Daniel and Kelly’s Extraordinary Universe - Listener Questions 14: Black holes, aliens and zombies!

Episode Date: January 26, 2021

Daniel and Jorge talk about what kind of elements are inside a black hole, how to respond to aliens and whether physicists are useful or useless in a zombie apocalypse. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

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On the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam. Maybe her boyfriend's just looking for extra credit. Well, Dakota, luckily, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend's been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now he's insisting we get to know each other, but I just want or gone. Hold up. Isn't that against school policy? That seems inappropriate.

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Hey, Daniel, congratulations to making it to the year 2021. Thanks. It was a bit harrowing. wasn't sure we were going to get here. Our physicists is preparing for what 2021 might throw at us? Man, I'm hoping we don't have to. If we get to the point where we need physics to save us,

it's probably not a small problem. I guess CERN can't help with the plumbing issues there. You know, if you want a black coal flush down your pipes, give us a call. I think we'll save our call to CERN for the big stuff, you know, like asteroids and zombie apocalypse. Oh my gosh, 2021 will probably be the year of the asteroid zombie apocalypse.

That's a new show. It's called the orbiting dead. Hi, I'm Jorge. I'm a cartoonist and the creator of PhD comics. Hey, I'm Daniel. I'm a particle physicist, and I love all science fiction except for zombie apocalypse movies.

That doesn't count as science fiction to you? No, it counts as science fiction. I'm just not that into it. Because you don't like it or it makes you afraid? I'm not that afraid of zombies, you know, in real life. But it's just kind of boring. They're always just getting chased by these slowly shuffling zombies and it's always just like, you know, how many heads can you explode before they kill you?

Oh, man. You've been watching the wrong zombie movies. Don't you know they run and they climb walls now? They've upgraded. All right. I'll look for zombies 2.0. Welcome to our podcast. Daniel and Jorge Explain the Universe, a production of IHeard Radio. In which we tackle the biggest questions of the universe. We toss our minds into the depths of space and try to understand where everything is made and how everything works.

We zoom into the littlest particles and try to wrap our minds around what they're doing and why. Our goal on this podcast is to literally explain the entire universe to you. Because there is a lot of a universe to explore. And there are a lot of mysteries out there, a lot that we don't know about the universe, about what it's made out of, what's out there, what can happen, and what is possible in this vast cosmos we live in. That's right. It turns out even 250 episodes of this podcast is not enough to explain the entire universe. It's a big place with a lot of mysteries. And we love talking to you about it. And we love hearing from you what you'd like us to break down.

Yeah, even after 250 episodes, people still send us questions. We get questions through social media. media, email? Do people ever show up at your door, Daniel, with questions? You know, you joke, but when we had classes in person, I used to hold office hours in person. And occasionally a random person from the street would show up and said they'd look me up and came in with a question about the universe. So yeah, kind of. Wow. Is there a Zoom equivalent now for that? You know, there is a Zoom equivalent. I have monthly public office hours where people can drop in and ask physics questions. Wow. Cool. All right. Well, today we are actually addressing listener questions.

We are taking in questions and trying to break them down in 50 minutes. Because we know that while we do our best to talk about the mysteries of the universe in a way that makes sense to you, there's always some angle we didn't consider, something that makes you wonder, something that doesn't make sense to you. So when that happens right to us, let us know what you're still wondering about and we'll break it down for you either over email or on the podcast. So on the podcast today, we'll be tackling. Listener questions, number 14. 14. This is our 14th episode, yes. We are officially teenagers.

Well, I think we were teenagers. One episode ago, technically. But yeah, that's a lot of questions we've answered. Each time we answer like three. So, you know, you would think after 250 episodes, we would have answered. Everyone's priorities about the universe. You think so, but they keep coming in. Yeah.

So today we have three awesome questions about black holes, about our favorite topic, aliens, and our least favorite topic. zombies. That's right. So thank you to everybody who sent in questions. And if you have a question, please don't be shy. Yeah, we'd love to get your questions. And Daniel loves to answer them. We'll usually answer them, right? I mean, you'll usually answer them. Oh, I answer every question. You engage with us on Twitter or send us an email. You will get a reply. I guarantee it. But if they don't get a reply, that means we might be doing it on the show, right? No, actually, I write back to everyone. Sometimes people also get a special podcast episode.

if I think the question is exciting enough that everybody might want to hear the answer. Like if there's zombies. Then I would think you want to stay away from that question, but maybe physics will save us from zombies. We'll see. All right, well, the first question is about black holes and it comes to us from Patrick from Nashville, Tennessee.

