Why don't we have electric airplanes?

00:00:08
Speaker 1: Hey, Katie, I have a question for you about the future. All right, Well, let me polish my crystal ball over here. All right, Well, I'm wondering what's the invention that will tell you that the future has arrived? You mean, what will make me feel like I'm living in a science fiction novel. Yeah, exactly, and not something like a global pandemic or climate disaster. Let's avoid, you know, dystopian futures. Well, I'm tempted to say transporters, or food replicators or sentient toasters, but I think the number one classic is the flying car. Nice. But you know, it makes me sure her to imagine what l A Freeways will be like when they go three dimensional. I thought you wanted to avoid dystopian futures. Yeah, you know, you're right, but driving in l A is a dystopia already. Hi. I'm Daniel. I'm a particle physicist, and I definitely want to be able to talk to sentient toasters. And I'm Katie, and I host a podcast called Creature Feature, and I think sentient toasters would be It would be an awkward conversation when you got to get your toast and spurnt like you weren't clear enough about how much you wanted it toasted. I thought, this is what you wanted. You're talking about an emotional toaster. Yeah, exactly. I would probably just eat burnt toast to spirits feelings. Man, you just identified a huge downside to AI, and now we have to worry about how everything feels. Oh my gosh, exactly. Well, at least we don't have to worry about how planes feel yet. Well. Well him to the podcast, Daniel and Joy explain the universe, in which we don't worry about how the universe feels, but we do try to explain all of it to you. We dive deep in the very nature of reality with the tiniest little particles are doing, what is real, what's going on down there, and we zoom all the way out to the hugest questions about the very nature of the universe, where it came from, where it's going, what it's got going on, and what it means to be human in this crazy, bonkers, beautiful, wet and wild universe that we find ourselves in. Usually I'm joined by my friend, co host and collaborator Jorge Cham the fabulous cartoonists behind PhD Comics, but he's on vacation today, and so we have our wonderful, hilarious guest host, Katie Golden. Katie say hi to everybody. Hi everybody. And one of the things we like to do on this podcast is not just wonder about how the universe works, but also wonder about how we can make it work for us. One side benefit to understanding the universe, of course, is fig hearing out what those rules are and then bending them to our will, figuring out how to make our lives the best they can be given our knowledge of the universe. Why understand the nature of the universe if you can't, for example, invent ascension toaster? Yeah, what the heck is the point? Like, come on, Daniel, get on it. Modern medicine, energy and dependence, none of that is nearly as important as sentient toasters. I want my toaster to giggle when I put a toast in it. Tickle ish toasters. Wow, this is getting a little personal now, But it does seem like we are making progress. I mean, I look around me, and I see a lot of stuff that exists that feels sort of like the future. You know. I think electric cars are maybe the best example, because every time I see an electric car sneak up on me super quiet, or accelerate from zero to sixty and like two seconds, I'm like, wow, this definitely didn't happen when I was a kid. It makes me feel that jarring effect when the world just changes quickly and feels like the very nature of human existence has suddenly shifted. It doesn't help that electric cars also have that spaceship noise, you know, when they kind of get close to you or it's like, oh, I think that's great. It makes it harder for them to sneak up on you, but yeah, it also does give them that futuristic vibe. I wonder if everything that's getting electrified is going to have like a weird space noise, like when you electrify your garden equipment. Is your lawnmower going to make like pep sounds? I hope. So. I think that it's really fun whenever sort of retro futurism becomes correct, like how the spaceship noises that cars make, or or ads being everywhere, and it does really seem like everything is getting electrified. Right, We're definitely aiming to reduce our dependence on fossil fuels and other dirty technologies that are harming the planet and causing global climate change and making it like very hot right now where I am. I'm in Copenhagen for the sun or and it is a ridiculous heat wave over here. I'm sitting in a little apartment, but I'm sweating down my back, and I'm sure lots of folks out there are experiencing the extreme weather we're having. So we were these sentient toasters the whole time. Are we the toaster or the toast ee? Sometimes I feel like the toasted or toast we don't do something about our dependence on falsil eules, we are definitely getting toasted. And so people have been making a lot of progress and lots of stuff is getting electrified. It's really cool to see. But you know, there is one industry that still relies entirely or exclusively on fossil fuels, and that is jet airplanes. It's one of the saddest parts about traveling, where you think, well, there's no way to travel without using an immense amount of fossil fuels. But it's also so exciting that planes have brought our world so close together so that you can fly from the US to Copenhagen, or I can fly from the US to Italy, and so what the heck, where's our electric planes, Daniel, Exactly where are our electric planes? Because we all know that it might require some sacrifices to adjust the patterns of human life so that they're more amenable to you know, having our grandchildren and not be living in caves, for example. But we hope that we don't have to give up international travel, because yeah, that changes the way the world feels. And it would be weird if we have to go back to a place where, you know, it took a long time to get to the other side of the planet, where China was like days or weeks or months away. Imagine if you had to sail to get to China or to Japan or the far East. You know, all of human culture would have sort of a shift in reverse, and it would look really weird in history, how things got closer and closer and closer, and then for like a hundred years or fifty years, the world felt like one place and then it cracked and broke again into various regions. It would be weird if that was