. Like most people stuck to stars or galaxies as maybe evolving, but nobody thought about the universe evolving. It's sort of too crazy, you know, it's sort of too big an idea to even leap to from this concept. It's sort of bold. But you know, I like that. I like that about bold ideas. Like for as you hear about someing, you think, what, that's great. Hold on a second, maybe that makes a little bit of sense. That's the nice thing about crazy, big ideas. I guess. You know, even ideas like the multiverse, at some point, you know, seem crazy and insane, and but now people seem to kind of accept it, and some people even assume it's true, like people like Marvel. That you can't necessarily turn that around. Just because some ideas which now make a lot of sense once seemed crazy doesn't mean that every crazy seeming idea will eventually make sense, right right, right. Sense only works one way, It only makes sense, it makes sense one way. There are a lot of crazy seeming ideas that we don't talk about it anymore because they still seem crazy right the whole, Like the universe is like turtles and turtles all the way down on top of some elephants or something that also seemed bonkers. But that doesn't mean it's true. Yeah, exactly, it's gotta have some legs, it's got to solve some problems, it's got to open up avenues for exploration, and it's got to sort of hang together mathematically. Well, I mean, turtles do solve all problems you think about it, and they have legs and they do have legs. Yeah, although they do it kind of slowly, so I mean we're still waiting for those turtles. All right, Well, to step us through this, Daniel, this big idea, what is the cosmological natural selection? So cosmological natural selection is a really fun creative idea by a physicist named Lee Smollen, a theoretical physicist, and it's in solution to what physics calls a fine tuning problem, which is just a fancy way of saying, like, why is the universe the way that it is, because it seems like it could have been lots of other ways. So before we dig into how he tries to answer that question, let's make sure we have like a good grasp on what the question is. What is the problem we're trying to solve. Why is the tricky to understand that the universe is this way and not some other way? Right? Because you know, as physicist, you've been sort of drilling down on the equations that make the universe work, and at some point you come upon something that you're like, you can't explain, like it just seems to be the way it is, because it seems to be the way it is, Like you can't really explain why pious three point one four or the cosmological constant is is X. Right, that's exactly right. You know. The grand goal of physics is to summarize everything we see, all phenomena, all matter, all energy, all forces in terms of one concept, you know, like maybe a single equation that we could write onto a T shirt. And so we've made a lot of progress there. We have a few equations. They don't quite fit onto a T shirt, but they're kind of beautiful and compact, and you know, they describe a portion of the universe that we understand that we've explored. Well, it depends on the size of your your T shirt. Just get a bigger T shirt, Like I said, just adjust your expectations of what a T shirt uh is or how many people can fit in. It might solve your problem. That's right. If we go to micro font and then it's no problem. We can describe the whole universe on a T shirt. But currently we have this model of particles and their interactions. We call it the standard model, and as you say, there are parts of it that we don't understand, you know, not just the structure, but there's lots of questions about the structure of you know, like why are their copies of these particles electron, Muan, Tau, but also just we find numbers in these equations, and those numbers have no explanation that we can find. They are just numbers, and the theory doesn't tell us what those numbers have to be. We have to go out and measure them. One of these numbers, for example, as you say, is the cosmological constant, this rate at which the universe seems to be expanding. We don't know why that number is what it is. We have no theoretical prediction for what it should be. It's just like a placeholder, like a parameter. It's sort of like you're in the control panel for the universe and it just has these knobs. You know. The structure of the universe is this control panel, and you could turn the values of these parameters up or down and maybe get different universes that follow the same basic laws of physics. But you know, with different settings on those knobs, right, they seem like arbitrary, like somebody came in before you and adjusted to those dials, and then you came in and you're like, why did you set these dials? Yes, exactly, we have no explanation and for why these numbers are where they are. And you might be tempted to think about numbers like this speed of light because we don't know why the speed of light is the speed of light, you know, why isn't it not faster or slower. It's a little tricky because the speed of light has units on it, right, it's meters per second. So the actual number there depends on the units you choose. If you change the meter or change the second, you get a different number. So physicists like to focus on dimensionless numbers. You can rearrange all these constants of the universe in ratios and whatever to get rid of the units in unit with pure numbers numbers that just are. And you know, if all those numbers were one, we'd be like, cool, that makes sense. Where if all those numbers were ten or something, it would make sense. But they're all really different. Some of them are really small, some of them are really large, and we just have no explanation for them. So, as you say, they seem kind of arbitrary, and we wonder, you know, like could they be different? Could you have had another universe