The SF Universe of Alastair Reynolds "Revenger"

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Speaker 1: Hey, Daniel, do you think scientists make good science fiction authors? Oh? Sometimes? I mean Carl Sagan was a scientist and he wrote some really excellent science fiction. Yeah, you're right. I am a big fan of contact. But what do you think about the opposite? Do you think science fiction authors could make good scientists? Well, I will happily read their papers if they read my science fiction stories. That sounds like a fair trade maybe, But do you think they could do real science? Do you think that after being immersed in the fictional world, you could actually sit down and deal with real numbers. I'm not sure, but I think they already contribute in an important way to actual science. Do they discover new particles or new kinds of black holes? Even better, they put crazy ideas into the heads of scientists who read their fiction. I see, And then you guys take all the credit, right, Yeah, well, maybe we can allow them to name the new particles in that case, or maybe it could be a joint Nobel prize, you know, physics and literature. That's right, And I would a Nobel Prize for the acceptance speech I give for my Physics Nobel Prize. Hi am or handmade cartoonists and the creator of PhD Comics. Hi, I'm Daniel. I'm a particle physicist and an aspiring science fiction want to be Does that mean that you want to be science fiction, like you want your life to be science fiction? Or you want to write science fiction? Oh? I think all of the above. I'd love to write science fiction, and I'd love to live in the science fiction universe. I mean one of the fun things about writing science fiction is imagining yourself in that universe, teleporting places, shooting ray guns. I mean, that's why people play with lightsabers. Right, I'm definitely I count myself an aspiring jet pack owner. I'm still hoping for that. But welcome to our podcast, Daniel and Jorge Explain the Universe, a production of our Heart Media in which we like to talk about the rules of the universe. We break them down for you. We explain to you how our universe works, what we're doing to figure out what those rules are and whether they make sense at all. And sometimes we like to talk about also the universe that maybe doesn't exist, or we'd like to talk about ideas that we don't know are true yet but that they might be, or that at least it's making people curious and it's tickling their imagination. And this is an important part of understanding our universe is thinking about what other kinds of universes could there be. How would the universe look if the laws of physics were a little different, or what would the laws of physics have to look like in order to allow Horey to have a jet pack and Daniel to have a lightsaber. So this is an important part of actual intellectual exploration of our universe is imagining new fictional universes. Yeah, because you know, I guess science isn't just you know, hitting rocks together or breaking rocks apart and looking at data. You also kind of have to exercise your imagination, right and and consider maybe what are possible crazy solutions that could explain what we're seeing. That's right, And you know, I know you've been out of academy for a while, but it's actually a very small fraction of our time we spend banging rocks together. Sometimes you rub them together to move beyond the rock stage. Now, yeah, they're just you're still banging rock standards, they're just getting smaller and smaller. It's all rocks. It's rocks all the way down is that we're there you go. What's I mean? Isn't a proton kind of a rock? Really? I guess that makes me a rock and roll physicist. Oh, there you go. That sounds like fiction as well. Well, I said, I wanted to be a writer, So there you go. Anyway, we like to talk about these fiction universes and to understand how they work and to get in the minds of the people who create them. It's right, and so we have the series of episodes in which we or at least Daniel, interviews famous or well known or popular science fiction authors and asked them about their world and about the physics of it and how they came up with all of their amazing ideas. That's right, because when I read a science fiction novel, part of the joy for me is figuring out what are the rules of this universe? What did they create? How does it work? And that's also the joy of physics. We are literally living in the universe where nobody is telling us the answers, and we have to play detective and figure out what are the rules? How does this work? And so it's the same joy, but just encapsulated in a novel, and usually in a novel, it's more satisfying because you get some answers. Also, your career doesn't depend on reading the science fiction novels, so it's probably more relaxing, that's right. And there are fewer rocks involved in the novels. That's why they're called asteroids. Yeah. So to be on the program, we'll be tackling the science fiction universe of Alistair Reynolds. Right. So Alistair Reynolds, he's pretty well known, right as a science fiction or is he more he's more sort of in the hard science fiction genre. He definitely writes hard science fiction, and he's sort of best known for his space operas. He writes stories that take place across an entire galaxy and eons and eons of time, and usually you're buried deep into the future upon layers and layers of crazy history. Yeah. And so to the end, the question that's kind of interesting you and then you asked him, I imagine in the interview is can you write realistic science fiction about life in space? Like? Do do these books really portray what it's like to be in space and to move around in space? Because being in space is tricky, It is tricky indeed. And for this set of books that we're talking about in today's podcast, it's a trilogy starting with a book called Revenger. It takes place in a solar system sort of deep in the future, and he really thinks carefully about how you would navigate that solar system, how you would go from place to place, the fuel needs involved, how you would turn your guns to aim at another ship, how you would even know whether those ships are there. It's really fascinating and you can hear that he is really thinking carefully about the physics, and that's no coincidence. Yeah, Apparently he is inspired by, you know, stories of pirate ships and nautical stories, and he wanted to bring that into the science fiction universe. That's right. And he himself is a physicist, or was a working physicist. He is a PhD in astrophysics, and he studied binary stars at the European Space Agency and then started writing on the side. So he comes into science fiction with a deep understanding of the science behind it. Hopefully his Jesus wasn't fictional. Imagine shred wasn't. I hope he kept a careful wall between his fiction and nonfiction. Yeah, and he's won a bunch of awards in England and for his novels, and some of his stories have been adapted also to television. I actually I have seen a couple of them, Realiz, think who it was? That's right. There's a whole series on Netflix called Loveday and Robots that adapts a bunch of fun short stories, and several of them are his. Yeah, and this is one of your favorite writers, right, Daniel. I mean you're you're definitely fanboying here when you talk to him. Yes, that's right. He is one of my favorite writers. And one reason is that the physics of it is so good. It's so insightful and interesting and so real and so carefully thought out. And you know, then on a personal note, it's just it's nice to see somebody who was a physicist make this amazing transition into being not just a published science fiction writer, but I well known, well respected, multi award winning, international best selling science fiction writer. So hey, a guy can dream, right, You're like somebody got out. Yeah, I cannot dispute that with my