Where Does The Earth's Magnetic Field Come From?

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Speaker 1: Orry. Did you know that the Earth has a mysterious invisible field protecting it? What do you mean, like a like a force field? Yeah, basically it protects us from cognate rays and space weather. And also it's a crazy radiation. That's amazing. That's like a that's like Star Wars, right, like all the spaceships have a force field that protects it. How do we have this field? It's pretty amazing. It's the Earth's magnetic field. Actually, what is that? Suddenly less exciting to use its magnetic than a force field. It's not very attractive unfortunately. Um no, I mean what do you mean? It's it's just like the like the North pole and the South pole. Is that what you mean? Yeah, the earths magnetic field serves a really important purpose. But what a lot of people don't know about it is that it's changing. It might not be around forever. Oh what hm? I am Ran and I'm Daniel, and welcome to our podcast. Daniel and Jorge explained the universe, in which we take everything about the universe and try to make sure it makes sense to you. Things in the sky and things under our feet. That's right, all the positive things, all the negative things in the universe, all the north things and all the South things. That's right. Today on the program, we're going to ask the question what's the source of the Earth's magnetic field? Like why is the Earth a huge cosmic magnet? Right? Like that's crazy to think about, like that that's basically what we are. We're just the giant flying fridge magnet. That's right, And the Earth is a huge magnet. It's really powerful. Is that this huge, single magnetic field envelops the entire Earth. It protects us from radiation, allows us to navigate, Like where does it come from? Why does it exist? Are we lucky to have one? Does every planet have one? Where does it come from? Can we turn it off? I have so many questions, and it's super important because without the Earth's magnetic field, we would literally be toast, right, Like we would just get burned to a crisp? Is that a technically accurate use of the word literally? Like would you turn into toast? Like? Could I spread butter on you and eating for breakfast? Uh? Dina, depends on what do you like. I'm not sure I'm into toasted Jorge for breakfast. But yeah, without the magnetic field, there would be a huge amount of radiation that just bombards us. As we said before, the magnetic field bends the path of charged particles. It deflects them, so it doesn't like stop them. It's not like a force field where it goes when it gets fizzled out or anything. It just bends them. But if a charged particles moving really fast, then all you need to do is deflect it and it will go somewhere else instead of write into your brain and give you cancer. Right, And it's not just like a little bit of charged particles or it's a lot like the field is doing a lot right now. Yeah, it does a lot of work. Without it, we wouldn't have an atmosphere, right, we would. We wouldn't be able to breathe, we would, Really, the earth wouldn't be the same. Yeah, it does a lot of heavy lifting every day, and most people, most people just ignore it. You know, most people aren't even aware they're aware of everything that's being done for them by the magnetic field. Right. Ever, ever, wonder if it feels resentful, if it's like, man, nobody ever gives me props. I'm doing all this work here. Everybody just takes me for granted, right, it should just turn itself off for a few days just to teach us a lesson. Yeah, yeah, I think people do take it for granted. You know, it's kind of like nobody ever pays attention to to which way is north. You just think that it's always going to point to the same direction. But it's not right exactly. And we've had a magnetic field for billions of years. As far as we know, the Earth's magnetic fields formed pretty soon after the planet came to be. Okay, yeah, that's that's something I didn't know. And in fact, let's let's talk about a couple of things that maybe people don't know about the magnetic field. Some interesting facts about the magnetic field is that it's not perfectly aligned with our rotational access. That's that's pretty surprising to me. Yeah, it's off by about eleven degrees. Right. Yeah. The Earth, it's like it has two north poles. Right, one is the one it spins around. Right, the whole Earth is spinning. Right, Who gives us day and night as the Earth turns towards and away from the Sun. Yeah, we're spinning. The Earth is spinning. And so if you put a line through around where it's spinning, you would get one north pole. But you're saying the magnetic north Pole is not aligned with that one. That's right, it's not exactly aligned with this. So if you were standing on the rotational north pole, the point around which the Earth is spinning, right, and you looked at a compass would point away from that place, it would say, Nope, you're not at the magnetic north Pole. Because the wait, so then where the Santa Claus live? Does he live in the rotational north Pole or the magnetic north Pole or does he have two houses? That's a big secret. I think we should save that for an entire other podcast. So the magnetic north Pole is different from the rotational north Pole. They're