just a moment, a window in history. Yeah, that wouldn't be good, especially in terms of cuisine, because you know, we would just suddenly have the stagnation and probably the British would have to go back to eating like weird horse parts. And in America, I don't know what we would do. I don't know what American cuisine would look like without a steady flow of people from other countries, but I don't think it would be pretty. Oh my gosh, beans on toast all over the world and so on the podcast today, we'll be asking the question why don't we have electric airplanes? If we've made so much progress electrifying everything else, toasters and garden equipment and boats and cars and all sorts of other stuff in your life, why don't we yet have electric airplanes? Why can't we make airplanes that are smooth and quiet and zero emission? And this is what some of you had to say about why we don't have electric airplanes, some very clever responses, that's right. So before you hear these responses, think to yourself, do you know what the limitation is for electric airplanes? And if you'd like to participate for future podcast episodes, please write to us two questions at Daniel and Jorge dot Com. Here's what some listeners had to say. We have lots of electric hairplanes, but we don't have electric versions of say commercial passenger airliner type power planes because we don't have good enough batteries. We don't have a way to store electricity that's as energy tense as Jeff Field. I'm going with weight on that one. Well, actually airplanes can list a ton of weight. I'm going with storage capacity or or weight and storage capacity. I don't know if we could put some batteries together that could could put out that much thrust or that much force for hours at a time and not just run out or overheat for that matter, because they need more power, and our electric motors aren't powerful enough to fly a plane like they're okay for driving cars, but not for flying planes. First store on electric planes would be the electromagnetic field is so much stronger the further way you get. Let that be less parties in the air. So I guess possibly that would be an issue with running batteries that high, having a wonder perhaps to set the batteries. I guess that the rhythm for which we still do not have any electrical airplanes, there are technical limits in the energy storage. I think that the batteries are still too bulky. Maybe the storing of energy to make them a viable solution for commercial flood. I'm thinking right now that we can do you know, like those trolleys or tramps that you have the electric cord and you just touch it and you can go. We can do that, like we can we can actually to a zip line between us, like North America and Europe and other continents and do this electric zip line, electric hipplanes. I don't know how you would get the propulsion with an electric airplane. Besides, it probably would be extremely heavy. I feel like people came up with some pretty good ideas. I mean, speaking as someone who knows very little about batteries and how they might go inside of a plane. I do like zip lining electric airplanes. I like the idea of a trans continental zip line. Trans continental zip lines. Wow, that seems pretty crazy. I'm not sure I'd feel comfortable like snapping into a zip line where I can't even see the other side, and it's like stretching over the ocean. I mean, they're gonna give you like a boat to fall into inciece it snaps. I don't think that would help some like inflatable raft or something like, I am definitely not glibing into that. Yeah, just hold an inflatable raft under you and it'll be fine. There's some good questions in here also, like the basic question of how an electric airplane does propulsion? Right, how does it even move forward if you're not burning gas and exploding the results out the back of a get engine? How do you even get propulsion in an electric airplane? Which is a good question. And then of course lots of good stuff about batteries. So why can't we just plug a plane into a battery, make a big old battery and get it going, Because it seems like if we can get a car to go, you know, we should just be able to scale that up to plane size. Why don't we just like strap a bunch of testla's together and launch it into air? Right, there's already tesla's in space, so we got them above the air and below the air? How going to be so hard? Well, it is tricky, And you know, to answer one of those listeners questions about the propulsion mechanism, essentially we're talking about fans right about like turbo props, just like in a tesla, you have a battery which then binds an electric engine and that engine pushes the air back. So you don't have a jet engine. There's no electrical equivalent of a jet engine, but you can spend something, and spending something is a fantastic way to get airborne and to get this sort of forward thrust you need. But the real issue with an airplane is that airplanes need a lot of power because you need to move forward to get that lift over the wings. That they also have to be light like. This is not as much of a constraint on a car. Car just sits on the ground, and you prefer it to be lighter because then you get better acceleration. But it's not like it doesn't work if it's heavy, right, And so for an airplane you have this delicate balance between power needs and weight, and batteries are not great at that. Now, hang on, Daniel, you say that airplanes need to be light, but if you've ever tried to power lift and airplane all on your own, I think you would find it's pretty heavy. Right. Airplanes are pretty heavy. These things do weight tons, but there's a limit, right, If you're heavy enough off then they just cannot take off, or you need an impossible amount of thrust. What you really need is energy density. You need lots of power per unit weight. If you just don't have enough power per weight of your fuel or of your battery, then you're not getting up off the ground. You can get off the ground if you're really heavy, as long as you have enough power for all that weight, right, which is how, for example, a seven forty seven gets up off the ground because its engines are enormous and the energy density of its fuel source is pretty good. And that's why we use so much fuel for a plane. Right, That's right, that's why we use so much fuel. And you know, this actually reminds me of like the rocket ship problem. You know, taking off from the ground into the air is