Daniel and Jorge, my name is Patrick O'Leary from National Tennessee. I have a question for you guys. I was curious, what would the chemical or elemental makeup of a black hole consist of? If our sun is made of hydrogen elements fusing into helium and if other life stages of stars include heavier elements fusing and so forth leading up to this big collapse, wouldn't it seem reasonable that a black hole will consist of some super heavy element resulting from some sort of hyperfusion occurring during and after the gravitational collapse? Would there be an element that doesn't fit on the periodic table that may have some sort of infinite density? Would it even be an element, or would this singularity potentially be something entirely different? Is there something else that this matter in the black hole could theoretically be?

I just want to see what y'all's thoughts are. We really enjoy the show and look forward to hearing your answer. Thanks. Well, that's a super heavy question from Patrick. Yeah, it's an awesome question. It's thinking about weird places in the universe that can make weird kinds of matter. So super awesome question. Thanks, Patrick. Yeah, I guess a fundamental question is, what is a black hole made out of?

We know it's black. I mean, it's made out of like charcoal. It's just an aluminum sphere with black paint on it. I mean, sorry to break everybody's bubble here, but that's all it is. Oh, I see. It's a hoax. It's fake news. Yeah, exactly. It's fake physics news. Huh. I can see his reason in there. It's pretty interesting and pretty convincing. Like if you think about heavy objects in our universe, like stars, they're made out of hydrogen and things are fusing inside and gravity's crunching them down and they get older and explode and come back together. They're making heavier and heavier elements.

And so does that mean that when you get to the ultimate dense object, does that mean it's made out as super heavy elements? Yeah, this is a super fun question. I thought it'd be fun first to think about like what is the mass of the stuff that turns into the black hole? Like just before it becomes a black hole, what mix of stuff do you have there? And then we could talk about what happens to it as the black hole is collapsing. Like, does it form some new weird state of matter? Could you even call that an element, et cetera, et cetera? Oh, I see.

Like the scene of a murder, let's go back to right before the actual event and see what conditions are there. And then maybe that would tell us what happens when the actual black hole forms. Yeah, exactly. We're not murdering any iron here. I think of it more like cooking, you know, and we want to make sure. we understand what are the ingredients. We're just killing irony. We're going straight to the answer.

That's right. Or we're cooking it up, one of the two. All right, well, he mentioned stars because a lot of black holes come from stars, right? And stars collapsing or supernovaing. Yeah, and so there's two categories of black holes. They're the supermassive ones at the centers of galaxies. But let's focus on the other ones, the smaller ones that are stellar black holes. And this happens when you have a star and it gets too heavy and the gravity sucks it in and eventually becomes a black hole.

And he's totally right that this is where heavy elements are made. I mean, the universe started with mostly hydrogen. And the way you get heavier elements is that you fuse hydrogen nuclei together to get helium and then helium together to get heavier stuff. And you work your way up the periodic table, eventually getting to iron. And so in the center of stars are these conditions to take two elements and turn them into a new element, right? This amazing thing that we once thought was impossible. Alchemy actually happens all the time at the center.

of stars creating new kinds of matter. So that happens in our universe. That's pretty awesome. Yeah, because elements are just different combinations of the same three things, right? Quarks and electrons. And so, you know, if you get something that has three quarks and two electrons and you compress it with something that has four quarks and another three electrons and you get something that's additive, right? Yeah, exactly. You just add them together. And to make a new element, though, what you need to do is to add a new proton to the nucleus. Like a typical atom has protons and neutrons, which of course are made of quarks in the nucleus and then surrounded by electrons. To get to a new element, like to go from helium to lithium or something, you need to

add protons, change the charge of the nucleus and then add more electrons to make it neutral. The other thing you can do is add neutrons, right? If you add neutrons, it doesn't change the element, it just changes the isotope, right? You've heard like uranium 238 or uranium 235. That tells you how many nucleons are in the nucleus. They're both uranium because they have the same number of protons, but they have a different number of neutrons. Right. And so that's what's happening inside of stars is that you're making these heavier and heavier elements, but only up to a certain point, right? Like you can build it up through carbon and silicon, but then you get to iron. Yeah, exactly. If you want to make super heavy elements, you can keep doing that fusion process,

but only up to iron. Up to iron, it releases heat. And so it drives the reaction. It makes it happen more and more. Above iron, it absorbs heat. So you can fuse. two iron nuclei together to make something heavy, but it costs you heat. And so it cools down the star. And that's why stars that build up too much iron inside them collapse and form supernovas, because it's the pressure from that heat that keeps the star from collapsing. So if the fusion actually causes the star to cool down, then it's actually encouraging it to collapse. It's working in the same direction as gravity rather than pushing out against it. So that's why stars collapse after they get a big enough iron core. Right. And when these stars collapse, that's when you get

the heavier elements, right? Because of the explosion or what? Well, actually, that's something we've only recently understood for a long time. People thought that you got the heavier elements, gold and platinum in that collapse or in the supernova that happened just afterwards. Because they thought maybe the conditions were crazy, hot enough in a supernova to force extra neutrons onto an iron. And then those neutrons would decay into protons and you end up with a heavier element. But it turns out that's not the case that most of the gold and the platinum and the heavy stuff in the universe is not actually made in supernovas. Really?

