Daniel and Jorge Explain the UniverseDaniel and Katie explain how electric current, lightning and static electricity emerge from the strange quantum nature of electrical charge.
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Hey Katie, I'm thinking of starting a magazine all about electricity.
What are you gonna call it?
M I was thinking.
Events sounds like it should be free of charge, but.
It's going to be filled with all sorts of shocking news.
Gonna make my hair stand on end.
Only if the writers find their creative spark.
It's probably going to get a lot of ads from volts Wagon.
I'm not going to be resisting their money, that's for sure.
Who put you in charge?
I'm going to stay neutral on that question.
I feel like you have an advantage when it comes to electricity puns over me.
The physics PhD is good for something. Finally, Hi, I'm Daniel. I'm a particle physicist and a professor at UC Irvine, and I'm all here for the shocking puns.
I am Katie Golden. I am the host of a podcast called Creature Feature all about animals, and I do not know what is going.
On here, and welcome to the podcast. Daniel and Jojorge explain the universe, in which we pun our way into understanding everything that's out there in the universe, the biggest things, the smallest things, the squishiest things, the positive things, the negative things, and everything in between. We think the universe, as beautiful and complicated and mysterious as it is, deserves to be understood and deserves to be explained to you.
I am excited to learn more about electricity because all I know is there is a certain type of blanket that makes my hair stand on ind And my dog loves this blanket because it's warm, but it also makes her hair stand on ind And I need your top physicists to figure out why this blanket is causing this to happen.
You need me to explain to you why your dog loves you when you're using an electric blanket, or whether it loves you or the blanket. You really want to get into that.
Uh, yeah, I maybe I don't want to know. No, but this is like a microfiber blanket that just generates a lot of static electricity. I feel like it should be studied by like ser or bring your top scientists and take a look at this blanket.
Oh, I see, it's not that your dog loves your heated electric blanket. You seem to have a blanket which violates the laws of physics and gathers up an incredible amount of static electricity.
Something like that. I don't know if it's violating the laws of physics or if it's just a superconductor. Maybe we've found something.
I hope you don't open a portal into another dimension using your blanket and kill us all.
You can't tell me what to do.
No, but I can give you some advice. I don't think that Katie's blanket is going to kill us all, but sometimes it does seem like electricity is the the closest thing we have to magic. I mean, you can levitate things, it can shock things, It creates incredible light shows from the sky to the earth. It's incredible to me that physics can explain it. That this is just part of the natural world sort of blurs the edge there between things that should and can be explainable.
Yeah. No, it is kind of like magic, right, because we've all kind of I guess gotten used to it in day to day life. We just take it for granted. But if you showed this, say to an ancient human, all of the things that we have manipulated electricity to do, they would essentially think that we're wizards. Depending on the era you're in, they would burn you or think you're a god. And I mean it really you only have to look at like the sky right when there's like a big thunderstorm to see how I mean, it looks so mystical and so impressive that it can be so impressively destructive. But the only time you see it is when it's in that kind of like plasma form. But otherwise you can't really see electricity unless it's being used by something or funneled in some way.
Yeah, it's fascinating because it is a part of our natural world. But it's not a common experience, as you say, like you go about your everyday life and mostly it's just like walking around on the surface of the Earth and feeling gravity and trying to stay warm and fed in this kind of stuff. Your everyday life, you don't tap into these awesome powers. It's that incredible power of electricity that makes it so almost mystical, because when you do crack it open, you do get hit by lightning, or when you can tap into it to like levitate a train or whatever, it does seem awesome. It seems like a power that maybe you should be beyond what humans can tap into. And yet it's not even the strongest force in the universe. So I love that these things that sometimes seem magical to our ancient ancestors can actually come across the line into the category of natural, into something we can explain using mathematics and physics and learn how to manipulate.
And it's really interesting the history of us trying to understand electricity, right, like, it's one of these things that sure now we have a much more sophisticated view of it, but that there are some experiments into electricity that were quite early and even though they were crude, we were starting to learn how to actually store it, like long before we had modern things like computers or even light bulbs that could be powered by it.
Yeah, and I feel like it's a real triumph for reductionism. It's an amazing success for the whole idea that you can explain everything we see in the world in terms of the microscopic story, Like how do you understand what lightning is? How do you understand why electric eels shock you? How do you understand what magnets are? It turns out it's all explained by the tiny particles and their properties and what they're doing. And everything in our world in the end bubbles up from the properties of those particles and how those particles direct and dance together to make our world. So if you see something weird and mysterious and potentially mystical in the end, you can't explain it. If you can zoom down to the tiny microscopic level and see what's going on down there, that's where the answers are.
Yeah, and I mean it's so interesting because even though electricity is by science well understood, I think for most of us, myself definitely included. Our understanding of how it actually works is pretty limited. I'm like, I plug in this cord to the wall, and things flow in from the wall and make my Nintendo go make good games.
Exactly, and keep your rice cooker going. And even though we can understand a lot of electricity in terms of tiny particles, there are a lot of deep fundamental questions remaining about those particles, why they have electric charge, and what that even means. And so today the podcast, we're going to be tackling the question how does electricity work? Like? What is electricity anyway? What's going on down there at the tiny particle level? How do electrons and protons and all those other charged particles make your rice cooker work? And static electricity and electric eels and lightning and alternating currents and electric cars? How does all that bubble up from the tiny particles and their properties.