with different values of those numbers? And we think through like what the physics could be like. But the physics would be really really different in the universe would be totally different from the one we see. And so we wonder, like, why are these values what they are? They seem to be sort of just right to give us the universe that we have. So these are like ratios, I imagine it would be like saying, what is the rate at which the universe is expanding? It's like, you know, there's seven point four seven percent and so that's that's a dimensionless constant to write a percentage. So is that what you mean? Like ratios of like the number of so and so particles through so and so other particles. Yeah, that kind of thing. So one of the most important dimensionless constant is called the fine structure constant. It includes the speed of light and the charge of the electron and planks constant. And if you change that number, then physics changes because that affects like how strongly. Electrons and pausit trying to repel each other, and you know the distances at which things feel these kinds of forces. Other important ones are ratios of the masses of the particles, like why is the muan so much heavier than the electron? Why is the top corks so much heavier than everything else? You know, if you change those numbers, you also really change how physics work, you know, like what if the electron wasn't the light just leapt on? What if we had muans in our bodies instead of electrons because muans were lighter mass, Like that would really change everything, right, But you're you're really sort of asking two questions, right, aren't you. Like you're asking, for example, in the case of the electron, like what is the mass of the electron the way it is? And also why is the mass of the other cousins of the electron you know a certain number of times dead mass with the electron? Yeah, exactly. And so there's lots of different ways you're going to arrange these things. But fundamentally, we're looking at a set of numbers, and those numbers control the way the universe is, and we don't know why those numbers are what they are, and you know, as you said earlier, one possible explanation is, we know if those numbers were different, who would be here asking that question? And that's a popular answer, and it goes by the name of the anthropic principle. It just says that if the numbers were different, you wouldn't get humans and you wouldn't get intelligence, and nobody would be asking. So only in a universe where things happen to work in just this way do you have people to ask that question? So you want to ask that question when it's possible, And that's sort of like a circular explanation, but a lot of people like that answer. Sort of like my kids asking why is our house designed that way? It's like they are just born into the house. Been born in a different house, they would be asking a different question about that house. Yeah. Or it's like kids asking, you know, why am I here? Why was I created? And not some other kid? You know, like, well, if I had had a different kid, because you know, you've been conceived in a different moment, that kid might be asking the same question, or you know, have different interests or whatever, ask a different question. Right, Basically, you want to tell your kids they're not special. Of course, my kids are special. Everybody else kids I don't know about. Yeah, it sounds like anthropic parenting. And my complaint with this is that it's sort of like giving up. It's sort of like saying there is no explanation, look no further, Whereas what I like in science is when you're always trying to dig deeper. You're always saying, there must be a reason for this to happen. Let's look deeper, because it's possible that there is a deeper sir. Right, We certainly don't have the final theory of physics. We know that our description of particles and their interactions is flawed and limited, because we know, for example, it breaks down if you have really really high energies. Our theory just doesn't work. And so we know we need some sort of deeper theory. And so maybe you know there is some deeper explanation one we just haven't found yet, that explains these values and says these values have to be certain numbers, like, there's not arbitrary. It only works if they are these numbers. We just don't quite see the full picture yet, And so I don't like the entropic answer, because I always want to strive for that deeper understanding, right, Like maybe you'll dig deeper into the equations and find that if the electron had half the mass that it does right now, it just doesn't make for a logical universe or like a universe dead. You know, it gives you tupiles to equal seven, Like that's what you want. You wanted to boil it down to one question and say, look, if you change this, then you wouldn't it wouldn't logically work, right, because that's kind of the only alternative when you say, like it's think things have to be a certain way, like not being able to be a certain way mean that it would be illogical. Yeah, And people are looking for a theory of the universe that's self consistent, right, So the sort of philosophical implication there is that only self consistent universes can exist. And so maybe there's a reason why those other values of those numbers make for some inconsistency, and there you need to have some sort of physics principle we haven't yet discovered, right that shows us why those things would be inconsistent, you know, And we don't have that, but we can sketch the sort of like rough idea. You know, maybe for example, string theory is correct, and at the basic level the universe are these little, tiny vibrating strings and they can only vibrate in certain ways and because of their basic fundamental nature, and that leads to certain properties that we then measure, you know, at our scale, which have to come out this certain way, and that you just