What Is A Dyson Sphere?

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Speaker 1: Hey, or hey, what do you think is the most impressive thing humanity has ever built? It's a pretty good question. Let me think about it for a second. I think I think I would have to say probably the most impressive human achievement is the refrigerator. Obviously, I mean the refuge every day. I couldn't live with that without it. It's pretty awesome. That's a cool answer. I was sort of thinking things like, you know, the Great Wall, or the Golden gate Bridge or the Birge Khalifa, you know, stuff that would inspire all you know, things that like last for generations. Well, you know, there is still in my fridge that's been there four generations. I don't know. I look at these projects sometimes and I think, you know, humanity can really accomplish great things when we work together. It's really sort of impressive what we can pull off, and we we all work together. Yeah, well, I don't know. I mean I once ate everything in my fridge all by myself. I mean I didn't meet the rest of humanity for that. Yeah, well, you can accomplish great things by yourself. But it makes me wonder sometimes like what future humans will build, Like what are the great what's the Great Wall of the twenty one century. You know what kind of achievements will we what kind of monuments will we leave behind for future humans? The Great Refrigerator of China. That's right, a huge refrigerator in space that you can see from space, that you can see from space that it needs to be cleaned. Hi, I'm poor. I'm the cartoonists behind the comics are piled Higher and Deeper or PhD comics. And I'm Daniel. I'm a particle physicist. And I smash protons together at the Large Hagon Collider to try to figure out what the universe is made out of. And together we wrote a book called We Have No Idea, which explores all the things we don't know about the universe. And right now you're listening to our podcast, Daniel and Jorge Explain the Universe, a production of I Heart Radio, in which we try to mix accessible science with a huge quantity of low quality jokes. What do you mean? Are you saying my jokes are low quality or no? I'm saying we spray a huge number of jokes and our editor just picks out the ones that are best to our listeners. Think we're funny, Yeah, are awesome editor exactly our producer who we should give a shout out to for sure, Taylor, thank you so much for making us funny. Thank you for making us sound funny. And speaking of human achievements, today's podcast is all about monumental constructions and accomplishments. What can civilizations do when they get together and build something enormous? Yeah? What can humans? What are humans capable of making? Like, what are the limits of our ingenuity and resources and our ability to work together? That's right, because you know, there are a lot of problems right in the world, like a global energy consumption and global warming, and that's right, and some of those are being tackled, right, like we're developing solar power so that we can get energy just from the sun and not burn fossil fuels and to meet the global energy demands. Right, But if you extrapolate forward and you think, like, what is humanity gonna need? Our global energy consumption is just increasing and it seems unlikely unless we have some cataclysmic event in our civilization that that's ever going to turn around. So if you project forward, you might wonder, like, how is humanity going to meet its energy needs in the future. If we don't invent some fantastic new form of fusion, right, what can we do to to rapidly increase the amount of energy we have accessible? And that's the question two of our listeners had, and so they sent us questions via Twitter and via email. That's right. So we owe a shout out to Evertenson and to Steve Davis for requesting this topic. So today on the podcast we'll be covering the topic what is a dycen sphere? That's right? Yeah, so the dycen sphere? Daniel, Um, So this is the idea that you know, we could maybe build something that can really take advantage of all that amazing power that's coming out of the sun. Right. That's right. If you think about like grabbing solar power and you think, well, we might need a huge amount of it for your first instinct is like, let's just put a bunch of solar panels in the desert, right, Let's just like build solar panel after solar panel. After all, nobody's really using that land. Is a lot of sun out there, right. But as humanity gets more and more greedy about energy, you might think, like is there enough room on Earth to put enough solar panels, right, So is that true? Like? What if we covered all of the Sharad Desert in solar panels, would that not be enough? I think that would be enough today. Like actually, I think today all you need to do is cover like Delaware with solar panels and you'd have enough energy to power the entire United States or maybe even the Earth. What really, yeah, exactly, solar pan So you're just ready to Delaware, Delaware. That's where all those fake companies are set up, aren't they. Um, we probably have listeners in Delaware, so you might want to check with them before you. They might appreciate the shade, you know, being relocated. Sorry, um all we have authority here from J. H. Cham a podcast host, or we're gonna raise your house and put solar pants emin eminent podcast main being moved out of Delaware. Well, I just check the numbers, and it turns out Delaware is actually a bit too small. I think you need to add Maryland to hope. That's okay with Maryland. No, But the point is that I think today human civilization can survive using energy captured by a pretty small fraction to the Earth's surface. But imagine in the future. Right, what