Daniel and Kelly’s Extraordinary Universe - Listener Questions 9

Episode Date: March 31, 2020

Daniel and Jorge answer questions from listeners, like you! Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

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I was diagnosed with cancer on Friday and cancer free the next Friday. No chemo, no radiation, none of that. On a recent episode of Culture Raises Us podcast, I sat down with Warren Campbell, Grammy-winning producer, pastor, and music executive to talk about the beats, the business, and the legacy behind some of the biggest names in gospel, R&B, and hip-hop. Professionally, I started at Deadwell Records. From Mary Mary to Jennifer Hudson, we get into the soul of the music and the purpose that drives it. Listen to Culture raises us on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Hey, Jorge, maybe you're not aware of it. You recently coined a word that I now use all the time. Oh yeah, banana smoothies?

No, the word that you made up that I really like is the word, engineeringly. That was pretty good word, but how do you use it in a sentence? Let's see. You could say, for example, a warp drive is physically possible, but engineeringly impossible. That just sounds to me like you need better engineers. We definitely need better engineers. And I hope that they're out there in our audience listening today, because we have some engineeringly very challenging projects on the docket. Hi, I'm Horham, a cartoonist, and the creator of PhD comics. Hi, I'm Daniel.

I'm a particle physicist, and I'm happy to put off my problems onto engineers. Even your personal problems? There does seem to be a proliferation of engineers. Back in the day, there was mechanical, electrical. You make it sound like, a pest or... But, you know, now you got software engineers, you got social engineers, you got every kind of engineer. It's crazy. So, yeah, maybe Daniel's personal problem engineers.

As opposed to physicists who, there's only one kind. There are only a few of us. Yeah, that's true. There's like solid state matter, wet matter, dark matter. It's been a while since we invented a new kind of physicist. Yeah, maybe it's time. Maybe it's time. Yeah, Daniel's personal problem physicists. I don't think any of my personal problems can be solved with physics. There are no laws there to be found. But welcome to our podcast, Daniel and Jorge Explain the Universe, a production of I-Hard Radio.

In which we focus on the questions that can be answered and the questions that might one day in the future be answered. Questions about how the world works, about what the universe is like, how it will end, and how it is put together on the smallest scale. Yeah, we love questions and we love questions. for which we know the answers, and we love also questions for which we don't know the answers, because there are still a lot of questions out there in the universe that nobody knows the answer to. And often on this podcast, we take a tour of some of those questions. We show you what's in the mind of scientists at the forefront of knowledge is they try to peel back a layer of reality and expose the universe as it really is. And sometimes we take you on a tour of the minds of our

listeners thinking about what everybody out there is wondering about. Yeah, and we love taking questions from listeners because they really sort of give us an insight into what people are thinking and what their what our podcast is kind of making them think about. That's right. And not just because they give us sort of like a checkpoint so that we understand what listeners are getting and what they're confused about, but sometimes listeners questions really put their finger on something amazing about the universe. When I teach, you know, freshman physics here at you Irvine, it's when they ask a question that it makes me think about a topic in a new way, it makes me explain it in a new way, and then it really makes me understand it. So listener

questions are really a source of insight. Yeah, and let's face it, we have, I think, the best listeners in the universe, Daniel. Oh, of course, we have the best looking listeners. I mean, of all podcasts on Earth, and I would say anywhere else in the universe, I think we have the best listeners. That's right. And we're talking specifically about you. You know who you are. We're talking about you. You right there, listening to us right now. You're the best. You're our favorite listening. You're the best looking.

You smell great today. And you ask awesome questions. I tell my kids that all the time. I'm like, you're my favorite daughter. And she's like, I'm your only daughter. That I know of. Oh, Daniel and Jorge dig into Jorge's sordid past. Hey, you know, if this is going to be Daniel and Jorge starting to tell a novella,

then you're going to have some sort of, you know, other family show up at some point in season seven. My evil twins. Hmm. Wait, maybe you're the evil twin. Since your twin is genetically the same, does that mean their kids are sort of also like your kids? Boy, interesting. I just had a great listener question. Yeah, or does that mean if you can be twins and one of you is evil, does that mean that evil is not genetic?

