Daniel and Kelly’s Extraordinary Universe - Listener Questions: Black Holes, Dark Entropy and a Radio Free Zone!

Episode Date: April 22, 2021

Daniel and Jorge answer questions from listeners like you! Got questions? Come to Daniel's public office hours: https://sites.uci.edu/daniel/public-office-hours/ Learn more about your ad-choices at h...ttps://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

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Starting point is 00:00:00 This is an I-Heart podcast. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, everything changed. There's been a bombing at the TWA terminal. Just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, terrorism. Listen to the new season of Law and Order Criminal Justice System
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Starting point is 00:00:58 People write bikes because it's fun. We got more incredible guests like Megan in store, plus news of the day and more. So make sure you listen to Good Game with Sarah Spain on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Brought to you by Novartis, founding partner of IHeart Women's Sports Network.
Starting point is 00:01:17 In sitcoms, when someone has a problem, they just blurt it out and move on. Well, I lost my job and my parakeet is missing. How is your day? But the real world is different. Managing life's challenges can be overwhelming. So what do we do? We get support.
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Starting point is 00:02:17 Hey, everyone. It's Daniel and Jorge. And we are excited to make a very special announcement about a new project we've been working on kind of in secret for the last year or so. Is this related to your new wardrobe, Daniel? Nope, my wardrobe is unfortunately frozen in time as physics professor casual. But that's a great question and a great lead-in to our new project, which is all about questions, actually. That's right. Daniel and I have written a new book. It's very exciting.
Starting point is 00:02:44 It's called Frequently Asked Questions About the Universe, another humble title for our work. And it's inspired by all the questions that you folks have been asking us, All the questions you wonder about the nature of the universe and how it works and all the questions that science is working on. So we took some of your most awesome questions that you sent to us and we put them in book form and actually answered them. As best as we can. There are questions like, where does the universe come from and why can't we teleport or can we? And have aliens visited us and why is it exactly that we can't make it out there into the cosmos? So the book is coming out this November 2nd, 2021.
Starting point is 00:03:23 but it's available right now for pre-order. So go to universefaq.com and order your copy today. So stop what you're doing right now. Go to universefaq.com and pre-order our new book, frequently asked questions about the universe. It's filled with science, silly jokes, and Jorge's awesome cartoons, and maybe even a few answers. Hopefully, I mean, it's in the title.
Starting point is 00:03:48 The title just says questions. Oh, nice. Hey Jorge, did you know... What? What? What? What's going on? Daniel, we have to be quiet. Why? What's happening? It's noise pollution. If our podcast is being broadcast near a radio telescope, we might be ruining their data. Oh, no. What if we're making a dumb banana joke, right when an alien message arrives? Yeah. Or what if the scientists think our jokes are so bad? We must be aliens.
Starting point is 00:04:21 Humor is so difficult to translate. Maybe we should just be quiet. Hi, I'm Horham, a cartoonist and the creator of PhD comics. Hi, I'm Daniel. I'm a particle physicist, but I will definitely laugh at all the aliens bad. jokes when they come here. Really? What if it offends them for you to laugh at their jokes? But, you know, it could be a totally different culture, Daniel. It's sort of like smiling and nodding can be something totally different in another culture. You know, like doing the okay sign with your fingers is an insult in some cultures. I'm probably not the right person then to send
Starting point is 00:05:09 to talk to the aliens the first time. Or to sit in on their comedy shows. But welcome to our podcast, Daniel and Jorge Explain the Universe, a production of iHeart radio. In which we make light and laugh at all of the crazy mysteries of the universe, everything that we know about the universe, the bonkers, crazy ideas that we have learned about this beautiful, strange universe we find ourselves in, and everything that we don't know about the universe, the very edge of science, the things that scientists are thinking about
Starting point is 00:05:38 the questions that they are pondering, and the questions that you are thinking about every single day as you live in this universe. Yeah, because it is a pretty big cosmos. there's a lot out there to perplexes and there's a lot for us to ponder about how things work and why things are the way they are. And so it's natural for everyone to have questions about what's going on. That's right. You are here to have the universe explain to you because you are curious about the universe. You want to understand it. You want to somehow take the entire universe and
Starting point is 00:06:09 fold it up into a little idea that fits in your neurons. Amazing as it sounds, that might actually be possible. But along the way, sometimes two ideas don't quite fit. Or you wonder, hmm, how does this connect with that? Or this doesn't really make sense to me, even though I've heard the words. And that's what we're here for to explain all of it to you. Yeah, because it all starts with questions, right, Daniel? Yeah. Science, would you say, starts with a question? Like, what's going on there? Or how can I get more things to eat? Or what should I eat without dying? Yeah, science is nothing but questions. It's just people asking questions. I was giving a talk to some students from Puerto Rico last weekend, and one of them asked me, how do scientists figure out what question
Starting point is 00:06:51 to ask next? And I thought that was an amazing question. And I told them that it's just people asking questions about the universe. Scientists are just people with questions that they want to know the answers to so badly that they decided to spend their lives trying to figure it out. I see. You just turn it around and ask them a question without giving an answer. Is that what science says, Daniel, just all questions, no answers? It's mostly questions leading to other questions, but the questions are personal. I want to know what the universe is made out of. Somebody else wants to know we can make some special kind of superconducting goo,
Starting point is 00:07:25 and somebody else wants to figure out how life started. All of these questions are being pursued by people who decided this is the most important question. This is the thing I want to know most about the universe. So science is about questions, but those questions are also very personal. Yeah, and it's not just scientists that have questions. Regular people have questions, too. Yeah, or you could say regular. people are also scientists because they have questions, right? We're all doing science. We're all asking
Starting point is 00:07:50 questions. We're all trying to understand this crazy cosmos. That's right. We're all in this together. And so people have questions and sometimes they write to us with their questions, hoping that we would maybe answer it in an email or a tweet or maybe in one of our podcast episodes. Yeah, they do it all the time. We get dozens of questions every single day. If you have a question about something you heard about that you don't quite understand or you'd like us to explain to you, please don't be shy, write to us. We love your emails. Questions at Danielanhorpe.com. Daniel, you actually answer most, or if not all of the questions you get. I answer every single question I get. Usually within just a few minutes, sometimes I get
Starting point is 00:08:28 surprised responses from people saying, what? I can't believe you actually wrote me back. But yeah, I'm just sitting here plugging away in my research and I love that ding when I get a new email. Really? And I react so well to my new email dings. You actually listen to those new email things? I was pretty sure you had that turned off. I don't know if that's a feature on my phone. I'll have to check. But I'm glad you're answering the questions because I think I would just answer with more questions.