can't have an electron with a different charge, and you can't have them you want with four times as much mass as the electron. You have to have the numbers that we have now, and it comes out of some deeper logic that we just don't know yet. So we don't have that theory yet, but you know, you can imagine that kind of theory existing, right. But that is still satisfy you though as a physicist, like did you say, Well, that's just the way the universe is, and it has to be that way because of the way the universe is. I'll never be satisfied, absolutely not when we get that answer that explains all the mysteries we see today. There will just always be more questions. And that's what I don't like about the anthropic principle because it stops you from asking that next round of questions, whereas I feel like science is this cycle of digging every deeper into the most basic questions. And you know, even if we exhaust physics and we get just one single theory that describes the whole universe, will always have philosophy because we can always ask like, well, what does it mean? Man? What does it mean? And that's one potential way to answer why the universe is the way it is, Why those numbers are all the way that the numbers that they are. Maybe there's some asked yet to be discovered, you know, equation or theory that explains them all that makes them want to be those numbers or makes them have to be those numbers. But then there's another theory about what could explain them, right, Yeah, And another way to approach this problem is to say, maybe the values aren't arbitrary, maybe they are random, Like maybe it's possible to have different universes with different values, and all the universes would all the different values exist. This is the multiverse explanation to say that maybe all those possible universes are out there with these different values of the parameters, and there's different physics in each one, and this just happens to be the one that we are in, right. It's like you walk into a control room. You see all the knobs turning to a certain number for all the values of the universe, and you're like, why are they like this? And the answer is sort of like, well, that's because there's another control room next to you with the value said a little bit different, and next to that one is another control with the value said a little bit different at up to infinity. That's sort of an explanation, and it doesn't answer questions like, you know, well, who chooses those values? Or is it truly random like quantum mechanically random, or is it like systematic where you get one universe for every possible value? Are there an infinite number of them? There's so many questions opened up by that, and unfortunately, it's pretty difficult to probe that kind of theory, like where do you go from here? You know, if those universes exist or not? You know, can we ever discover them? No? Can we interact with them? No? So can we prove fundamentally that they exist? Folks like Sean Carroll would argue that you can sort of implicitly prove they exist if you demonstrate that it's the only way to make sense of the universe, that our theory of physics requires that they exist, and it's the only theory that you can develop. It's a bit weaker than actually finding them and exploring them. But you know, it's an argument to suggest that the multiverse might be real because I guess that would sort of explain why we have the one we have is that it's just like a random role to die, although you could you make the argument that you know, the universe only role to die ones like does it have to roll to die an infinite number of times? It's a great question and one it's hard to probe. But what we can do is look at the numbers that we have and ask are they likely? Is this a likely arrangement? And here we're get into really fuzzy territory. But physicist look at the numbers we have and they feel weird about them. They're like, the cosmological constant is very small, and these other numbers seem kind of large, and why is gravity so so weak? And you know why all the forces have such a different strengths, And they make these really handwavy arguments that suggest that the numbers we have are somehow improbable or unnatural, and it's more likely to get a different set of values, and that makes our universe seems sort of like weird on this like multiverse landscape. And I don't know if that's an argument against the multiverse exactly, but it suggests that you might need some sort of mechanism to explain why we have these numbers. And if this is the only one, then you know, the universe are really unlucky or lucky, depending on your point of view. I think that the universe is totally lucky to have us, at least you, Daniel. At least we're lucky to have you. All right, Well, we have this big question about why the universe is the way it is. There are some theories, but they are a little bit unsatisfying, and so there's sort of a new or emerging idea that's is really interesting and it's all about evolution. So let's get into that. But first let's take a quick break. All right, Daniel, what does it all mean? Man? Why are we here? Why is the universe way it is? What does it seem so suited to us? For us to be comfortable in our houses. Here having a conversation about the way it works. Yeah, exactly. Maybe we are just the beaks of those birds, perfectly evolved to fit into the trees and grab out those grubs. And you know, that's the inspiration, is that we see in biology that it's not random that animals are well suited to their environments, that they're very fine tuned, right, And they're fine tuned for a reason. There's a mechanism there. Natural selection operates by enhancing those that are well suited right and killing off those that are not, And so you're more likely to end up with ers that are well suited to the environment. So the environment then shapes the nature of the critters. And