Or maybe you are evil, but you don't know it. There are no good twins. Is that what you're saying? They should either both be good or both be evil. I'm sure that all the twins listening right now are both good. Well, anyways, we do have the best listeners, and they do ask the best questions that they send us through Twitter or Facebook or Instagram or by email. And if you're out there listening to this podcast and you have a question about the universe, you can also write it to us and we will eventually get to it on the podcast. That's right.

And we answer all of our listener emails pretty promptly. Sometimes people write in asking a good physics question. Sometimes people write in asking sort of off the wall questions. Nobody so far is asking for marriage advice. But here's a question we got last week, which sort of made me chuckle. It's from Gurd Singh. And here's what he had to say. He wrote, if we assume the world is a simulation,

do you think there's only one conscious being and the rest of the world are just biological zombies, or everyone is conscious? I love this question. It's like, am I playing a video game, or are we all playing a video game together? It's like, are you a non-player character? Or is there somebody really in there?

Interesting. Well, it just gets to the bottom of consciousness, right? Like, can a machine be conscious? Can a biological machine be conscious? Yeah, and maybe this guy spends a lot of time on video games wondering if those other players are real or not. But it's a fun question, but not one that I, you know, necessarily have any expertise or ability to answer. So I could pontificate as a physicist, but I think the physicists spend too much time talking about things outside their air. area of expertise. So I'm going to have to punt on that one. Maybe you've noticed that also.

Well, what if you're playing a bit of games where you have to kill zombies, then technically are those, they're zombies, but are those zombies conscious? But they can't because they're zombies. Yeah. Well, you could be committing digital moral crimes. But we love answering listener questions and sometimes we have episodes where we answer them. And so today is one of those episodes. So today on the program, we'll be tackling. listener questions about the universe that's right we'll be touching on exotic matter we'll be building roads that span the earth and we'll take our minds to other galaxies and wondering what life is like out there aliens basically we're i feel like we can't have a listener

questions episode without touching the hitting the alien button are you saying that's because our listeners are fascinated with aliens or are you suspecting that i'm picking the alien questions out of the slush pile. I feel like there's a van diagram there. Listener questions and things Daniel loves to talk about. If you have a question about anything, dear listeners, just put the word alien in it and it will increase their chances that we'll talk about it. That's fair. That's good advice, yeah.

Do you have a question about dark matter? Just wonder if dark matter could be made by aliens and I'm sure we'll consider it. My kids know that already. They're like, hey, dad, can I have 10 bucks? It's for aliens. Yeah, sure. Here you go. All right. So today we have three questions from listeners from all around the world. And so we'll be tackling each of these questions one by one. And so the first question comes from Maria from Canada. And she has a question about exotic matter.

Here's her question. Hi, Daniel and Jorge. My name's Maria, and I'm a listener from Victoria, Canada. And I was wondering, what's exotic matter? How is it different from dark matter or antimatter? And how many different kinds of matter even are there anyways? Thank you so much. Awesome questions.

I feel like she's sort of throwing a little shade at you physicists. I felt that. I felt that shade. Yeah. Like, hey, get this under control. Like, people are ridiculous. Yeah, this matter naming is getting out of control. We have as many kinds as matter as there are like fields of engineering and that's absurd.

We need a new feel for every kind of matter you guys come up with. So it's not our fault. We need exotic physics and exotic physicists. We're just trying to plug the holes that physicists are created. Thank you, by the way, for your tireless work plugging our holes. We do seem to have a lot of kinds of matter in our universe. There's, for example, barionic matter, anti-matter, dark matter, exotic matter, super symmetric matter. Yeah, the list goes on.

And this is a totally great question. And it's a fair question also because this term is used in lots of different ways. In a very general way, people use the phrase exotic matter to mean literally just that, like matter that seemed kind of weird, like exotic. something different from the everyday, you know, the everyday matter is made of quarks and electrons. And so from that definition, exotic matter could be like dark matter, you know, or other weird stuff that's out there. Oh, boy. Now you're just making it worse, Daniel. Now you're like overlapping all these matter designations. We're not great of that in particle physics. You know, we're like, after matter could just be any matter that is against something. Yeah, it could be. So it's a different opinion. It's a very vague term. And it could even be weird.