I'm excited to learn this because most of my knowledge is that I should not stick a fork into a toaster because something bad happens.
It will be the last thing you ever do. So, yes, do not stick a fork into a toaster. If you learn nothing else from this episode, remember that toasters are not friendly to forks.
There's worse ways to go out than being excited for nice toast. But I won't do that, and neither should you be careful around toasters.
You don't even get the toast in that scenario. That's the worst part. You die toastless.
Yeah, but you don't know that. You don't know that su're dead.
That's true of everywhere you go out, though it's true. Wouldn't you rather die with the taste of recently enjoyed toast in your mouth?
I would rather live with the recently enjoyable taste of toast in my mouth. Daniel, I'll toast that all right.
So we were curious if people out there knew how electricity worked and had an idea of how the particles and their charges come together to make the phenomenon we call electricity. So I went out there to ask our team of volunteers, who are so generous with their time and ideas about all these crazy physics topics. If you would like to participate in this audience answer segment of the podcast, please don't be shy. Write to me two questions at Daniel Ianjorge dot com and I will hook you up. So think about it for a minute. Do you know how electricity actually works? Here's what people had to say.
I do not know, but we did build a fence for the chickens that was electric, didn't we, Sophie, Yeah, yeah, and then I shocked myself with it by accident after I made it. So I don't know how electricity works, but I do know that it works.
I think electricity works by sending a current that's missing one of its key components, like an electrical imbalance, through a conductive means that will make it think that it's going to ground.
I really enjoy when we humans get hoisted by our own petard. We create an electric fence, you know, for chickens, and then we get shocked by our an electric fence. I wonder if the chickens if they have any awareness of this, and if they find it really funny.
Maybe the chickens manipulated him into building a fence to keep him out because he's like always bothering them, and they just like, man, we just need some time to ourselves.
I like the idea of super intelligence field of chickens.
And when they see him getting shocked, they're like, look, band, respect the fence.
I've seen chicken run. I know how these things work.
Yeah, exactly. So you were right when you said that electricity is an ancient concept. It's something we've known about since antiquity, and we haven't understood electricity in a microscopic picture, of course, until very very recently. But electricity is something humans have been experiencing at least since we've been humans, since there's like a cultural memory we can draw on.
Since we first rubbed our prehistoric socks against a prehistoric mammoth for rug, we have known.
Yeah, there's writing in like ancient Greek texts about electric fish. Of course, about lightning, you know, there's gods of lightning and this kind of stuff. But also even ancient Greeks knew that if you rubbed an amber rod with a fur, you could get static electricity. This is not something you niede Need complicated devices for particle accelerators or anything. You can summon the quantum, microscopic nature of the universe just using a piece of amber and a cloth. It's kind of incredible.
I mean, what is it about amber that makes it particularly good at generating electricity? Are we going to talk about that later? That's interesting to me that amber has that versus just say if you used I don't know, soapstone or a rock.
Yeah, we're going to talk about static electricity in a minute. And amber is just sort of historically like one of the first things that humans discovered could do this. But a lot of stuff can do it. Glass, rods can do it, wax can do it. It just depends a little bit on the electronic structure of the atoms at the surface. But the cool thing about amber is that it's influenced what we call electricity. Oh interesting because the word electron actually comes from the Greek word for amber. Like the Greeks knew that you could use amber to create static electricity. And then in the sixteen hundreds an English scientist wrote a book calling this phenomenon electricus, which means like of amber from the Greek word for amber. So electron, the word in Greek actually means amber. So all this time we're talking about electricity, Greek people are hearing like resonances with the word amber.
That's so interesting. I feel like puns in other languages must be really different, like the electrical puns. If your English is a second language, are not going to make any sense in our.
Podcast But imagine if you're walking around and people are talking about like tree sapicity, right, it must be really strange to hear this remnant of the ancient world in this word.
Yeah, when words do not originate from our language, it's hard to kind of connect the meaning that we have ascribed to them now with what they used to mean. But it's that's so interesting that all the way back in ancient Greece there was this sort of awareness of how to generate static electricity, and then all the way into well now we still use that build upon the knowledge.
I love these ancient clues about the quantum nature of the world. You know, the world that we live in is mostly like classical things move slowly, it's mostly just defined by gravity. You can ignore the fact that things are actually built out of tiny quantum objects because when you put ten to the thirty of them together, they act in a different way. They act in this weird classical way where things move smoothly with paths and are predictable and have trajectories and stuff. But we know that deep down the world actually is quantum and this is fundamental mystery in physics about how you go from the quantum nature of the world to the classical world, this connection between them. But electricity is awesome because it's like a crack. It shows you, like directly that the world has this other deep nature in it which is really different, and it gives you this glimpse into the incredible power of these particles. It's like this clear channel down to the microscopic nature of the universe to show you that something crazy is going on down there.
You mentioned in earlier Zeus like the god of thunder in the Greek and Roman pantheon, and then there's also Thor, who's like, you know, another god of thunder. And I think that's really interesting that these sort of ancient cultures maybe like gods and stuff was a way for them to start to describe how they are perceiving these kind of random and capricious things happening, like a lightning storm or this electricity that is disobeying sort of the rules that we understand as humans in terms of simple physics of throwing a rock or you know, jumping up and down, and so yeah, I wonder if like some of the theology that that developed at this time was a way to start to try to explain when we started to see more evidence of the quantum nature of the universe, more randomness, things that are harder to explain or that you can't see with the naked eye.