if we want to build a huge civilization, what we want to construct enormous things? We want to send ships across the stars. We're gonna need incredible amounts of energy and you know, not gonna be able to burn cold to do that, and we're not going to be able to necessarily cover the Earth and solar panels, and so people started thinking big. People started thinking what's the limit, Like, what's the maximum number of solar panel solar panels you can make? What's the biggest solar panel you can build? Yes? Exactly? And where would you put it? Okay, so this is where the question of what is the Dyson's fear comes from? Exactly? This is a thought a thought experiment by Freeman Dyson, a famous physicist, to think about what is the biggest solar panel? Is it possible? Could we build one? How would you do it? And could we see if other civilizations are doing it? Wow? That's amazing? All right? So we, as usual, we're wondering how many of you out there actually knew what a Dyson's fear was Like If someone approachedate on the street and ask you, hey, have you seen any dicens fears? Or hey, do you know what it is? Or would you contribute ten dollars towards building a Dicen sphere um. So, as usual, Daniel went out into the streets and ask people randomly out there if they knew what a Dyson's fear was. Yeah, here's what people had to say. Have you ever heard of a thing called a Dyson sphere? I know it in the context of looking for other life on other planets, because it's basically like a ring that you can build around a star to harness its light for energy. You look at the light patterns. If something interferes with the patterns and like in a certain way, it can lead to the assumption that maybe there's a Dicen sphere around it. There's something awesome. Okay, yeah, it's this gigantic thing that you've put around like a solar system and then you can harness all the energy. I heard of it. I don't know what it is, all right, So pretty much no across the board. Well, I would say we got our our typical set of binary responses, a bunch of news. I got a bunch of weird looks too, people like is you're making this up? Like is that a thing? Really is this like a test? You know, I wonder how many people have thought you were talking about the dice and vacuum cleaner. That thing really sucks. Um No, I think I think it was like people thought maybe it was a control question, like I was making things up, like have you ever heard of the you know, um smith gabakabui or whatever, And because it was like a trick question, like to see if you if you try to make up some funny things. Yeah, which actually gives me the idea I should do that, right, We should have a trick question and see if people spout off. Um, you know, Oh yes, I told I saw a Nova episode about that, and it's in balls, you know, electrophons and whatever. What would it be about? Let's be dark? Should be like dark, a dark black hole about that? Oh you know what, that's actually really cool. And people are written and asking whether you can have a black hole made of dark matter, which is a really awesome question, which we should talk about in a different episode. Um, but an anti dark matter black hole? Dark matter black hole? Yeah, isn't that a cool idea? An anti dark matter black hole? Oh well, we don't know if dark matter has anti particles. We don't even know dark matter is made of particles, so we don't know if there is such a thing as anti dark matter. But we know there is dark matter, and we know there are black holes. So people have this tendency to like ram them together anyway, So nobody thought you'd meant the vacuum cleaner because you know the Dyson vacuum cleaners. They are known for having this like sphere out front that that you used to pivot and to roll around and like it twist the head of the vacuum cleaner as you tilt and turn. Did you get some like check from Dicing company? Because I didn't get one. I don't understand why you're promoting the Dicing vacum Maybe if you used to link if you used to link Dyson slash or he got a check slash and didn't share it with Daniel. Well, um, let's break it down for people. Then what what is the Dyson's fear? So the dycens vary is basically the idea of maximal solar panels. Right, you want to build solar panels, you cover the earth. The Earth captures a tiny fraction of the energy from the sun. Right, It's it's like a tiny, tiny fraction right like to the Sun, the Earth just looks like a little marble way out there in space exactly, and so it's it's barely catching any of its rays exactly. So imagine a spear, and the radius of the sphere is the distance from the Earth to the Sun. Right. So, now imagine a sphere that's basically the size of the Earth's orbit. It's like a ball centered on the Sun that reaches all the way to Earth exactly, and it's made out of what well, I mean, just imagine the spear for now geometrically, and think about what fraction of that sphere is covered by the Earth. Right, this is the point you're making before. It's like a tiny dot. Most of the Sun's energy just gets rated out into space, right it. Maybe it hits a Jupiter or Saturn, but the vast majority of it just gets shot out into space. Right. So the idea is, if you really want to go big, if you want to build a huge project, you know, then could you build solar panels that capture a significant fraction or even dare I say, all of the Sun's energy? Right? All? Wow, So it's like a giant solar panel that surrounds the sun completely. Yeah, I mean, like, let's do with the thought experiment. Let's think as big as possible. How much energy would that be? Um, you know, how would you do it? And could you tell if other people had done it? And so this is the origin of it. Freeman Dyson thought about this and he wrote