forms of familiar matter. Like, if you take atoms and you cool them down and make weird quantum states like Bose-Einstein condensates, some people would call that exotic matter. Or if you make superfluids, you could call that exotic matter. Well, let's take a step back here. You're saying that the word exotic matter is not well defined in physics. Yeah, if you just Google, what is exotic matter, for example? You will see articles, physicists discover exotic matter, but then it turns out it's

actually about superfluids or physicists use exotic matter to communicate quantum mechanically. And then it turns out it's just Bose Einstein condensates. So you're saying just like in our culture, the word exotic is sort of outdated and inappropriate. Yeah, it's a little bit. It's been a bit abused. But there is also sort of a narrower version of exotic matter that has a very specific, fascinating meeting in particle physics that I think we could dig into. Oh, I see. All right. So in general, It can just mean any kind of non-normal matter. Weird, spooky Halloween matter.

In the loose sort of definition of it, yeah, spooky Halloween matter or, you know, matter from the Orient. Is that racist? Were you just being racist right there? It's Western-centric. But, no, you're saying in general sense it just means weird matter. But there's also sort of maybe a hardcore group of physicists who are, like, like, hey, this means something very specific. Yeah, they rock out to heavy metal and they talk about this kind of matter. They are hardcore.

And that's matter with negative mass. So in particle physics, we talk about exotic particles or exotic matter. And what we mean are particles that have negative mass. Like, you know, that mass is something we attach to particles and I have mass and you have mass. And a fascinating thing about mass is that it seems to always be positive. So we've invented this idea. maybe there are particles out there with the other kind of mass, some negative kind of mass. Right. Because mass is just kind of a label, right? It's not actually like stuff. It's just kind of

like an electric charge can be positive or negative. Yeah, we don't really understand it. And if you zoom down to an individual particle, particles have no volume. They're just points in space with labels, right? Like electric charge, as you said. And mass is another property. And mass is a property that these particles get from interaction with the Higgs field. But the fascinating thing about mass is that it always seems to be positive, right? We measure the mass of all these particles, and we see that they have positive mass. And that has fascinating consequences. Because the Higgs field always gives these particles positive mass, or like the interaction is always positive?

I guess anyone had a bad experience with the Higgs field, I guess. It only has five-star reviews on Yelp. So, yeah, the Higgs field widely loved. Would recommend, yes, Higgs field, good. But do you know what I mean? Like if something has negative mass, does that mean that when it interacts with the Higgs field, it gets the negative mass?

Or what does that mean? Well, if a particle had negative mass, we don't know how it would get that mass. One way to get mass is to interact with the Higgs field. We think there might be other ways for particles to get mass too, but we've never seen one like that. So there could be various ways for particles to get mass. It doesn't just have to be the Higgs field.

The Higgs field just kind of determines how it moves in the universe, right? But you can still sort of have mass independent of the Higgs field. Yes, you can get mass without getting it from the Hicks field. We haven't ever done that. Like, we don't know neutrinos.

Do they get mass from the Higgs field or not? Do they get mass in this other weird way and we can dive into that and a whole other podcast? But I think the important concept to remember is what you just said is that it changes how you move through the universe. Often when we talk about mass,

we really mean two different things. One is inertia. Like you give something a push. It takes a push. to move something, to change something's momentum, to get it started, takes a push. We call that inertia. Really, that's mass, right? And that comes from the formula F equals MA.

Force is mass times acceleration. To accelerate something, you have to apply a force. And the mass is the relationship between those two. So that's mass concept number one, is inertial mass. It's like how hard it is to push? Yeah. How hard is it to push to get going? And also, how hard is it to slow it down?

Like a semi-truck has a huge amount of mass. takes a huge force to slow it down. Can something have negative inertial mass? Is that possible? Where you push it and it goes faster? You know, like you push it and it actually pulls you or something. I don't even know what that would mean. That's what would happen.

If you gave it a push to the left and it had negative inertial mass, it would move to the right. It would push you back. Yeah. So the force would be the opposite direction of the acceleration. So the weird thing about negative mass is like, it seems weird. It's totally counterintuitive. but mathematically it kind of hangs together. Like we don't have a reason to believe it doesn't exist.

You could fit it into all of our equations. We just never seen an example of it. That kind of weird example could happen where you like push it one way with a force field or something, but it goes the other way. Yeah, you could do that. In theory, it's possible. We've never seen it,

but you can work out all the equations of motion and it works. So you push into the left and it moves to the right. But that's only one way of thinking about mass is a whole second concept of mass, which is mass in gravity. Like two objects that have mass feel gravity and attract each other. So if something has negative mass, it could maybe repel another thing with mass?