Starting point is 00:08:52 Like, hey, maybe you should ask Daniel this question. I think maybe they should. Or I would point to Wikipedia that's helpful too. But yeah, we get a lot of questions and sometimes we do episodes where we answer these questions live on the air or at least live on the podcast. Yeah, sometimes people ask a question and I think I bet other people want to know the answer to this one. So let's talk about it.
Starting point is 00:09:12 Or I just think it'll be fun. or it stumped me a little bit. I had to go off and do some research and figure it out. And then I'm excited to talk about it. All right. So today on the podcast, we'll be talking about. Listener questions. Number 15.
Starting point is 00:09:31 Wow. I can't believe we've done 15 of these listener questions episodes. It's been a while. Yeah. Listener questions is a teenager now. It's growing up. Oh, no. Is it now in its rebellious face?
Starting point is 00:09:43 refuses to acknowledge us or to clean up the room. But we secretly know it still wants to hear the answers. Oh, I see, I see. It's just a phase. Yeah, exactly. It's just a thin veneer of attitude. All right. Well, today we have three great questions from three great listeners and fans out there.
Starting point is 00:10:00 We have a question about peanut, right? Black holes. And also radio bursts and quiet zones, which would be great to implement here in my house sometimes. All right. So our first question comes from Beckham, from California, who is six years old. Here is his question.
Starting point is 00:10:17 Hi, I am Beckham, and I'm six years old from California. And if you squeeze the earth to the size of a peanut and it turned into a black hole, how far away would you have to be it to not get sucked in? And would eat the whole earth? And thank you. All right. I love black hole questions from six-year-olds. All right.
Starting point is 00:10:40 Do you get excited about all questions about black hole? Or are there questions about black holes where you're like, ooh? Those are the best questions about black holes. When somebody asked me something I hadn't thought about before and it makes me think about black holes in a new way or go open up that general relativity book again or something, that's the fun moment. All right, well, what do you think, Beck and what's thinking about?
Starting point is 00:11:01 Yes, if you squeeze the earth into a peanut and it became a black hole, how far away would you have to be to not get sucked in? Wow. Yeah, I think he's trying to make. black hole sort of concrete. Instead of thinking about black holes as something weird and far away, you're thinking, you know, could we turn the earth into a black hole and what would that be like? I see. Because I guess you can make a black hole out of anything, right? It's not like something exotic out there in space. You can literally make a black hole out of peanuts or by turning dirt
Starting point is 00:11:32 into a peanut. Yeah, it's just a bunch of mass and energy compactified and a small enough space that the curvature gets so intense that light can't escape it. That's really all a black hole is. And you're right, you can make it out of any kind of matter or energy. You could even make it out of photons. We talked about it once on the podcast that if you have really big laser beams and you cross them, in theory, you can make a black hole where they intersect. Right, because it's not about how much mass or the size of something or how heavy it is. It's really about the density.
Starting point is 00:12:02 Like if you have enough stuff in a small enough space, it becomes a black hole. And that could be something really small or it could be, you know, the size of ginormus, like a supermassive black hole. Yeah, exactly. And we think that you can make a black hole out of basically anything if you make it dense enough. There might be a minimum size to a black hole as things get down to like the quantum level. It's not clear if you can make a black hole out of like an electron size amount of mass. But you definitely can make a black hole out of like an earth size mass or a sun size mass.
Starting point is 00:12:32 Now most of the black holes we see out there in the universe come from stars. And so they're like 10 to 80 times the mass of the sun. Or they're at the center of galaxies. And then they're like thousands, millions, billions times the mass of the sun. So we don't see very many black holes out there that are like the mass of the earth. In fact, we've never seen one at all. That doesn't mean they're not out there. They could have been made in the very early universe, these primordial black holes that could be very, very small, up to very, very large sizes.
Starting point is 00:13:01 Right. Because I guess black holes that size don't get naturally made, right? Like there's no natural common process for them to make an earth-sized black hole. Like most of the ways are, you know, stars going supernova is how they're made. Yeah, gravity is a runaway process. And once it gets going, then it compactifies itself more. And then it gets more powerful and it compactifies itself more and gets more powerful. The Earth, for example, is not going to collapse into a black hole.
Starting point is 00:13:25 It doesn't have enough stuff in it to start that gravitational runaway process. So like the bonds between the stuff in the earth is more powerful than the force of gravity. So, you know, the structure of the rock and all that stuff is holding itself so that the earth will not collapse into a black hole. All right. So then if you took all of the mass of the earth and then you squeezed it all into the size of a peanut, then you would get a black hole. That's what Beckham is asking.
Starting point is 00:13:50 Yeah. And you would take some external force, right? You'd have to crush and compact all that mass. But yes, in principle, you could get a black hole just from the stuff of the earth. And you'd have to really squeeze it down. If you wanted the earth to be a black hole, you'd have to take the mass of the earth, all that stuff, and squeeze it down to something less than a centimeter wide. Wow. So including all the peanuts on Earth? Like, can you fit all the peanuts on Earth into a peanut?