different by eleven degrees. And remember it's like three sixty degrees all the way around the circle. Eleven degrees. So it's not a big difference. If you're in the US or in South America or whatever, or in Asia. You can mostly use a compass. It's going to point pretty close to the top of the Earth as we think about it rotationally, but not exactly. Wow, it's a big deal if you're in the north Pole, right, I mean eleven degrees must be like a thousand miles or something. Yeah, as you get closer and closer to the North Pole, becomes a bigger and bigger deal. Right, So that if you're standing on with the line that Earth rotates around, it's going to be kind of a big deal that the North Pole is far from there. But if you're far away from like most people are, most of our listeners are, then it's not really an issue. But I think it raises the interesting question like why aren't they aligned? Where does the magnetic field come from? Right, like a big bar magnet inside the Earth that's got like knocked over and tilted. Is it something totally different? That's what I think. It's it's quite fascinating. Um, so it's three point four billion years old, meaning that before three point four billion years we didn't have a magnetic field. Yeah, that's right. And it's basically because earlier than that, the Earth was just a hot ball of nasty magma and nothing was really organized. So before that you didn't really have all these structures we needed to generate the magnetic field, and so it's just like a yeah, it's just a ball of lava in space, basically a giant level lamp. Exactly a hot drop of rock. We've got from fridge magnet to level lamp. I guess we'll get in more into how that works. Um, But this is this is an interesting semantic point, which is that the north pole, but we call the north pole, is actually the magnetic south pole. Yeah. It's one of these things about definitions, right. It's like when they discovered electricity. You know, they defined positive negative currents, and it turns out that electrons have negative charge. Right, it's just a definitional thing. But when they first figured all this out, they define north as you know, whichever side of the magnet points towards the Earth's north pole. But that actually makes it the south right, because the southern the south pole of a magnet will point towards the north pole of another magnet, right, And so that's just a definitional thing. But it's kind of funny. So if you're holding onto your compass, the magnetic north pole of your compass points of course towards the Earth north pole. That means Earth north pole is magnetically south right, because the north pole of your compass is attracted to it. So we should change the name or change the laws of physics, which one should we do? First? Let's come up with better names, right, like not north and south, but like apples and oranges, or h I lift four blocks apple of here? Is that? Is that a general idea? I always thought it was weird that it was north and south. I mean, I understand where it comes from. It comes from the geographical question where are we in the Earth rotating and stuff? But from a physics point of view, you know, we like to think of these things is like positive and negative. Right. All the other charges we think about, like electric charge and gravitational charge or weak force charge, we all think about those in terms of positive negative numbers. So north and South is sort of archaic. So if I had to redo it all over again, I would just define one of them is positive and one of them is negative. It's like a big magnetic battery. And then we wouldn't be so concerned about the North Pole not being aligned with the rotational North Pole. Yeah, we would probably have a big political question like would you rather have the North pool be positive or negative? Right? Everybody, part of everybody probably wants to be positive. In the southern hemisphere would argue we should be positive your guys are so negative up there here being colonial exactly. That's right, that's right. Okay, So those are some pretty cool facts about the Earth's magnetic field. Um, but now let's talk about what what what's the source of it? How? How how come we have a magnetic field and other planets? Stone and I think a really important clue there is the fact that the magnetic field is not static. It's not just like, here's the magnetic field. It's always been this way, it's always gonna be this way. A big clue that the source of the Earth's magnetic field is something weird and interesting is that the magnetic field is changing. You know that the magnetic field is moving. It's moving quite a bit, and it's also getting weaker, Like the magnetic field was much much stronger when the Romans were in charge of the world than it is today really and even years ago, a couple of thousand years and um, eventually it might even flip, right, it might be that positive becomes negative, north becomes south. And so that's quite interesting, right, and tell is that there's something really interesting going on making that magnetic field. So let's dig into that. Yeah, let's let's talk about that um. But we were wondering how many people out there knew or had this idea that the magnetic field is not something that's given in on Earth. How many people out there knew what's