a paper about it, and he thought, could you build one of these things? And if another civilization around another star had done this, could we tell and could we use that to find alien civilizations? This is like a legit physics paper. This is a a legit physics paper is published in Science, one of the top journals, and really yeah, And the thing I love about that is about it is that it's visionary. It's like, what would we do in a thousand years, what would we do in a million years? And could we use those ideas if we could predict them, could we use those ideas to discover super advanced alien civilizations? Like let's not look for other civilizations at the same level as us. Let's look for civilizations that are like a million years or a billion years ahead of us and trying to anticipate what they would do and how we would spot them. So I love that kind of visionary thinking, like if if you use your imagination wildly, where could humans go? And then that we could maybe see or get evidence of from other civilizations out in the universe. Yes, exactly right, exactly like trying to think of what the grown ups they're doing, because we're basically kids. You know, we are pretty new to this whole universe. We've been intelligent for you know, maybe tens of thousands of years. We've been technological for decades, right, we've been communicating for you know, less than that, And so we are brand new on the universe stage. And there may be a pimples voices cracking if we're not even there. Man, we're not a puberty. We're growing hair and from places. No, we are still pooping our pants. Um, from the civilization point of view, like literally mean literally and here we're filling it with pop. We are pooping the bed, that's true. Um. And so you know, you might ask like what are the growing ups doing? And the same way it's hard for kids to anticipate, like what is an adult life like? And how would you tell what's going on? It might be hard for us to predict what super advanced civilizations would do and how they would live and how they would get energy. So that was the idea of Freeman Dyson. He thought, can we spot other stars being wrapped by their feet by these spheres? Um to what kind of physics is was he? Oh, he's famous for being really broad. He's like, he's done all sorts of physics. I think he even did some chemistry. Um, he did quantum mechanics. He's thought about consciousness. He's one of these modern day you know, renaissance men who have like thought endabbled in all sorts of different kinds of physics. I wonder if your name affixed that, you know, like, if you go around with the name Freeman Dyson, is it just the expectation that you really amazing personality? What that you only have that expectation because there's a guy in the him that who has an amazing hum But that's what I mean. It's like he's got the perfect name to be a renaissance man. It's the other direction. Man, he was a renaissance man, and now therefore his name is connected with being a renaissance man. It doesn't work the other way. It's not like you're born He's like the original cool guy. It's not like they're like Galileo that sounds like could be a great scientist. Yeah, No, I think it's the other direction. Um, But he does have sort of a mystical name. I always thought his name, you know, I always connected his name with like the Freemasons, you know, Freeman Dison. He sounds like he's probably the member of a secret society somewhere. Yeah, like cool people who are trying to build names, trying to build mega structures. Even that word is fun to say, right, mega structures. So he had this idea, he thought, hey, what could we possibly what could have aliens civilization much more advanced than us. What could they possibly be doing that we could maybe detect? And he had the idea that maybe they figured out a way to capture all of a sun energy, like building something basically like wrapping up a sun. Yeah, exactly. And that's pretty hard to do. I mean imagine, as you were saying before, that you had to build something that size, right, Like the radius of it is millions of miles, right, So you're gonna construct something that wraps the whole Sun at like the distance from the Earth to the Sun and grabs all that energy. I mean, the size of it is is boggling like um, the inside of that sphere did a few calculations, inside of that sphere would have the surface area of five hundred and fifty million earths. Wow, which sounds doable. Maybe, I don't know. It's it's hard to build something that big. I mean, in order to build something that big, you need stuff, right, you need materials, You need like, you know, matter, And if you're gonna build it, you need to basically use all of the matter in Jupiter and Saturn and the asteroid belt. You use up like all the stuff in the Solar system just to build that shell. Like it's just barely enough stuff to build a shell all the way around the Sun. But why does it need to be the radius of where the Earth is? Couldn't you just make it smaller and be more convenient to make make it the radius of what's the mercury the closest one, you know, as small as sphere around the Sun and then just have like a cable running to us to Earth. Yeah, you have to balance, right, the closing extension cord extend. The closer you get to the Sun, um, the hotter things get and things melt and it's harder to work, you know, So you want to balance there. You don't want you don't want to be like immediately surrounding the Sun. You don't want to be really far away because that's to be bigger um between tents to build something that close to the Sun. Yeah. The other advantage if you built it at the radius of the Earth is then you'd have an awesome livable surface, right, you people could live on the inside