Yeah, the fascinating thing about positive mass and gravity is that gravity is one of the only forces that so far seems to be just attractive, right? You get pulled in by the sun, you get pulled in by the moon. There's no way that you get pushed, by gravity. Whereas like electromagnetism, there's a positive and a negative. If you have the same charges, you get repelled. And gravity, it is only positive and it seems to only be attractive.

So if you add negative mass, then yeah, you could get repulsive gravity. Or I guess maybe in like the Einstein space bending picture, it would sort of bend space the other way. Yeah. Instead of having like a dent down into space, it would be like a like an explosion of space. a little bit. So things like slide away from you. Like a zip in space, like a, like a bump. A space zit. Like a space zit.

Don't pop that zit. Oh my God. That's like a gravity bomb. Yeah. You have a negative experience. Don't do it. It's weird though because this is a little counterintuitive. You know that positive mass, of course, attracts other positive mass.

It would also attract negative mass. And negative mass would repel negative mass and also positive masses. Wait, what? Yeah. It wouldn't be like electrical charges. It's not like electrical charges because, oh, you just said that we don't think of gravity as a force. We think of it as a bending of space. So positive mass makes like a dent in space, like a hole in space for things to fall into, regardless of their mass.

And negative masses make space zits. That was actually Einstein's term. And... Yeah, zits. I think he called them zits. Zits der spation. Yeah. And no, that's a joke.

But negative mass make these, it would make, he's like, you know, all right, I'm going to say zits in space, because we define everything, that repel everything, positive and negative. Yeah, regardless of the mass of the other thing, right? So positive masses attract other positive or negative masses, and negative masses repel negative or positive masses. It's like the opposite of a black hole. Yeah, and it's weirdly sort of asymmetric, right?

You like to think about the forces as being symmetric, so like it depends on like the product of the charges or something, but it wouldn't be. And that means if you have like a positive mass and a negative mass next to each other, then the positive mass is pulling on the negative mass, but the negative mass is pushing on the positive mass. What would happen? They would actually just like lead to this runaway motion because the positive mass is pulling on the negative.

The negative is trying to repel the positive. Attraction of the negative actually pushes the other direction, right? Because of negative inertial mass. So they would use a skip out of town. They would skip out of town. What? For real? Well, we don't know.

Like, this is the idea. So we've never seen this stuff. It's just sort of an idea. And it would be pretty helpful because if we did have exotic mass, we could use it to, for example, stabilize wormholes and travel through the galaxy and this kind of stuff. But we've never seen any of it. It's just sort of like. Yeah, I guess that's the next question, which is, is this even real? Or is it just theoretical?

It's just theoretical. But it's important. to recognize these sort of theoretical opportunities. Some of these other kinds of matter we talked about, like anti-matter, they started out as theoretical and somebody noticed, hey, the equations also work if you flip all these signs and make this other weird kind of matter. So maybe that's real. And it turns out it's true.

So seeing these mathematical symmetries are often guides to actually binding stuff in reality. And that will tell us more about the universe. Yeah. But the universe is asymmetric sometimes. Like, there's a lot of matter out there. very, very little anti-matter, if any. We don't know why that is.

So there's a lot of positive matter out there, none or maybe very little negative matter. Why is that, right? Fascinating questions. Yeah, maybe not all the matter matters. All matter matters, man. But all right, so it seems like to answer Marius' question, exotic matter can mean a lot of things, but it's generally used just to mean not normal matter, meaning the matter you and I are made out of. If it's kind of weird or unusual, some physicists call that exotic matter.

But there's also sort of the hardcore definition, which is that it means matter with negative mass. Which is theoretically fascinating, totally possible, but never been seen. But you know, she also asked another question, which is how many different kinds of matter are there anyway? And that's such a good question. It's a question that I have also because we see these symmetries in nature. We see like, oh, there's matter and antimatter. There's maybe positive matter and negative mass matter. And there's other symmetries like we talked about super symmetry on this program.