reaction. I finished his first book that I read, and I thought, Wow, was an amazing book. And then I read the about the author at the end, and I was like, oh my gosh, this guy could have been me or I could be this guy. Yeah, so it sounds like the physics in these books are really cool. And again, the series is called Revenger, the Ander Trilogy. The first book is called Revenger, which is not the sequel to The Avengers. It should be it should be the Avengers reboot. And so let's dive into his world. What is this world like? It's is it in the future, the near future? Millions of years into the future, so it takes place in our Solar system, but then millions and millions of years in the future, and it's so far in the future that the sense of history is sort of lost, Like you're deep into the future, but you don't really know how the universe that he puts you in has been assembled, and it looks very different from our Solar System, Like did something happen that caused all the history books to disappear or what. It's just sort of like, it is so so far. It's just so far in history. Yeah, and humans have left the Solar System and then come back and recolonized it multiple time. What do you mean they left and then they came back. Yeah. Well, this is a sense of mystery in this book is that you don't know the full story. You just hear dribs and drabs, and the characters themselves don't know the full story, Like do we know how many times humans have colonized Europe? We know there were waves and waves and waves from Africa. We don't know the full story, even though it was sort of us who did it right. And in that same sense, you imagine millions of years into the future, you might lose the history, lose the written records of why humanity went to the stars and why everybody died out in the Solar System and why they came back. And so this is that sort of to the extreme. That sounds pretty interesting. And you're telling me that they disassembled the planets in the Solar System. Yeah, so the Solar sistem is unrecognizable. The only thing you might recognize is the Sun, which is still there. But they have taken apart all of the planets and use them to build like a bunch of habitats, and so you have like lace worlds and little dicen spheres and all sorts of structures you can live on. But they've turned the eight planets into like hundreds or thousands of essentially space station like many planets. Yeah, sort of like many planets, but you don't but a planet is very inof Asian, right, you don't really need the core of it. And so they mind, I guess all of the materials from the Solar System and build all these crazy different shapes and structures for people to live. Oh, you can create more like surfaces to live on if you break the Earth into pieces exactly, take the Earth and sort of like unwrapid unroll it. You can get a lot more service area, and then people can be creative, right, and you can have like lots of weird layers, or you could you know, just live on the inside of a spear, or you could have a tube or a ring. Right, you could have all sorts of crazy stuff. I guess my question right away is how did they deal with the gravity then? Right, because if you have a smaller planet, the gravity is less, So how do you walk around? Yeah, so some of these things have many black holes at their centers. Of course, obviously, what do you mean they made a black hole? They captured a black hole? Well, you know, humanity in this story sort of just living on these found structures. They've discovered them. They think humans made the millions of years ago, but they no longer have the technology to create them, so they don't really understand them either. So they know there are black holes at the center of them. He never really explains how they were made, because again that's attributable to the ancient lost art of black hole manufacturers. Okay, so they're using a black hole there, and so it all takes place in our solar system just in the future. Yes, our Solar system, very far into the future. But most of these things feel more like space stations or space ships than real planets. I mean, you can walk around on them, but none of them are as vast as a planet. It's almost like, you know, if you took all the continents on Earth and broke them up into little islands, it's like a giant archipelago. Yeah, exactly, and then you have to figure out how to get from one to the other. And that's another whole fascinating aspect of his universe. This is where the like the sailing analogy comes in, like the nautical aspect of its space, nautical mechanics. Yeah, it's a lot like space pirates. They get around from one of the other using solar sales because it's very inefficient to use like rocket propulsion. You need a huge amount of fuel to get around, and so they take advantage of the energy of the sun. And they have these small ships. Each one is you know, like the size of a current human airplane, like a modern jetliner, and to get that thing around you'd need like square and kilometer after square kilometer of solar sail. So these ships are tiny, but then surrounded by these huge sales that capture the energy of the sunlight and use that to get around the solar system. Oh and they're not solar panels, right, They actually like they bounce off the energy of the sun. That's right. They're much more like sales than panels. They don't absorb the energy and then store it in a battery. They actually like reflect those photons and use that to get a little kick. And there's also a battles out in space right between these sailing chips. Yeah, yeah, there are a lot of these battles, and they have these railguns that they shoot at each other, and a lot of it is about staying silent, staying hidden. You know, not announcing your location, and so they try to keep as dark as possible so nobody can see where you are, and stay as quiet as possible. They try not to like let their railguns get too hot, because then they glow and other people can spot them. And it really gave me the feeling of reading nautical fiction from like the eighteen hundreds. It's all about like turning about and getting your cannons pointed in the right direction and making sure you're up wind, and a lot of this very strategic thinking limited by the physics of ships. In this case, it's limited by the physics of sun jammers, which is what he calls them. But I guess you're hanging out in space, don't you have when you have like a lot of energy, you couldn't need to have some a little bit of rocket boost there here and there you would need to. I mean, it's much easier to use solar sales to get like further away from the Sun. It's much more difficult to get closer to the Sun. And so they do have rockets also which they need to refuel, but they use that sparingly because you know, while there's always sunlight to capture just like there's always wind on a sailboat, you know, the the engine for their rockets needs fuel and that's a limited quantities cool. And there's a lot of mystery as well. There's like ancient technology that they keep discovering. Yeah, there's been like eight or ten layers of occupation from humanity, and the previous layers put a lot of their fancy tech into these like locked boxes which opened regular intervals, like every thousand years or every hundred years. They will open up and you can like crawl in there and try to grab some treasure and then crawl out before you get stuck. And so there's like a lot of these devices around the player role in the story that nobody understands their science. They're like left over from a previous layer of civilization and it's like found treasure. And so a lot of the book, which is just really good storytelling, is like sailing around from these treasure islands a treasure islands, capturing things, stealing them from other people, and then of course getting revenge on your revenger. So they find old technology and they can still make it