Yeah, and they learned this because they found bits of supernova in the ocean. What, next to the seashells and crabs? What does a bit of supernova look like? Yeah, well, on the outer layers of the supernova are these little seeds, like heavy elements, which then get covered in stuff from the supernova and blown out into space. And these are special little grains, which you can later identify. And like our solar system is made up literally of stardust, right? Well, some of that stardust are these little grains from supernova and you can find them and you can study them and they've looked at them and they've tried to understand whether they have evidence in those grains for the formation of heavy elements.

It's like a particular signal you need that shows you that heavier elements were made during the supernova expansion and they don't see them. You need this marker. It's plutonium 244 and they just don't see them in these grains that they find buried in the ocean crust. But now we have another candidate for how we think those. those super heavy elements were made. What's a candidate? Well, instead of being created during the supernova, we think that sometimes these stellar collapses lead to neutron stars,

these varied, very, very dense objects that are not heavy enough to collapse all the way to a black hole, but are heavy enough to be this crazy new form of matter, just neutrons. And sometimes those neutron stars can collide. They can find each other in a binary system, and they can spiral in and form this collision. And those are the conditions you need to make gold or platinum or these super heavy elements. What? That's wild. Wait, so I know neutron star is just like a giant mass of neutrons, right? You don't even have elements or atoms.

It's just all neutrons. It's just all neutrons. It's like some new element that's pure neutrons and no protons. It's a weird form of matter that, frankly, we don't understand very well. And so you're saying sometimes two of those collide, like crashing to each other. And then when in the crash, they create elements or when they break apart, they create new elements? In the crash, they create those elements. And the fact that there's a collision sprays those elements out into the universe, which is why now we find those elements on Earth, for example.

Most of the gold and the platinum on Earth, we think, is produced in the collisions of neutron stars billions of years ago. Wow. That's a weird sentence, a neutral collision. Like a collision that doesn't care. It's amazing because it means that formation of gold and platinum is much more rare than we thought. neutron stars don't collide as often as you have supernova. But when you do have a neutron star collision, you make a lot more of these heavy elements than you would in a supernova. So for example, we used to think that supernova collapses produced about one moon's worth of gold.

That's a pretty big chunk of gold and we think like the universe was sprinkled with all these basically moons of gold. But now we think that it happens more rarely. But when it happens, when you get these neutron star collisions, you get like a Jupiter of gold. Whoa. That's a lot of bling. And so it's more like the universe is sprinkled with these really big chunks of gold rather than more like evenly distributed with little, you know, sprinkles of gold. It's like chocolate chip cookies rather than chocolate sprinkles. All right. So let's get maybe back on track to the black hole. So that's how we get heavier elements in maybe neutron star collisions.

But then do those neutron stars become black holes or not? No, they usually just get torn apart. But sometimes if they get over the threshold, they can turn into black holes, but not all the time. Most of the black holes that are out there, these stellar mass black holes, start out as sort of larger suns, like 10 to 15 stellar masses, which then through a lot of fusion, builds up a heavy iron core and collapse straight to a black hole. And so there potentially, you could imagine heavier stuff being made or weird forms of matter being made. In a supernova. In the supernova, which leads to the collapse into a black hole. Yeah. Oh, I see. So there are heavy elements due to neutron star collisions, but when you get a black hole from a collapsing star, you may also make heavy elements.

You might. I mean, it's not something we understand very well. And, you know, let's think about the ingredients you have there. Say, for example, you start with like 10 solar masses of stuff. You have a big sun which makes a heavy iron nucleus and then it collapses. You might be imagined that you start with 10 solar masses of iron. But it collapses before it turns the entire. higher mass to iron. So you probably have like a heavy core there that's like one or two solar masses worth of iron that forms the sort of the gravitational center that leads to the black hole. So you got a lot of iron there. And then you've got a lot of other inrushing matter during a collapse. Exactly. And those are the conditions you need to make new kinds of matter. Right. You have iron, which is very heavy. And then you have a lot of protons and neutrons coming in. But it's a very strange situation. I mean, it's like much denser and much hotter than even neutron stars. So I think that's the guide. You might be imagining you have iron and

you have all these other particles and you're adding them together. You might be making heavier elements. Instead, typically what you make are not elements like what we recognize, but weird new forms of matter like you see in neutron stars. Right, because you need to get to the right density to create the black hole, right? So at some point, you do need to sort of create this weird kind of super heavy mass. Yeah, exactly. Formation of new elements requires you take a nucleus, you add protons to it, and then you sort of let it go off by itself and be stable. Here, we're taking the results and we're squeezing it down really intensely. So all the protons are just going to turn into neutrons because they're going to get an electron