similar to like accelerating a rocket or lifting a rocket up into the air. When you lift a rocket, you know, it's only like the very tip top of the rocket that actually is like the payload, maybe the satellites or the people or whatever. Most of the rocket below it is fuel because you need to lift a bunch of fuel to lift the rocket. And then because the rocket is so heavy, you need more fuel to lift the rocket, and it exponentially takes off and pretty soon you're mostly fuel. And so that's the same problem with an airplane is that if your energy source, like a battery, is too heavy, then you need more power to lift that heavy battery, and so then you're gonna need to bring more batteries, which are also need more power to lift them, and pretty soon you're trying to fly the Empire State building. So if a human was a rocket or an airplane, basically we'd be legs filled with like food, just kind of splashing around and then like a teeny tiny head and teeny tiny body. That's disturbing. Oh, I love the biological analogy. Imagine if your stomach was like of your volume. Wow, they'll take a lot of toast. And really the issue for batteries replacing jet fuel is that it just doesn't compare in terms of energy density like jet fuel. The reason it's so amazing is that it's super duper concentrated. There's so much energy packed in per kilogram of jet fuel because it's basically ancient sunlight that's been like boiled down into this chemical that stores that energy super duper effectively. So if you get a battery that could do the same amount of work as jet fuel, the battery is going to be a lot heavier. The battery is going to be a lot heavier exactly. So we measure this in terms of energy density, so that's like energy per weight, So like what hours per kilogram And you know, what hours is a really weird unit because what's are like energy per time and then you multiply by time to just get energy back. So I understand why they don't just use energy instead of what hours. But anyway, this is sort of the standard, and jet fuel is really really good in terms of energy density. It has like twelve thousand what hours for every kilogram of jet fuel. And if you're not familiar with what a what hour is, here's like a stat of get you acquainted. Like one person working for eight hours doing manual labor can do about five hundred watt hours of work in an eight hour day. So that's half of a kilowatt hour in an eight hour day. So that's what you know an individual person can do, So that's what watt hours. That's a lot of wat hours. And you know you've probably, for example, looked at a light bulb and saying, oh, this light bulb is a hundred watt bulb that measures how much energy it uses per time. And so for example, you have a hundred watt bulb, it takes ten hours to use a thousand watt hours because a hundred watts times ten hours gives you a thousand watt hours or a kill a watt, So it gives you a sense for like how much a kill a watt is. And jet fuel is really concentrated, has twelve kilowatt hours per kilogram of jet fuel, So like a kilogram of jet fuel, which is you know, a couple of pounds of jet fuel is as much energy is like twenty five guys working all day. So this stuff is really really dense with energy. All right, Well, if we get a bunch of guys in an airplane on a giant hamster whale running the engine, I think we've cracked it. The problem is twenty five guys weighs a lot more than one kilogram, right. That's the amazing things that there's all these energy in one kram of jet fuel. What about real, real little guys, tiny elves that could do is much work at twenty five grown men. Santa's really onto something that's why I uses elf labor. That's the amazing thing about jet fuel, and you know that's why it takes millions of years to boil it down from sunlight into plants photosynthesizing and then decaying and then getting compressed and turning into jet fuel. It's amazing stuff. It really is pretty incredible. It's just too bad. It's so bad for the environment. Yeah, because when you think about it's like Earth has been creating this fine wine for millions of years, just incentrated sunlight, and then we just kind of burn all of it up. It's too bad that we're not a little more respectful of this the stuff that Earth has been cooking and storing so much carbon in for so long. That's right, Well, I guess we will be when we run out of it. And so the relevant comparison, the reason that like batteries can't power an airplane right now is that they just don't have the same energy density. They have about two hundred and fifty watt hours per kilogram. That compares to twelve thousand for jet fuel. So it's a factor of like forty or fifty. Jet fuel has forty to fifty times as much energy per kilogram than like the best batteries we have today. I understand why jet fuel is light because it's super concentrated, But why can't we get batteries to be super concentrated. That's a great question, and we'll talk about it in a minute when we talk about the physics of batteries and how people are working on making better battery But first let's take a quick break. So I just asked you, Daniel, why can't we make batteries super concentrated, Like maybe put a super dense neutron star inside a battery, or really muscular hamster and a hamster whale. How do we get a battery that is super dense but not too heavy that it takes down a plane? Yeah, Well, the answer is we're just not smart enough yet. It might be theoretically possible to make a battery that energy dense, we just haven't really figured it out yet. And part of that comes from the materials we use to make batteries, of course, because you want really light stuff in your battery if you don't want it to be really heavy. But to dig into that, we probably have to have a better idea of like how batteries actually work. Yeah, because when I look at a battery, it just this little canister of mystery that I put into my clocks and my remote and it makes them go. But I just think of, like, Okay, I know there's acid in there, right, because when I leave battery out for too long, it this acid spills out. But the rest of it is very mysterious to me. Yeah, batteries are actually really amazing, and I have a lot of fun digging into the chemistry of how batteries work. So this is gonna be like between my expertise and yours, because like I think of chemistry sort of sitting between physics and biology. But it's still pretty fun stuff. Kudos to all the chemists out there, of course, we