work or it just works, you know, like it just turns on and you can use it. Yeah, it just turns on. You can use it, and you know, some of it is inert and they don't understand why, but a lot of it they can just use. You know, they have like special armor that makes you invisible and they don't know why. And they have you know, technology that lets them see things that are far away. And they also one of the coolest bits is how they communicate from ship to ship is that they find these skulls of alien beings from the deep past, non humans so humans. Just to clarify, everyone in the book is human, so they're just super future humans. They're super future humans. There are a few aliens also, just a few characters who are aliens. So in the book we have met aliens and can communicate with them. And also we have the skulls of ancient long extinct aions and these skulls have this property that they can like communicate between each other. The dead skulls can talk. They can they have some sort of like telepathic ability. And if you like wire into it and attach you know, your head to these skulls with wires and somebody else does it in the same way, like on the other side of the Solar System, then you can communicate back and forth using this sort of like you know, hopped up neural telepathy. Wow, And it's sort of awesome because it's like piggybacking on what these aliens maybe could have done and we don't really know, and like, are there tendrils of those aliens brains still in their skull? Why does it work at all? And it just barely works. It's very difficult. Yeah, but it's sort of like you know, using a hand radio. You don't really understand it. You sort of connect your brain to it, you tweak the knobs, you see who else is out there? And so I think that he's trying to capture not just the sense of like sailing on the open seas, but also like limited communication abilities. Alright, wow, that's a lot of a lot of interesting ideas here, and so let's dive into the physics of it, whether or not some of these things are possible or impossible or maybe in our near future. But first let's take a quick break. All right, we're talking about else. There's Reynolds science fiction trilogy Revenger, and the incredibly interesting ideas in it, including alien skulls that can make you telepathic somehow, somehow like a Ham radio, Like if you put a Ham radio on your head, that's right, or if you had like an Internet connection in your brain. I wouldn't recommend that, though you probably get hacked by Russians. I think I think people's phone spend so much time near our heads that it's probably might just as well be connected. We're basically there. Yeah, all right, So what's the physics of this series? Daniel? So, first of all, there's planet disassembly. They break apart the planet, and is that possible? Could you, like, can I split Jupiter into two? You know, I think it really is possible. I think that it's a problem that's technologically very difficult. It's you know, engineeringly difficult, as you would say, But physics wise, there's no reason why you can't. I mean, think about the solar system is just a bunch of raw materials and use that to build whatever you like. It would just take a huge amount of energy and planet to like break the even the Earth, which is a small planet. How would you even break it apart? Yeah? Well you would start by building you know a lot of solar panels and use that to capture the Sun's energy and then use that energy to mind more raw materials off the planets. Probably you would start with mercury because mercury is very close to the Sun, so there's a lot of energy there and has low gravity. Hot property has low gravity, so it's easy to build stuff on the service and launch it into space. And it's metal rich, it's like solid iron core, has a lot of oxygen on it. And so you start by disassembling mercury and using it to build like essentially a dice and swarm. Remember we talked on the show once about a dice and sphere, like a huge superstructure that envelops the entire Sun. This is basically like that, except instead of one big superstructure, which is kind of implausible because it would break up, you build a lot of smaller and so they did this the ancient humans. Apparently the ancient humans did this. Yeah, they disassembled but not just mercury, also all of the planets. There are no original planets left over. What it's a completely different solar system completely, yeah, exactly, you know, and they redesigned it. You know, you come, you buy a house and you redo the kitchen. They redid everything. They stripped this thing down to studs. Oh I see. So it's not like they took Jupiter and broken. It's more like they they just like minded, they like broke, you know, little by little, they took chunks and put it into other parts of the Solar System. And the hardest thing I think about the physics is that the Solar System is mostly hydrogen. Like, of course the Sun is mostly hydrogen, but even the other planets is mostly Jupiter. Jupiter is the most massive anything, and it's mostly hydrogen in some helium heavy metals like the kind of things we find on Earth and mercury are much more rare, and so you don't want to build your superstructure or your swarm out of hydrogen. And so I think that's the limiting factor. The amount of surface you can build is not just limited by the mass of the stuff in the Solar System, but the amount of heavy metals you need to make it. Oh I see, So maybe there there aren't another four. Do you think he did he actually count how many how much metal there is in the Solar System? Yeah, I think he did a bit of careful accounting, And I'm imagining that he used the hydrogen to form those black holes like if you can't build something out of it, and you need to make a black hole, Well, a black hole is just a big pile of stuff that's gotten compressed down into a small area. So take Jupiter and turn it into a black hole or a few black holes, and you could put those at the center of your little structures and they would provide enough gravity. Oh, that's why you would do it, just to have more gravity. Yeah, if you want gravity on these structures, then you need a lot of mass. And if you have a lot of mass you can't use to actually build the structures, right, all this hydrogen and helium, then you might as well use it to make the black holes, I guess would give you like earthlike gravity in a small asteroid kind of yes, precisely, because it's much more dense than Earth, and so you can get Earth like gravity. And you wouldn't want all the Jupiter in one black hole because that's way too much gravity, right, the gravity and Jupiter is crushing compared to the gravity on Earth. But you can make little ones, yeah, and you could. If you have this power, you can divide Jupiter up into a hundred little black holes and use that to provide gravity on a hundred little structure. It seems kind of dangerous still, because like what if you fall into it, or what if you're you know, you know, what if your structure touches the edge of it. Yeah, well, you're worried about the people, you know, living on this thing. I'm worried about the people manufacturing it, you know, like I hope they're being careful and they're wearing hard hats when they're manufacturing black holes. Oh yeah, because if you touch a black hole, that's it. That's it, man, there's no coming back. You're not pulling your hand back out of those things. Okay, So then what about the solar sailing? That's pretty plausible and realistic. That's totally plausible. Solar sailing is a real thing. I mean, there's real physics there. It's just a big sheet of very very light material, and when a photon bounces off of it, it pushes on it. It's like if somebody throws a ball and it bounces off of you, it's giving you a little push. And photons have no mass, but they do have momentum, and so when they bounce off of a mirror, for example, they are giving