Like maybe every spin half particle has a spin one particle that bounces it and vice versa. And all these symmetries tell us something deep about the universe, about the way it's put together, about the what it reflects at its deepest level. And we don't know what the answers are, but every time we find a symmetry, I feel like it's revealed something about the universe that we've been desperate to find out. Every time you find a new kind of matter or think up a new kind of matter, it kind of pushes your definition of what can exist. Yeah, and these symmetries are really important. We talked also on this program about how the universe is left-handed. It prefers particles that spin in a certain way relative to their motion. We don't know why that is.

And so people suggested maybe there's another kind of matter called mirror matter, where it's the opposite. And every time you have these symmetries, you have to ask, why is it this way and not the other way? Why is the universe sort of bifurcated into two options? What does that mean about the nature of the universe? At some higher temperature earlier in the universe, was this all unified into something beautiful and crystalline and then it's just sort of cracked and fell apart? We don't know.

I think my favorite kind of matter are the matters of the heart, Danu. All right, well, we hope that answered your question, Maria. Thanks so much for asking the question. And so let's get into our two other questions for the episode. And these are about the biggest road ever built. and also about intergalactic aliens. 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., 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 be. 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. Well, 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. 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. I'm Dr. Joy Harden Bradford. And in session 421 of therapy for black girls, I sit down with Dr. Afea 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? 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 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 hairstylist play in our community, the pressure to always look put together, and how breaking up with perfection can actually 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 iHeartRadio app, Apple Podcasts, or wherever you get your podcast.

All right, we're answering listener questions today. And so our next question comes from Rahul from India. And so he has a question about an interesting idea for an infinite road. Here is Rahul. So imagine you start building a bridge or a highway above the. surface and it goes all the way around the earth and meets each other. Now you have this one long continuous bridge. So obviously those bridges have pillars.

And now you decide to bomb all the pillars that supports the bridge at the same exact time. So what would happen to the bridge? Will it stay floating above the surface or will it fall down? And at which direction? Or will it hula hoop the earth? The second condition is what would happen if the Earth was a perfect sphere. So I think this one might be more in your alley because it's a quote of a question about, you know, whether something is engineeringly possible.

You're like, this one's not interesting to me, Jorge. You can take this one. It's just about building a road. Now, if aliens built a road, that's interesting. Well, let's just pause that. Let's just imagine we're in an alien planet. But the question is kind of interesting, and I have to say it took me a sense. second to sort of get it. So he's asking, what if you build a road all around the earth,

like a suspended road, right? And it goes, you know, from, it starts here in California, goes through the U.S., crosses the Atlantic, goes over Europe, Asia, and then it comes back around and connects in a perfect circle to where we started the road. And then, so you build this road, it rings the earth, and then you take out all the columns, the pillars that support it. with bombs, right? I like that detail. Yeah, that would probably be the funnest part, actually. But you remove the pillars all of a sudden,

does the bridge stay up, floating? Or does it all fall down? Yeah, and it's a fun question because you imagine, oh, you build a road, you support it with pillars, you knock the pillars down, the road falls down. But in this scenario, you've made it go all the way around the earth. And so then he's wondering, like,

is it possible for a road to float in the air? Would it be in orbit, Daniel, or would it just be sort of like a hula hoop held around your waist? Let's answer this from a physics point of view, which means we have to, like, simplify things a little bit, and then we'll make it a bit more practical. So first, let's start with the... Let's hear answer A from Daniel.

First is a perfectly spherical Earth, like very smooth, no deformities, et cetera. And so the road is like 100 meters or 100 feet or whatever above the surface all the way around the Earth. Now, in that scenario, you knock out all the pillars, Think about the gravitational force on this thing. It's going to be balanced. Like the Earth is pulling on one part over California, but it's also pulling on another part over China.

And those two things are going to balance. And if the road really goes all the way around the Earth, then for every part of the road, there's a counterpart that's balancing its force. And so it should just hover there. So that's your answer, that it would stay up floating? If it's a perfectly spherical Earth and a perfectly circular road, it would stay up there floating. You don't believe it?

Well, so I have an engineering answer, but I'll just keep going with your physics answer here for a bit. The other way to think about it is just by symmetry. Like if it goes in one direction, which direction could it go? You'd have to choose a direction. And if the Earth is a perfect sphere, then there's no preferred direction. So it can't go in any direction. So it would keep rotating with the Earth? It would keep rotating with the Earth.