love you. Yeah, well, let's get chemical chemical. And so the way battery works is you have to have two different kinds of materials. Each one sits in sort of like a fluid like an electrolyte, and you've got to find two different weird metals. Metal number one has some kind of atom that really wants to dissolve into that fluid, and when it does so, it leaves behind an electron. So you need some sort of like kind of atom that has like an electron and its outer shells that it really wants to get rid of, and it's dying to like dissolve into this liquid so that when it does, it leaves behind that electron in like the bulks, you like a slab of metal, and it's dropping little bits of that metal into liquid, and it's gathering extra electron so it's getting more and more charged as it happens. So that's like metal number one in one quarter. It's becoming more and more like electronified. Right, It's just very annoyed with its own electron, so it's trying to escape by dissolving and then leaving behind a bunch of annoying electrons. And then on the other side, you've got the opposite situation. You find some metal whose atoms really don't want to leave it, like they want to reattach if you have them in solution. They want to like precipitate out of solution and back onto the bulk. But to do so they need another electron, Like they want to form bonds with their friends back in the blob, but they can't do it without another electron. So you have this material here that like wants electrons, and then you just connect them with a wire, and what happens is that all the extra electrons from metal A will flow along the wire to where the electrons are wanted, because that's what electrons do. They go where they are needed, right, And you might wonder like, well, how did the electrons know to go from A to B. It's not like you know this little electron monster dot com where it's like advertising for electrons over here, please Craigslist for electrons, miss connections, looking for a metal who needs an extra And it's fun to think about electricity microscopically, and the key to doing that is remembering that in physics everything is local. Right. There's never like piece A says to piece B, hey send me all your electrons, or the other way around, or here come a bunch of electrons. Everything is super local. It's all about like one particle talking to another. And so at some point along that wire, you're gonna have a spot where it wants an electron. It's ready to take an electron. It's gonna be next to a spot that has an extra electron. It's gonna be like the interface and it's going to suck up that electron because that's what it can do. Wanting an electron means that there's like a low potential left for an electron to fall into. And then because it's stolen an electron, now another electron further down the wire is gonna say, I'm crowded over here with all my friends the extra electrons. It's gonna slide over into that empty spot. And then essentially that just happens over and over again. So it's kind of like a relay racer or what am I trying to say? What are those things where you're like, are in a big line and you're passing one item down the line. It's like an assembly line. Yeah, that's what I'm trying to think of. Exactly, Yeah, exactly. It's just like an assembly line. And the net effect is that you get electricity because you're moving electrons from one side to the other. They're flowing through the wire and so you get electricity flowing from that wire that connects A to B. So A will dissolve more, getting more and more electrons flowing along the wire to be who needs those electron to let its lost bits reattached to its bulk. So that's what a battery is. You just gotta find metals with those properties and suspend them in this electual light, connect them with a wire, and boom, you've got a battery. And that's to release the electricity. If you want to recharge the battery, you just have to somehow force electricity the other way. You put a potential across it and drag the electrons the way they don't want to go. Then the opposite chemistry will happen. All the depositing and dissolving that we're happening before will reverse. And that's how you recharge a battery. You like, return it to its original state. And so that's the physics, and I guess the chemistry and maybe the psychology of how a battery works. That's what happens every time I recharge my phone, when I let it get down to like one person and just forcing all those electrons back and reverse in their congolne and I imagine they're not too happy about it exactly. Now we have to worry about the feelings of individual electrons. Man, I'm never gonna get anything done. Gotta right so many I'm sorry cards to those electrons. Well, maybe we should just do everything democratically right. Every time we make a decision, we have all the particles vote, and then we just do what everybody wants. I'm not sure we're gonna get anything done, and I feel like that would be very explosive if we talk to certain electrons. And so the thing that limits us the thing that tells us how energy dense the battery is, because remember our goal here is to have a lot of energy stored with a very few kilograms. Are the weights of the materials we're using, right, and here, for example, lithium here is an excellent, excellent choice for building batteries because lithium, for example, is on that side of the periodic table where it really wants to lose an electron, right, And so it's very good for building this kind of metal. And then you can mix it with other kinds of stuff like cobals and other stuff, and you can get the opposite kind. You can get both A and B. You can get the depositor and the dissolver using lithium. And lithium also is pretty low on the periodic table, so it's not that heavy, right. It's elm at number three after all, right, so we've already got a pretty light metal. It's just not not light enough to make these batteries as light as gas or as light as Jeff fuel exactly. And the key is what lithium is connected with. It's not pure lithium, right, These are lithium ions and lithium alloys, and currently we use things like cobalt in there to make the particular mix of elements. We need to get a good dissolver or a good deplet, and so that's really the key is how much energy is released per electron that moves from A to b, right, And so if you can get either more energy released from A to B, which depends on you know, the energy levels of the atom you're