that mirror a little push. If you put a mirror out in space, the Sun's photons will push it through space. Yeah, we have a whole episode about solar sailing if you search our archives. And the problem is that solar sale helps you move away from the Sun, but it doesn't help you move towards the Sun. That's right. And there was this really fun moment in that podcast when I was being so excited about solar sales and then you were like, well, but what about turning? Can you turn? I've never thought about that before. Oops, But it turns out you can, right, You can turn with a solar sale if you angle it, because it means the photons get reflected off, like to the side a little bit, which gives you a push sideways. And you can't use a solar sale to go in towards the Sun, but you can use it to like slow yourself down. Like say you're in orbit around the Sun and you want to go to a closer orbit. You can sort of angle your sale to bleed off some of your velocity so that the sail is pushing away against the direction you're moving in orbit, and that will help you fall into a closer orbit. It can't actually pull you in. Only the Sun's gravity can pull you in. Photons can just provide an outward or sideways force, But so going in is harder than going out, but it is possible. I guess it makes me kind of think about how, you know, how you would navigate a solar system where everything is broken up. Do you think that that those ancient humans or aliens when they broke up the planets that they think about like creating stable orbits and and things like that, or is the whole Solar system just this chaotic mass you know, they planted very carefully. It's called the constellation. And these little habitats are all in different orbits that sometimes gets close to each other and sometimes further away. And some of these things are on larger orbits because some people like living out in the middle of the darkness and coming back occasionally every hundred years or something, and so you have lots of options, and these things sort of get closer and further apart, so it's easier to jump from one to the other. And doesn't it take years to go between these islands or colonies. Well, he I think set the whole thing sort of close enough to the Sun that these sun jammers are powerful and distances are not so far, but it does take weeks. Right, You're not like teleporting from from place to place. And that really is a factor in the story that sometimes it takes weeks or months to get from one habitat to the other. And you know, it sort of feels like ancient chips, Right, you got into a boat. You don't just get to America six hours later. You know, after watching three movies, it took months or sometimes years to get around the world. So we sort of captured that by transplanting it onto the Solar system. Can you get space scurvy? You can? There are versions of that. Really, huh? All right? And then the last bit of science fiction here is this skull communication, Like some of the skulls can communicate telepathically even though they're the debt. Yeah, that's right. And as I was reading, and I was wondering if he was going for faster than light communication here, because it does seem fairly rapid. But he's also he's kept the whole universe of his book barely tightly around the Sun, and so the distances are not large, so it might be fast in light or might just be like as fast as light. Um, but you know, could aliens have some telepathic ability to communicate? Certainly? Right, there's nothing physics can say no to to telepathy. Perhaps you can really generate some signals in your brain. Sure, I mean think about the engineering generates some signals in your brain that somebody else can read. I mean basically a walkie talking. Yeah, yes, exactly. Telepathy is just another wave to communicate. It's like I already do that. I generate signals in my brain which create waves in the air which go into your ear, which generates signals in your brain. Sound is telepathy. And this world we're living in, then you just approved, just physics approved telepathic aliens. I don't see why it's not possible. You know, the bit that stretches it is like, well, could you use their skulls to do telepathy after they are long dead? I don't know, but hey, it was a fun book, all right. Well, so you actually got to talk to him, and we're going to play the interview for everyone here in a in a minute here, Um, but what are some of the questions you you asked him? I asked him what motivated this and whether he was interested in keeping the physics real. And then of course I asked him how to become a science fiction author if you were a physicist hypothetical hypothetically of course, yes, because we all know your dream is to be a podcast host. That's right, one day, one day? All right, Well, here is Daniel's interview with Alistair Reynolds, author of the Revenger science fiction trilogy. So I'm very happy in honor to have with us today on the podcast the multi award winning author and former physicist Alistair Reynolds. Alistair, thanks very much for coming on the podcast. Good afternoon, Daniel, A very great pleasure. Thank you for having me. And do you consider yourself a former physicist or is somebody a physicist forever? I thought about this a lot, actually, and I used to say it was a former scientist, but no, I think it's sort of in the blood. It's just a way of a way of looking at the world that you don't just cast off the day you stopped being paid to do science. So I'm yeah, I'm a scientist for the rest of my life. And tell us a little bit about your background. How did you come to your science fiction writer, how did you what was your education in its sort of to to sort of parallel strands. Right through my life was an interesting space and science and also an interest in science fiction, and they've just been there for as long as I have. And uh, I started writing stories from the point where I could hold a pen and I just never stopped, really so right through my early education and the sort of point where I decided I wanted to maybe try and become a physicist, there was also also the creative writing going on, and then I guess I think it's when I was about sixteen, I decide, you try and take the writing more seriously. So I started reading about the ways into publication magazines, that kind of thing, never never thinking that would be a career option, but I thought it would be something I could do, you know, as seriously as a lot of other science fiction writers who had proper jobs as well, but they're also sort of successful writers in their own right. Yeah. But so I also kept on studying to become a scientist as well right through that period. But there was never a point where I woke up when they said, Okay, I'm gonna be a writer. It was always there. And what exactly was your area focus in science? I wanted. So I did a degree in astronomy and physics at Newcastle, and I didn't really have particular sense of what direction I wanted to go in when I started that degree. I just wanted to be a scientist. In fact, what I really wanted to be as an astronaut um And I thought, this is going going back to sort of the early to mid ninety eighties. I thought, by the time I've become a professional scientist, there will be sort of lunar observatories, you know, radio telescopes on the dark side of the Moon and all that kind of stuff. So I thought, Bill, it will be you'll go into space just by being an astronomy kind of like the Antarctic surveys kind of thing. So I thought that would be a good way to get in space. But no, I did a degree, and by the end of the degree, I kind of I was taking an interesting cosmology as suppose in particle physics. I was very interesting in things like the nature of the neutrino and the solar neutrino problem, which were things that weren't really resolved in the mid eighties, and I started getting interested in I suppose the early stories about dark