so the idea was, take that and can we use that to explain sort of how we find the universe to be fine tuned? Is there some mechanism we can use to explain how the universe itself selected these values? So in this analogy, in this idea to explain why the universe is the way it is, somehow like the universe has been evolving in some environment and it's sort of arranged itself or it came to be the way it is now because of some natural selection process that that's kind of the idea, right, Yeah, But it's not being selected for us or for physics that makes sense, or for physicists or for cartoonists. Is being selected for universes with lots of black holes in it? What? Yeah? So the basic idea is maybe universes can give birth to other universes by creating new universes inside their black holes, and that would tend to give you lots of universes that have lots of black holes in them. You would ended with more universes that have lots of black holes than universes that don't have lots of black holes. And so maybe our universe is fine tuned to have the sets of parameters you would need to give you universes with lots of black holes. WHOA, Okay, I feel like you just introduce a lot of crazy ideas here, Like, first of all, like universe giving birth to other universes, don't you need to universes? Is this a mono biological birth? What do you call those animals that can just split off and just butt off? A sexual reproduction? Yes, that's right, yes? Right? Is the universe a sexual Yeah? It could be that universe is reproduce in lots of different ways. We're open minded on this podcast, but the idea is not totally bonkers. It comes from the recognition that there's a connection between what happens inside a black hole and what happens at the beginning of our universe, and that connection is a singularity. Right. We know that our universe started with a singularity that's this crazy dense moment when the universe is like infinitely dense and then expanded out really rapid that we call that the Big Bang. And we know that there's a singularity at the heart of black holes, or we think there is according to general relativity. And so this idea says, like, maybe every singularity at the heart of a black hole is actually a singularity to create a new universe. WHOA, But then I guess. So then the idea is that the universe that is created inside of a black hole exists within the black hole, or does it grow out and take over its parent universe exists within the black hole. So the idea is that instead of imagining inside a black hole, you have like a dead singularity that's just like super dense point that instead you have something dynamic that it's a bounce instead of like just to collapse into a singularity that matter collapses, you get this moment of great density, and then you get a new expanding region of space time within the black hole and never escapes. You can't see it from the outside of the black hole, but that maybe inside black holes we have this region of expanding space time began with the singularity of infinite density, just like our universe, and so it's sort of like this bounce moment where it collapses into a singularity and then starts expanding out again, expanding but still inside of the black hole, still inside the it's like a little bubble inside of the black hole of regular space. And this sort of connects to an idea we talked about recently about whether black holes actually are black holes, and we talked about how these objects, whatever they are, are in regions of very warped space time, which means that their time slows down dramatically. So when you're looking at a black hole, instead of looking at something which is sort of like a dead singularity, you might be looking at something dynamic which is collapsing and then going to bounce back. But it's just super duper slowed down, so that what takes micro seconds and its time takes billions or trillions of years for us. So this is sort of a similar idea to say, maybe black holes are not just like static little dense objects collecting more mass, but there are this bounce where you come to a point a great density and then start expanding out into effectively, what's a new universe inside each black hole? WHOA, But then wouldn't that mean that each universe is like bounded or finite, you know, like it has a limited amount of energy to it, whereas you know, it seems like our universe has almost it looks almost infinite, and it has almost infinite amount of energy. How did all this stuff that we're living in come from, like a tiny black hole for example? Yeah, exactly. That would mean that there is a bound on the universe, But we don't know if our universe is bounded. With some of our theories of cosmology suggests that it should be infinite. It would be most natural if it were infinite, but we just don't know that, and we can only see a limited part of the universe. The portion of the universe we can see now is about ninety three billion light years wide, and we just don't know what's beyond that. And we also know that our universe is expanding, and the mechanism for that is totally unexplained. So it is possible that our entire universe is inside some like mega black hole that's just unimaginably wide. Okay, So then the idea is that in our universe, or basically any universe, whenever there's a black hole, it's sort of creating a whole new kind of universe, and those new universes are the same or slightly different than the parent universe. They're slightly different. So when you create a new universe inside a black hole somehow, and this is like where the magic happens, the laws of physics tweak a little bit, like that process of bending space time and that singularity somehow changes the fundamental constants of that universe a little bit. And this part of the theory is extremely fuzzy because like we don't have a mechanism to understand how that might happen. It's just like a what if. And