squeezed into them. And then most likely, instead of forming weird new elements, you're going to get really strange neutron rich matter, you know, strange new kinds of matter. We haven't even imagined weirder things than neutron stars. Right. Maybe the answer then is that in a black hole, or at least as you're getting into a black hole, like regular elements can't exist. Like you can't have an element where it's like neutrons and protons and electrons. It's like it's, the conditions are so extreme. Everything

is compressed into this weird new type of matter. Yeah, exactly. And the distinction between like this atom and that atom breaks down when the atoms get so close together and get so pushed on each other. What you're really going to get is some sort of like weird fluid of neutrons and protons and electrons and electrons. And that's going to get compressed into something even weirder. And you might get, for example, like a quark gluon plasma where the quarks are no longer bound even into neutrons and protons because they're so dense and intensely pressured. So basically you're like recreating the conditions of the early universe sort of in reverse. Wow. All right. Well, that's just leading up to the creation of the black hole. Let's get into what might be inside of

it once the black hole is made. But first, let's take a quick break. Ah, come on, why is this taking so long? This thing is ancient. Still using yesterday's tech, upgrade to the ThinkPad X1 Carbon, ultra-light, ultra-powerful, and built for serious productivity, with Intel core ultra-processors, blazing speed, and AI-powered performance. It keeps up with your business, not the other way around. Whoa, this thing moves.

Stop hitting snooze on new tech. Win the tech search at Lenovo.com. Unlock AI experiences with the ThinkPad X1 Carbon, powered by Intel Core Ultra processors, so you can work, create, and boost productivity all on one device. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys.

Then, at 6.33 p.m., everything changed. changed. There's been a bombing at the TWA terminal. 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 has. 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 my boyfriends professor is way too friendly and now i'm seriously suspicious oh wait a minute sam maybe her boyfriend's just looking for extra credit well dakota it's back to school week on the okay story time podcast so we'll find out soon this person writes My boyfriend has been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her.

Now, he's insisting we get to know each other, but I just want her gone. Now, hold up. Isn't that against school policy? That sounds totally inappropriate. Well, according to this person, this is her boyfriend's former professor, and they're the same age. And it's even more likely that they're cheating. He insists there's nothing between them. I mean, do you believe him?

Well, he's certainly trying to get this person to believe him because he now wants them both to meet. So, do we find out if this person's boyfriend really cheated with his boyfriend? professor or not. To hear the explosive finale, listen to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. All right, we're answering listener questions. And our first question was about what element is a black hole made out of? Like, is it some kind of new kind of super heavy element? And it seems like at least going into the black hole, we don't have actual elements. By the time you're dense enough to create a black coal, you're in this weird state of matter.

Yeah, because elements are not fundamental, right? They're not like a basic thing in the universe. They're sort of like a special configuration or quarks and electrons that require certain conditions, you know, certain temperatures, certain densities. And if you get hot enough and you get dense enough, then you just don't have elements anymore. So it doesn't really make sense to talk about like, is this plutonium, is this uranium, is this black holium? It's some new other weird kind of matter. Black holium. I like that.

Sounds holy. All right. Well, that's before you go into the black hole. So, like, at the core, in, like, the time of birth, the black hole is probably at the core made out of this weird, super heavy neutron soup. But what about, like, after it forms? Like, boom, suddenly I have a black hole and, you know, stuff keeps falling into it. What can we say then about what it's made out? Like, if it grows, then it's probably not mostly this neutron soup.

That's right. We're talking about the super dense conditions that are going to be, like, at the very core of the black hole. What's sort of like on the outskirts of the black hole, just inside the event horizon, for example, but not super close to the very dense material at the center that's maybe forming a singularity. But we think that inside a black hole, space mostly works the same way as it does outside the black hole, except that it's sort of like oriented towards the center. So for example, if you toss a banana into a really big black hole, one where the spigetification doesn't happen until you get close enough to the center, it'll just pass over the event. horizon and continue drifting in towards the singularity. From its point of view, there's nothing special there at the boundary. It'll still be a banana.

But for how long? First of all, then it didn't get spaghettified. And does that speditification also kind of get rid of elements? Does it, is it a soup? Is it a banana soup by the time it goes in? It's definitely a banana smoothie by the time it goes in. When you take a banana, you make it in a spaghetti, then you put that spaghetti in a blender, and you get a smoothie.

Banana spaghetti. that's probably not very popular in Italy. What kind of sauce? Or wait, can you put Parmesan cheese on banana spaghetti? It's gluten-free, though. That's a good thing. As you approach the center of the black hole, then obviously the tidal forces are going to be very, very strong.