matter and you know, really sound health fundamental particle physics mapped onto cosmology and things like that. But that's a really hot and very popular area of astronomy. Everyone wants to go into, you know, So I didn't really have the sort of mathematical chops to do that. I don't, but I sort of segued into stellar astronomy. So my PhD was on the mathematic of the properties of interacting binary starts, particularly a class of binary star where you have a style that's rather heavy in a relationship to the Sun, sort of ten ten to twenty solar matters, and then the other partner in the binary would be a neutron star. These are these are sort of high mass extra bineries, and there's lots of different types of them, but many of them have a rather short orbital periods, so you can study the orbital cycle over a few days, which makes them good targets for say short campaigns on big telescope. So so you would aim to go to Australia or Hawaii or something like that and bag for nights of observations on a number of these different high miss extra binaries. And the big sort of topic that was of interest was the limiting mass of the neutron star, because there's all sorts of theories that sort of said, what the what the mass of the neutron start to be For some of the observations that have been done in the sort of sixties and seventies, we're a little bit sketchy, you know. So there was some question about whether the neutron stars were were lighter than than they should have been. Cool stuff, It was cool. Yeah, it's really interesting. Yeah, Well, let me ask you some questions to get to know how you think about the universe, and do you think the universe is really really big or actually literally infinite? I think my my sort of take on it is probably just bog standard modern cosmology with um, you know, a big band inflationary park or whatever you want to call it. And then we sort of a you know, thirteen and a half billion years later, we're here with an observa an observable universe which is bigger than the age of the universe multiplied by by by years, which some people have trouble wrapping their hairs around, but not infinite. Um. So yeah, I think we live in a sort of bounded universe. But I'm not Zella is about it. To me, the actually infinite universe makes the most sense because it's hard to imagine having a bound abound in space or a bound in matter theme harder to explain the actual infinity. Even though infinity is difficult for humans to wrap their minds around, it may actually be natural. You know, the the universe is no stranger to bizarroness. So but let me ask you another question. Do you think that human interstellar flight will ever be a reality? Is that's something people will will ever actually do? Do you think will be stuck in our Solar system forever? I mean, there's like so many different levels to that question. It's like, is there a technical capability that we could achieve if we so wanted? That? To me is probably a fairly firm yes, in that we already know a little bit about Say, you know, we could build a fusion spacecraft based on fairly well established principles that could get us up to about ten speed of light. So he might have trouble slowing down, but at least we could take a go about our star into a forty years or something like that using technology that's not absolutely beyond beyond the sort of pale when we sort of talk about sort of the stuff in my look sort of like relativistic instead of travel one g. Where you sort of get up to the speed of light and then you decelerate again and you have sort of significant time relation factors. That's a much bigger ask, and I think that's like, if that's even technically feasible, it's probably thousands of years in the future. But one of one of the sort of things that does sort of trouble me slightly. I'm not sure. I mean, my feeling is that once we have the technical technical capability to maybe do interstellar crude interstellar exploration, we might not have the will to do it anymore. Because in parallel with that development scientifically, in terms of scientific and engineering capabilities, presumably our knowledge of the universe is going to expand as well, and we may have what we consider to be a completely comprehensive, self consistent picture of our position in in in the galaxy and the galaxy within within within the larger universe, and we may we may just reach a point where we just not we're not interested in going any further than our solar system because we've we've sexually established to our own satisfaction that we know what's out there. And I think when when you know already we know a lot more about the broad conditions of many solar systems. We know about thousands of extra planets in different solar systems, So we have a sharpening sense of what's out there, not just in our immediate interstellar neighborhood, but out to thousands of light years with the sort of transit observation. And as that picture firms up and develops over the next century, it may we may think, think, realize that actually Earth like planets are incredibly rare, and all that's out there is just more stuff like the Solar system, you know, more more sort of versions of Mercury and Jupiter. And would we be sufficiently motivated to explore if we already sensed that we had we had all the answers already, So I don't know, Maybe depends on what we see. Then if we saw something really interesting, if we sort of resolve the structure on the planet, I mean, they don't necessarily necessarily mean an artificial structure, but if we resolved say a continent with green bits or something like that in a blue seed and then that would be a significant motivator for some form of exploration. But I think it's far from settled that there will be this grand You know, the default science fiction future is that we go into the Solar System, best around there for a few hundred years, and then we developed interstellar capability, sometimes even faster than like capability, and we burst out into the universe. And that's like a sort of cosmic destiny. Um. I'm happy to play with that in science fictional terms. As a writer. It's there's a lot of literally fun to be had from that prectice. But I'm probably a little bit more doubtful about it now than I was when I start in my career. And so that leads me to my next question about the Fermi paradox. In your books, there's almost always aliens and there's been contact, but in some cases the galaxy is like mostly wiped out by some prehistoric galactic battle. So what does you take on our current situation, like why haven't the alien visited in your opinion, here in our in our actual physical galaxy. Again, I always say what day of the week is it? And I'll give you a different answer. I mean, for a long time because I read this very book that a lot of science fiction writers read in the eighties, which was The Anthropic Cosmological by Barrow and Tippler, and the sort of takeaway message of that is that the reason, the sort of explanation for the Famie paradox is that there's no one out there because the mechanics of interstellar colonization using relatively slow propulsion systems but say replicating robots and things like that, I mean that you could in effect colonized the entire galaxy in a very short span of time, much less than a million years, and that's just a tiny fraction of the existing age of the galaxy. So the argument is that only would have had to have happened once for the sort of evidence of it to be obvious. There's been many, many opportunities for it to happen, and it doesn't seem to have happened. Therefore, there's no aliens out there apart from maybe single cell slide things. That I took that as goss for for a long time. I think it was a very sort of persuasive argument, but I'm a lot I'm not so smitten with it now because I think one also has to think if if there were imagined that we had been visited by super intelligent