dealing with, or you can get the atoms to be lighter, then you can get a better energy density ratio. And that's exactly what people are working on. First of all, people are working on like making lithium ion batteries more powerful without switching to some new kind of technologies and new basic element and people are working on that every year, like shaving off a little bit here, making that more efficient, or tweaking with a kind of you know, mixtures of stuff that you need. And we're seeing some improvement like the lithium ion batteries that we have now have twice the energy density as the first prototypes that were invented in the nineties. So that's some pretty good progress. Yeah, our phones keep getting smaller or sometimes bigger, depending on what people want. I can't figure it out. They're getting thinner but wider, and eventually our phones were able to toast bread and maybe even fly across the ocean. Sure, I'm into it. But yeah. So we have the lithium which really wants to shed its electron that people are working on to maybe make that more either more efficient or try to use another lighter element than lithium. Do we have any issues with the dissolvent, Like what is the other metal that is trying to get the electron? Yeah, it's mostly lithium, but they mix in the cobalt and other kinds of stuff in there, and you know, without getting too nitty grady on into the chemistry of folks I talked to said that they think that lithium iron batteries might be able to get twice as energy dense as we have them today. Right now, we're like two hundred and fifty watt hours per kilogram. We might be able to get to like four hundred five hundred by twenty five, So that's a factor of two. That's pretty good, but that means we're still like a factor of twenty away from jet fuel, and that's not going to make for an economical airplane. We'll have way for thin phones though. Yeah, Well they just get bigger and bigger and last longer and longer, and people won't care. I keep pushing for a smaller and smaller phone. Everybody around me has these like basically these like many tablets in their pocket. I don't understand. Maybe I have just like little pointy fingers, but I'm also team small phone. It's kind of fit in your pocket or it's not a phone, right right exactly, it's gotta fit in girl pockets to people, scientists either invent girl pockets that are bigger, phones that are smaller. Pick one. My daughter is discovered this also that like pants for women don't have real pockets, and she is outraged. She's like, what's the deal here, Like, why do I have to wear men's pants if I want pockets? It doesn't make any sense. Sometimes the pockets are just a ruse to it just looks like a pocket and there's nothing there. So you know, we need to crack the code for electric airplanes so we can save the planet, and we need to crack the code for women's pockets so we can put freaking phones in there. Guys, we might be able to solve the secrets of the universe on this podcast, but I don't think we're ever going to crack the secrets of fashion. That is definitely just beyond us. But back to the researchers. You know, these folks have been working on this for a while and the actually want a Nobel Prize in two thousand nineteen for the development of lithium batteries, Like it was a big step forward when people were able to make lithium batteries work. They're much lighter, much more rechargeable, much more efficient, and also more cycles than other kinds of batteries. Like, you want a battery that can hold a lot of energy. You also wanted to be reusable. You don't want a disposable airplane, right, You don't want a car that you charge it up, you use it and then it's done. I do imagine what the disposable airplane. It just flies from airport a right into a junkyard where people disembark. I know, I know, and we're all experienced with like lithium batteries working really really well when you first get your phone or your laptop and then degrading. That's because they start to grow these like filaments and deposits on the surface of the lithium bits that prevent them from depositing or depleting as well. But they've gotten pretty good. You know, a laptop, for example, they expected to be able to recharge it like five hundred or a thousand times over the lifetime of the laptop, and for a test level for example, the goal is that it lasts like ten years, which is something like, you know, maybe three thousand charges. So lithium batteries already really impressive. I feel like we're sort of already living in the future for lithium batteries, but of course they're not yet good enough. Yeah, I mean so, because if we wanted to make a really tight plane, we could potentially have a battery strong enough. Could we have like personal a plane for one person that could have a modern day battery in it? Or they still not efficient enough. No, we'll talk about that in a minute. And you can probably have electric airplanes for a smaller number of people. But if we want to do like you know, cargo or seven forty seven's, that's going to be a challenge. And so people are working on other technologies to improve batteries. The problem is that some of them are also not that stable. Right. You want something that has a lot of energy per electron and can also can give that up and doesn't weigh a lot, but some of these combinations are literally exclusive. This is what I was going to ask, because we've seen these stories of Tesla's just spontaneously combusting and driving around on autopilot while on fire, which is bad enough for a car, it seems particularly frightening if it's a plane. Yeah, exactly. And you know they have these limitations like even checking something in your luggage that has a lithium battery in it for that reason, and so people are really careful about the stability of these things. And some of these technologies that people are working on for the future of batteries involves like lithium in combination with oxygen or lithium in combination with fluoride, because fluoride is very powerful and very and much lower on the periodic table than cobalt, so you can get a lot more energy like per electron, maybe even up to twenty times are current batteries which would bring us like in the realm of jet fuel, But it's very tricky and nobody's really sure if you can make a lithium fluoride battery work and if you can overcome the stability issues. Right, it seems like when we try to have some of these really really light flying