the source of the Earth's magnetic field? Yeah? So I went around and I asked a bunch of unsuspecting undergrads that you see Irvine, and said, what do you think about this question? So before you hear their answers, think to yourself, do you know where the Earth's magnetic field comes from? Could you explain it? If you had to build a planet from scratch, how would you make sure it had a magnetic field? Yeah? Would you put just a bunch of fridge magnets in the middle, like a bunch of fridge magnets. Well, here's what people had to say. Something to do with the core. It's across gravity that atmosphere a little okay, gravity, Um, I assume it's the rotation um of the Earth's core. Is it the core? The core, the Pole's north pole? Softhpore? Al Right, pretty I think there's a pretty good credit to those students at the University of California, Irvine. Um, pretty good, said gravity, it's always gravity. It turns out, actually they're not entirely wrong. Gravity as always plays a role. My favorite answer was the one that said the north pole in this south pole that gives the magnetic field. It's like, cool, cool, good, complete, complete answer without actually revealing any information. Yeah, and not making fun of these people of course, you know, I put them on the spot answer random physics question. I'm I'm just impressed that they were even willing to share their thoughts with me. Yeah, I know it takes it takes some certain amount of bravery to talk to you in public, Daniel, I don't even know how to respond to that one. Um. No. I usually try to avoid talking to myself in public also for that same reason. Yeah, it's not it's frowned upon. Um But No, what I mean is a lot of people answer they need to have something to do with the Earth's core, something about the core and the magma and the crust, something about the something going on inside the Earth itself. Yeah. Yeah, And it's like thinking about the Earth is a big machine, right, which is kind of crazy because you walk along the surface of the Earth and you think of it just as a big rock, right, But underneath there are powerful forces and crazy things happening, and all that is happening in order so that you can have a magnetic field. So it's I'm just glad that people are aware of all the work the Earth is doing for us. Yeah, there's there's stuff happening inside the Earth, right, like it's an active machine. It's an active device. Yeah. Absolutely, it's like a boiling kettle of magma and crazy stuff is happening in there. And if it wasn't, we wouldn't have a magnetic field. So we're glad to have sort of a young hot planet. Yeah, well let's get into it, um, but first let's take a quick break. I'm an engineer, and I have to admit that I don't really understand how magnets work. So I thought, maybe, welcome to the podcast. He came to the right place. This sounds like a great episode. I'll tune in, UM, But let's take a step back maybe, and then talk about the magnets in general. Yeah, magnets are really pretty amazing. They're one of my favorite things because they're like physics that you can see with the naked eye. Right, you can see a fridge magnet um sticking to the wall, you can even get these things to push away from each other without touching. It's like the first sign of a force that you can really play with and identify with. It's it almost looks like magic. Of course it's not because we understand it, but it has something in common with it. Right, it's powerful, it's visceral, it's physical. It's right there in front of you. It's a lot of fun because most things don't act like magnets, right, Like, most things don't stick to the wall. If you put them there, those things don't push against you without any direct line of connection. Right, It's so it's weird. I don't know how many things have you tried. I've thrown a lot of different things at the wall, and a good number of them actually stick. You know, spaghetti sticks to the wall, sticks to the wall, lasagna sticks to the wall, Lots of different kind of foods. Don't you have young kids? You should be aware of how many things do actually stick to the wall. Once again, I'll i'll them, I'll decline your invitation to visit your house just where you know, all rubber clothing. It's no big deal. I mean, just we just hose off after dinner. Um, no, you're right, and not everything is a magnet, right, and so not everything sticks to sticks to things, and so let's let's talk about that a little bit. How do you how does something become a magnet? What makes something a magnet and something else not a magnet? Right? The amazing thing is that it's all about electrons. Okay, like the kind of magnet you're familiar with, you know, a fridge magnet and normal like a piece of metal that has become magnetized that sticks to something. How does that work? Well? The way that it becomes a magnet is because it has bill ends of tiny little magnets inside of it. Each electron has something we call quantum spin, and it's not actually spinning around or doing anything physical. It's a quantum mechanical property we call its spin, and it generates a little magnetic field. So this electron does this weird thing and it generates a very tiny magnets. So every electrons is like a little magnet. So it's not actually spinning. Physicists of just are spinning it as