Starting point is 00:14:15 You can. And in fact, because a peanut is about the right size, you know, it's about one centimeter. Or maybe we should have a new unit called the peanut. The P Valley for the peanut is one centimeter apparently. Yeah, just about. So yeah, you can fit all the peanuts on Earth and all the bananas on Earth and all the rocks and all the gold and all the uranium and all the helium and all that stuff down in a really compact space. Remember that the space between things, the volume of things, depends on the forces between them. Like the reason that a rock has the size it has is not because of the pile of stuff it's made out of, but because of the forces between those particles sort of pressing against each other, fluffing it up. It's really like a pile of little bubbles where those bubbles are made by the electrostatic forces repelling each other.
Starting point is 00:14:59 If you can overcome that, then you can squeeze it down to whatever you like and eventually get a black hole. Right. So that could happen to the earth if somebody came in and squeezed it all. into a black hole. But then I guess Beckham's question is whether or not we would get automatically sucked in or like are we doomed if the Earth suddenly became a black hole or do we have a chance of getting away? The question is how far away would you have to be to not get sucked in?
Starting point is 00:15:24 Well, I consider myself to be part of the Earth and so, and I'm usually on the Earth. So if somebody comes along and compactifies the Earth into a black hole, then I'm inside the black hole already. But, you know, if you happen to be on a trip to the space station, the earth turns into a black hole, then I guess you can ask the question, like, can you be around it safely nearby? I mean, let's make this realistic, right? Right.
Starting point is 00:15:47 Yeah, let's pretend that you're part of this earth, Daniel. Let's delve into that fantasy. And you hear in the question this idea that black holes suck stuff in. And it's true that black holes have strong gravity, but they're not like vacuum cleaners. You know, they just pull on stuff the way everything else with gravity pulls on stuff. The earth pulls on you right now. And that doesn't change just because it's turned into a black hole. So, for example, if you're standing on the surface of the earth, you feel it's gravity.
Starting point is 00:16:15 If then underneath you, the whole earth turns into a peanut-sized black hole, that doesn't change the force of gravity you feel because it's the same amount of mass pulling on you with the same gravity. Right. Like nothing would change, basically, except that you would maybe just lose the ground under you. You would lose the ground under you. And so now, if you want to avoid falling into the black hole, I prefer the phrase falling in rather than getting sucked. in because it tells us about the gravity that's happening there, you'd need to go into orbit around the black hole. The reason you don't fall to the center of the earth now is because the earth is holding you up. If that's not the case, then you need some other way to avoid falling
Starting point is 00:16:50 into the center of this new black hole, and that would be to go into orbit. Basically, you need to be moving fast enough that you keep missing the earth as you fall. That's what an orbit is. I see. So we would feel the same gravitational force, which means we would fall into the peanut-sized black hole if the earth certainly turn into a black hole. And so it's not a matter of distance because I guess technically you would feel the force from this black hole anywhere in the universe, right? Technically speaking. You do feel it anywhere in the universe because gravity is infinite in extent. I mean, it falls off like one over distance squared. So it drops off pretty quickly. But yeah, in principle, we feel gravity from Andromeda. That's why that neighboring galaxy is
Starting point is 00:17:31 coming towards us and we're shooting towards it. We feel gravity from things that are infinitely far away. That's true. But the value of that is pretty small. And so as you get closer to something, its gravity gets much, much stronger because it increases like one over R squared. Right. So like technically we are getting pulled into all the black holes in the universe right now. Like every black hole in the universe for which there might be an infinite amount or trillions, we're getting sucked into them as we speak, right? Yeah, they are tugging on us. But they're being defeated by the gravity of the Earth, of course, and the Earth being pretty massive and pretty close, is overpowering it. Think, for example, about the Sun. The Sun is so much more massive than the Earth. Why is it
Starting point is 00:18:12 that you don't fall into the Sun right now? Because the Earth, even though it's much, much smaller mass, is much closer to you. So it's winning the gravitational tug of war and keeping you on the surface. Right. But technically we are, me and the Earth, we are still falling into the Sun. It's just like, as you say, we're in orbit. We have some kind of velocity in a difference. different direction than the direction of the sun. And so that's why really we're not falling into the sun. Exactly. We have just the right velocity and just the right direction to be in a stable orbit around the sun. So you can avoid falling into something if you orbit around it. And in fact, a lot of stuff orbits around black holes. If you think about like the picture you have in your
Starting point is 00:18:50 mind of a black hole, it's this black sphere, but it's surrounded by a disk of swirling stuff. And you might wonder, well, why is that stuff there? Why isn't it just immediately falling into the black hole. And the answer is that it's spinning. It has rotational velocity and that helps it avoid falling in immediately. So you can stay in orbit around a black hole for quite a while until you lose that velocity by bouncing off of other stuff and then you fall into it. Right. So I guess technically if the Earth turned into a black hole, you would get sucked in even as you're standing there now, but also maybe if you're relatively far away like at the distance of the moon or something, you would fall in unless you can get into an orbit. Yeah, that's right.
Starting point is 00:19:29 If you were on the moon, for example, you'd already be in the moon's orbit. And so you just stay on the moon and the moon would keep orbiting around the black hole. If you're on the surface of the Earth, however, you're probably not moving fast enough to stay in orbit. I see. So the trick to avoiding falling into the black peanut hole is to start running really fast. Yeah, exactly. Or get on a spaceship. And how fast you have to go to be in orbit depends on how far away you are from the black hole.