aircraft options, sometimes it kind of ends up in a Heisenberg Lindenburg Lindenburg Heisenberg's uncertainty principle for really futuristic planes where the plane just blips out of existence, and the Hindenburg for the more balloon shaped planes. It seems like a very significant problem because every kind of engineering issue that you would have on the ground is going to be even more drastic when you have it in the air, because you have this giant hunk of metal that you do not want to suddenly explode and lose that sort of airborne nature. Do you know, like how we make these chemicals more stable? Are people working on trying to get them to be safer or is it just too hard to get these combinations of chemicals to be stable. People are definitely working on it, and Mad props to these folks, because this is crazy materials engineering. You know. It's not like you start from legos and you get to build anything you want. They can do anything you want. You got to start from the materials we have around and the properties that they have, you know, and so you're very limited in your toolkit and combining these things in just the right way to get the electron transfer without being explosive. It's a real challenge, and there's lots of folks around the country working on this stuff because not only would be like hugely valuable, right, like to be able to make batteries twenty times as energy dense as the current ones, Like wow, that pattern would be worth a jillion dollars, but also it's a fun puzzle. You know. I work at like the smallest little particles and think about how you can combine them to make other particles. But this is much more difficult. These folks really are limited in the toolkit they have, and so mad props to everybody out there creating new kinds of goo and all sorts of new materials that have these weird electronic properties. Maybe someday we could have just like a sort of bag full of liquid, like a water balloon type thing we put in a plane. That's just is a big old squishy battery. Well good chemicals. That would be cool, especially if the battery could get used up and smaller. Another real downside of batteries we haven't even talked about is that the battery doesn't like shrink as you use it, right jet fuel, as you burn it up, it disappears. So seven forty seven is much lighter when it lands than when it takes off, and so it's like not using as much jet fuel for the second half of its trip as it did for the first half of its trip. But that's not true for a battery, right. A battery doesn't get lighter as you use it up, and so that the airplane is just as heavy in the second half as the first half. So they actually would have to be more energy dense than jet fuel to have the same basic economics. Not if we make strip poker compulsory on planes and everybody has to participate and throw their clothes out the win though, wow, and what if those clothes have AI and then we have to ask those clothes, you know, how do you feel about this situation. Yeah, darn it, darn those super intelligent shirts. But I want to hear more about my own personal aircraft. But before in, let's take a quick break while I see if I have enough money to buy myself my own personal little bubble aircraft. I think I've got some change in my couch I'm going to go through, all right, So, Daniel, how am I going to get my little electrified Katie plane that can just carry me and maybe my dog across the Atlantic just on a whim and I park it in a garage? Like how close are we to that? Well, you know that might be a reality pretty soon. This energy density issue is an issue for long flights where the plane is really really heavy and you need to go really really far. But if you're willing to take a smaller, lighter airplane or just not go as far, then it's totally possible to have electric air planes. And some of you might even remember that crazy flight of the Voyager that was solar power. Remember that one that flew around the world for like twenty four hours. That was an electric airplane because it took energy directly from the sun and used it to power its motors. Yeah, because when you're flying a plane usually you get above the cloud cover. So it seems like having a solar power airplane is a pretty good solution if you can get it to work. If you can get it to work. And the key for that airplane was it was super duper light and had almost no cargo, and the pilots, for example, like lost a bunch of weight before they even took off, you know, like they didn't even bring a toothbrush along. You know, this is very very much on the edge of what people could do. So you definitely could not use solar power to power a large, heavy airplane where you're actually carrying stuff and people. But it turns out that the biggest part of flying actually is not like launching seven forty sevens from here to China. Most of the people who take airplane chips don't go internationally or you know, from l A to Sydney. Something like half of the airline tickets sold last year were for shorter trips like under five hundred miles, and the airplanes that we use for those trips right now are actually ones designed for much longer flights. And so it's really pretty initiaient right now. We're using these like airplanes designed for thousand mile flights on all these short little hops. So I sense that you're saying flying cars from l A to San Diego? Am I wrong? Yes? Exactly. You know, like if you fly from LA to San Diego, it just like a hundred miles. Then the airplane basically never has a chance to get up to cruising speed where it's most efficient for using jet fuels. So it's like always speeding up or always slowing down, and that's really inefficient, and so it produces a huge amount of CEO to sort of per mile. And so instead if you develop like smaller airplanes that are not capable of doing these longer flights, but are only capable of doing a hundred three hundred, five hundred mile trips, and you don't need as much energy because the whole plane is smaller, is lighter, and so that opens up this window where you can like satisfy a huge fraction of air travel much more efficiently than you can with jet fuel. So with these planes, they would take like the pilot and then maybe ten people or something like little little tiny commuter planes. Yeah, that's the kind of thing we're talking about. And people are working on lots of different kinds of stuff, and this is real. This is not like, you know, people are doing research and maybe this will