if it was spinning. That's right, it's physics spin. Yeah. We use the word spin because the thing it does, the quantum spin has a lot of similarity with physical spin. Like the mathematics we used to describe physical spin angular momentum. A lot of that mathematics can be copied over and applied directly to quantum spin. And that's what makes this compelling as a as a concept, and we should have a whole episode about what is quantum spin because it's fascinating. But but the point is that each electron itself is like a magnet. It's like a really maney little magnet with a with a field as its own little magnetic field. And in some kinds of materials, the way the electrons are organized in their shells, etcetera. Gives you an overall magnetic field for the atom. Okay, and some of them that they don't just cancel out you get nothing um and some of them you do get little magnets for the atom. And then in some of those atoms they like to organize in a way so all the magnetic fields are aligned. So, for example, in iron and a lot of metals have these properties that you can align all the little magnetic fields of the atoms so they point in the same way. So when you have a piece of magnet like a chunk of metal that sticks to your fridge. The reason it has a magnetic field is because all those tiny little magnetic fields are all going in the same direction, so they add up to kind of a big magnetic field. You have another piece of metal, it's not magnetized, and all they're just sort of scrambled. They're all in different directions. So there are magnetic fields in there, but they're all just sort of canceling each other out. And it's not just metals. I mean you and I and the chair, riman, this wooden chair, theman it's it also has these billions of tiny little magnets. But the problem is they're not all pointing in the same directions, so they all cancel out, and so overall it's not a magnetic thing. Yeah, exactly. You have to be magnetic. You need to have these little magnetic fields, and you have to have a structure where the substance likes to organize in a way so they all point in the same direction. Um, so we're all magnetic. We all have magnetic personalities. You want me to tell you you're a magnetic dude, You're a magnetic dude. That's about um. And that's how something can become a magnet also, right, Like you have a normal piece of metal and it sits next to a magnet for a long time, Right, how does that become a magnet? Well, the first magnet is aligning all the little magnets in the other one. It's pushing them in the same direction, so eventually becomes a magnet itself. But let's um, let's see if we can get into maybe a little bit more so, what does it mean that each electron is like a little magnet? Why? White White said? Why does the electron have a field? You know, like white white and it white, it a pointed field. Well, there's a very close connection between electricity and magnetism, right. In fact, we think of them as one theory electromagnetism, and there's a lot of connections, like anytime you get electricity moving in a circle, that makes a magnetic field, okay, and and the other it works in the other direction to any magnetic field that changes in time will generate electric currents. So we think of these things electricity and magnetism is sort of separate. Turns out they're really closely connected. They're really just two sides of the same coin. And That's why it's not really surprising that the electron, which is like the most basic charged particle we have, could generate electric fields because in the end, it's a charge and it's not physically spinning, but it has quantum spin, and so you can think of it as like having a small quantum magnetic field. It really is a quantum mechanical effect, Like every fridge magnet is a quantum mechanical effect. Wow. So it's just something kind of embedded in the laws of the universe, is that whenever you have something with charge, like an electron, is just sort of automatically, by the laws of physics, associated with a magnetic field. Yeah, charges plus motion gives you magnetic fields. In this case, the motion is the quantum spin, right, And that's how you can make a non permanent magnet, right, Like that's how you make electromagnets exactly. So there's a little electrons, they spin and they make their own little magnetic field. But you can also do something else with them, is that you can move them in a circle, right, make a loop of wire and pass electricity through it, and it generates a magnetic field. Why, well, that's just one of the Maxwell's equations. That's one of the laws of electricity and magneticism that currents moving in a circle will generate a magnetic field, because magnetic fields and currents are very closely connected. As I said before, there's just really two parts of the same thing. This is pervasive quantum field that that fills the universe. Right that let's just up into the electro magnetism at any point and moving charges through it will generate the magnetic field, right. And it's so it's kind of like if you take a bunch of electrons and you get them to go and move in a circle, they all sort of aligne and add up to create all of their little magnetic fields to create a big magnetic field in the center of the circle. No, it's not their personal magnetic