Starting point is 00:19:56 The closer you are, the faster you have to be moving. And the further away you are, the slower you can move and be in a stable orbit. All right. So then I guess the answer to the question is really that it's not about being far away. It's about having some sort of speed that lets you be in an orbit around the black hole. Yeah, precisely. And if you were, for example, at 100 kilometers away from the black hole, which is pretty close, you'd have to go like 60,000 meters per second to avoid falling in.
Starting point is 00:20:23 And if you were at one kilometer, it'd be 10 times that speed. And if you were just like one meter. away from this peanut-sized black hole, you'd have to go like 20 million meters per second. Wow, which is a, you'd be toast, right? Because you can't go around that fast, around something that small, can you? Certainly you could. You could be a meter away. You could be whipping around really, really fast. It'd be hard to accelerate to that speed without like crushing your internal organs. But you know, even that speed, though it sounds fast, is a pretty small fraction of the speed of light. So in principle, you could actually go that fast.
Starting point is 00:20:59 Right. And what about here on the surface of the earth? How fast would you need to be going? Like if I'm in the highway going at, you know, 70 miles per hour, am I safe if the earth suddenly turned into a black hole? Yeah. So if you're at the surface of the earth, which is 6 million meters from the center of the earth, then you need a velocity of about 7,900 meters per second to avoid falling into the surface of the earth. All right. That sounds not in the millions. How does that translate into miles per hour? That's like 17,000 miles per hour. So it's definitely faster than you're moving right now. If you're just standing still on the surface of the earth, then you know the earth goes around one time per day, obviously. Then you're moving at like 460 meters per second. So you're moving a lot slower than you would have to be if you wanted to avoid falling into a black hole at the center of the earth.
Starting point is 00:21:47 Okay. So then the answer then would be we would all fall in, as you like to say, unless you just happen to be breaking some sort of crazy speed record on land. Yeah. Or you had access to some really powerful rocket or a spaceship or something. Oh, I see. You could activate it as soon as you hear news that the Earth turn into a black hole. You could activate your jetpack and then fly away. If I had a jetpack and I saw the Earth sort of crumbling beneath me into a black hole,
Starting point is 00:22:14 then yeah, I would turn that thing on. That's why you have it. Oh, I see. I would have given it to my kids first, but, you know, that's just me. No, I'm just kidding. First, put the mask on yourself, then help the child nasty. Isn't that what they say? All right, well, Beckham, fortunately, I don't think you have to worry about that, right?
Starting point is 00:22:31 I don't think the earth is in danger of turning into a black hole anytime soon. Unless Beckham has some evil plans to grow up and compactify the earth into a black hole, and we've just aided them. Well, why did why they need to grow up? They could be a child genius, evil genius. Well, here's hoping you're not, Beckham. But thanks for asking the question. All right.
Starting point is 00:22:51 Well, let's get into our two other questions for today. One about entropy and time and the other one about radio bursts. But first, let's take a quick break. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., every day. changed. There's been a bombing at the TWA terminal.
Starting point is 00:23:26 Apparently the explosion actually impelled metal, glass. The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and order, criminal justice system is back. In season two, we're turning our focus to a threat. that hides in plain sight that's harder to predict and even harder to stop listen to the new season of law and order criminal justice system on the iHeart radio app apple podcasts or wherever you get your
Starting point is 00:24:04 podcasts i'm dr joy harden bradford and in session 421 of therapy for black girls i sit down with dr ophia and billy shaka to explore how our hair connects to our identity mental health and the ways we heel. Because I think hair is a complex language system, right, in terms of it can tell how old you are, your marital status, where you're from, you're a spiritual belief. But I think with social media, there's like a hyperfixation and observation of our hair, right? That this is sometimes the first thing someone sees when we make a post or a reel is how our hair is styled. You talk about the important role hairstylists play in our community, the pressure to always look put together, and how breaking up with perfection can actually free us.
Starting point is 00:24:53 Plus, if you're someone who gets anxious about flying, don't miss Session 418 with Dr. Angela Neil Barnett, where we dive into managing flight anxiety. Listen to Therapy for Black Girls on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. Get fired up, y'all. Season two of Good Game with Sarah Spain is underway. We just welcomed one of my favorite people and an incomparable soccer icon,
Starting point is 00:25:18 Megan Rapino to the show, and we had a blast. We talked about her recent 40th birthday celebrations, co-hosting a podcast with her fiancé Sue Bird, watching former teammates retire and more. Never a dull moment with Pino. Take a listen. What do you miss the most about being a pro athlete? The final. The final.
Starting point is 00:25:37 And the locker room. I really, really, like, you just, you can't replicate, you can't get back. Showing up to locker room every morning just to shit talk. We've got more. incredible guests like the legendary Candace Parker and college superstar AZ Fudd. I mean, seriously, y'all. The guest list is absolutely stacked for season two. And, you know, we're always going to keep you up to speed on all the news and happenings around
Starting point is 00:26:01 the women's sports world as well. So make sure you listen to Good Game with Sarah Spain on the Iheart radio app, Apple Podcasts, or wherever you get your podcasts. Presented by Capital One, founding partner of IHeart Women's Sports. I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast. Here's a clip. from an upcoming conversation about exploring human potential. I was going to schools to try to teach kids these skills and I get eye rolling from teachers or I get students who would be like, it's easier to punch someone in the face. When you think about emotion regulation, like you're not going to choose an adapted strategy
Starting point is 00:26:36 which is more effortful to use unless you think there's a good outcome as a result of it if it's going to be beneficial to you. Because it's easy to say like go you go blank yourself, right? It's easy. It's easy to just drink the extra beer. It's easy to ignore, to suppress, seeing a colleague who's bothering you and just, like, walk the other way. Avoidance is easier. Ignoring is easier. Denials is easier. Drinking is easier. Yelling, screaming is easy. Complex problem solving, meditating, you know, takes effort.