That's the difference in the gravitational force between one side of the banana and the other side of the banana. That's what's responsible for the spaghettiification. It's going to pull it apart. And then as it gets closer and closer, those tidal forces get stronger and stronger, pulling those little bits of the banana part further and further. And eventually, it's got to hit some really dense part of the black hole,

some place where the matter is really dense. And then it'll just, you know, join whatever that is. Whatever that is? Is that an official element in your physics table? That's the official way of us saying we really just have no idea what's going on at the center of the black hole. So yeah, whatever that is. So then that's kind of the real answer.

Because all these things that we think are might be happening beyond event horizon, and we don't really know, right? For sure. We don't really know for sure. And there's sort of two directions in which we don't know. Like, we don't know from a sort of nuclear physics theory perspective, what happens if you squeeze neutrons together even harder than the conditions of a neutron star? Like, we can't do those calculations right now for a neutron star.

Like, we can't sit down on a computer and simulate a neutron star because the calculations are too difficult. So even heavier than that, even crazier conditions, that we also cannot do. Also, from a sort of like black hole theory point of view, we just don't know what the distribution of matter is inside the black hole. General relativity says there's a singularity of invented density, but we know that doesn't really make sense. And quantum mechanics says it's impossible. So there's a lot of questions about what's going on at the heart of the black hole, not just like what is the matter made out of once you get there. All right. Well, it sounds like the answer for Patrick is that a black hole is made out of we have no ideal.

Exactly. Or black hole you know. It's kind of a mystery, but we know that when you make a black hole, it's not like an element. There aren't any elements inside. It's more like this kind of hot mess of a soup of neutrons. Probably. Probably. Exactly. All right. Let's jump into our next question, which is about aliens from space. So we have a question from Ignacio, and he's from Jupiter. Is that Jupiter, Florida? No, I'm not sure if he's talking about. Jupiter, Florida, or Jupiter, the solar system. He might actually be an alien. In which case, why is he asking us? All right, everybody, get ready to listen to the first message from alien. His name is Ignacio. Here is his question. Hi, I'm Juancio from Jupiter, apparently.

My question is that, well, we are always wondering how it would be to receive a message from an advanced alien's realization. But if we were to discover indisputable evidence of an able to civilization existing in a far away planet that is roughly equal to us in technology, how could we send them a message? How will we make ourselves known to them? All right. That's a pretty cool question.

The question is, if we ever find evidence of aliens, like if we get a signal from far away or like we figure out their aliens out there, how can we ever reach them or call them or text them or send them a DM. Yeah, that's a really fun question. I mean, I always like to think about what it would be like to get that message. But then it's really interesting to wonder, like, how could we respond, what technology

is available to us and what should we say? Yeah, like I guess if you find that there are aliens like, you know, the next star over, like four light years away or 30 light years away, like do we have technology that can beam a message that far? You know, we do, or at least until very recently, we did. You've probably heard of the Erecebo radio telescope. That antenna can receive messages, but it can also send messages out into space. It's a giant, like dish.

Wouldn't we want something more, I guess, focused? Or can that do, like a focused beam of message? Well, the dish allows you to basically capture a bunch of the messages put out by the antenna and focus it all in the same direction. That's the idea behind a parabolic dish, is that it bounces off the message from the antenna all in a parallel direction. So it allows you to create a directional beam. And a directional beam would be very, very important.

Otherwise, the power of your message would fall really, really quickly as it got further and further from Earth. Right. Like if you transmitted like in a broadcast antenna, it would just kind of spread out in all directions. And by the time it gets to, you know, 30 light years away, they probably couldn't hear it. Yeah, exactly. Just like a candle in the dark, it's very bright close up, but it falls off like one over distance squared. And so twice as far away, it's one full. fourth the intensity and a hundred times away, it's one 10,000's the intensity. And so I've actually

done this calculation to figure out how far away could an alien planet be for us to hear a message using Erecebo. And it turns out that if they have an Erecebo-sized telescope and they're broadcasting in every direction, we would have to be within one light ear of their planet to hear it with our Erecebo telescope. That's not good enough because we're further away from that. That's right. There are zero stars within one light year of Earth. So basically for us to get a message from another solar system, they would either have to broadcast it in all directions much more powerfully than our technology could, much more powerfully than Air Sevo could broadcast, or they would have to beam it at us directly, which means they would have to know we are here and send it to us

intentionally. Now, can you do that? Can you send out an electromagnetic signal in a focus way, kind of like a laser? Sure, exactly. You could use a laser, for example. I mean, Radio waves are just a kind of light. A laser also sends out a beam of light. So it's just a question of like, what frequency do you want to use? The best way to communicate through the universe is to choose a frequency that's not easily scattered or distracted or absorbed by other stuff. And so things in the radio spectrum are actually a great way to communicate.