of that sphere, Like you could put dirt down and plant crops and you'd be at the be in the habitable zone. Right, you'd be the right distance for the Sun to have the right temperature. Oh, you build it at the rates of this Earth and where the Earth is, then really it could be like um, sunny Florida all year round exactly. I mean, let's all around the solar system. Yes, let's think big. Let's think like, you know, we're gonna do this, what would be the best thing to do, Like humanity is gonna be huge and having a huge amount of energy. Um, then let's like, let's prepare for the future of humanity and build five hundred and fifty million times the land of the Earth. The amount of energy to this thing with capture is just ridiculous. Like if you captured all of the energy of the Sun every year. There's this number which is pretty hard to understand. It's three hundred and eighty four yatta watts, right, what's being stive energy and yatta being at a lot of what a whole lot of exactly? No, it's um three point eight times ten to the twenty six watts, right, Like, it's just a ridicul list number. So I thought, well, let's explain in terms of how much energy humanity currently uses. Right, So currently the power use of humanity is one thirty three trillion the energy put out by the sun WoT three thousand billion times how much we use right now? Yeah, so we don't really need this thing today or tomorrow or next year. Right. This is the kind of thing that would that would support a civilization with enormous energy consumption. You know, the kind of thing where you're like building huge spaceships and you're pushing them to other star systems with like lasers, you know, like light sales that capture laser beams, Like, you would have an incredible amount of energy if you could really capture all of the energy output of the Sun. Okay, I have a lot of questions, but first let's take a quick break, all right, So that's a dicense fear. It's this idea that you can maybe build a shell around the Sun and capture all of the energy that's coming out of it. And you would want to build it kind of far away from the Sun because otherwise it would just melt. Uh. And but it would be humongous. It would be bazillion times the surface of the Earth. Would take a lot of stuff to to build that shell. You take a lot of stuff. It would be enormous. And there's a lot of other problems, Like problem number one is you'd have to be really strong. I mean, this thing is going to have a huge amount of weight on it, right, yeah, like a and and just like it would get toussled around, right because it would have to hold together. Yeah, and it doesn't. You wouldn't also have any gravity, right, like the gravity we experienced from walking around on Earth comes from Earth. But if you're if you build a huge shell the size of the Earth radius and and build it around the Sun, then it's balanced gravitationally, right, you don't feel it doesn't feel the Sun's gravity. There's no net gravitational force on it for the Sun, so it'd be sort of like floating around the Sun, nothing to keep it in place, which means it could like drift, you know, and like one side of it could get too close and maybe bump into the Sun or something. It would be pretty hard to maintain. You need like jets on it to keep it in the right place. I think an interesting idea is that just the idea that you can envelop a sun, right like it, you know, your intuition. My intuition tells me that if you cover it up the Sun it would snuff out, but not so right like you could. The Sun doesn't need any feedback, right, it's just pumping that energy out. It doesn't need It doesn't need or care, doesn't need to know or care about what happens to the photons and protons that it's flying out. Yeah right, that's what I mean. Like you could you could capture a sun literally, yeah exactly, and it would burn happily inside your you're pumping out energy, yeah exactly. And you know, that's basically what we want to do here on Earth. On a much smaller scale, I mean that's fusion, right. Fusion says, build a little plasma, make it really hot, have it burned, and have a pump out radiation which we then capture. That's energy. Um, So we want to do that, and you know, we want to do that in a miniature way on Earth and a controlled way. But we basically have a huge fusion furnace already and it's going pretty well and it's not too far away. So some people say, let's just capture that energy, right, Why have fusion here on Earth when it's already going in the center of a whole lot of you exactly, um, giant trillion size shell. That sounds much easier. Yeah, and uh, and so you might be thinking also, like, all right, well a huge shell sounds like too much, Like you don't need to complete the shell, right if if you don't need thirty three trillion times our energy, what if you just build a partial shell, right, Like, I mean, that's basically every solar panel, right, the one you have in your roof right now is a tiny little bit of a Dicen sphere, right, It's a tiny little license sphere element. So you might think we don't have to go all the way. It's not like a you have just a few little solar panels, or you have the whole thing. You might just build you know, part of a shell, like half a shell, or just a ring of the shell or a patch of the shell. Yeah. Yeah, like a good middle ground is like a ring. And you can imagine putting them like in Earth orbit, right, so they're all in the same orbit, so they don't bump around each other. You got a bunch of like really big solar panels in Earth orbit gathering all this energy um and and sending it back to Earth. But you know you were you were saying earlier, like and then you just put out a big cable. That's actually kind of a tricky problem, Like how