And I think it's interesting. It sort of tracks humanity's attempt to understand the world, starting with like mythological explanations of saying, we don't understand this, therefore it must be some entity, something with intention that's making these decisions. It can't just be explained with some mechanistic understanding. And then in the sixteen hundreds and the seventeen hundreds, people doing more experiments, people developing an understanding of it bit by bit. And you know, electricity spans so many different kinds of phenomena, from static electricity to lightning to magnetism. All this kind of stuff was investigated independently, and then in the seventeen hundreds, research by all sorts of people fair Day, including Ben Franklin, all this kind of stuff led to a unified theory by James Clerk Maxwell of electromagnetism. How all these ideas are actually just reflections of one single concept, this electromagnetic force, which can explain everything we see. Really an incredible moment of unification of understanding, not just mechanistic explanation like oh, there's not people in the sky making these decisions, we can actually predict it with mathematics. But bringing together so many different concepts into one harmonious idea. It's like really a triumph for the whole idea that physics can simplify the universe.
It's like that whole a bunch of blind men trying to describe an elephant, but the elephant is made out of electricity, and it's a bunch of scientists all over the world. That's yeah, that's really interesting how we have it seems like with a lot of these discoveries in physics and other sciences, you have these waves of parallel discoveries or complementary discoveries that all kind of happen in these bursts as we start to build on old knowledge and our technology and scientific abilities improve. It's not just one guy, right, Like Ben Franklin did not discover electricity, Thomas Edison did not make electricity usable. They certainly contributed to it, but it's a bunch of different scientists and researchers and people who kind of like in these waves of like, oh, now we have the technology to be able to observe or study this. Now a bunch of people are contributing to the research and coming up with ideas at the same time, and.
It seems like a burst, but it's only a burst on historical time scales, Like you look back and there's like decades between experiments and discoveries. So that's sort of frustrating to realize, like, Wow, they could have figured this stuff out much sooner.
Pin I had cell phones, We could have.
Had iPhones, like one hundred years earlier. If people had been on top of this stuff.
We had Twitter back then, it would have either really helped or doomed society. I don't know.
But then it's the late eighteen hundreds, after Maxwell has understood what electromagnetism is, we have an idea of a charge. JJ Thompson was the first person to figure out, like the beginning of the microscopic story, worry of how this actually worked, like what charge was and how it moved. When he discovered the electron, he was studying cathode rays and playing around with these tubes and putting electric fields and magnetic fields near them and seeing how they bend the rays. We have a whole podcast on the discovery of the electron, and the key thing that he discovered was that the mass and the charge were linked. If you were going to bend this ray, there was some stuff to it, and the charge and the stuff couldn't be separated. The charge was attached to the stuff. This is like the beginning of the modern concept of what a particle is. That there was some tiny little bit that had these labels and you couldn't pull those labels apart. They were like deeply linked together mass and charge. He called this thing actually a corpuscule, and it was only later renamed into an electron. I'm glad so we should all be.
Could have been disgusting, otherwise.
We'd have like corpuscular engineers running the world.
It is interesting because like there was I know that throughout the history of science sort of the distinction between the physical and the non physical got kind of confused and modeled. Like it reminds you of sort of the idea that the mind, right, our conscious experience is actually connected to our physical brain. We didn't come out of the gate knowing that, you know, we didn't know that our brain was responsible for thoughts and feelings. For a long time. So that sounds kind of similar to this, where it's like discovering that electrical charge has sort of a physical manifestation.
Yeah, and that's not something that we still really understand. We've like kicked the can down the road a long way as we're saying, what are these electrical effects? Where does charge come from? Oh, it's attached to these things we call particles. We can call them electrons. We can say they have electric charge and they have mass and they whizz around. And in the next segment of the podcast, we'll talk about all the amazing electrical effects and how they come out of electrons. But we still don't really understand what is an electron and what is electric charge? Like we can say that it's there. We can say electrons have this property electric charge, and we can say that what that means, but really it just means they push on each other or they pull on each other. It's a way to explain the things that we see by creating this label and putting it on electrons. We don't know, like what charge is, why do some particles have it and other particles don't have it? Like doutrinos have no charge at all, But quarks and electrons certainly do. Why is charge conserved in the universe? Like you can do all sorts of chemical and physical processes, but you cannot increase or decrease the amount of charge. That tells us that charge is something really important to the universe. It's deeply embedded somehow in the nature of reality. But like if you ask me what is electric charge, I can just describe it. I can't define it or really explain it.
Well. I think if you and I put our heads together, you with your knowledge of part article physics, me you know, being here, I think we can figure it out. And so let's take a quick break, and when we come back, I'm sure we will have discovered the mysteries of electricity.
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So we are back, Daniel. We had a good thinks you any closer to solving the mysteries of electricity?
No.
I took a little nap and I was hoping that they're a lightning bolt of inspiration, but nothing came. But I do feel better and I'm ready to dig in to understanding electricity. I think that's amazing how science works in stages. You know, like there's a huge mystery and you can explain it in terms of something smaller, and then you can focus on that thing smaller. Then you explain that, which turns out to reveal a smaller mystery and a smaller mystery, and in some ways you are developing an understanding. In some ways you're just sort of like recursively kicking it down the road. This answer depends on the next one, which depends on the next one, and we hope eventually there is a deepest layer.