Starting point is 00:27:06 Listen to the psychology podcast on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. All right, we're answering listener questions today on the podcast. And our next question comes from Dave, who is from Germany. Here's Dave's question. What I would like to know is in one of your podcasts, Daniel explained that when space is generated, each increment of space is containing its own newly generated increment of energy. And I understand that energy, when it's, it's existing that it can be converted.
Starting point is 00:27:51 Now, normally when energy is converted as to my understanding, there's also entropy generated. I wonder what happens with this entropy. Far as I know, entropy and time are the only two physical components which move forward in time or rather are generated only in one direction. So are there any connections between entropy and time? And if there is a connection between entropy and time, would the time freeze when there's no more entropy to be generated in our universe? All right.
Starting point is 00:28:25 Thank you, Dave, from Germany. It's kind of a complicated question here. I think he's asking whether, you know, I think we've talked about how energy is generated when new space is created in the universe. And so there's maybe some entropy associated with that energy. And so what's going to happen, you know, at the end of time when maybe the universe is not expanding or we run out of entropy? What do you think he's asking?
Starting point is 00:28:49 I think he's got a lot of fun questions. I think he had more questions sort of generated in his mind as he was asking his initial question. And I think that makes sense because a lot of these things are connected. I think the heart of the question is probably about how the expansion of space is connected to the end of the universe. You know, like is the expansion of space dooming us to a certain eventual fate of the universe? And I guess specifically he was asking like when the universe,
Starting point is 00:29:16 expands, is entropy increasing as well? Yeah, that's a really cool question because, you know, we've talked about how the expansion of space breaks something else, which we always thought was fundamental and ironclad rule of the universe, that energy is conserved. And, you know, energy is conserved, but only when space is static. Remember that a lot of these conservation laws come from symmetries. They come from assumptions that we can make about the universe. And one of them is that space is static.
Starting point is 00:29:45 And so energy is only conserved when that holds. And if the universe is expanding, that doesn't hold anymore. So it makes sense to also ask like, what else gets broken when space expands, when the universe is creating more space? So is entropy being created with new space in the universe? I wouldn't say created, right? Entropy is not something that, like, you create. It's not a physical thing.
Starting point is 00:30:08 It's like a calculation that we can do to evaluate a situation, say, what is the entropy of this? You know, you can, like, run the numbers and say, what's the entropy of this situation versus that situation? I don't think of entropy as like a physical thing that's actually made. But you can't ask the question when space expands, when new space is being created, does entropy go up or down? I see. Is it being created or not? I'm just kidding. I guess, is entropy increasing when space increases as well?
Starting point is 00:30:38 That's the question. Yeah. And it makes absolute sense. And I think the answer has to be yes. And not just because of the second law. of thermodynamics that says that, you know, entropy always goes up, but because of the nature of entropy, right? Entropy is a really slippery concept. And I think a lot of people think of entropy is like the amount of disorder or disorganization sort of in the universe. The amount stuff is sort of
Starting point is 00:31:00 mixed up. It's a messy topic. And that's a helpful way to think about it sort of approximately. But what entropy actually is is sort of a measurement of our ignorance about what's going on at the smallest level. To calculate entropy, you have to make like a statement about something macroscopically, like it's temperature or its volume or something, you know, macroscopically that we can see in measure and then compare that to what we know about it microscopically. So entropy is related to the number of different ways you can make microscopic arrangements that are consistent with your macroscopic statements about things like temperature. So it's like a measure of like how much we don't know about the microscopic states.
Starting point is 00:31:40 Right. It's almost like, you know, the messier things. are, the more different ways that that messiness can be. But if you want something really neat and ordered, you only have so many options. Yeah, it's like if you have a bunch of coins and I tell you all the coins are heads. Well, then I've told you exactly how every coin has to be. They all have to be heads. It's only one way for that to happen. Right. That's low entropy, right? Yeah, that's low entropy, exactly. But if then I tell you, well, half the coins are heads, then now you have a lot of different ways to arrange all those coins. As long as half of them are heads, you're free to decide for this coin and for that coin, whether it's heads or tails. So there's a lot
Starting point is 00:32:17 of ways to arrange the coins to satisfy my sort of macroscopic statement that half of them are heads. And so that means it's high entropy because there's a lot of configurations. And the second law of thermodynamics is nothing more than that. It's just saying things that have high entropy are more likely to happen because there are more ways for it to happen. And usually that happens with time, right? And usually that happens with time. Like the more time passes, the more the things that are likely are likely to happen. Yeah, exactly.
Starting point is 00:32:46 It's a foundational idea in quantum mechanics that every possible state microscopically is equivalently likely. But if more of those states represent the same thing macroscopically, like they're close to a 50-50 split heads and tails, then they're more likely to happen because they're just more of those possible outcomes. It's like if you roll a huge handful of dine, you add up all the numbers, you're much more likely to get something near the middle of the possible outcomes within the very maximum value or the very minimum value just because there's more ways to get that outcome. And there's only one way to get the maximum and one way to get the minimum. So it's really just a statement of probability.
Starting point is 00:33:22 So then does that mean that as you get more space in the universe, there's kind of more ways for things to be arranged and therefore entropy, it just naturally increases? Yep. That's exactly what happens. The more ways you have for things to be arranged, arranged under the hood, the more entropy you have. And the more space means more microstates.