so in that way, you can sort of like explore different possible universes. You can in one universe create lots of babies with different sort of properties, the same way that in natural selection, if a spider has a thousand offspring and they're all a little bit different than the ones that are best suited to survival, will continue. So in this model, you create lots of baby universes in law two black holes and the ones that are more likely to create more black holes within them. So now black holes within black holes are more likely to create more universes, right, and so you can just call those black holes turtles, and it is sort of turtles all the way. Now, I think a big question here is you know, like in natural selection and regular biological evolution, you have DNA, and that makes sense that like your DNA changes a little and then your kids carry on that DNA that's changed a little bit. But like you said, there's sort of no known way in which like that new universe we will have different constants, right, Like, like why would it have different constants if it's being born in the in the universe with certain laws and certain constants. Yeah, absolutely, that's not something we understand. And you're right, Like for natural selection, we understand the mechanism of it, right, you have the genetic code which is then modified. And so in this case we have no explanation for how that happens, no mechanism for it. You know, maybe the fundamental constants of the universe are ord in some deep process and the creation of a singularity disturbs that process. Really just speculating, and the theory itself has not been fleshed out. We don't have any sort of like DNA like mechanism that explains where these parameters are like stored and how they might be modified by a singularities. Really just speculation, But you know, physics works this way. Sometimes we're like, let's, uh, you know, put a bunch of dots down, and we'll come back later and connect to those dots. But let's see how far we can get with sort of a string of big ideas, and you know, we'll circle back and filling some of the crucial details later. All right, Well, so then the basic ideas that you know, our universe makes a whole bunch of black holes, and each of those black holes has a universe, and some of the our baby universes make more black holes, and some of them don't make a lot of black holes, and so the ones that make more black holes are then going to have their own kid universes who are also good at making black holes, and some of them will make more black holes. And eventually, don't you get to a universe that's all black holes. And that's the idea that this process is more like to give you universes that are likely to have black holes, and so you should end up with universes where the numbers are fine tuned to sort of maximize black holes. And so that's the argument at least Moan makes is he says, I'm looking at the parameters, and it seems to me like if you change some of these parameters, you end up with fewer black holes in the universe. And so maybe our universe is sort of like at the maximum black holiness. Oh, I see, that's the idea that somehow, maybe we're at the maximum black hole capacity, Like this is the most that any universe can make of black holes. That's sort of the argument, and we'll talk later about whether that's actually true. But you know, it's got to maximize something, and it's interesting this idea that it doesn't maximize us, right. I like this idea because it's not anthrocentric. It's not like the universe was created for us. It's like, oh, it turns out we're a byproduct of the universe being optimized for something totally different, which is production of black holes. And that's pretty cool. And you know, it's interesting how many black holes there are right there, black holes everywhere. Every galaxy is a super massive black hole in it. Stars are collapsing in the black holes all the time. It does seem like the fate of our universe, as you say, is to end up as a huge string of black holes. And so it does kind of feel like we are a maximal black holiness and we should rename the podcast to maximal black Holiness. That has a better ring to it. Maybe. All right, well, let's get into what does it all mean, man, and is this theory right or is it totally bonkers? But first let's take another quick break. All right, we are talking about cosmological natural selection, the idea that the universe somehow evolved to be the way it is and that's why it is the way it is. We talked about how maybe the universe is the way it is because we're at like optimal black hole making capacity of the universe, and so that's why the universe is the way it is and not some other way. Yeah. So I so I question was, why do we think that we're an optimal maximal black holiness or black hole making capacity, Like couldn't it feels like there's a lot of rooms still left in the universe for to make more black holes? Yeah, how would you make our universe black holier? I don't know, I just poke a bunch of holes in it, you know, Like why not? Like could in the universe be such a way that they pop up more randomly or something. It's really interesting to think about. And you know, it takes some of these parameters like the mass of the strange cork for example, you know, relative to the mass of the other corks. It's interesting because that actually does help determine the number of black holes in our universe because it creates an opportunity for matter to form something that's not a black hole, that's a neutron star. Like if you have not enough stuff in your star, then sometimes when it collapses, it doesn't form a black hole. Instead it forms a neutron star. And it forms a neutron star because gravity isn't powerful enough to overcome the nuclear force. Is that are preventing the collapse, and that's partially controlled by the mass of the strange cork. You know, what happens inside a