We're also using electricity to think about electricity because our brains use electric potential charges to have the firing of our neurons on when you take a nap to think about electricity, your brain is manipulating the flow of electricity so that your body stops moving, but your brain to some extent remains active only in certain areas. So it's electricity all the way down.
It's meta electricity.
It's a good band name. Good band name.
I'm going to copyright that when nobody take that one.
Yeah, no, it takes these back seas.
So I do want to take the time to pull apart some of the phenomena that we call electricity, the day to day experiences we have of electric current and bonds and lightning, and explain that in terms of electric charges and electrons what's happening on the microscopic scale. But I don't want people to forget that we don't understand that what's going on at that smaller level, Like we can build this bridge between the microscopic and the microscopic, but the microscopic remains a mystery that hopefully one day somebody will understand, like what charge is man?
Yeah, See, science isn't over yet. Everyone out there who's listening, who wants to be a future scientist, there's a lot of stuff left free lat of scraps.
There is in the end charge, just this label we put on some quantum fields and not on others, and it's something we see and describe in the world. But that doesn't stop us from building up an understanding from this microscopic picture of charge understood or not up to the macroscopic experience of electricity. And electricity itself is like this grab bag of related concepts, all of which come out of the charge of electrons and of quarks. But you got like electric bonds, you got electric currents, you got lightning, you got static electricity, electric heating, you even have biological electricity. So let's dig in.
So let's start with electric bonds. I know there are different types of forces and different types of bonds, and there are like weak and strong forces. Like where do electronic bonds sort of fall?
Yeah, if you're going to build the macroscopic world, our experience of the world out of particles, you got to click those particles together. And we know that there are some fundamental forces in the universe. There's the strong force, the weak force, electromagnetic force, and then there's gravity and the particle world. Gravity is irrelevant because it's so weak, and these particles have basically no mass, and so it's just not really a player. The strong force is the most powerful, but it's so powerful that it locks itself up and neutralizes itself really quickly. So a few quirks will feel the strong force, but they tie themselves together into like a proton. Once you step outside the proton, you can't really feel a strong force anymore. It's sort of the same way that like an atom is made of a positive electric charge and a negative electric charge, but when you're far away from it, the whole thing is neutral because those two charges balance. Then the same way, a proton has the strong force inside of it, but it's so powerful that it's locked itself up and it's neutralized, and so then what you're left with is electromagnetism and the weak force. And the weak force turns out to actually be part of electromagnetism. Check out our podcast on the electro weak force. But essentially it's a electromagnetism that then builds our world, that takes protons and electrons and symbols them together into atoms and then lets those atoms link themselves together with electronic bonds to make chemistry and biology in everything that we experience.
So I've got a glass of water here. Does this glass of water need electricity to be a glass of water?
Oh?
Yes, absolutely, the water needs electricity. You know, water is H two Oh. And the hydrogen and the oxygen why do they stick together. It's the electrons around the hydrogen and the electrons around the oxygen that are doing that bonding. The electrons are like the glue in chemistry right. Without them, the protons in the nucleus would not want to hang out together. So it's electronic bonds. It's electricity at the particle level that builds water out of H too and oh. And that's why they call it electrolysis, the opposite of making water. Right, you break water down into H and oh using electrolysis because it's in the end electricity that is building our world.
Well, I just drink some of it and it tasted normal to me.
So that's shocking.
Eh. That is interesting that the thing that makes stuff possible, like physical stuff are bodies, biological processes, are these electronic bonds and differences in charge, right.
Yeah, exactly. And the reason like some things are sticky and some things are shiny, and some things react and some things don't. All comes out of its chemical properties, which are determined by the electrons in their orbitals and whether they like to interact with other stuff or not. So like, really, in a very concrete, tactile way, it's electricity that determines your experience of the world. The reason you can't pass through the wall is because of the electronic bonds linking those atoms together. The reason gelato tastes delicious is because the interaction of those molecules on your tongue, which are electromagnetic interactions, right, the electrons linking together or not clicking together into those receptors or not. Our whole world and our experience of it is electrical.
Yeah, just like I said earlier, our ability to think about it is also based on these differences in charges. The ability for synapses to communicate with each other, but also just for any cellular process, right, depends on different charges. It's very interesting because there's like I mean, it's hard to call it a desire because these are particles, but it almost seems like particles kind of seek out this homeostasis, like this neutrality that you describe, which is also very similar in biological processes. Like a cell is going to try to The kind of osmosis of water through a cell membrane is due to this kind of behavior and physics of like you know, salt ions in water or the lack of salt ions. There's this need to become stable where you have this homeostasis, and so all of that, Like the nature of these particles is also reflected in the nature of these biological processes exactly.
But electrons and electronic bonds and electronic orbitals lead to all sorts of fascinating phenomena beyond just like why gelato is tasty and why water is transparent and all that stuff. There's more, at least probably the most amazing and powerful concept. And electricity the one that people mostly think about, which is electric current. Right. You know, when you plug your thing into the wall, it's creating electric current. When you're charging your phone, it's using electric current. This is about the motion of charges through.
Materials, and I mean this exists outside of just human inventions, right, Like there are currents that occur in nature.
Oh, absolutely, currents flow in nature all the time. You can have like streams of particles. You know, the sun for example, generates all sorts of charged particles electrons and protons and even some anti electrons, And when you get down to it, like what is a electrical current, it's just the movement of charge. So if you have like a beam of electrons moving through a vacuum, that is current, right, charge in motion. That's all that current is. We'll talk in a minute about how that happens inside materials and it turns out to be more complicated and really fascinating, but its most basic level, electric current is just the motion of charges. So you take a single electron and you like throw it through space, boom, you have electric current.