fields like the ones that come from their quantum spin. It's the fact that they're moving in a circle generates the magnetic field in the center. So they still have their own little fields from their quantum spin, but it's their motion in a circle. The current moving in a circle will generate a magnetic field as well. But why um? But why the deep question? Man? I think the um there's a technical way to think about that question, which is, look at the equations that describe it. And those equations have symmetry in them. They're called Maxwell's equations. You can google them and look at them, and they show you that electric fields and magnetic fields really are connected. But I think the intuitive way to think about it is just as part of one, right it. Don't think that moving currents generates magnetic fields, like this one kind of thing generates this other kind of thing. Just think of them as part of one combined thing. Right. There's a close connection between electric fields and magnetic fields, and a fascinating insight comes from thinking about how electric and magnetic fields change if you look at them from different velocities. Like, if you have an electron at rest, it mostly gives you an electric field. Right, It's a very small magnetic field because of its quantum Spinlet's ignore that for now. But somebody else driving by, they see that electron not at rest, they see it is moving, right, and moving charges give magnetic fields. So if you're at rest with respect to the electron, you mostly see it an electric field. If you're in motion with respect to the electron, you see an electric field and a magnetic field. This really is a clue that the two are different parts of the same thing, and you see different parts of it if you're moving at different speeds, so they really can't be separated. They're really just two parts of the same beast. Oh. Okay, so that's magnets um there. They can either be permanent, meaning that it's just the electrons inside of the material adding up to make a big magnetic field, or you can also make it field by moving electrons around in a circle. Okay, So so the Earth is which of the two? Is the Earth a permanent magnet or is it like a like an electric motor. Well, it's a great question. For a while, we didn't know because it could have been that the Earth had basically a bunch of permanent magnets buried in it, right, because you know, there is this crust and it's got a lot of rock, and a lot of those rocks are metallic, and you might imagine maybe there's just a bunch of magnets and they all got a line somehow. Right. Yeah, that wouldn't make sense, right, it would make some sense, right, You can imagine that happening, and then the Sun has a big magnetic field, so you can imagine maybe the Sun magnetized the Earth. And well, before we go too far into that crazy speculation, the answer is no, the Earth is not permanent magnet um and we know that because the earth magnetic field seems to penetrate from the core right, not from the crust, and also because it's changing. It's not static. It's not the same all the time, and a permanent magnet by definition, it would be permanent right if it was. If it came from a bunch of buried magnets inside the Earth, then those wouldn't be changing. In fact, we do see the earth magnetic field changing. So how fast is it changing? Is it changing by the hour or by the one thousand years? It's more on the thousands of years schedule, but we don't really know. Um. The amazing thing is that we can see the history of the Earth's magnetic field. And the way we can do that is that we um we look at magnets being generated over time on the sea floor. So there's these like volcanoes that spit up magma and lava and stuff on the floor of the ocean, and what happens when they come up the floor of the ocean is of course they cool very quickly because you know all that cold water and lava, and it cools very quickly. But the lava is sometimes magnetic, right, has a bunch of little magnets in it, And so what happens before they cool is they get aligned with the Earth's magnetic field and then they get frozen. So each of those rocks is like a picture of the strength and the direction of the magnetic field when it was formed. I was about to ask you how we know have we been measuring the magnetic field in our history books, But we don't have to it. It's kind of embedded in the Earth itself. The history of that it's really amazing. And because the volcanoes underwater just continuously spew this stuff out, we have this like unbroken record of the strength and the direction of the earth magnetic field over thousands and thousands and millions of years. And that's the crazy thing is that not only is the earth magnetic field changing, like it's getting weaker and it's sliding off the north pole a little bit. It used to point the other way. What, yeah, like one eight degrees. Yeah, exactly, like if you jumped into a time machine with a compass. Today and went back eight hundred thousand years the compass with point in the other direction. Okay, so there's stuff going on and it's changing, which means that the Earth is not a permanent magnet. We're not a giant fridge magnet floating through space. Um, so what's going on in there? What's what's what's causing the field? Then inside the Earth? Yeah, well