alien beings at some point in our history, I think it would be an absolutely trivial problem for them to conceal all evidence of their activity. I think they could even be here now we wouldn't see. That's why, in a way, it's why I take I don't take UFOs seriously because I think any any extraterrestrial civilization that wanted to visit our skies could do so without being detected. They would just that would just be a trivial, little technological problem for them just to avoid detection. So yeah, I kind of haven't really answered that. I think the family paradox is. One possible answer is that we're alone, and that's that's sort of it's quite interesting one. I don't find it depressing, think it's interesting. But but the other one is that really want to speculate about the motives and activities of highly advanced extrastrial beings. We're you know, we're really we don't really have a lot of experience to base our suppositions on. It's a lot of speculation from one data point. It is an enormous amount of speculation. Yeah, well, I quite like the idea that. I mean, someone did the mathematics. So it's about, you know, what are the orders of finding, say a single alien artifact in the Solar System. We had like an alien civilization somewhere else out in the galaxy, because at some point some of their space also wander away from their system, and you know, there might be sort of like a spanner on the moon or something like that. So I think it will be I mean, well worth keeping our eyes open as we as we sort of moved out through. I had hopes for MUA being a bit of space junk passing through the system, but unfortunately doesn't look that way. I know, no, no, it's just a dirty comment or something like that. This is super fun, and I have more questions for our guest science fiction author Alistair Reynolds. But first let's take a quick break. All right, we're back and I'm talking to Alistair Reynolds, science fiction author of the trilogy Revenger. So then let's turn to this novel that's the topic of our episode today, which is actually your trio of novels, this Revenger series, and in this book, we're sort of in a world where the old planets have been deconstructed into a vast series of artificial worlds, and the ships that moved between them operate on solar sales. It's it's a fascinating topic, and it felt to me very much like a novel that could almost be set in a bunch of pirate ships navigating between islands in the eight hundreds or something. What gave you the idea to use this concept? Um? So what made you want to write this book? Where did this idea come from? Did you start from the science concept of solar sales? So did you start from the story and look for the right setting? Actually had to ideas that was sitting on my computer for a long long time, and we're talking to the ten, ten, fifteen years, because I quite often I have a lot of ideas on the back burner, which is I think a lot of writers are like that, because writing is a bit like a conveyor. You know, you write one novel and you've you've got to kind of have some ideas germinating for the next one. So I write a lot of stuff that's very sort of notes, notes and sort of ideas to myself computer that don't necessarily go anywhere for years and years. And the first sort of part of that was that I tried to write to set the stories about explorers breaking into alien structures where they had a certain random time limit where they had to get in, get the treasure, and get out, sort of Indiana Jones stuff, but they didn't really know how long that they would have, so it was very sort of high risk, sort of like safe cracking, but with an element of alien big dumb objects and things like that. And I thought there's definitely something in that, there's some mileageing idea, but I couldn't really get its catch fire, and I tried telling it within some of my other literally unit It's maybe it just didn't happen for one reason or another, but I had still have the idea on my hard drive. And then again about fifteen years ago, I really liked the idea. I mean, there was a science fiction writer you probably aware of who had a big burst of productivity in the sixties bychall Larry Niven, and he wrote a bunch of stories about what it kind of goes back to that thing we were talking about of the manifest destiny of going into the Solar System. And then we move out into interstellar space. But his stories were quite good fun because by the time we had an interstellar society, we've met lots of different alien civilization and some of them were trading their technology with So what I quite liked about the Larry Diving stories and space stories was that you'd have a sort of spacecraft, but bits of it would be made by one set of aliens, and you know, the puppeteers would make the hulls because they were very good at making indestructive and material, you know, and then there'd be some of the systems supplied by someone else. And it was a real sort of cosmopol and quite fun and colorful sort of civilization. I always like, I like the spirit of that, and I thought, I really want to put my own spin on it. So I started coming up with notes for a set of stories that were setting a dicens sa, so not not a sphere around the start, but a literal globe of lots of little microworlds. And I thought, what if, rather than deal with the people who built it, what if some human explorers sort of stumbled up long after it was constructed, and in fact after that sort of fallen into ruin, and then they could have a sort of little micro civilization where they're playing amongst these enigmatic leftovers from sort of previous glory civilizations glory lens. But you can see so that that was an idea. It didn't go anywhere either. But then a long long time later, I I sort of spotted that those two ideas could be sort of jammed together and made something else. And then the sort of third of the two ingredients, you know, just mention it was just a longstanding love for nautical fiction, and that's that's where all the sort of the Pirate High Treasure on the Seventh Seas and all that stuff comes from, which just I just love that stuff. I've steeped in it, and I always wanted to write a sort of science fiction prestige of sort of the age of fighting sale something that sort of went back to Robert Stevenson also a lot of the sort of twentieth century writers who who did stories about sailing ships. So just it all just came together. And then what I quite like was that because you're the whole action is only confined to a volume about the size of the Earth's orbit, that's quite important. So it's sixteen light seconds wide. It's human civilization. Even though there's thousands of thousands of planets within that sort of sphere. I thought, well, within that bound you could just about get around and some solar sects. And you know, if I thought, well, the use orbit takes us round some once a year, so that would be the fun. It takes about a year to get from one side to the other of its body of worlds. And I sledged it because solar sales are very good to get you know, they're getting a way from the Sun is obviously trivially easy with the soil of sale, you just use the light pressure. Attacking inwards is more difficult, but I read a paper about using Anglo momentum effects to sort of tack your way deeper into a gravity. Well, so that's all I need. The rest of it is just just pure handwing ion drives in there, just like I could sort of a get out. If anyone were to say this is totally impossible using solar sects. They've also got ie on capability. They're just prefer not to use it because the solar cells. Solar sailing comes for free as soon as you turn on the ion drive you're burning fuel money, and so how important is it to you that there's always sort of a physics explanation for everything that happens in your novel. It's critical to you that you have a physically self consistent universe, even if you get to