So it's the electron moving So like the electron is equivalent to charge, so it's the movement of electrons, which is the same as the movement of charge.
Well, electrons do have charge. You don't need electrons. Like you could throw protons also and that would make an electric current. But anything that's charged and in motion, that's what electric current is. That's like very literally the definition of electric current, and that can come out in a more complex way from the interplay of all sorts of complicated stuff inside metals, and it's a little bit more subtle way and it's most pure form. The simplest kind of electric charge is just electrons in motion.
I understand that metals, I mean, depending on the type of metal, is conductive, So I would assume there's some kind of structural property of metal that allows this, and I don't know what that is, probably to the horror of my electrical engineering father.
The electricity in metals is super fascinating. And people sometimes try to describe electricity as like water flowing down a hose. You know, think about like a tube of electrons flowing down a hose, And that's almost right, but there are important differences that will dig into. But essentially it is the motion of electrons through a metal. And like, why can electrons move through a metal? If you imagine, like your table, it's a bunch of atoms click together, and you think, well, they're clicked together with those electrons, how can those electrons jump around? Well, if you imagine your basic picture of the atom, there's like energy levels, right, you know, the electron can the lowest level or the next level up, or the next level up. Our idea of like the hydrogen or helium atom, there's all these different orbitals. There's ladder, the electrons allowed to live in. And that picture works for one atom, but when you have like a bunch of atoms together in a lattice, the energy levels become more complicated. Instead of having sharp atomic orbitals for individual atoms, instead the interactions between the atoms make these bands of allowed energy levels for the electrons. So there's like these clusters of energy levels the electrons are allowed to be in, rather than just these sharp atomic hierarchies.
It's almost like creating a channel for this charge to move through because the atoms are nested together. Is that what you're saying, Yeah, exactly, And.
So electrons can sort of slide back and forth between atoms. If an atom is totally isolated, the description of it having these very precise energy levels is totally valid. But bring another atom nearby, and now the nucleus of that other atom is going to affect the electrons in the first one, And so the right way to think about it is that the whole like cluster of atoms have energy levels for all of the electrons, and they're not really individually assigned to one atom as much anymore, and so you just think of them as like they have these bands of energy levels the electrons are allowed to be in, and they're called the valiance band, which is the lowest level of electrons, and then the conduction band. And the conduction band is where electrons can like hop around. If there's empty energy levels in the conduction band, the electrons can easily just sort of like slide around the material from atom to atom.
So essentially, these atoms are just behaving like a bunch of hippies, sharing food and stuff and letting sort of the bruskis just flow freely, and you don't know who's bruski it is really at this point. It's just this free flowing hippie experience with these atoms and their bands of energy levels.
Yeah, exactly, it's like polyamory for electrons. You know, everybody just into sharing.
I don't think I've ever heard of an atomic structure described as a polycule, but I'm here for it.
They're just sharing the love. And of course, you know there's different kinds of atoms, and those different kind of atoms have different energy levels because you know, the different number of protons different number of neutrons change those energy levels. And so, for an example, in a metal, these lower level bands, the valiance bands, which are filled with electrons, are very close to the conduction bands, so it's very easy for an electron to like get enough energy to get up to the conduction band and like fly around the material, whereas in an insulator like a ceramic, for example, there's a big gap in those energy levels. So the lower energy levels where all the cold electrons are really really far below the super highway where electrons can move around, so it takes a lot of energy to get the electron up in there. So a conductor is one where it's just easier for the electrons to get up to this free flowing pathway where they can jump around.
So metal is like dense serb and planning like New York City, and ceramic is like the boonies in the most rural parts of America.
Yeah, exactly right. And you might wonder, like, well, why can't those electrons at the lower energy levels also like flow around the material. The reason is that they're like densely packed in there. It's like the reason that it's hard to move through a crowd because it's so crowded, you know, there's no room for anyone to slide around, or it's like one of those puzzles, you know where you have to like get this piece over there and there's only one hole. I hate those slide all these things around.
So bad at them.
It's a pain, right, It's a pain to get anything from one side to the other because there's always something in the way.
Yeah, i'd be a terrible conductor based on my performance with those puzzles. I'd be like ceramic.
Yeah. And so the valiance band is like that, it's packed really really full. It's like, why it's so much harder to get water to slosh in a full bottle than half empty bottle. A full bottle is nowhere for the water to move, but in a half empty bottle it's easy to slash things around. So the conduction band tends to be more empty, which means is room for those electrons to zoom around, whereas the valiance band the lower ones usually packed full. The conductor is a material where the electrons can jump up into this like free roaming range where they can move around.
Okay, So it's like if you've got a clogged freeway on ramp, you're not getting on, but if you can move and you can merge, we got a zipper people. We all got a zipper. We got to learn from the electrons and learn how.
To zipper exactly. And so when current flows through a wire, what's happening is the electrons are moving and the charge is flowing. But it's not exactly right to think of it like water flowing through a hose or remember that picture we had a charge of like electrons in a beam in a vacuum, because the motion of the electrons here is more complicated. The electrons are not moving through the wire at the speed of light. They're just sort of generally like flying around everywhere, and the electric field that you impose tends to move them in one direction, but it's still a busy area, so they're bumping into each other and changing directions. So it's more like a wave is moving through the electrons, and that wave is moving at the speed of light, even if an individual electron is not. It's sort of like the way a wave can move through a crowd or like a mosh pit or something, even if an individual person is still just sort of like bouncing around a little bit.