do you get this energy and bring it back to Earth? I don't know, you can't. You can just run an extension cord. Yeah, you need a whole lot of yadda extension chords. Um yea yeat a mile. Now you need some sort of wireless energy transfer, which is pretty tricky. I mean, we know how to do this, but it's not it's not that easy. Basically, it's lasers, right for long distance energy transfer. The only way we know how to do it is lasers. So so you're saying, let's build a giant laser out into base and pointed at the Earth and shoot and point out at the Earth. Exactly. It's like um or you can think about more like a magnifying glass. Like basically it's like take the Sun's rays and focus them on the Earth, right, you know, so we're basically like you know how you take a magnifying glass when you're a kid and like fried little bugs. We're basically doing that to ourselves. So it's that's pretty dangerous, right. You need some sort of way to absorb that energy here on Earth in a safe way, and you know, there's a lot of things to figure out, but as usual, we can just leave that to the engineers. Okay, So let's see you're saying, it's kind of an alternative to what if you just cover like the Sahara Desert. Wouldn't that set us up for the next billion years or something that would set us up for a while. Yeah. I think there are people who own the Sahara Desert though, so they might have something to say about that. Um they can move to Delaware. You were just solve some problems all over the place Man Global Solutions by or hit chand Um. So we we definitely do not need this any time in the near future, Like like we if we invested in solar power, we would be set up for a while. Oh, I see you're saying we don't need it, but maybe aliens needed. Well I'm saying we don't need it now, but like, let's think big, right, Let's think about like what is humanity needed a thousand years, in a million years. Let's if you're gonna build this thing, you got to start thinking about it now so you can figure this stuff out. And it's always fun to think aspirationally, like could we build this? You know, is it possible? What technology would you need? Because often that spurs ideas, right, people like m I wonder if you could transfer laser from an orbiting ring of solar panels to the Earth. How would you do that? And then they get interested. Then they come up with some invention which makes, you know, for better Hamburgers or something. But a lot of cool stuff comes out of just like thinking aspirationally. I say, you're saying, like, what if in a thousand years there are thirty three trillion yodda people in on Earth? And we need all that energy. Maybe we should think about these kind of crazy he is in advance, Yeah, exactly, before we have covered Delaware. We covered the Sahara. It's not enough. Yeah, so you could do the whole sphere, which seems a little crazy because you need all this material. You could do a ring right of orbiting orbiting solar panels. That's sort of um, you know, intermediate, but there's also a lot of other purchase, Like you could have a few rings, right, you have like different rings at different radius or you know, orbiting different directions or something they have to think about, you know, collisions and shadows and stuff like that. But that kind of stuff is pretty practical, isn't that a famous science ficture novel like the ring idea where a ring around the Earth? No ring world. The Hillary niven Um had this idea of a ring world. I don't know if he had a son in the middle of it or not, but yeah, definitely you could build a ring and you could be spinning, you know, so you could live on it that kind of thing. Um. Okay, so that's one idea. Ring. You can also do like a patch, right, or like small patches. Yeah, exactly, you have these small patches, and some people are thinking about the idea of uh, they're not satellites. They're called stat heights because they don't move, But they're basically just big floating patches of solar panel and they they avoid um flow falling into the sun because they partially absorbed the Sun's energy. That's where you get the energy for the solar panel, but they also partially reflect it. Right, think about what happens when you reflect energy. Basically you're getting a push, right If A if a photon comes and bounces off of you, then you're getting a little push from that photon. So if a if a big solar panel is half reflective and half absorbent, then half the energy goes into you know, electricity or whatever, and half of it keeps the solar panel from falling into the sun. So these things could basically like float on the solar wind um, which I think is pretty cool. There's something beautiful about about all these like huge super thin solar panels out there floating on the solar wind um. Half half the energy keeping them a light, and half of them the energy keeping our televisions on. They're not fling around the Earth they're just floating out in space and we would kind of swing by them every year. Yeah, exactly exactly, and they would be stationary with respect to the Sun. Right, they wouldn't be orbiting the way we are. Um. And that would be pretty cool something something really cool about that, um. Right. And I think the thing that God Freeman Dyson thinking about this is if aliens were doing this, how could we spott it? How could we tell if somebody was doing this? And initially you think, well, if they build a whole sphere, then they're blocking out their sun. We wouldn't even know their son exists, right, So how would we even know anybody is there? There could be out there tons of stars covered up in these days, in spheres. I mean, I'm sure they call it something different unless Freeman Dyson is an alien, which would explain as cool is but