Is there such a thing as a radio laser? Can you shoot like a radio beam? Actually, yeah, there are people working on building semiconductors capable of generating radio frequency laser beams. So that would be super cool. That's one way to communicate with aliens is to send them a message basically using electromagnetic radiation, which means, you know, light or ultraviolet or infrared or radio somewhere on the

spectrum, pick something that is sort of quiet in the universe. But, you know, if we get a message from aliens, then we should respond basically in the same way that they wrote to us, right? If you get an email, you don't then send somebody a text. Why not? That's totally inappropriate, man. If you get a text, you write back with text. You get a phone call.

You don't write somebody a letter in response, right? So if somebody sends us a message via EM waves, you know, radio message, then we should respond in the same frequency. Right. But I guess the problem might be that maybe we got it in one way, but we don't have anything powerful enough to send it the same way back. Yeah, well, I guess that would make a pretty good case for funding, right? Like, hey, look, we got this message.

Although, you know, I'm not sure. it's such a great idea to respond to aliens. You know, we don't know these folks at all. It's like, do you pick up the phone when you get a number you don't recognize? Not all the time. Depends how bored I am, and how lonely I am in this pandemic.

I mean, imagine that we're out there in a universe and we've just become technologically savvy enough to get these messages. We're probably the youngest civilization out there because we've just burst on the scene. And so we'd be a pretty easy mark, you know. All right, well, so beaming with some sort of radio laser would be our main option. Do we have any other options to send the message out?

Well, basically, it's just all kinds of radiation. And the kinds of radiation that can transmit through space are either photons or other kinds of particles. So we could imagine, for example, shooting a beam of particles at an alien star and use that as a way to send messages, you know, like Morse code via neutrinos, for example. I wonder if the problem would be like if we shoot a laser at an alien civilization, would they interpret that as an act of war or something, you know? What if they don't get the message? What if it just goes over their head and they're like, they're shooting out us?

Well, I would encourage us to not use, for example, Morse code in nuclear explosions. But I think that a laser beam would not be interpreted as an act of war. I mean, by the time it gets to them, it's going to be so faint, they would have even trouble picking it up. So if they interpret that as an act of war, then they were just looking to start something. I see. They were trigger-happy. In which case, maybe we shouldn't be sending them. Exactly. Exactly. All right. So it sounds like the answer is we have the technology to write to any alien civilization.

And we have done it, in fact. In the 70s, there was a really weird message that we saw come from space. It's called the wow signal because nobody understood it. And at the time that we saw this message come in, some astronomer wrote, wow on the transcript of it as it printed out from the old school printer. And we got this and it came from space and we don't understand it. We don't know. Was it aliens? Was it just some weird new kind of star? Nobody's ever understood it because it's never been repeated. It was just a one-time event. But we drafted a response and sent it out back in the direction of the signal, hoping maybe someday somebody would read it. Wow. What are we saying in this message? What's up?

We said new phone, who did? No, what we did is we communicated something about where we live and how our life works. We showed them our number system. We described the basics of our chemistry. There's a little illustration of the shape of the human body and then sort of directions to the solar system. Wow. Everything a alien species would need to come and conquer us, basically. Yes. All of our passwords.

Our biggest weaknesses. Exactly. Our save words. Exactly. Our elementary school teacher, all that stuff. Yeah, it was sort of a naive message, but it's sort of like hopeful. We hope that somebody reading it would understand it. and in the spirit of exploration of the universe and physics and whatever, come and send us a message back and tell us something about their civilization.

All right, so we sent that using the Arecibo antenna, and do we think it made it? Or do you think it's too weak by the time it gets there? It might be too weak, but we don't know what their technology is, but it won't get there for quite a while. We don't know who's out there maybe receiving that message, but the message came from something called M13, a globular cluster that's about 25,000 light years away. So it's going to take a while before it gets there if that's where their original message came from. All right. Well, it sounds like we have options for sending messages, neutrinos, or a radio telescope, or maybe these radio lasers.

But you were telling me that there is one way right now, if you want to broadcast a message out into space, there is a way to do it. It turns out that if you use Craigslist, there's an option on Craigslist to broadcast your message out into the solar system. No, what? Seriously. The CEO of Craigslist, this guy Jim Buckmaster, bought a bunch of time on the Deep Space Communication Network, this place in Florida that can broadcast into space. So they are picking 10,000 ads to broadcast into space. So if you're having a garage sale and you think, you know, maybe Ignacio from Jupiter should come by and check out what you're selling, then, hey, click the button and Craigslist will advertise in space. Wow. That's crazy. So not only are we inviting people. to come attack us reminding them to come radar garages too. I'm like, I don't

want my junk to just reappear somewhere else in the neighborhood. I want it off planet. Well, we do have a lot of junk and it would be good if an alien came and took away all of our unused and outdated toys. Hey, one species junk is another species gold, right? Yeah, maybe they love

all televisions and satellites. All right. Well, thank you, Ignacio from Jupiter for that question. And now let's get into our last question about zombies. But first, let's take a quick break. Ah, come on. Why is this taking so long? This thing is ancient. Still using yesterday's tech, upgrade to the ThinkPad X1 Carbon, Ultra Light, Ultra Powerful, and built for serious productivity with Intel Core Ultra processors, blazing speed, and AI-powered performance. It keeps

up with your business, not the other way around. Whoa, this thing moves. Stop hitting Sneak, news on new tech. Win the tech search at Lenovo.com. Unlock AI experiences with the Thinkpad X-1 carbon powered by Intel Core Ultra processors so you can work, create, and boost productivity all on one device. December 29th, 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 terminal.