Okay, So, like this charge is moving even if the electron itself is not just individually transporting it all the way to its goal.
Exactly, one individual electron is going to zigzag a bit, and it's going to pass that energy down to another electron, and another electron and another electron. So in effect, the electric field and the charge is moving at the speed of light, but no individual electron is like actually moving through the wire at the speed of light. So this is the difference between the speed of an individual electron and the speed of the waves through the electrons, which is what is moving at the speed of light.
That's really interesting. It's not as simple as like cars moving on a road. I mean, even in say like you have crowd dynamics with people. Once you get people squished in enough, which is not good, it's very dangerous, but you do start to see people moving as like particles, and you see this thing where energy transfers from person to person. Even though the people themselves aren't pushing the people at the very front, the people at the very front will start to get shoved just by this force, even if it was started by someone at the back.
Yeah, and the traffic analogy is really helpful. Also, if somebody along the freeway slams on the brakes, then the pattern brake lights moves backwards through traffic much much faster than any of the cars are moving. Right, So there you can see like the wave is moving faster than any of the individual cars. And that's exactly what's happening with electricity and electrons. In metals, an individual electron is mostly flying around. You apply a field to sort of like get the electrons to move in one direction to create a current, But the individual electrons are mostly just zigzagging around. They're bouncing off each other, and the net effect is to get some current down the wire, but no individual electron is actually moving at the speed of light.
Is this why there are certain metals and certain things that are better conductors or worse because you've somehow optimized the ability of the electrons to kind of zigzag in the right direction.
Now, that has to do mostly with the difference between the valance band and the conduction band. How easy it is to get the electrons from the convalence band. It's like jam packed creative electrons up into the highway where they can move more freely, where it's like less traffic.
I see, Okay, the on ramp is very important.
Yeah, exactly, It's all about the on ramp.
Well, I'm going to come up with some more driving metaphors during a quick break, and then when we get back, let's learn more about electricity and how to drive safely.
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Okay, so we are back in an electron traffic school. So I'm an electron and I'm part of this big party moving through this wire, and I'm bonking into the electron in front of me, and we're just kind of creating this wave of charge that's moving through whatever conductive material we are in, exactly.
And that motion happens because you have an electric field, somebody's applied an external voltage, you have a battery or something putting an electric field on all those charges to move them along. And it's very easy to move things along in a metal because there's all these electrons that are free. But you could also try to do this to something that's an insulator something where there aren't a lot of electrons, very easy to move around, and then it takes a lot more energy to create a current, but it is possible if you have a very strong electrical field between the clouds and the ground. Eventually it will rip those electrons off of those atoms and they will create a current between the cloud and the ground. And that's what lightning.
Is, okay, And is that why there's just so much energy in lightning?
Yeah, exactly, because it takes a huge amount of electric field to ionize the air, to rip those electrons off of those atoms inside the air. To create basically a channel where that current can flow, because air is not that easy to ionize in a very strong electric field to have to build up a lot of power and then once it's released, it's very dramatic.
And is that all coming from these water particles that are contained in these clouds that are all having a bunch of activity, right, Like you know, the classic understanding of lightning is it comes from clouds kind of rubbing up against each other. But it seems like maybe at the sort of particle level that would be more complicated.
No, I think that's basically it. It's cloud friction. You know, air molecules and suspended water drop like the collide as this around in these clouds, and then the warmer airs and the water droplets rise, carrying those charges with them, and so as a result, you get this excess of positive charge near the cloud tops, an excess of negative charge in the bottom layers of the clouds. So that's how you get like lightning within a cloud. So the friction basically between these droplets is creating an electric field, and eventually you need lightning to sort of smooth that out.
That's really interesting to me because I was not as aware of like the lightning that just occurred within the clouds, because when I lived in southern California, for some reason, most of our lightning storms was the lightning where it's the difference in charge between the cloud and the ground, where it actually hits the ground. But here in northern Italy there's a ton of lightning storms where the lightning never actually hits the ground. It's all happening in the clouds, and it's happening a lot, like very rapidly, which is new to me, where it's just this constant kind of one after the other, but none of it is hitting the ground.
Yeah, it's really fascinating because the lightning inside the cloud then helps build up and create lightning between the cloud and the ground. So you have like the top of the cloud becomes positively charged, and then bottom of the cloud becomes negatively charged, and the ground is positively charged. And then when the negative charges on the bottom of the cloud reach a level that's sufficient to overcome this insulation of the air, then that's when the lightning strikes from the bottom of the cloud to the ground.
Why is the ground positively charged? Is that just the nature of most sort of physical objects or is it something specific about the Earth's ground.
I think as these water droplets evaporate, they tend to pull up the electric charges to the clouds, leaving the ground positively charged.
Oh.
Interesting. If you're about to be hit by lightning, right, and you're a little human, what should you do? Should you run around in a circle screaming? Should you get under a tall tree, should you curse at the heavens? Or maybe like bow down to thor like, what's the game plan for me a human? If I am caught in a thunderstorm, you.
Should take that last bite of toast and get your fears in order.
I'm gonna take a raw bread and like holt it up over my head, so if I get struck by lightning, I'll have some toast.