um, you're right, like, there could be stars out that there are covered up by alien civilizations. We just don't know it because we can't see them. Yeah. So he actually had a cool idea. He said, all right, if you build these things, it will block out the light of the Sun. But if it's made of matter and it's absorbing the energy, of their sons. Then it's gonna glow, it's gonna get hot, and it's going to give off infrared radiation. So you won't see the stars the way you normally would, you know, in the visible spectrum and all that stuff, but you would see sort of a black patch of sky plus a bunch of infrared radiation, which shows you that there's something hot there. No, really, you would attribute that to an alien civilization building a shell the size side a giant shell around this area, and not just some like hot rock or well, how do you get a hot rock? How do you get something out in the middle of space, not next to a star that's warm? Right? Are there stars that are like basically like cinders kind of? Yeah? There are some. Yeah, Well this is the point of his paper. He's like, how could you see this? And he had the idea like, let's look for infrared radiation. And I'm sure you know reviewer number two had your reaction no, come on, um, But he talked in the paper about like other things that might mimic the signal and how you could tell, etcetera. Um, but it's a good idea, right, Like, how else could you spot these things unless you saw them building it. Right, Unless you watch them building, you could see the star like winking out year by year as they're constructing this thing. That would be super awesome. But wouldn't it take them like hundreds of years to build it? Right? I mean even an advantage. We're talking about hypothetical super advanced aliens. I could say anything. Right, maybe they spend like a million years building it and then it's just like unfolds in one year or something. Right, who knows just as we're looking at their star. Yes, you'd have to be super lucky. Right, So I think either you're super lucky because you're seeing them build it, or you see these things radiated. And people have done this. People have like looked out in the night sky and said, are there places where all we see is infrared emission? Right? And and um, so people did this third way and they found seventeen candidates, seven team candidates, and um most of them they were able to explain due to other astronomical things. You know, it's a dead star, wars, it's this, or is that? But there were four candidates. I looked at the paper and they described in this way. And I have to quote it directly because I've never seen this in a scientific paper where they say that four of these candidates have been named quote amusing but still questionable, which means like what people call me, I mean they feel so connected to the to the universe. Now, yeah, I mean tells you what scientists find funny. But there is something hilarious about like finding things out there and not really understanding them, and like what is going on out there in space? And the thing I love about looking at in space is that every time you do it you find something weird. Is you're always surprised. There's always something weird out there. What do you think they meant by amusing but still questionable. I think they meant we can't rule out alien megastructure. And that's what's amusing about it, right, Like it makes you seriously consider that, you know, And if you're an astronomer, we don't know what's amusing in the sense of like it makes you think, it makes you muse about it, or it makes you hope. You know, astronomers always have to keep in mind that they might that today might be the day they discover alien civilizations. Right, it's a it's a low, it's low on the list, right, they gotta rule out a thousand other things first. But one day I think we will discover alien civilizations, right, and somebody will be it will be today for somebody, It'll be right now for somebody, and so you always got to keep that in mind. Right, Wow, all right, let's get into it. But let's take a quick break first. Okay. So Dyson's fears are this idea that you can surround the whole Sun with some kind of structure to capture all of its energy. And Dyson proposed this as a way to maybe detect alien civilizations. That's right, And he said, let's look for let's look for stars that might be blocked by alien megastructures. And so you're saying that we actually maybe found one of these stars. Yes, a couple of years ago, there are astronomers that were looking at stars and they saw this one and they were watching it, and the light from it did this weird thing. It wasn't constant, right, most stars, the life from this constant. I mean you see a little bit of twinkling from the dust between us and them, but mostly the lights pretty constant. And astronomers look at these stars sometimes to see if they can spot planets in those solar systems, and the way they do it is they look to see if the planet goes in front of the star, and if that happens, if you see a little dip and how bright the star is, because it's basically a little mini eclipse, but that dip is like, you know, one percent maximum, Like if you were watching our Sun from really far away and Jupiter went in front of the Sun, the Sun's brightness would dip like one percent. So that's the kind of thing people are doing. They're watching stars looking to see if they dip. And then they found this star and they saw a dip not one percent, not two, but like twenty percent, like a huge fraction of the star's brightness just went away. But then it came back, and then it went a way again, and then it came back and then like it's not regular, right, it's not like you know, if if a planet is orbiting a star and