Yes, but it wouldn't have to rotate either. What if something knocks it off of alignment a little bit? like what if the wind blows in it in one side of the earth and not the other and now it's a little bit closer to one side than it is to the other side of the earth yeah so we're leaving the world of perfect physics scenario and we're adding things like wind and disturbances and you're right that it would be very unstable because if it moves like one foot closer to the earth here then it's a foot further from the earth on the other side so now the force is stronger on this side and weaker on the other side So it's unstable. As soon as it deviates from the sort of like perfect spot it's in, it's going to come crashing down. Oh, I see. It moves a little bit. And so now, let's say it moves down here in California.

So it's closer to the earth. And now the center of mass of the whole thing is not aligned with the center of the earth. Wouldn't that just make it come back to the center of the earth, realign? I'm pretty sure it's unstable. And the reason is that the mass of the earth is distributed as a function. of the radius. So you can't just think of the motion of the center of mass of two objects. These are two large distributed objects. And as one side of it gets closer to the earth, the other side gets further, then you're going to get a relative force difference on the whole thing

that's going to push it further from stability instead of closer to stability. But I haven't done the simulations. So maybe we should actually build this thing and find out. To answer Rahul's question, let's spend a trillion dollars. Why not? Are you got something better to spend it on? Sounds like a plan. Let's crowdsource it. Everybody send in 10 bucks to build Rahul's Road. Okay.

So you're saying that from a physics point of view, it is possible for this thing to exist if nothing touches it or knocks it out of balance or moves it at all a little bit. It would just float above the earth, circling the earth like a ring, like a Hulu Hoop. Yeah. And I think the key there is that

as soon as you build something that's the size of the earth, you can no longer apply the rule. of your intuition that you apply to things that are the size of you or your house or even your city. Things can float up in space in orbit. That seems weird. Why don't they fall, right? That's because

they're large. They're moving at cosmological astronomical speeds. And so here it's an object really of astronomical scale. And so it wouldn't necessarily fall into the Earth. It's like an object that spans both sides of the Earth, of the center of mass of something big.

Yeah. And this actually appears in a novel, I mean, not as a road, but in Neil Stevenson's recent novel Seven Eaves, Earth becomes uninhabitable because of XYZ plot devices that won't spoil, and humanity builds a huge ring around the Earth, like a mechanical ring and they actually live on it. Well, I think that's the physics science. I guess, you know, as an engineer, when I saw this question, I didn't, you know, sit down and make the calculations, but I think right away my thought was that, no, it would fall apart right away. You mean because you couldn't build something that big that was rigid? I think I was thinking, you know, the limitations of whatever you build it

out of, you know, would collapse. Like nothing, I don't think anything that we know of can withstand those kinds of forces. And so it would just crack and fall apart. You mean forces from like an entire 24,000 mile road segment pulling on the individual piece? Yeah, you know, like there's a reason you can't just make a suspended bridge without any columns. Like if this was possible, then you could just build a bridge. And if you make it the curvature of the earth, earth, then it would just stay up, wouldn't it? If you just hold both ends? Yeah, well, not an expert on mechanical engineering, so I'll take your word for it.

I think you're right. And I think there are other practical issues also, you know, like you have to have it at the same height above the earth all the way around. But of course, there isn't a constant height above the earth. You know, you have to clear mountains and all sorts of stuff. And so that would throw the whole thing off balance. All right. Well, I think that's maybe Rahul's answer, which is that it's sort of,

would be possible and it would hang there floating above the earth if nothing touched it or nothing perturbed it at all. You had no weather. And if it was made from like this incredible material that would withstand these incredible forces

which I'm not sure we have that. We definitely don't because if we did we could build a space elevator which is sort of weird in similar ways. Something hanging out there in space you could actually climb up. And one of the limitations there is just building a rope that could even hang that that's that that is that long right yeah something that can that

wouldn't just crack under under all those uh forces it's under but uh definitely cool and fun to think about thanks raoul for sending in your crazy question all right are we ready to talk about aliens because i'm ready you're always ready daniel all right let's talk about aliens but first let's take a quick break Ninth, 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 2, 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. Well, 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. I'm Dr. Joy Harden Bradford. And in session 421 of Therapy for Black Girls, I sit down with Dr. Othia 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? 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 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. We 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. 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. All right, our last question comes from Nanu from Argentina, and she has a question about life from other galaxies. So here is Nanu. Why when we talk about life in other planets, do we always talk about it in terms of our own galaxy? Do we not consider life in other galaxies because they are so far away it would be inconsequential for us?