happen in twenty six. You know, United Airlines invested a billion dollars last year in an e plane startup. This is for an aircraft that's designed to fly like up to sixty miles and just carry like five ish people, and they're expecting to have like commercial flights in twenty four. So that's basically around the corner. Like, this is a billion dollars by a big company. This is not like, you know, somebody investing a million dollars on a whim. This is a real investment. This is kind of thing that's actually going to happen. Now, do these aircraft like get up to the altitude that the larger planes do. Are they more low flying? Yeah? I think for shorter flights you don't need to get as high, but you definitely want to get up to a certain height for the lower air pressure so there's less resistance and then you can be more efficient. But there are people working on all sorts of different scales of these things. You know, there's some people working on even larger ones. The largest plane anybody has made so far that actually has flown, like in reality in our universe is like a retrofitted version of a Sessna and it can take nine passengers and it's fully battery powered. And this is something that like exists today. Yeah, that's really interesting. I mean, it's kind of like because when I think about some things that feel like impossible flying feats, I think about the Quotquotalists, which is this ancient pterosaur which is like a pterodactyl but the size of a small Cessna aircraft, which after researchers found its bones, they thought, okay, maybe it has wings, but maybe it just didn't fly because it was so big. But they were able to work out through physics and math that yeah, they could actually fly, and they probably flew these long distances. But of course these things don't use jet fuel to fly. They just use the power of muscles and whatever unfortunate little probably proto mammals they were eating. So this idea that if a pterosaur can figure it out, it seems like we should be able to figure it out without using jet fuel. Yeah, and it goes back to the question you asked originally, like why can't you get this thing off the ground if you have enough batteries And the answer is you can. You can basically fly almost anything you want enough batteries on it. It just won't go for very long. And so if you want any distance at all, you've got to find that sweet spot between shorter distances and smaller airplanes so they can actually take off. And so that's what people are working on, and you know, people are hoping that like by twenty thirty, there might even be a electric jet that can fly like a hundred and fifty people up to five kilometers. Easy Jet is working with a startup called Right Electronic to develop this kind of prototype that might be in service in twenty thirty. So we have the technology today for these smaller planes to go smaller distances. And there's also really advantages. You know, we talked about the energy density of jet fuel, but we haven't talked about the cost. Like jet fuel, that's expensive stuff. As you say, it's been cooking for millions of years. You got to gather from under the ground, right, It's complicated, whereas electricity, you know, it just falls down on earth from the sun and you can create it in lots of different ways, and the cost of electricity is really dropping because of the amazing solar power build out, and so one of these assessments that was retrofitted with an electric engine, for example, it costs like five bucks to take a flight, whereas otherwise it would have been four hundred dollars in jet fuel. So airlines are pretty interested in this because that's a huge part of their cost is spending on jet fuel. And I, as a passenger and someone who does like the planet, I am also interested your pro planet. I'm pro planet because I live here. I'm biased, and so I think what we might see is like a real revolution in the way air travel works, because if you have a lot of these smaller, cheaper airplanes that can go shorter distances, then you can actually start taking advantage of a lot of little airports. Can ever drive down the highway you see like a little airport and it's basically nobody taking off. Well, there's tons and tons of these underused regional airports all over the country. We already have the infrastructure to make these short flights to go from like little airport to little airport. Those things already exist, and so all we need are the airplanes. Basically, it's just the airlines dominated from mega airport to mega airport, but smaller airplanes that can go shorter businesses and cheaper. We're gonna get like this much richer network of destinations. You know, that would really change the tapestry of big countries like the US too, because currently things like where jobs are located, where people can find work, even things like the successive farms depends on proximity to airports. And if you have more airports for commuters to be able to fly to, it seems like it'll mean that, you know, we won't have as much because right now we have this big problem of population density in these big cities where people have to crowd. You know, people wonder like, well, why does everyone go to l A or or San Francisco or New York, these big cities. A lot of places people are dependent on being near an airport, And so if we kind of spread out the airports, it seems like we'll be able to have more jobs kind of spread out throughout the US. Yeah, exactly, And so I sort of look forward to that possibility where people can take these little hops from place to place on a quiet, clean, cheap electric airplane. That sounds like a lot of fun to me, But people, of course are still working on the long haul. We talked to the beginning of the podcast about like connecting different parts of the world, and you know, if you can't take a flight from here to Japan in twelve hours, if it really takes a lot longer to get there, if you have to take like, you know, fifteen little hops to get from here to Japan, it really would make the world feel different, and so it's definitely worth working on. But you know, it seems hard to understand how we could get there unless we manage one of these incredible breakthroughs in battery technology using like lithium fluoride. So people are being creative and working on like weird other solutions. One of my favorites is this idea of like wireless power transmission. We talked about like carrying the energy with you on a battery. But we've