blocking it, then it's regular. And you can use that to figure out like how quickly does the planet orbit the star? Right, what is the period of it? And they watch it um for many periods and they figure these things out. You can measure the mass the planets. It's really awesome. But there was no pattern here, right, There was like dips and then days would go by when it would be bright again, and then more dips would come, and then it was like two years when there were no dips, and then another huge dip came, and so people were like, what is going on with the brightness of this star? What is this? And so immediately that little voice in everybody's head was like, could this be Aliens? Aliens? Could this be it? Could we be watching an alien megastructure be constructed? Really? That was the first thing that came to people's mind. Of course, was of course it was anybody anything strange, You're like, Aliens, that's right, Aliens. I've never seen a car like that before. Aliens? What is this fruit called? Aliens? How did you do that magic trick? Card trick? Aliens? Exactly? How can one man eat so many bananas? Aliens? Aliens? Yes, it's always on our minds, right, And of course the first thing they did it's like, all right, let's kind of try to come up with other explanations. What else could explain this? And so they went through a long list of reasons to explain it. But it's really unusual. We have not seen another star like this. It's not like you see this all the time. And so you have a bunch of ready explanations, right, people have to really stretch their minds to imagine how you could block like twenty percent of the light of a star and not be an alien megastructure. How do you know it was one star and not like two stars. I think they know the star pretty well. I mean you can you can tell the difference between one star and two stars. I mean two stars would orbit each other. Um, I think you could resolve them. But I don't know. It doesn't matter. I don't know me. Um. But what they think, hey, maybe let's consider other all turn out as besides then, what they did is they looked. They did something really interesting is they went back through historical measurements and they said, you know, people have been taking pictures the night sky for decades and decades, and not all of his digital and not all of his as good as recent data, but we have pictures of lots of the night sky going back like a century. So what they did is they went back and they looked for pictures to this star over the last hundred years, and what they found is that over the last hundred years, this star has been gradually fading, like getting less bright, yeah less right, Like it's twenty percent less bright than it was a hundred years ago, but it's steadily Yeah. Well, we don't have really constant data over the last hundred years, right, we have like snapshot and then the snapshot in the snapshot in the snapshot. Recently, because we've noticed the stars weird, people have been watching the star a lot more and so they've been seeing a lot more of these dips and trying to understand them. Um. But the dips can be very dramatic and they're not regular, um, and it's kind of hard to explain, all right, So um, so you're thinking it could be aliens, it could be alien. How how would alien? What would aliens be doing? You're like just flipping the switch on and off kind of like my kids do know they would be building a dicen sphere, right, Maybe why would go on and off? Maybe they're partially maybe they're part way done with constructing their dicensphere, right, And what we're seeing is like orbiting the Sun and blocking it. Rights, it's irregular. Over the last hundred years they've been building it up, and now you're saying it's might be operational and it's rotating and that causes these dips. Yeah, exactly. And when the dicensphere is between us and their star is when the is when the when the light from that sun gets dimmer. It's it's hard to have. It's hard to come up with other explanations for irregular dips in the light. And so let's go through them. Though, because it's um in the end, people think it's probably not aliens, which is you know, the story of every scientific discovery ever um. But there's not really one convincing explanation. Okay, so what are the possibilities here? The leading possibilities are that it's a it's like a lot of dust, like a huge cloud of dust. And but it's not regular. It's not like our asteroid belt where like the asteroids are sprinkled all the way around the Sun. It's some like asymmetrical cloud of dust. I mean like a patchy like a patchy clumpy. Yeah, it's like spread up. You know what you need in that case, then you need a dice and vacuum cleaner. Fear somebody clean up with it's a mess. Got the best section the code dice and dot com slash to anyone. Exactly. It's like mega made from spaceballs. Somebody's cleaning up that system. Um. Yeah, so like maybe like a huge patch of dust. And what they did is they looked at the light from the star and they noticed that the light from the star is not dimmed equally across all wavelengths. Right. Remember light has different wavelengths from the reddish to the bluish and the invisible wavelengths as well. It doesn't dip the same at all frequencies of light. Yeah, and you know, one the basic idea that Dyson had was let's look for light. Let's look for stars that are basically only emitting in the infrared, because that's what a huge mega structure would emit. But the direction of the spectrum which light is absorbed in which light is coming out, suggests that it's dust. It looks like the kind of thing you would get if there was a big dust cloud, would maybe like pockets where the sun shines through. Yeah, exactly, And that's what the are. And