tweak the laws of it a little bit, but it's not colossally important, and it varies quite striking. And I would say from one universe to another. I mean the the two sets of books that I'm probably best best known for, the books I wrote earlier in my career here which I've returned to set in the Revelations space, which on one level is quite grounded in hard physics because it has this implacable rule you can't travel faster than light. And I tried to work out all the relativistic effects correctly, and I try to do the sort of dynamics of planetary systems and atmospheres as realistic as I could get it with my own limitations, and at the same time tell a story that was hopefully interesting more than one person. But even within that there's sort of crazy science, creative sort of tacking on signaling from the future, inertialist drives that kind of thing, even a bit of time travel. So there range of stuff is even more like that because you have this on the foreground. The humans use the technology that's broadly familiar to our own, you know, so they have rockets for short distance navigation, and I was thinking real buck rogers rockets here. So they like sort of bullet shaped cylinders with little fins on the back, and rock keute motives really with with portholes and riverts as well. That was important to have lots of riverts. But that's like within within our technological sort of horizons. And the ships not outlandish in the sense that they use solar sales. But I didn't I didn't tie myself down to I mean, if you sort of do the math, so I said, right, my ships are about the size of a seventary seven. That's that's what I decided, because I wanted them to be big enough that you could sort of have a bit of drama within the compartments, you know, maybe room enough for a crew of ten or twelves or something like that. But I didn't want to be sort of enormous space dread or dreadnought sort of kilometers long, you know, seven three sevens good, it's about the size of a of a galleon or something like that. But the amount of area of solar sales you need to accelerate even the Secretary seven to any any kind of acceleration, and the accelerations in the Book of the Ships and the books are quite low by as quite of the SciTE fictional statard. It's sort of like, I don't know, a third of a tenth of a g or something like that, but you wouldn't an enormous collecting area to do that. So I just didn't want to go down that road of scrupulously fact checking myself because because fundamentally these books are about the spirit of adventure, a sense of drama and atmosphere that the sort of mix of what no a sort of fiction and nautical fiction, of a bit of gothic horror coming in there, and I didn't really want them to be paradigmatic hardest fet books. That's why there's so the science is kind of crazy as well. When when there's stuff the humans opera utilized, there's alien technologies, former human technologies left over, even though we never used the word human in any of the three books, but they have access to weird things that they don't really understand how they work, and I, as a writer, put as little explanations I can get as I can get away with from the page. Tell me a little bit about the bones that they use to do faster than like communication. Is this something you imagine might one day be possible with some crazy alien tech and our civilization? Or you think faster like communication is totally out of bounds for humanity. But I think I kind of fudged. I kept it. I never resolved to my own satisfaction whether the skulls work faster than like. The humans don't really know because they're because they're operating within this sort of relatively small volume of space. It's not apparent to them whether they're, whether they're instantaneous or not. I perhaps perhaps they are kind of But actually the genesis of the skulls idea was that, originally, to go back to this idea of humans utilizing bits of alien technology, originally the whole ships are going to be skulls. So it was just like you're going to have like a three h foot long discarded skull from some alia you find floating in space, presum presumably some long vanished staffaring alien, and I like the idea was the humans sort of get these skulls and they sort of scoop out all the jump that's left over and then put rocket boats on them or whatever, and then they just fly these skulls around. And I was really going with this, and then I went to Z Guardians of the Galaxy and why some at some point in this film they go to this sort of I think it's like asteroid moneys or something like that, and the bases a skull. It's just floating in a nebula, and I just can't do it now because it's been done, you know, they've had a big space skull has been done. So then I downscoped and I thought, well, if if the ships can't be skulls, then they will have something inside that uses the idea of the table Scott and I was just thinking about old fashioned crystal radio sets, you know, and a little bit of that, a little bit of sort of weiji boards just to keep it spooky, but really it was just to get a sort of slightly recarb gothic vibe in to the stories, and it gave the cruise another specialization idea that people with this particular talent to be able to get a signal a skull, but I didn't really know how whether that would just be a little background detail or started the books. Well, to me, it seems really evocative of a lot of the other things I like about your other novels, the fact that the protagonist in the book are we surrounded by leftover bits from ancient civilizations? Like there's constantly there's vast quantities of previously understood but now lost knowledge. And I like that because it resonates with the way I feel about our universe, that we're surrounded constantly with information about the universe and we don't understand, you know, we're bathed and clues but totally clueless. This is something you're explicitly going for in your books or is this just the way you feel about the universe? Probably just the way way I feel about the universe. But it's also I mean, it's like there's some the cynical answer is actually it Actually I've always said it's far more interesting to describe the spacecraft that's covered in rust than than well it's kind of all shiny and chrome, because there's lots more adjectives you can use when things are sort of crumbling, falling up. So I've always liked I've always been drawn to that sense of decrepitude and lots of old things have bolted together more or less work but don't work reliably. Just it's just far more interesting. But I think the more serious answer would be that a lot of that's fiction. I read a lot, a lot a lot of the science fictions, but I was influenced by had that sense of antiquity, of layers of antiquity, and the future built on top of of the past. I mean, in literary science fiction. I think the writer that I got the most sense of that from would be Jean Wolf, because the books of the New Sun, which I read when I was at university, kind of feel like fantasy, and it's you sense that you're a long way into the future of this dying earth. But gradually little bits of science fiction sort of intruded into the narrative and you realized that, you know, this is very very distant time is built on well almost literally on these geological strata of different ages, and I really love that, and I love the fact that there were bits of technology, weaponry, whatever left over from more sophisticated times that the characters could could use but not necessarily understand. But so you have on the surface, it's kind of sort and sorcery, very game of Throne sort of stuff with citadels and guys in cloaks with swords. But at the same time, very rich people have ray guns because they found rey guns, and some people are flying cards because they just left over bits of leftover technology. And I love that. I love that sense of just archaeological