You should hope that there's a lightning rod in nearby, something that the lightning wants to zap instead of you, right, because the lightning is going to choose the easiest path. It's going to find the channel that's easiest to ionize. If you watch a lightning strike in action, it's actually really fascinating. You have this image in your mind that it's like a bolt from the heavens, right, it comes from the top to the bottom.
Yeah, it's Zeus throwing a zigzag down at Earth.
Yeah. But if you watch it in super slow motion, it's fascinating. You can see the bolt exploring different options, like lightning coming down to the ground is splitting and exploring lots of different ways to potentially find the ground. And only when it makes connection does the energy actually pass up from the ground to the cloud. So in solmotion it's kind of slow and explorational, like branches, and then once it connects to the ground, you see this huge bolt pass up from the ground to the cloud.
Yeah. No, I have actually seen video of that, and that's so interesting because it's like this sort of almost vein like structure of the lightning. Another interesting thing is that people who survive getting struck by lightning, which I don't recommend, they actually sometimes have these scars, not like Harry Potter with a zigzag. It's that same sort of like reticulated, like vein like pattern. Because the way that the electricity is moving in you know, in the clouds or in the sky, is probably similar to the way that electricity is moving inside the human body.
Creepy, that is creepy, isn't it.
It's kind of cool though. I think that if I got struck by lightning, I would want a cool lightning scar. So people believe me, because if someone tells you I've been struck by lightning, I think, well, okay, I don't know, because you would be you'd be toasted.
M m.
Well.
It's also just cool to think about the microphysics of what's happening there. You know, these incredible electric field between the cloud and the ground are enough to pull the electrons off the atoms in the air, making them charged, turning this thing into a plasma. A plasma is just a gas where the electrons have been pulled off of their atoms and now those electrons are free to move because they're not bound to the atoms, and so now it's conducting. It's like a wire of air. And then the electricity passes through that in the same way. You know, the electrons get pulled by that field and the ions move in the other direction, and that's how the charge passes. And it's an incredible amount of energy in one of these things. You know, a single lightning strike has a billion jewels of energy, which is a lot of energy. I mean, like just to calibrate the rock when he punches. Somebody has about four hundred jewels of energy. So getting hit by lightning is like getting punched by the rock two and a half million times.
I think I could take that on the chin.
You're pretty tough, kittie, but I'm gonna have to go with a rock on this one. But lightning is not something we even really fully understand because if you look at the field between the cloud and the ground, it's not actually enough. They can calculate how big an electric field you need to make this ionization to create a tube of plasma, and then they measure the electric field and it's not big enough, so they don't actually understand like where all that energy is coming from. One theory is that maybe it's cosmic rays, like particles from space shooting through the cloud with incredible energy, are maybe like sparking this lightning and making it happen. It's a field of open research right now, and people are doing things like trying to understand where in the world is there more lightning, because it turns out it varies a lot. Like Europe, lightning is much more rare than it is in like Florida for example.
M Yeah, that's interesting because there are and it seems like it depends on things like the environment, right, like the type of biome that you're in. And I've heard of things like ball lightning or something which I don't even know like if that's an actual thing that really exists, because it's really hard to document, but you know, it's something that people say they've seen, and it's always in like these very very humid areas. So it seems like having like a very different area, very different region, might affect the way that these electric charge forces work.
Yeah, we're gonna have a whole episode on ball lightning. That is a crazy bonker story with a lot of really fun history.
Oh I'm excited to listen.
But next, let's talk about your dog and your blanket.
Oh yeah, let's do that. I like my dog and I like my blank I've got a photo of her hair standing on end. Maybe I'll share that with you all because it's very cute. She doesn't seem to be bothered by it, and like I said, she loves this blanket.
So what's going on when you have like your hair standing on end, or when you're wearing a blanket and you get a zap on the carpet or something like that. That's static electricity. It's basically a miniature form of lightning. You know, lightning occurs when you have a strong electric field across an insulator. So the insulator there aren't usually electrons that want to move to create a current when you apply a field, But if you make a big enough field, it'll break down. It'll rip those electrons out of the atoms. That's lightning right. Well, static electricity is the same phenomenon, just over a much shorter distance. So you don't need a huge cosmic electric field to create static between like your finger and the doorknob, or between like you and your dog. You need a much smaller field, and so you can get a bunch of electrons like from one thing to another. You can eat this imbalance, you can create this electric field and you can get static electricity.
So I can understand the little zap I get from like my fingertip to the doorknob. But why do things stick to me? Like if I rub my socks on the floor, I can get a balloon to stick to me. You shared a picture of this cat covered in little pieces of styrofoam that are stuck to it, which I love this picture. Thank you for that. So why does static electricity make us sticky?
This picture is actually featured on the official Wikipedia page for static electricity. Well suggests everybody go to this famous cat that must must have had like the worst day ever, or maybe the best day diving around a bunch of styrophoaming nuts.
Looks like he's having fun.
Yeah, So this is static cling. If you move a bunch of electrons from one object to another, then there's going to be a force of attraction between them. And that's fundamentally what's happening here is that you're moving electrons from one thing to another. If you take a piece of styrofoam and you rub it on your cat, right, then the electron is going to move from one object to another. And now one of these things is positive and one of these things is negative, and so they're going to attract each other. So, now the styrofoam peanut is attracted to your cat because an electrical bond between them.
And it's got to be light enough, right, because the styrofoam and the balloon, these are both very light things. If it's too heavy then gravity is actually enough to pull that away from you if you're in a space station. Is static electricity like more powerful than it is on Earth?