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

podcasts. My boyfriend's professor is way too friendly and now I'm seriously suspicious. Wait a minute, Sam. Maybe her boyfriend's just looking for extra credit. Well, Dakota, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend has been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now, he's insisting we get to know each other, but I just want her gone. Now, hold up.

Isn't that against school policy? That sounds totally inappropriate. Well, according to this person, this is her boyfriend's former professor, and they're the same age. And it's even more likely that they're cheating. He insists there's nothing between them. I mean, do you believe him? Well, he's certainly trying to get this person to believe him, because he now wants them both to meet.

So, do we find out if this person's boyfriend really cheated with his professor or not? To hear the explosive finale, listen to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. All right, we're answering listener questions. And our last question here is sort of debatable whether it's a physics question at all. Maybe. I don't know. we have a question from Lucas from Finland

Hello Daniel and Jorge Greetings from Finland This is Lucas I have a question Which would you more likely survive using physics A nuclear winter or a zombie apocalypse Wow

Yeah I guess the question is In an apocalypse What are physicists useful for Besides food maybe Like if you had a physicist In your little survival group Are they an acid Or are they a liability?

When you say food, you mean to cook the food, right, as a chef, right? Not as a source of sustenance. That's what I'm assuming you're talking about here. You know, in the apocalypse, you know, you got to be flexible when you're thinking. You really learn who's your friend when the apocalypse comes and who's your dinner. I've really learned, yeah, from shows like The Walking Dead. Maybe I should watch some of those shows. Yeah, you want to be prepared.

This is a fun question because I often put questions on the podcast that stumped that I'm like, hmm, I don't know the answer to that right away. I got to do some reading. And this one definitely stumped me. Were you a little offended that they would, someone would question your usefulness in a post-apocalyptic scenario? No, I'm amazed that they think that physics could be useful in the apocalypse. I've often thought of myself as definitely a luxury of a society.

I'm not a blacksmith. And when the end times come, I don't have that many useful skills. Like, nobody needs calculations done or the rates of particle collisions when you're scrambling to escape the zombies. I definitely see myself as something supported only by a wealthy society. Zombie food is what you're saying. Well, I'm an engineer, a mechanical engineer, and actually this question kind of gives me anxiety, you know?

Like, what if it's the apocalypse and someone's like, quick, you're a mechanical engineer, make us a water filtration system with a power source and be like, I could draw you one. I could simulate it using MedLab. I could send the order out to a machine shop. Yeah, it'd be kind of difficult. you something about how far we've come from all being like self-sustaining little societies, you know, that can live off the land and do everything for themselves. We're so far developed as the society. We're so specialized that if society fell apart, a lot of us would find ourselves

useless. All right. So I guess the question from Lucas is that if you're a physicist or if you knew a lot about physics, which one would you most likely be able to survive? A nuclear winter or a zombie apocalypse. Yeah, exactly. And so a nuclear winter, right? That's a scenario where, where you have a nuclear war and a large fraction of humanity's arsenal of nuclear weapons get exploded and they send into the atmosphere a lot of dust and ash and all sorts of stuff.

And then basically you block out the sun. So you get this layer of cloud which blocks out of the sun from a significant fraction of the planet causing an artificial winter. So it's basically constant winter. Yeah, like a permanent winter. Yeah, like a permanent winter.

And you know, that can be like a runaway effect because plants need sunlight and without plants to grow, then you're not going to get food at the bottom of the food chain, and then us apex predator, us physicists and mechanical engineers, won't have anything to eat. Right. And that's trouble because everything on Earth depends on that solar power, right?

I mean, all the food we eat, all of the weather that kind of creates, you know, rivers and hydroelectric stations, that all depends on the sun. So if the sun is blocked, we're sort of energy less. Yeah, exactly. You are almost literally pulling the cord on the entire ecosystem if you yank out the sun. At the base of it all is solar power, gathered by plants or gathered by rocks or whatever. All of it is in the end, solar energy. And so this is like asking the question, what would happen if the sun went out, right?