I still have a hard time figuring out distances, so I am wondering, could it be possible for a millions of years old alien race to take up intergalactic travel and arrive to our own? All right, Daniel. Did you just get really excited when you opened up your inbox and saw this question? Did your heart start racing a little bit? Did you get excited?

I got excited and then I got a little offended, you know. What do you mean? Well, she said, how can we never think about intergalactic aliens? And I was like, what are you talking about? I think about intercollecting aliens all the time. It's one of my favorite things to think about. I think maybe she thinks she's talking culturally, the culture in general. Or responsible scientists rarely talk about intergal.

galactic aliens. Yeah, I guess, and is that true? I guess do most people think of aliens is coming from this galaxy? I think so. Even in science fiction, often the drama takes place across the galaxy or in one galaxy. And there's a reason for that. The reason is that galaxies are huge, right? They're big enough to span enormous space operas and lots of different empires and thousands and billions of stars. Plus, they're super far apart. So it's like each galaxy is an island and all the other galaxies are so far away, they're almost irrelevant. It's almost impossible to think about communications between galaxies or to travel between galaxies. Yeah, or travel between galaxies. You know, not to mention like intergalactic marriages,

you know, all the problems that that would raise. Long distance. I know. You got the kids over there for one weekend. I got the kids over here for another weekend. It's a nightmare. But let's give them a sense of scale, right? Like the Milky Way is like 100,000 light years across. That's already like, it's incredible. It's incredible. incredibly big. Even if you were going at the speed of light, it would take you 100,000 years to go from one end to the other. Yeah, exactly. So it's hard to even imagine having like an empire that spans a galaxy because you send people a message like, all right, let's raise taxes 1% and it doesn't get there for 100,000 years. It's impossible to coordinate. That's why people

invent, you know, faster than light travel and faster than like communication just to get stuff done within one galaxy. In novels and movies. and hopefully one day in reality, but yes, mostly novels and movies, yes. You seem to mention it like, we already have that. People are working on it. People are working on it. Hey, we were talking about wormholes a minute ago, right? So that's the idea.

But you were saying, so a galaxy, a typical galaxy is 100,000 light years wide, but the distance between galaxies is, you know, many times that over by several orders of magnitude. Yeah, like the nearest galaxy is Andromeda, and that's, That's two and a half million light years away, right? Two and a half million years. Light years. It's 25 times as wise the whole galaxy. It's like if you have a house and the neighbor's house is like, you know,

it blocks and blocks away from you. So we're basically living in the middle of the woods. So maybe that would explain why we don't see it much in movies and novels because, you know, the plot logistics would just be too much. but and also I think maybe it's also kind of recent you know this idea that there are other galaxies is kind of new isn't it in the last 50 to 60 years or something like that before that we thought like our galaxy was it

yeah it's about a hundred years old it originates with Hubble he's the guy who measured how far away these little smudges in the sky where he thought maybe they were nebula they were gas clouds he measured their distance and found that they were crazy far away they were further away than all the other stars and that's what made him realize oh these are other galaxies and the whole universe just became much bigger in his mind. So you're right, but we've had about a hundred years to get used to this idea that the

universe is incredibly vast, but we haven't sort of mentally populated it with aliens. And I think you're right. One reason is that they're just so far away, it seems almost irrelevant. We may never hear from them or see them or visit them. We may never, that's true. But we can still think about them. And I think a really fun angle on this question is wondering, like, is life, if more likely to occur in those galaxies or in ours.

Is our galaxy unusual? The same way we think about is our solar system unusual in our galaxy? We can ask, is our galaxy unusual in the universe? For us to have developed here or evolved here, like maybe most, like maybe all other galaxies are too dangerous for life to evolve in. Yeah, maybe we're in a special place, right? Or maybe we're in a totally vanilla galaxy. And so we do know something about that, right?

We know that the Milky Way is a spiral galaxy, and spiral galaxies are one of the most common kinds of galaxies. We look out in the sky, we see lots and lots of spiral galaxies. So there doesn't seem to be anything particularly weird about our galaxy. It's not the smallest, it's not the biggest, it's not the brightest or the darkest. It has dark matter like other galaxies. So it's sort of a generic galaxy. I mean, I love it. It's beautiful.