it's kind of a mess, um. But you know, the one option is permanent magnets. If it's not, that has to be a current, right. You need some sort of charges moving in a circle to generate a magnetic field. So what could be doing that. It's not like somebody built a huge machine made of wires down under the ground, right. Instead, what we have a sort of basic picture of what's inside the Earth is you have the crust which we're standing on. Under that, there's a big liquid layer of various rocks and metals, and then there's a solid core, right, and that liquid layer is sloshing around. There's a lot of heat that's coming up from the gravitation of pressure and from the radiation of all the crazy stuff inside the Earth. It's keeping that sort of bubbling and frothing it's like a big soup of liquid little and basically the currents in that soup of liquid metal are what's generating the magnetic field. So all those electrons in that soup moving around in a circle is what creates the earth magnetic field. Yeah, if you take something that can conduct electricity, like iron, and you melt it down right and you slosh it around in a circle, you'll be generating little magnetic fields because you have electrons and they're moving in a circle. Right. And it's a little bit more complicated than that, because it's not like the liquid inside the Earth is just slowly moving in a circle and that generates the magnetic field. It's much more turbulent than that. Right. This convection going on is it's things that are dense fall and things that are light bubble up to the top and that's making all of this swirling. And there's this cool effect called a dynamo. And what happens is you get a little magnetic field from some initial swirling, and because electricity and magnetism are so closely connected, that magnetic field will push electrons around. Right. Like we said, the magnetic field of the Earth deflects charged particles. Right. Well, when you get a magnetic field started in the Earth, it builds on itself because the motion of the electrons gives you a magnetic field. That magnetic field pushes those electrons around even more, which gives you more magnetic field. So it's sort of a feedback effect, like a perpetual motion machine, kind of like feedback. Yeah. The source of energy is that you have this all this heat that's coming from the gravitational pressure the Earth being squeezed by its own stuff and the radiation. So it's not like a perpetual motion machine because it's constantly being fed energy, right, So it's more like a like a bubbling cauldron of stuff right that generates these magnetic fields, and and its motion is sort of related to the Earth's rotation, right, I mean it's um like the Earth spinning is kind of what creates these currents going in a certain direction, which is why the magnetic field is sort of aligned with this rotational access of the Earth. Yeah, exactly, these currents are the Earth movie relative to its liquid core. Right. If you ever held like a you know, a ball that has liquid inside of it, you know they don't roll normally, right, If you have a ball half filled with liquid, you roll across your garage floor, it's gonna go all wonky and be really unpredictable, right, And if you spin it, similar things happen, and so it creates crazy currents inside of it. And so this this is like it's hot and it's bubbling and it's spinning. So you definitely get lots of really complex fluid dynamics going on inside there. But it's related to the spinning, but it's not completely dependent on the spinning, which is why it's the two axes are not aligned, that's right, Yeah, but they're definitely related, right, definitely related. But you know what's generating the magnetic field? The short version is that it's you know, spinning hot liquids inside the earth, spinning magnetic conducting liquids inside the Earth are generating our magnetic field, which is crazy, right. Yeah, the Earth is is hot, it's magnetic, it's attractive. It's amazing to me that it's stable at all. You know that that would like not just be pointing. And also it's a in the directions, you know, like you watch a pot of water bubble, right, and it's crazy, it's going crazy all the time is this direction in that direction? Then somehow the Earth's magnetic field is surprisingly stable, given given all the craziness that's happening under our feet. Well, let's talk about that, but first let's take a quick break. Let's get into that is it stable? Because you said earlier that it it flipped a long time ago and it's moving over thousands of years, that that doesn't seem super stable. Our magnetic field is remarkably stable compared to others, Like the magnetic field of the Sun. It flips direction every eleven years very regularly. What. Yeah, the Sun's magnetic field like has a huge impact on the solar system like where to charge particles go and how does the solar wind blow and all this kind of stuff, and every eleven years it just flips flips. What causes it to flip? I mean on Earth, what causes our field to flip? We don't really understand it, um, But the short version is that it's a big hot mess and it's sort of unstable, and so you know, it's mostly supporting itself and you get a feedback effect. But these things can be crazy. It's like when you roll that half filled ball