Starting point is 00:33:41 More microstates means more entropy. I see. All right. So then is that what is causing entropy in the universe to increase? Or is it just helping entropy increase in the universe? Entropy would be increasing even without dark energy. If space was not expanding, then entropy would be increasing anyway. Just because that's what the second law of thermodynamics says, that if you start from a low
Starting point is 00:34:04 entropy configuration, unlike the arrangement of your microstates, you're going to end up in a more likely arrangement as time goes on. So even if space was not increasing, if there was no expansion, entropy would still be gradually going up. But as you say, it's helped by the fact that space is expanding. And so there's more stuff to get mixed up. And so entropy is increasing that way as well. I see. So entropy is accelerating in the universe because of dark energy, which is the expansion of the universe. Mm-hmm. Mm-hmm. And he asked another sort of fun question there because he was talking about energy conversion. You know, every time you turn one kind of energy into another kind of energy, it's never perfectly efficient, a little bit leaks out as heat. And that also is an increase
Starting point is 00:34:50 in entropy. But it's really the same thing because heat spreading out is really just like more microstates sharing in the wealth of the energy and it's spreading out. It's more likely for energy to be spread out than for it to be compact. But he's talking about how when you convert one kind of energy into another, entropy goes up and he's wondering about like the actual process of creation of space itself, does that like leak heat out into the universe? What? I guess if you're creating space, you're creating energy. And if you're creating energy, you're heating things up.
Starting point is 00:35:21 Yeah, it's a really fun question. I never really thought about that before. The problem is that we don't have any idea for what that process is. Like, we know that the expansion of the universe is accelerating and that means space is being stretched and created. But we don't really know what the mechanism is for that to happen. We don't have an explanation for that. Some people think it might come from negative pressure from quantum zero point energy and all the fields that are in space. But if you do the calculation, that doesn't actually work. It doesn't explain what we see. So we observe that space is being created,
Starting point is 00:35:53 but we don't know what's doing it. So we have no concept for this mechanism. We don't know if it actually involves an energy conversion from some other source of external energy we haven't been aware of, or if it's actual creation of energy itself. I see. So we're too clueless to really answer that question. Sorry, Dave. Well, if there's entropy being generated by dark energy, can I call it dark entropy? You can call it whatever you like.
Starting point is 00:36:21 I think I'm going to reserve that for my new sci-fi novel, Dark Entropy. That is a cool title, actually. mysterious and chaotic there you go all right and then there was a sort of an appended question at the end here about whether you know at the end of time or at the universe
Starting point is 00:36:38 keeps expanding and expanding and entropy keeps increasing does that mean that time is going to end or freeze yeah everybody wants to know the answer to that question Dave and unfortunately nobody does right we just don't know what the future of dark energy is will it continue to pull stuff apart and
Starting point is 00:36:55 spread everything out and increase the entropy of the universe till an eventual heat death, we just don't know because again, we don't know what the mechanism is and we don't know if it will continue. Remember that dark energy has not been persistent in our universe. While we think the cosmological constant might be constant, because it's called the cosmological constant, dark energy itself only took over around five billion years ago to create this accelerated expansion. So we don't know why it turned on around then. We don't know if it's going to keep going, if it's going to stop, if it's going to turn around and shrink the universe back down to some other crazy dense state.
Starting point is 00:37:31 So we just really don't know. We can't predict because we don't understand this mechanism at all. All right. So then I guess the question is stay tuned and or we have no idea. Sorry, Dave. We have no idea. Stay tuned. We may still have no idea in a billion years.
Starting point is 00:37:47 It's going to be messy either way. All right. Well, thank you, Dave. That answers that question. And so let's get into our last question of the episode from Robin. and it's about radio bursts. But first, let's take another quick break. December 29th,
Starting point is 00:38:09 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA. a terminal. Apparently, the explosion actually impelled metal glass.
Starting point is 00:38:33 The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and order, criminal justice system is back. In season two, we're turning our focus to a threat that hides in plain sight. That's harder to predict and even harder. to stop. Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts.
Starting point is 00:39:10 I'm Dr. Joy Harden Bradford, and in session 421 of therapy for black girls, I sit down with Dr. Ophia and Billy Shaka to explore how our hair connects to our identity, mental health, and the ways we heal. Because I think hair is a complex language system, right? terms of it can tell how old you are, your marital status, where you're from, you're a spiritual belief. But I think with social media, there's like a hyper fixation and observation of our hair, right? That this is sometimes the first thing someone sees when we make a post or a reel is how our hair is styled. You talk about the important role hairstylists play in our community, the pressure to always look put together, and how breaking up with perfection can actually
Starting point is 00:39:53 free us. Plus, if you're someone who gets anxious about flying, don't miss session 418 with Dr. Angela Neil Barnett, where we dive into managing flight anxiety. Listen to therapy for black girls on the Iheart radio app, Apple Podcasts, or wherever you get your podcast. Get fired up, y'all. Season two of Good Game with Sarah Spain is underway. We just welcomed one of my favorite people and an incomparable soccer icon, Megan Rapino, to the show. And we had a blast. We talked talked about her recent 40th birthday celebrations, co-hosting a podcast with her fiance Sue Bird, watching former teammates retire and more. Never a dull moment with Pino. Take a listen. What do you miss the most about being a pro athlete? The final. The final. And the locker
Starting point is 00:40:39 room. I really, really, like, you just, you can't replicate, you can't get back. Showing up to the locker room every morning just to shi-talk. We've got more incredible guests like the legendary Candice Parker and college superstar A.Z. Fudd. I mean, seriously, y'all. The guest list is absolutely stacked for season two. And, you know, we're always going to keep you up to speed on all the news and happenings around the women's sports world as well. So make sure you listen to Good Game with Sarah Spain
Starting point is 00:41:06 on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Presented by Capital One, founding partner of IHeart Women's Sports. I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast. Here's a clip from an upcoming conversation about exploring human potential. I was going to schools to try to teach kids these skills and I get eye rolling from teachers or I get students who would be like it's easier to punch someone in the face. When you think about emotion regulation, like you're not going to choose an adaptive strategy which is more effortful to use unless you think there's a good outcome as a result of it if it's going
Starting point is 00:41:43 to be beneficial to you. Because it's easy to say like go you go blank yourself right? It's easy. It's easy to just drink the extra beer. It's easy to ignore to suppress seeing a comment. who's bothering you and just like walk the other way avoidance is easier ignoring is easier denial is easier drinking is easier yelling screaming is easy complex problem solving meditating you know takes effort listen to the psychology podcast on the iHeart radio app apple podcasts or wherever you get your podcasts All right, we're answering listener questions today on the podcast. And our last question comes from Robin from Oregon.