Like?
Could you get something heavier to stick to you?
Can you get bowling balls to stick to your space cat? Is that what you're asking me?
Yeah?
Yeah, actually you could. That's true. I don't think anybody ever tried that. I'm going to try to get that listed on the official experiments we're going to do on then iss, that sounds great.
We need a cat, some styrofoam, and some bowling balls.
And so this is also revealing like the microscopic nature of charge, That charge is carried by these tiny, basically invisible little particles that can move from one thing to another but then have a visible effect. Right, it's this way the universe is like cracking open and giving you a clue that deep down there's something to learn about the tiny invisible world that makes up our visible world. So I love about this effect. And some living things, of course, have figured out how to use this to their advantage. They are, of course electrical eels, but they're also like fish that can like sense electric fields, aren't there?
Yeah, so electric eels are actually not true eels. They are knife fish, but there are multiple fish in the world, multiple like species in groups of fish that can sense and produce electricity. So one of these knife fish, which is sort of eel like, so we call it an electric eel, produces its own sort of electric field, and it's this electrophorus electricus, and that's the most famous one because it can really zap you because it produces quite a strong electric field.
So it's got some organ inside it that can make electric fields.
Yes, that's right. Which, so the way these organs work is it's similar to how our muscles work. So our muscles actually produce a little bit of electricity when they are activated. And so this is actually what enables electroreceptive animals like sharks and platypuses. Actually platypuses have electro receptors in their bills and so they can hunt down earthworms much like a shark can hunt down fish. Because both of these animals have electro receptors. Totally different species, totally different evolutionary path So in these electric eels, which are actually nine fish, they produce this electric field through an organ that is basically like a really kind of powerful muscle where it's the power is through the ability to produce this electrical charge, this electrical field, not in its ability to say, like lift weights. And so this is the case for a lot of species that produce this electric field. So what's interesting is a lot of these animals that produce electric fields also have electro receptors, so they are using their electric field to see their world. You know how dolphins and bats will send something out into the world and then receive information back in order to see so bats use sort of like a sonar where they send out a ping, a little squeak, and then they receive it back so that they can see dolphins the same thing. They're doing this with electricity, So they are generating this electric field, and if things in their environment disrupt this electric field, they can sense that because they also have electro receptors. And it actually this is evolved in multiple types of fish. So like there's also a fun one which I think is less well known than the nine fish, which is the elephant nosed fish, which has a really long nose. It's very goofy looking and it's actually not a nose. It's a protrusion of the lower jaw and it's got the best name of any body part in all of evolutionary biology is called this.
Is it safe for work?
It is safe for work. Yes, it's called the Schnauzen organ, which I don't know. Maybe if you speak a German it's not safe for work, but it sounds fine to me. The Schnauzen organ.
I'm sure it's very dignified. I'm sure it carries itself with great poise.
It's very goofy looking. And yeah, that Schnauzen organ contains all of these electro receptors, and then it also has on its posterior that electric field generating. It's much weaker than in that electric eel that I mentioned, but again it uses the same sort of method where it generates that field, and if there's disruption in the field, then it can locate things. It's like human sonar that we use in terms of like sending out a ping and receiving it back just using that electric field.
Wow, amazing, It's incredible to me. The humans have discovered this in the world, but the animals have been using this for millennia, right, It's something more natural intuitive. I wonder if it would have been easier for us to figure out how electricity worked if we had electrical organs, or if electricity played like a more tactile role in our experience, not just like within our nervous system and inside of our brains.
Yeah, if we had electro reception, you know, there could be a whole different method of communication.
Right.
If we had both an ability to produce an electric field and electro reception, maybe we could have formed some kind of communication that is like similar to telepathy, where we don't need to say anything, we just sort of detect the waves in our electrical fields.
Yeah, and then you could get phone calls without needing a phone, right, or here radio stations in your mind.
Fun.
I think the bigger picture here is that electricity really is a product of the quantum particle nature of our world. This is not just something particle physicists think about. This is something that we can experience day to day. The charge of particles, the forces between them, This is part of our experience too.
I really like how these patterns of how particles work on this quantum level also seems to be kind of reiterated in the more bigger picture, like on the macro level in terms of cell processes and in terms of like say, how a herd moves or how people move.
It's very interesting, it is fascinating, and of course huge questions remain. What is the charge of an electron? Why does it exist? Why do quarks have charges? Why don't neutrinos have Why does the universe respect to charge so so deeply when other symmetries and conservation laws are broken here and there and at the edges. These are mysteries. I hope one of our listeners will one day figure out, and then we'll invite them on the podcast to explain it all.
To you, and you'll write a paper titled what is going on?
Thank you Katie for coming along and for delivering the very best and the very last electricity.
Puzzy of the episode. Thanks for having.
Me tune in next time.
Everyone.
For more science and curiosity, come find us on social media where we answer questions and post videos. We're on Twitter, Discord, Instant, and now TikTok. 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. When you pop a piece of cheese into your mouth, you're probably not thinking about the environmental impact. But the people in the dairy industry are. That's why they're working hard every day to find new ways to reduce waste, conserve natural resources, and drive down greenhouse gas emissions. House US dairy tackling greenhouse gases. Many farms use anaerobic digestors to turn the methane from manure into renewable energy that can power farms, towns, and electric cars. Visit you as dairy dot COM's last sustainability to learn more.
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