across your garage floor. Sometimes it mostly roll straight. Sometimes it does a crazy loop. And so if one little random thing happens, it can push it sort of off course. That can build on itself and feedback in the wrong direction. So these are instabilities from equilibrium and when that happened. Once that happens, it can very quickly go off course. Imagine you're like driving your car down the freeway at ninety you know everything's going fine and and your and your and it's all good. Suddenly a tire pops right and you're flipping over, or you veer, you know, your kid makes the noise in the back seat, and you pull your hand on the steering wheel a little bit, you start going in the wrong direction. It's suddenly very hard to get back on track driving smoothly right. It's sort of like that with the magnetic field. One little random effect, one little random occurrence can sort of build on itself and make things go crazy, and eventually things can even flip over and go the other direction. It's kind of like a chaotic system. Absolutely, absolutely, that's the word. It's a chaotic system. So what happens when it flips is it is does it just happen overnight, Like one day, who I'll see my compass point in one way and then suddenly else seet flip pointed the other way. Or does it build over hundreds of years? Well, Um, the fossil record we have is not very precise down to like them the minute or the year or something. Um. But as far as we can tell, it doesn't happen overnight. You know, these things are all geological time scales, so it takes a little while. Um. But the interesting thing about the earth magnetic field is that the periods of flipping are not predictable as far as we can tell. Like, sometimes it will flip, like you know, every hundred thousand years it will flip, and sometimes it'll go fifty million years without flipping. But does it flip one eight degrees or can it flip sideways? It's flips usually so that the north pole is at your house yet Clause, I've always thought you kind of look like Santa Claus. Yeah, the Chinese Panamanian version of Santa Claus. Many people don't have the actual historical origin of Santa Claus everything, like everything else, we've just stole in our culture. Um. No, it's it's um. There are too, more stable set situations, and one is um, you know, the north pole, on the Earth's rotational north pole, and the other one is on the Earth's rotational south pole. I see. Those are the stable coming because they sort of aligned with the spinning of the Earth. Exactly. It can't just be random because the spinning of the Earth does play a role in generating those currents and maintaining them. Oh, I see, but maybe there's a few thousand years in between where it's sort of wandering around the Earth. Yeah, exactly, and it can drift, and that's what's actually happening right now. Like, right now, the Earth's magnetic pole is moving forty kilometers per year. Forty kilometers. Wow. Yet I was stunned. It's fast, right, I mean you might think, well, forty kilometers per years not a lot of meters per second, and that's true, but you know that adds up over a bunch of years. And not only that, but it's getting weaker, right, It's getting weaker every year by several Percentum. We don't know what's going to happen because we can't predict these things, but you know, if you do sort of like a trivial straight line trajectory, then it's getting weaker and weaker and it might eventually flip. You know, we we have records from earlier times when humanity was around, and like the Romans, they had a magnetic field that was twice as strong as ours is. So it's definitely active. It's not like it's right now just hanging out like things are happening. The magnetic field and the thousand years could be different dramatically than it is today. So if I took just like a regular compass and I sat it on my table, and I filmed it for you know, a couple of years, and then I spit up the video fast forward, I would to see it. You might see it drift a little bit. Yeah, yeah, if you wait long enough and you're far far enough north, then yeah, you could see the compass drift a little bit exactly. And you know, I wonder about things like animals. You know, a lot of animals use the magnetic fields for navigation. Right. We've recently figured out that, like birds, some of them can see magnetic fields and use them to help figure out where to go. I wonder if that like totally screws up the birds. Yeah, well forty kilometers a year, and it's it's a lot. I mean, that means Santa Claus every year has to move forty kilometers, has to pack everything up the whole factory. Moving sucks, so it's such a drag. And if you've got all that stuff in the workshop, at least he's got a little little elves to help him, right, Yeah, maybe that's why he has it helves, you know, just to help him move. Originally, that's why he contracted the elves. But I mean it's not it's not a little bit. It's forty kilometers. Every year you have to pick up move forty kilometers and that's where the new north pole would be, the magnetic pole. Yeah exactly, Yeah, okay, And you said it's getting weaker, Yeah exactly, it's getting weaker. Also, it's like just not as strong. Um thousand years ago it was stronger than it is today, and every year it's getting a little weaker. And we