neutron star is not something that we understand very well. It's the strong force at work, zillions of bluons back and forth all the time. But these things are very sensitively dependent on the masses of the corks that are involved. And so, for example, if you increase the strange cork mass, if we were in a universe where the strange cork mass was larger than those forces would be more powerful and lots more stars would collapse into neutron stars instead of black holes. So you tweak this parameter, you get fewer black holes in our universe. But then wouldn't that work the other way to like, if you decrease the strange cork mass, and you would get more black holes. So why isn't the mass of the strange cork smaller if we are an optimal black hole making capacity? And that's one of the main criticisms. Lee Smolin came up with this argument, and he suggested that a lot of these parameters are tuned for black holes. But then other people came and looked at these parameters, like, actually, it's not that hard to make universes that are black holier Joe Silka, famous astronomer, tweaked the parameters and he came up with a universe that could make ten thousand times more black holes than our universe. And you know, number one is you decrease the strange cork mass, and number two is you crank up the strength of gravity. Right, so it tends to collapse things faster. You don't want to crank it up too much, right, You want a large number of black holes, not just like a single black hole. So you've gotta left stuff spread out a little bit and then collapse into a lot of black holes. M oh, I see you're saying things are being like this for a number of black holes, not like, let's make a giant black hole, because if you do, then that means you only have one offspring. Kind of That's right. As fun as that sounds, let's make a giant black hole, it's maybe not the best plan if your goal is to have lots and lots of baby universes, not just one mega baby, right, But I guess you also don't want to have you know, lots and lots of or like an infinite number of tiny baby black holes right or small tiny sort of easy to evapp for a black holes, you want like a good number of significant black holes as your children exactly. If your black holes are too small, then they will evaporate, as you say, because black holes are not completely black, they give off a little bit of energy, and they give off more energy the smaller they are, so smaller black holes are more likely to evaporate away into nothingness. So you need to be big enough that they can be sustained that they can keep gobbling things. So you don't want one mega black hole, you don't want an infinite number of tiny ones. There is a little bit of a balancing act to play there. So the basic ideas that maybe all those control maps in the universe, all those numbers that we can't explain, are the way they are because somehow they maximize the universe's conditions for making the right, the most and best kind of black holes exactly. And that doesn't argue that the universe has to be maximized for black holiness, to suggest that there are lots of universes out there, but there are more that are close to this maximum because they tend to produce more. And so if you're gonna randomly choose among uni versus to be in that you're more likely to end up in the universe that's closer to the maximum. Oh I see, yeah, because I was wondering, like in this idea of the universe evolving or universe is evolving, there's no natural selection process really, right, There's no like predator killing off weak universes or you know, something destroying the universes that don't make a lot of black hole. It's more like you're more represented in the population of all the universes that exist if you're good at making black holes. Yeah, everybody can make as many babies as I can, and then it's just a race to have the most babies. Nobody's eating anybody else's babies. But if you're gonna randomly pick somebody to be you're gonna end up in a family that makes more babies. Right, So there's like an infinite savannah out there in some universe Africa. There are no predators. You know, you can multiply as you see fit. But the animals or universes that are good at multiplying, they're just gonna be more overrepresent they're going to basically take over the savannah, right, this infinite savannah. And so then that means that we are if we are going to this in the universe, we're more likely to exist in the universe that's good at making baby black holes. That's the argument. And you know, there's a lot of steps there and a lot of questions, but it's sort of the structure of it interesting. So then it's still sort of tentative. And so what are some criticisms I guess, or what does it all means do to have any interesting implications if it were true? Yeah, there aren't criticisms of it. People argue that we're not actually that close to maximum black hole production, as I say, people to tweak the parameters and done some simulations and suggested that you could get many, many more black holes than you have in our universe. And you know, the thing about this argument is that it's impossible to disprove that way. You could say, oh, well, this is the way the universe works. We're just a little bit unlucky. We're close to the maximum, we're not necessarily at the maximum. We're gonna get the best parents have pretty pretty good parents we're not in the biggest family, but you know, we're not doing too bad. But it does definitely weaken the argument. It would be a more compelling argument if we were like right at the maximum and you have this good argument to suggest that certain values of all these univer as parameters overwhelmed everything else, than so the universe should be totally dominated by numbers very very close to the optimal values. So that's not exactly the case. Well, I guess that counter argument to that counter argument is that, like, maybe