so maybe what we're seeing is basically the profile of this dust cloud. But that's not really a satisfying explanation, because like where does this dust cloud come from? You know, most stars don't have dust clouds around them for several reasons, like especially old stars like young stars who's like just been formed, that it's being formed inside a huge cloud of gas and dust. Then, yeah, you expect a lot of um of gas and dust. So like stellar nurs certainly, let me guess, Let me guess, Daniel, you think it could be Aliens? I always random guess to what physicist might think it is Aliens. Well, you're both right and wrong, like one possibility is. So the point is you don't get dust around old stars usually, right, because that dust gathers together and forms planets or or even just gets blown away by the solar radiation. Right, Like solar radiation pushes dust out of these systems. So maybe a planet blew up, right, maybe it's Aliens and they had a huge war and like one of them blew up the other one's planet, And what we're looking at is like planetary debris or something. What that would be super awesome. Right from this fully operational battle station, you're seeing the remnants of the Death Star. Yeah, but but before people get too excited about that one. That one doesn't really hold together because in that case, you would see it would be like warm, right, because like the planet blows up, you got these big blobs of glowing matter um, and it would glow in the infrared. But we don't see that. So it's consistent with cold dust um, which is kind of hard to explain, Like we don't understand how you can get this rear, irregular blob cold dust around the star. What if it was a planet destroyed by like a cold freeze ray aliens? What is that superhero that that shoots freeze rays? Yeah, yeah, ice Man, the Ice Man. Yeah exactly. Ice Man came and froze their planet and it's shattered into a bunch of fruit. Might as well offer that as an explanation. I see. So you're scoffing on my explanation of aliens, and but instead as a more likely explanation, you're suggesting the Iceman came and froze. Yeah, that's what I always go to first, superheroes. You know that's true. I guess the cartoon is would go to superheroes first as an explanation. Um, I'm just saying I think I think I should get a physics degree. You know, I have a stow upon you from Daniel and Jorge University, an honorary PhD in superhero physics. Oh man, that should be a great product for a store. And you know how how much value I put in honorary PhDs. That's why you have three of them. That's why I have exactly zero of them. Um. And so another explanation, another idea is that maybe it's just a really weird star. Maybe there's no dust there. Maybe the star is just like doing something weird inside of it, Like it's not glowing constantly as something weird going on inside. It's like flickering, you know, it's not burning consistently, but there's something inside it's like absorbing at the energy, or it's sputtering a little bit. Um an unstable star. Yeah, yeah, some some kind of weird process that gives variable light. But the problem with all these explanations is that it's a big universe and we've looked at a lot of stars and we've never seen anything like this. But for and so, any process you propose to explain this have to also explain why it's only happening to this star. And not to any of the other zillions and gazillions of yadas and yadas of stars that we've seen, right, Right, Like, if it's a cluster of comets or of planet that blew up like you would expect, if it's not totally impossible, that would be happening dozens or hundreds or thousands or millions of times we've seen other ones. So that's the real puzzle. That's what makes this star interesting is that it really does seem unique, right, So maybe we're seeing something really really unusual, right, that could happen um or maybe it's aliens because you're seeing we're seeing we can see like billions and trillions of stars, right, that's just one of them that's doing something weird. Yeah, well, our soulars, our galaxy has you know, hundreds of billions of stars. That's a lot, and so we can't see all of them, of course, but yeah, we've observed a lot of them and we've never seen anything like this, So it's pretty weird for one star to stand out in the galaxy. Wow, So it could be an alien license fear, yeah, or could be the you know, the villain's layer for Iceman. Well, you know Ice alien exactly. Yeah, all right, so that answers the question what is the dicens fear? And hopefully people out there founded amusing but not questionable. That's right. And maybe someday we will build a dicense fhere and aliens far far away, we'll be having a podcast talking about could we see if they had built a dicense fhere around their son um? You know, maybe humanity will be able to accomplish these great enormous infrastructure projects and work together and not just to ourselves. It makes me hopeful to think that one day we could we could build such a vast projects and have that much energy at our fingertips. Yeah, that would be cool, and it would spare dela like a refrigerator. So everybody in Delaware, no need to pack up your bags anytime soon. We're not taking over. That's right. Rest easy, Delaware, Sleep well tonight another day when we didn't find aliens. All right, Thanks for joining us. I hope you guys enjoyed that. We'll see you next time. Thanks for tuning in. If you still have a question after listening to all these explanations, please drop us a line. We'd love to hear from you. You can find us at Facebook, Twitter, and Instagram at Daniel and Jorge That's one Word, or email us at Feedback at Daniel and Jorge dot com. 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.