don't know what's going to happen. Next year. It might like drift back towards the rotational north pole and get stronger. Right, these things are unpredictable. But there are a bunch of people working on this and they have really complex computer simulations that describe like all of the physics we think is happening inside the Earth and um, until recently those simulations didn't agree with what we were seeing. But now they're more sophisticated and they can model all the complexities and the simulations are pretty good, so we think we have some understanding of all the crazy effects that are happening in there. And they even do predict things like the earth magnetic field flipping. They can't specifically predict when our magnetic field is going to flip, but you know, they have a computer model in which sometimes they see it flip. Right, But this idea that it's protecting us and keeping our atmosphere in place, we don't need to worry about that, right, Like it's getting weaker, but it's not going away. Should we worry? Sort of a deeper philosophical question, you know, in general, in general, should we worried? My Jewish grandmother says, yes, Um, I think we're not likely to lose our magnetic field. Right. Look at a planet like Mars, right, Mars used to have magnetic field, but it doesn't anymore, and the reason is that it's insides have gone quiet, right, it's cooled, and it no longer has like a lot of crazy stuff happening on its inside. So it lost its magnetic field. That's not likely to happen to the Earth anytime soon. And so we're gonna have some sort of magnetic field protecting us from space. It may be stronger, maybe weaker, may point in another direction, but we're still we're likely to still keep this force field. Okay, so I don't need to stockbell on sun block or refrigerator magnets silver panels. I wonder if how how many refrigerator magnets would take to protect yourself from cosmic rays? All those a tinfoil had people a little do they know it's fridge magnets. You gotta put them on. He put them on your head. We're gonna spawn a whole generation of refrigerator magnet hat people. Now, Yeah, we should sell those in our store. Oh my gosh, let's sell refrigerator magnet hats. Force field had personal force field, had the well and and actually would be real science. It really does generate a force field, and it really does deflect radiation. Yeah, oh my gosh, somebody get the lawyers on that. Yeah, we need to open Daniel and Jorhe dot com slash store, ap slash Crazy Science Protection Store. Alright, well, um, let's take a step back here. I mean, it's pretty amazing to think that our planet is currently in our Solar system. It's special because we have this magnetic field and and without it there wouldn't really be any life on it, that's right. But you know a lot of planets have bangnetic fields. Jupiter has one, all the big gas giants have one. Basically any planet that's rotating and has stuff going on inside it has a magnetic field. So we expect that a lot of rocky planets out there probably have met magnetic fields. And that's absolutely essential. Mars is sort of unusual, right, Mars and Venus also doesn't happen, right, Yeah, that's what I mean. Yeah, And and we have and it helps us have an atmosphere in life, and so we really wouldn't be here without the Earth magnetic field. No props to the magnetic field, man, it's absolutely essential. Yeah, And without it would blow away our atmosphere, right, The solar wind wouldn't be deflected, it would rob us of atmosphere slowly over time, like what happened to Mars. So it's definitely very important. And you know, we still have a lot of learned to learn about the sort of extra planetary magnetic fields. Like I would love to understand why the Sun's magnetic field flips so regularly and so dramatically every eleven years. It's a mystery. And you know, we even have moons out there in the Solar System with magnetic fields. Our moon doesn't seem to have one because it's basically a lump of rock. It might have had one earlier in its lifetime. Um, but like Ganymede, is big enough to have like stuff going on inside it to have its own magnetic field. So it's sort of like a property of a planet when he gets like big enough, you know, exactly when you're a real planet, you have a magnetic field. Yeah, it's amazing to think that at the scale the Solar System, things are kind of chaotic, right, and the Solar System is changing all the time, and it's doing crazy stuff, it's flipping its fields. It's yeah, the Earth is not just a rock, right, it's a it's like a really big machine doing crazy stuff out there in space for us. All right, I hope you found that an attractive topic with two magnetic personalities current importance. I hope that charged you up for your day. Yeah, and maybe next time you go out there and you think about the fact that you're swimming in this amazing and unpredictable field that is protecting the earth. Yeah, so go out there and get the fields for your magnetic field. Thanks for joining us, so your next night. If you still have a question after listening to all these explanations, please drop us a line. We'd love to hear from you. You can find us at Facebook, Twitter, and Instagram at Daniel and Jorge That's one word, or email us at Feedback at Daniel and Jorge dot com.