we don't really know if we are optimized for optimal black hole of production. Maybe we are, which just don't understand the universe well enough to say, like, no, this is this is the best number of black holes. If we had ten thousand more black holes, you know, the universe wouldn't be sustainable, or those black holes wouldn't be good enough to make other universes, do you know what I mean? That's certainly a good point. We don't know how to stimulate the whole history of the universe and accurately predict the number of black holes, so these simulations are approximations, and there's lots we don't understand about the evolution of the universe, big deals about you know, what is dark matter and how the universe is expanding and why and when. So there's definitely a lot of uncertainty, they're sure. And this also has consequences about the like the faith of the universe, right, like maybe that means that the universes don't implode eventually. Yeah, and this idea is not Actually that new sort of been developing over a few gades, and it was sort of more in vogue when people thought that the universe was going to end in a big crunch, when we thought that maybe gravity was so powerful that it was going to bring the whole universe back together into another singularity that like inside black holes, you have this like cycling bounce theory a singularity and then expanding space time like a big bang and then come back to a singularity. Because people like this idea that every universe starts with a singularity and ends with a singularity that connects it to like what's happening inside a black hole. But now we know that the universe is less likely to do that because we discovered twenty years ago that the universe is expanding and that expansion is accelerating, so it seems like a big crunch is less likely to be in our future, so that takes a little bit of the shine off of this theory. You know, more likely in the future of our universe is not one big crunch, but as we said earlier, lots and lots of very widely distributed black holes, as each sort of local clump of gravitationally dominated matter falls into a mega black hole which is super separated from all the other clumps of matter which is falling into their own black holes. So you end up with like a universe with lots and lots of black holes in it and nothing else. I see. You're saying, like this new theory, but natural selection assumes kind of a bouncy universe. But we are not seeing that the universe is bouncing. We've seen that it's expanding forever. It's expanding forever. Yeah, and we are going to end up with more singularities in our future because of all these black holes, but not like one meta singularity that pulls it all together again. But that's not actually critical. That's not a fatal flaw because you don't have to assume that inside every black hole is a universe that's going to bounce. You can just assume that you create a new universe, and whatever happens inside the universe happens inside that universe, even if it means creations of lots of different black holes inside that black hole universe. So that's not a fatal flaw, right right. What happens in a black hole stays in the black hole. That's definitely true. More concerning is that, you know, we don't understand what the implications are for like black hole mergers. We see black holes gobbling up each other, like fouring a mega black hole as they combine, and that probably happened even for things like the black hole the center of our galaxy, because our galaxy is likely the product of the collision of several galaxies, each of which had their own black hole. So Sagittarius A at the center of our galaxy probably is the result of several black holes. But if each one had a universe inside of it, what happens when they emerged the universes collide, you get some other crazy thing happening. They would have different laws of physics inside each black hole. So like, do you have some sort of like how Senate Reconciliation Committee where you negotiate with the new laws of physics are and we know that always goes smoothly and perfectly. That's right. You know, black holes default on their dead limit, et cetera. And so that's not something that's understood. And again this is because this came about before we understood how often that happened. When LEGO turned on and we saw black hole collisions, we discovered, Wow, black holes are colliding and merging all the time. It's not rare. So it's sort of a new thing to face for this theory. Right, Well, we don't know what happens, but that's not necessarily an argument against this idea, right, Like, maybe you can merge universes that that are different, or maybe they annihilate each other and they form a new universe, like you, you don't know it yet, right, We just don't know. It's an open question because we don't understand the mechanism for like storing and changing these parameters. We don't understand what would happen if two universes with different values of these parameters came into contact somehow. And well, there's also the other question of like you're sort of assuming that all of these universes that are making more universes. Do you all work with the same laws. We just can't explain the parameters of those laws. But it assumes one set of laws for all universes in this giant savannah exactly, and we don't understand that structure at all. It's like saying, well, all right, I'm explaining why the control panel is set this way, but like, who built the control panel? Why do you have this many parameters? Why are there twenty six parameters and not one? Why have any parameters at all? Can't you imagine other universes without parameters? So it doesn't answer that deeper question. And that's what I find frustrating about a lot of these explanations is that they don't go all the way I want to go all the way to explaining the universe down to know numbers. You mean us a giant