accretion of different layers, so that came into the It's also in lots of Doctor Who as well, lots of classic doctor Who had that sense of really really deep time, deep deep paths. So I just as well, I find it fascinating but also a bit painful because it gives you the sense that somebody knew these answers, somebody mastered these topics, and then the knowledge was just lost. And to me, that's as endlessly first doing um. But let me let me ask you a sense. You are in a unique position being in both the academic community and the science fiction community. I had a sense that science fiction authors actively and realistically contribute to sort of progress in academic scientific research and engineering by coming up with sort of the craziest ideas on the edge of possibilities. Having been in both communities, how do you feel about the way those two inter relate intellectually? I didn't sense that exchange. On a personal level. In my experience as a scientist had very little to do with science fiction because I was working in a particulars, particularly a subsets of astronomy and instrument science when I was working through in Space Agency, sort of photon camping and things like that, which also played into astronomy. But I mean, I kind of kept my science fiction credentials to myself for a long time, so I didn't really I wasn't sure how people would take it. And I've found a general rule. Some scientists are really receptive to science fiction, and they love it. They they've been stimulated by it, and they see the potential in it. But others are really disdainful of it. And I don't, you know, I didn't want to run foul of the latter, so I just I'm not going to make a big deal of this. But since I stopped my former scientific career, I have taken an interest in this. I mean, I've sort of looked at, for instance, the way that our scientific and literally understanding of the planet Mars has evolved over sort of the last century and a half. That's of interest to me. I've done lectures on that because it's a real two way process where science fiction and science have sort of moved hand in hand. Our science fictional understanding of the universe, and with with Mars as a case study, as has evolved and sometimes like behind the science because sometimes as writers were very attached to a particular image of something, and when the science appends that image, we often don't want to let go of it, but eventually we come around to it eventually, I think the know with with with Mars, you know, there was there was a sense that we had to say goodbye to the romantic idea of Mars, of Edgar Ice Burrows and even Ray Bradbury as somewhere where where there might be civilizations and ruins and wonders, and we had to confront the idea that Mars was really just a a barely less prospicable version of our own move you know, it's a an arried, nearly airless rock floating in space. But now we have we kind of come to terms of that, and now we now we can see the grandeur in the beauty in the real marks. That eventually led to a whole second wave of science fiction books that drew their inspiration from Viking and then subsequent Martian expeditions, and that process is carried on. There's also sort of two way, the traffic in the other direction, where you get little bits of science that draw their inspiration from from science fiction. It's not as easy to trace those connections, but they're certainly there. I mean, he's on my level. You have scientists who say I became a scientist because I read science fiction. It's probably to some degree true true of me. I don't know. Did you read science fiction as were absolutely did? I think that that's for me. The science fiction authors were the ones thinking about the deepest questions. You know, day to day science work, we're not answering big questions about the universe or making big discoveries, and so to sort of connect with the romance of the mystery of the universe, science fiction really tapped into that much more directly from me than the actual research work that I do on a day to day basis. To me, that's why they provide a nice balance. I mean, The one sort of case study that I can sometimes present to people as a clear case of science fiction shaping scientific thinking is when Carl Sagan was writing Contact, he wanted to come up with some plausible means of using First of all, he had an idea of travel through black holes, and then he went to speak to Kip Thorn, and out of that came the idea that a traversible wormhole was a much more interesting idea. And then Kip Thorn, sort of, I think for almost for his own sort of self gratification, came up with the sort of mathematics of of traversible wormholes, with the idea that you needed exotic energy to stabilize the throat. But that's still a whole viable discipline in I don't know what whether you call that particle physics or you know, spacetime physic gravitational physics, but lots of lots of papers are still are still coming out with reference to traversible wormholes and the physics of so that whole subdiscipline probably wouldn't have existed without at least the germ of a piece of science fiction. There many many other examples, but that's a really clear couple one well let me ask you as the last question about your future work. I hear that you're working on a new novel in your Revelation Space universe, which I'm very excited about, and I wanted to want to ask you what makes you decide to sort of revisit a universe that you've created previously, or to create a vast new intellectual playground. I don't know. I think they just feel like itches that you've got to scratch and you can't fight it. You just have to go with the the muse. Not to put too pretentious a term on it, but every now and again an idea sort of. I mean, Stephen King says another what's the what's the expression using like the muse shots into your head and you've got it. It's a really horrible expression, but it's true. You just can't predict it. And I've always just been ateful that a if you have a desire to write something that's good, it's far better than waking up and having no ideas. So I've always been quite grateful for the fact that the ideas keep coming and never complained about it. It's far better's and have too many, too many books in the queue. If you like them too few, But yeah, I don't know. I don't analyze it too too much. Really, I just go with the flow and hopefully people are happy to go along with it, read them, publishers are happy to publish them hopefully. Well. I've thoroughly enjoyed them, and I've also very much enjoyed talking today. Thank you very much for taking your time to answer our questions and to share your thoughts about writing and science and crazy aliens. It's probably very great pleasure. Thank you, really great questions as well. We could talk all day. I think, all right, pretty interesting, pretty cool guy. And also I just incredibly he has a he has like a perfect name for it for nautical adventures and pirate pirate story. Yes, Alistair Rent and his Welsh accident. I guess mix them sound a little bit like a wi now. He was really wonderful to talk to. So thanks, thank you, Alistair for taking your time to talk to me and for letting us hear about the physics of your universe and what goes on inside your brain. Yeah, we hope you enjoyed that, and hopefully I got you to think a little bit about what could be possible out there in even in the far future, millions of years from now. That's right, So go out and check out his book. It's the Revenger Trilogy from Alistair Reynolds. He also has written many other wonderful books, including Chasm City and Revelation, Space and Pushing Ice, which I also recommend. Yeah, so thanks for joining us, see you next time. Thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of I Heart Radio. For more podcast from my heart Radio, visit the i heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows. No