I don't mean generic in a bad way. He's called it generic in a totally vanilla way. By which I mean that there's possibilities for life in other galaxies the same way there is here. By which you mean, it's the example by which all other galaxies are aspiring to, right? I mean, it's the role model galaxy. It's the exemplary galaxy, precisely. And it means that if there's life here, there's no reason to believe there couldn't also be life in those other galaxies. But could we ever find it? Could we ever communicate with them? Could we ever shake hands and spend time at a chalkboard, you know, revealing secrets of the universe together?

Boy, that's hard to imagine. But maybe not that hard to imagine. I mean, if we can imagine us contacting aliens within this galaxy, you know, them crossing the large amount of space between us and them, you know, it's not that hard to imagine doing that 20 times over to do it between galaxies, right? You won't drive an hour down here to Irvine to hang out with me, but you'll drive 20 hours somewhere, is that you're saying? I'm saying if I really wanted to see you,

The difference between one hour and 25 hours wouldn't be the... If I was an alien, then you would drive 25 hours to come talk to me. If it took 25 seconds to go see you, Daniel, I don't know if I still would. Oh, oh, oh, no, it's a good point. You're right that if we're going to explore our galaxy, we either need to do it very, very slowly over billions of years or figure out a way to overcome these distances, which are already an obstacle in our galaxy.

And once we do that, then maybe we can also... hop to nearby galaxies. Yeah, right? Like if you invent or you figure out how to do wormholes or warp drives or suspended animation, what's the difference between a year and 25 years to go to another galaxy? That's true. And, you know, while we're tossing our ridiculous ideas, remember our recent episode about stellar engines. We could drive the sun out of the Milky Way and go visit another galaxy. We could like move galaxies and go hang out in Indromeda. All right. Well, to answer Nanu's question, And I guess the answer is we don't know. We don't know why we don't think about aliens for another galaxy, but maybe we should

because it's not that far off from aliens in our own galaxy. Yeah. And it's true, Nanu, that in millions of years, alien races could use intergalactic travel to come here and tell us all about what it's like to live in another galaxy. And they'd be like, whoa, this is a better galaxy. You're right. It has better reviews on Yelp. So thank you to everybody for writing in those amazing,

questions, and thank you to everybody else who's writing in questions on a daily basis, we'll get to your questions as well. And if you have a question, feel free to send it to us. Daniel likes to sit around and answer questions. I like to be distracted from my real job by thinking about your crazy ideas about physics. So thanks for listening. We hope you enjoyed that. See you next time. After listening to all these explanations, please drop us a line we'd love to hear from you. You can find us at Facebook, Twitter, and Instagram at Daniel and Jorge, that's one word, or email us at Feedback at Danielandhorpe.com.

Thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of IHeartRadio. For more podcasts from IHeartRadio, visit the IHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. It's important that we just reassure people that they're not alone, and there is help out there. The Good Stuff podcast, Season 2, takes a deep look into One Tribe Foundation, a non-profit fighting suicide in the veteran community. September is National Suicide Prevention Month, so join host Jacob and Ashley Schick as they bring you to the front lines of One Tribe's mission. One Tribe, save my life twice. Welcome to Season 2 of the GoodSyside.

stuff. Listen to the Good Stuff podcast on the Iheart radio app, Apple Podcasts, or wherever you get your podcast. Do we really need another podcast with a condescending finance brof trying to tell us how to spend our own money? No thank you. Instead, check out Brown Ambition. Each week, I, your host, Mandy Money, gives you real talk, real advice with a heavy dose of I feel uses, like on Fridays when I take your questions for the BAQA. Whether you're trying to invest for your future, navigate a toxic workplace. I got you. Listen to Brown Ambition on the IHeart Radio app, Apple Podcast, or wherever you get your podcast. Culture eats strategy for breakfast, right? On a recent episode of Culture Raises Us, I was joined by Valicia Butterfield, media founder, political strategist, and tech powerhouse

for a powerful conversation on storytelling, impact, and the intersections of culture and leadership. I am a free black woman. From the Obama White House to Google to the Grammys, Valicia's Journey is a masterclass in shifting culture and using your voice to spark change. Listen to Culture raises us on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. This is an IHeart podcast.