savannah full of infinite universes having baby black holes. That's not hardcore enough for you, Like, do you want to go more extreme than that? I mean, it's extremely imaginative and it's evocative mentally, but it doesn't really answer questions, you know, because it doesn't let you grasp of those things and and ask deeper questions, you know, about like this, like why are there all these parameters? You know it's a limitation of the theory, but couldn't you also apply the same idea though, to this idea of laws, like maybe when you make a new baby black hole universe, the laws also changed a little bit, not just the parameters, and so then you also have natural selection of physical laws. All right, I'm gonna call that the smoll en cham theory of the universe done. Noble Prize. Here's my address. You win one black hole, sir, I get half of a Nobel prize. I'll share with Sleep. I've mentally at least more than before. I'll be happy to share it with him. All right, that sounds like a plan. All right, Well, that's the idea, and there's something also about the timing of it that's complicated, right, Yeah, It's hard to really think about the timing because you need to think about like the framework in which this happens. Like we're arguing that these universes would create more universes with more black holes in them. But you know, if you think about how long it takes our universe to make black holes, it's like millions or billions of years. We do see black holes having formed in the early universe, like after a few hundred million years or maybe a billion years, but that's kind of a long time. Imagine you had other universes that very rapidly formed a smaller number of black holes. They would then create their babies when they were very very young, and so even if they're not creating as many black holes per universe, they're reproducing so quickly that they in the end there are more of those universes than ones with more black holes in them, just because they had babies sooner than everybody else. Yes, but you know that depends on this idea of like clocks, Like are the clocks and universe really sink to the clocks in that universe? When did this whole process start? Is there really sort of like a timing for the meta universe. It's sort of fuzzy, right, because, as we've talked about the at time sort of slows down as your approach a black hole, right like when you bend gravity that much, time works totally different. Are you Are we saying that time works the same inside of the black hole. We don't know what's going on inside a black hole, right, And this theory would suggest that time inside the universe, that space time is expanding inside that universe instead of just being like twisted by the singularity. But this is a question about like whether you have some meta clock that's you know, is counting like how long you've taken to create babies, and that like the clocks inside the universe are sort of somehow connected to this concept of how many universes there are and how long it's taken to make those universes. I think what you're saying is that evolution is complicated, right, It's not just about optimal solutions, like in and in the animal world, you know, we're not necessarily the most the most perfect animal out We're just happened to be the best animal that seems to have survived the most, right, Like, like there's still a question of why we have toes, Like nobody knows why we have toes, but we're there. They're there because you know, something needs to collect lint, I guess or you know, the idea is that we're not necessarily optimized. We just got here first. Yeah, we're the product of our specific history and you know, and wild biologists look to explain toes physicist look to explain theories of everything, which are also toes. Yeah, there you go. So are we Is this the pinky toe of the universe or is this the big toe? Oh, it's definitely it's the big toe. It's one megato. It's the meta too, it's the alpha toe. All right. Well, I think the main takeaway here is that we we don't know why the universe is the way it is, Like, we have really no idea, and so we're open to any crazy idea, even like giant savannahs full of competing universes. We really are at the beginning of our exploration of all these crazy ideas, at the point where we really should take seriously concept that seem bonkers, that seem at first is like what that's insane? It might actually make sense and it might actually describe our reality. Yeah, And I think it points to also how much there is still to discover about the universe. Right like any kids listening or any young aspiring physicists listening to this, or any old help physicist to like who aspire to make a big break there that you could sort of focus on these big questions and there's still a lot to explain about why things are the way they are. That's right, and I hope it's the young physicists to figure it out because I gotta go take a nap. But why do you have to take a nap, Daniel? Why do you have to take a nap now and not not a later? Or why in your couch and not in your futon. There's a fundamental parameter of the universe, the number of naps per physicists. I see. It's the big end. Nobody understands it. And is it dimensionless or or do you sleep forever? Or is there a set amount of time that you are units of time that do you sleep for? I sleep in many dimensions? All right, Well, we hope you enjoyed that and made you think about why we are here and why we are in this universe, which seems pretty good. But who knows. Maybe it's not subot well, maybe we are in the pink toe of all the universites. Whatever universe it is, I like it. Thanks for joining us, see you next time. Thanks for listening, and remember that Daniel and Jorge explained the universe is a production of I Heart Radio or more podcast from my Heart Radio. Visit the I heart Radio app, Apple podcasts, or wherever you listen to your favorite shows. H