also talked on the podcast about crazy ways to get around the universe, on things like solar sales, which is this thing which you know, gathers the energy of the sun and uses it to put yourself through space. The advantage there is you're not bringing any fuel with you. You don't have to carry the weight of the fuel and then the weight of more fuel to push that fuel. So people are talking about like beaming energy to the plane, but if you don't have to have a huge battery, you just like fire a laser at a spot on the plane. That's like absorbing that energy turns into electricity and then spins the engines. But if someone gets in front of that energy, being like say a flock of birds, they just get bisected. Right, Yeah, exactly. And this is sort of similar to what we've talked about on the podcast. Another time, we talked about space based solar power, like gathering energy up in space and then beaming it down to Earth using either lasers or microwaves. It seems a little bonkers, like you're inventing a death ray, but you know, people have tried this. NASA has actually done this demonstrate this technology with like a small unmanned solar craft that you could like beam energy to it and like recharge its batteries and it can fly longer because it doesn't have to have as big a battery if you can recharge it. I'm not sure how they would do that for like international flights. I can have to have like laser stations in the ocean to like recharge these things or beam it down from space from satellite. The whole thing seems kind of impractical, but you know today's impractical idea. Maybe it is tomorrow's future. But it would if you did get in the path of one of these energy beams, you would be toast right, because that seems like you would need a pretty concentrated high energy thing there. Or are they not as deadly as they sound? No, you're exactly right. And in the case of space based solar power, they avoid that by having the beams not be very dense and having like really large collection stations on the ground. But you can't do that for an airplane, right. An airplane is the size of an airplane, and so yeah, basically you're like zapping death rays in the air all over the planet just so you can go to Japan and do some shopping. Right, you'd have two problems if you miss the plane. One, the plane wouldn't get its energy and that would go down. And the other whatever you're hitting on the ground is not gonna be too happy with having its atoms completely rearranged. Yep. And then on the other side from like zapping your airplane with a hot laser, is the idea of bringing other kinds of fuel or like a hybrid. Remember when we went to electric cars, we didn't go straight to electric cars. We went to hybrid which had like you know, gas powered engine that could recharge your electric engine, and the electric engine which is for like getting around a little bit around town. Well, people are talking about hybrid approaches to airplanes where you have like a battery, but also you bring something along like hydrogen, which is like a fuel cell that can create electricity. And the advantage there is that, like hydrogen is much more energy dense than a battery. It's not quite as good as jet fuel, but it's much better than a battery, so you can like effectively bring along more energy. I'm getting a deja vu though, talking about hydrogen gives me an unsettling sense of deja vu with other aircraft that maybe shouldn't use exactly that is dangerous and all. So these fuel cells have to be very cold, like negative four hundred and twenty three degrees fahrenheit, and so not only do you have to bring the hydrogen, but then you have to bring along like very complicated cooling equipment to keep this thing frozen, and so it gets very complicated very quickly. But you know, there's some nice advantages to these hybrid solutions because you can do a little bit of this and a little bit of that. Right, we just don't want like a Hindenburg situation with the hydrogen. Nobody wants that. And you know, we could also do some other kind of combination where you have like some hydrocarbon fuel like jet fuel plus some batteries as a hybrid, and there are ways to do that in a sustainable way. We can take solar power, for example, and use it to generate hydrocarbons to like pull carbon out of the air and generate our own synthetic fuel and use that to power our airplanes. And then you know, when you burn it, it releases that carbon back into the atmosphere, but you've already pulled it out of the atmosphere to make the fuel, so it's not like you're releasing ancient carbon there that was stored millions of years ago back from the atmosphere. It's like fresh carbon you just took onto the atmosphere, store into fuel, and then release again. So there are ways to make like hydrocarbon fuels that are net carbon zero for the planet, and maybe combine that a little bit with some batteries and some electric propulsion and you might get net carbon zero long haul electric airplanes. That'd be cool. I just hope that's not too explosive exactly. And the bigger picture is that we have lots of ways to get there. Maybe improved battery technologies will let us get to the same energy density as jet fuel, or maybe some of these other clever, crazy solutions will let us get enough energy stored on a really huge plane to fly at halfway across the world. But even if we don't, we have bright prospects for short hop electric airplanes that can get you from LA to San Diego, or from New York to Philly, or somewhere else to somewhere else, And so I think we'll be seeing those a lot in our life, and pretty soon it's going to feel kind of like the future, you know, now I think about it, giant death ray is getting you from l A to Japan actually seems really cool, and I'm kind of on board. It's pretty metal. It does sounds like something in a science fiction novel. And maybe it can automatically toast your bread right just so to stick your bread out the window and it gets zapped by the laser. Killed two birds with one giant death ray. All right, well, thanks everyone for listening. If you're going on this crazy electrified ride with us, stay tuned for more episodes about everything that's crazy about the universe and the future of technology. Thanks for listening, and remember that Daniel and Jorge explained The Universe is a production of I Heart Radio or more podcast For my heart Radio, visit the I heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows. No