Starting point is 00:42:30 And she has a question about the National Radio Quiet Zone. Hello, Daniel and Jorge. This is Robin Marks in Coburg, Oregon. I just got done listening to your show about fast radio bursts. And it got me thinking about the National Radio Quiet Zone in Greenbank, West Verst. Virginia where basically nothing electronic is allowed. No microwaves, no cell phones, no Wi-Fi. I thought it would make a great episode on your podcast. What do you think? All right. Thank you, Robin. That sounds like a great place to visit for a vacation. No cell phones, no electronics. I mean, you go a little crazy the
Starting point is 00:43:12 first couple of days, but maybe you would reach some sort of Zen state afterwards. Yeah, it's an amazing sort of spot in the country where they've really tried to keep things quiet. so that astronomers can listen to the skies and not be crowded out by all the crazy radio signals that humans generate. So this is an actual place in the United States in West Virginia? This is an actual place in West Virginia. The most powerful radio telescope in our hemisphere
Starting point is 00:43:39 and the largest steerable radio telescope is now at the Green Bank Observatory. In West Virginia. Exactly. And, you know, this thing is listening to the sky and it's listening to the sky, Not in terms of sound, of course, but in terms of a special frequency of light that we call radio waves. And if you want to listen to the sky, you have to make sure you're not drowned out by basically light pollution from other sources of radio emissions.
Starting point is 00:44:06 And I guess all of our cell phones, most of our electronics, they use these radio frequencies. They do. They use these radio frequencies. We're constantly beaming radio waves around the world, right? For radio, right? If you're listening to us on the radio right now, then we have been transmitted to you using this kind of electromagnetic radiation whose frequency puts it in the radio band.
Starting point is 00:44:29 And not just our cell phones and not just our radio towers, but a lot of our electronics accidentally, sort of incidentally, generate radio noise. Well, this is interesting. How big is this national radio quies? Is it like a federal thing? Or how do people all agree in that large of a space to not use their cell phone? It is a federal thing.
Starting point is 00:44:51 It was created in 1958. It's this big rectangle of land. It's about 100 miles on a side. And so it's really pretty spacious. And it surrounds this Green Bank Observatory in West Virginia. Cool. And you said it was created in 1958. Did we have radios?
Starting point is 00:45:07 I guess we had radios in TV. But no cell phones back then. No cell phones. But these days also they try to restrict Wi-Fi usage. What? Because that also operates in the similar frequencies. All right. Forget it.
Starting point is 00:45:18 I mean, I can go on a vacation with no cell phones, but Wi-Fi. Yeah, so they try to be as quiet as possible, and they actually drive around with this truck listening for radio signals. No kidding. Trying to catch people, like, emitting in their radio. What? And, yeah, they do. They drive this patrol truck around listening for emitters because some people just aren't aware. Like, if you have an old microwave oven that's poorly shielded, it can generate a lot of radio noise.
Starting point is 00:45:44 I see, but then if they find somebody, how do they radio it in to come take them away? They can't. They can't. They just politely knock on the door and ask those folks to stop using it. It's not heavily enforced. Like you can get a $50 fine for emitting radio in the quiet zone. But they mostly just try to work with people and help them understand the importance of radio astronomy and what they're trying to do. That would be an expensive phone call if it costs you 50 bucks.
Starting point is 00:46:09 And this is a real concern. There's this hilarious story from Australia where they also have a big radio telescope where they saw these weird signals. And, you know, they're listening for messages from outer space and they saw this bizarre signal they couldn't understand until they finally tracked it down after more than a decade to be the microwave in the break room where the grad students hang out. What? They couldn't figure out why this signal always lasted the same amount as the popcorn setting on the microwave. Yeah, basically, grad students eating frozen burritos created a false signal of extraterrestrials. I guess these telescopes are pretty sensitive, right? Like you're trying to detect really weak signals from space.
Starting point is 00:46:49 Exactly. We are trying to listen to really quiet signals. Remember that the power of a signal falls very quickly with the distance. You know, if you shout from the top of a mountain, then people can hear you if they're close by. But as they get further and further away, it's harder and harder to hear that shout. It falls with the distance squared. And so the message, for example, from an alien civilization could come with a very small amount of energy by the time it gets here. I see.
Starting point is 00:47:15 It's like, I think you were telling me once, it's like the energy of a falling snowflake. Yes, it's a very, very gentle ripple in the electromagnetic fields. And that's why this dish is huge. This thing is as tall as the Washington monument. It's got two acres of area on the dish. What? Yeah. Also, it's kind of beautiful.
Starting point is 00:47:33 You should check out a Google image of this thing. Is it bigger than like the Arecibo? It's not bigger, unfortunately, but it is steerable, right? Erecebo is sort of built into the ground. This thing is above ground, but they can turn it. So they can point it in various directions. And that helps them understand, like, the location or the source of a signal. Wow.
Starting point is 00:47:51 I guess one question is, why aren't there more of these radio quiet zones? Like, you know, I've been to Hawaii and the telescopes and nobody finds me for using my cell phone up there. Well, they don't have radio telescopes in Hawaii. Most of those are optical telescopes. So this is a special kind of telescope that's listening for radio. And so it's mostly sensitive to radio noise. And radio telescopes aren't as common as optical telescopes. optical telescopes. It's a sort of special branch of astronomy.