So then physicists would be useful because maybe you could make us a new power source. Maybe we could go into overdrive, I guess, with nuclear power or fusion power. Would that be enough to kind of sustain a civilization to grow plants and things like that? It could. It would be a big effort. But, yeah, there are ways to generate power that do not rely. on the sun. Obviously, solar power is out. Even things like wind power, right, are mostly driven by patterns of wind that come from solar heating. So you need something like nuclear power, but of course

nuclear power to scale to support agriculture and have massive grow farms would produce an enormous amount of waste. So really, I think what you would need to do is just accelerate the fusion research and really try to ramp up fusion as a source of power. Because remember, fusion can provide electrical power, basically just using water as a fuel. All right. So then physicists would be kind of useful in a nuclear winter apocalypse. Although, to be fair, you would have to also blame them for the nuclear winter apocalypse because they made the nuclear weapons in the first place. They designed the nuclear weapons. They didn't drop the bombs, right? I see. I just made the thing that killed us. I didn't use the thing that killed us. No, I joke, but that's an important question. And, you know, my parents actually both work at Los Alamos and worked on weapons programs.

and I, on purpose, became the kind of physicist that would be totally useless when it comes to weapons development. Because there are real moral complications there. If you are developing weapons of mass destruction and you know they will be pointed at cities, then yeah, you could be considered complicit if they're ever used. Yeah. All right. So then now let's consider a zombie apocalypse. Let's say that zombies are real. What could a physicist do? Could they engage in dialogue with the zombies or I don't know, shoot lasers? Can you develop a zombie killing laser? They could bore the zombies with calculus lessons or something? Well, that's the mathematicians. You got to use them for something. I don't really know, like, how a physicist would be helpful here.

Perhaps if the biologists figure out what the zombie weakness is, then yeah, the physicist can develop some kind of weapon that could use that weakness, a laser that goes right to the heart of the zombie brain or something. Or maybe we just decide, hey, Earth is toast. It's covered in zombies. It's contaminated. And we need the physicists to ramp up work on development. of terraforming technology for Mars. I see. Go there and then have another apocalypse in Mars. So now we have Martian zombies.

Hold on a second. Who's putting the zombies on the spaceship? It always happens, Daniel. There's always that one person who gets on board and they're like coughing and sweaty and you're like, oh, should we let them in? All right, let them in. And then it all turns out badly.

One scientist who brings some zombie tissue along, you know, just to study. Yes, yes. Scientists agreed. Well, I always wonder in these zombie movies and shows, it's like, it doesn't seem physically possible. I feel like zombies violate the loss of physics. Like, where do they get the energy? That's true.

I mean, it's like they never sleep, right? You know, I certainly can't eat brains for that long every single day. You mean, like, what's power in the zombie? Yeah, what's powering? If they're not eating all the time, you know, they always show zombies like standing around forever. Yeah, where do they get the calories to move their muscles and things like that? Maybe they're solar powered. So maybe what you need in the zombie.

zombie apocalypse is a nuclear winter to block off all the solar power so the zombies fail. Or better, you make the zombies into a power source. Instead of making solar panels, you just have like zombies on a treadmill. You're just like shoveling zombies into the furnace. Like having them power like a hamster wheel or something. Oh, I see. Right. You like dangle a brain in front of them and you just get them to walk forever. Yeah.

Yes. All right. Better start thinking of that, Daniel, just in case. Okay. All right. I'll drop some diagrams this afternoon. I'm just desperate to find a way to be useful in the end time so you don't eat me. Or get eaten.

I got to prove my worth. All right. I think that answers Lucas's question, which is most likely a nuclear winter you would be useful, but you will also be kind of partly to blame. Yeah, I'll take it. But there might be ways for you to redeem yourself in the zombie apocalypse. I'll do my best. That's all I can promise, Lucas.

All right. So those are our three questions. Thanks to everyone for sending in their curiosity and their thoughts. Thanks to everybody for sharing with us your desire to understand the universe and for writing to us with those things that make you wonder. We're here to help you understand and hopefully not eat you in the end times. All right. We hope you enjoyed that. Thanks for joining us. See you next time. Heart Radio, visit the IHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. core ultra processors, blazing speed, and AI power performance.

It keeps up with your business, not the other way around. Whoa, this thing moves. Stop hitting snooze on new tech. Win the tech search at Lenovo.com. Lenovo, Lenovo. Unlock AI experiences with the ThinkPad X1 Carbon, powered by Intel Core Ultra processors so you can work, create, and boost productivity all on one device. December 29th, 1970.

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 on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam. Maybe her boyfriend's just looking for extra credit. Well, Dakota, luckily, it's back to school week on the OK Storytime podcast, so we'll find out soon.

This person writes, my boyfriend's been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now he's insisting we get to know each other, but I just want her gone. Hold up. Isn't that against school policy? That seems inappropriate. Maybe. Find out how it ends by listening to the OK story. Time Podcasts and the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. This is an IHeart podcast.