Starting point is 00:48:18 I see. And it's a really exciting one. I mean, there's lots of really interesting things you can learn about the universe just by listening to the sky in the radio. You know, this is how we discovered, for example, that the center of our galaxy had a black hole because people heard this weird signal from the center of the galaxy. And they thought, what's that? What could be there making this weird pulse? Wow.
Starting point is 00:48:38 Then we pointed one of these telescopes to the center of the galaxy? Yeah, that's how we figured it out. radio astronomy the whole field was sort of invented accidentally there was an engineer at bell labs who was asked to figure out like could we beam signals using radio waves across the atlantic how much interference is there so he just built a huge radio antenna to sort of listen for the amount of noise he was more worried about thunderstorms but then he heard this weird signal and he discovered hold on a second this isn't even coming from earth it's coming from somewhere else and that's when radio astronomy was born we realized that the stars were sending us information in another
Starting point is 00:49:13 frequency and nobody had been listening. Interesting. I guess the university is sending a signal in all frequencies really. That's why we listen in the radio, in the x-ray, in the optical. We look at gamma rays. We look at every sort of kind of frequency because different parts of the universe glow at different frequencies of light. The hotter you are, the higher your temperature and the more energetic, the higher the frequency you emit of your radiation. So radio waves come from sort of cooler, or quieter stuff, but it's also very powerful. It's very good at seeing dark stuff that you can't otherwise see, like huge clouds of gas and dust that aren't glowing in the visible light.
Starting point is 00:49:50 Right. And sometimes when you see those photos of like giant space nebula or giant clusters of stuff out there in space and you see it has all these colors, that's really what it is, right? Like they sort of manipulate the signals from all these different frequencies and they assign colors to them. Yeah, a lot of times they do a color map, right? They take things which are invisible to your eyes, right? You can't see radio waves.
Starting point is 00:50:10 Even when they hit your eyeballs, you can't see them. And then they shift their frequency so that you can see it. They map it into the visible spectrum. All right. So then this national radio quiet zone, can anyone go visit? Is it open to the public or do you have to like sign in or get permission? No, it's a huge area of land. So it includes like cities.
Starting point is 00:50:28 People live there. Like people's homes are in this area. It's not like a closed off region. People live there, but there's no radio signals, right? There's no radio stations. You can't use cell phones. not supposed to have Wi-Fi. There's like whole towns with no cell phone or Wi-Fi signals?
Starting point is 00:50:44 Yeah, there's like a whole mountain resort there that has like, you know, landlines and phone booths and all sorts of quaint stuff. Wait, what's a phone booth? It's this thing I see on Doctor Who. I don't really know what it's for. And some people really like to live there. Like some folks feel hypersensitive to electromagnetic radiation. You know, they don't like to live near sources of it.
Starting point is 00:51:05 And so if you're that kind of person, then this is made for you. or if you're a radio astronomer. Wow. I wonder if people are happier there. Do you know what I mean? Like I feel like maybe my life was a little happier before this sort of constant source of noise in my pocket. All those email dings that you don't pay attention to this night.
Starting point is 00:51:22 All these things that, you know, I have to ignore. I don't know. It's a great place to do radio astronomy, but it might also be a good place to do a psychology study of the effects of modern communication. I'm sure somebody's looked into that. Interesting. Unfortunately, most of the people who live there are physicists,
Starting point is 00:51:35 so, you know, that drags the happiness quotient down. It definitely skews the sample for sure. It wouldn't be a scientific study. All right. Well, thank you, Robin, for that question. It was a fun topic to explore. I had had no idea about this national radio quiet zone in West Virginia. That's right.
Starting point is 00:51:52 So if you are driving through it, please don't blast your stereo or turn on your Wi-Fi or open up your phone because those astronomers want to hear the message from the aliens when it comes and not your silly emails. Yep. All right. Well, those are our three questions for today. And once again, it's amazing. First of all, that people are listening to this podcast. Thank you so much for being there for us.
Starting point is 00:52:14 And it's amazing the range of questions we get from people from all over the world. That's right. And remember that science is just people asking their personal questions about the universe. So keep asking your questions. Think to yourself, if I could get the answer to one question about the universe, what would be my one question. And if you know what that question is and you don't know the answer, hey, write it to us.
Starting point is 00:52:36 Maybe we can help you figure it out. Maybe we'll ask the question right back at you and avoid answering it like we did some questions today. And then we'll run away to the radio free zone and avoid your email. Sounds like a good deal. All right. Well, thank you for joining us. Hope you enjoyed that. See you next time.
Starting point is 00:53:00 Thanks for listening. And remember that Daniel and Jorge Explain the Universe is a production of I-Heart Radio. For more podcasts, from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. Then everything changed. There's been a bombing at the TWA terminal, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, terrorism. Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts.
Starting point is 00:54:01 Get fired up, y'all. Season two of Good Game with Sarah Spain is underway. We just welcomed one of my. favorite people, an incomparable soccer icon, Megan Rapino, to the show, and we had a blast. Take a listen. Sue and I were, like, riding the lime bikes the other day, and we're like, we're like, people ride bikes because it's fun. We got more incredible guests like Megan in store, plus news of the day and more. So make sure you listen to Good Game with Sarah Spain on the IHeartRadio app, Apple Podcasts, or wherever you get your podcasts.
Starting point is 00:54:33 Brought to you by Novartis, founding partner of IHeart Women's Sports Network. work. If a baby is giggling in the back seat, they're probably happy. If a baby is crying in the back seat, they're probably hungry. But if a baby is sleeping in the back seat, will you remember they're even there? When you're distracted, stressed, or not usually the one who drives them, the chances of forgetting them in the back seat are much higher. It can happen to anyone. Parked cars get hot fast and can be deadly. So get in the habit of checking the back seat when you leave. A message from NHTSA and the Ad Council.
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