SciShow Tangents - SciShow Tangents Classics - Waves

Episode Date: June 21, 2022

Inspired by last week's episode about beaches, we decided to take the week off and catch some rays. Please enjoy this encore presentation of our episode on Waves, and we'll be back next week!SciShow T...angents is on YouTube! Go to www.youtube.com/scishowtangents to check out this episode with the added bonus of seeing our faces! Head to www.patreon.com/SciShowTangentsto find out how you can help support SciShow Tangents, and see all the cool perks you’ll get in return, like bonus episodes and a monthly newsletter!And go to https://store.dftba.com/collections/scishow-tangents to buy your very own, genuine SciShow Tangents sticker!A big thank you to Patreon subscribers Garth Riley, Tom Mosner, Daisy Whitfield, and Allison Owen for helping to make the show possible!Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Ceri: @ceriley Sam: @im_sam_schultz Hank: @hankgreen

Transcript
Discussion (0)
Starting point is 00:00:00 Hey everybody, Sam here. Last week's episode on beaches inspired us to get outside and enjoy some summer sun. So we're taking a break from tangents this week, but I thought, what better compliment to our beach episode than our classic episode about waves? So please enjoy this encore presentation as you lounge in the summer sun,
Starting point is 00:00:19 or, you know, drive to work, or do dishes, whatever you do while you listen to podcasts. See you next week. Hello and welcome to SciShow Tangents. It's the lightly competitive knowledge showcase. I'm your host, Hank Green, coming to you with a new quality of audio. I'm not saying it's worse or better. I'm just saying it's new because it sat down to record this podcast and my computer
Starting point is 00:00:47 gave what Apple calls a prohibitory symbol. So I got a prohibitory symbol, which is not a great not great. It's just not great. It's overall not great. You got the Ghostbusters logo on your computer and it means that it's fucked up.
Starting point is 00:01:04 Yeah. My computer is very afraid of ghosts, but I am joined by our resident science expert, Sari Riley. Hello. Sari, should my computer be afraid of ghosts? Well, maybe if a ghost possesses your computer, then it'll start working again.
Starting point is 00:01:21 But do fun, quirky things to your files so you won't have to put all your creative input into it. The ghost will also help. So probably not. That sounds awesome. I'm looking forward to it. And I'm also joined by our resident everyman, Sam Schultz. Sam, should my computer be afraid of ghosts?
Starting point is 00:01:38 Absolutely. Everybody should be afraid of ghosts. They're all around us at all times. And they're watching, waiting, until they can pierce the veil and scare us uh what's a worse outcome really than oh hello computer ghost we welcome you to the podcast it's in the room oh no oh is that gonna happen through the whole? How do I make that stop happening? Well, you take a hammer. Oh, God.
Starting point is 00:02:07 There isn't much that is just more just like stubbed your toe annoying than a computer that like your job is to work. I cannot do shit without you. And it's like, I think that I've I think I'm done. I've lived a whole eight months and that was long enough for me. And I'm going to need you to go through about 10 hours of solid work to try and fix me before you give up and get a new one. That's the worst part is how weirdly physical trying to fix your computer is. And you're just like crawling all around it,
Starting point is 00:02:39 pushing buttons and holding different key configurations. Yeah. Horrible. Oh boy. So every week here on Tangents, we get together to try to one-up a maze and delight each other with science facts while also trying to stay on topic
Starting point is 00:02:52 and being way too stressed out about the situation regarding the data on our computer right now. Our panelists are playing for glory. They're also playing for Hank Bucks, which I'll be awarding as we play. And at the end of the episode, one of them will be crowned the winner. Now, as always, we're going to introduce this week's topic with the traditional science poem this week, according to my show notes from Sari.
Starting point is 00:03:15 I wave to you, you wave to me. The wave goes through a crowd. We talk about the wavy sea or waves of grain and fields plowed. Waves propagate to and fro in brains and ponds and air, but to add some flair, let's go where electromagnetism is. It's pretty cool there. Imagine a guy surfing on light, their arms are out as if in flight. The peak to trough gives us amplitude, how bumpy the journey is for this dude. More extreme highs and lows are what makes colors brighter, they tend to strut. While wavelength goes from peak to peak
Starting point is 00:03:48 and helps determine frequency. If the waves go faster, the hertz are up. But they can be long and gentle like a warm-up. And that's where all this stuff gets weird, because infrareds are longer and gamma rays are feared. Well, roses are red and physics is mathy. That's all I got.
Starting point is 00:04:03 I'm not going down that pathy. Really, really good. Yeah. I mean, that is how I feel about waves where it's like, okay, a wave. I've seen those. And then I can sort of like kind of get a sound wave. And then it's like, also, there are space waves in space. And I'm like, shut up, go away, I'm done.
Starting point is 00:04:28 Yeah, or like thinking that a radio wave, like the wavelength is as long as a building. I'm like, what does that even mean? What? What the heck? I can't see it. I can't really imagine it. And how are you picking that up?
Starting point is 00:04:42 How is my radio picking up a building wave? Yeah. And also people now these days are always like, well, what you have to understand is particles are just excitations, like waves in fields, just field excitations. I'm like, no, I'm not just excitations in a field. And if I am, I don't I don't want to know about it. Are you saying everything is waves? Yeah, everything's kind of waves. Everything's kind of particles and everything's kind of waves.
Starting point is 00:05:10 That's the wave-particle duality. And that's all we're going to say about that. Is that a real thing, the wave-particle duality? Yeah. A lot of people asked about that for the science couch. But as I wrote in my email, Hank and I are not great physicists. So we cannot tackle that. We need a Henry if we're going to shed some light on that. Yeah. I once wrote a song about quarks and I performed it on stage at VidCon and I came
Starting point is 00:05:39 backstage and Henry was like, love that song. Can I go over the ways in which it is incorrect? He was like, love that song. Can I go over the ways in which it is incorrect? Henry, if you don't know, is the guy from Minute Physics, Henry Reich. And what a lovely man he is. So the topic for the day is waves. Sari has given us a poem about waves, and now it's time for Sari to tell us what a wave is. So I think a wave, like a hole, this is another one.
Starting point is 00:06:09 Whoa! Excuse me. In the way that the whole episode was like, you know a hole when you see it. You know a wave when you see it. It's like, it's wavy. But if you want to describe it with scientific terms, then it is, this is the phrase that I found, a propagating dynamic disturbance of one or more quantities. So it's a disturbance from an equilibrium that fluctuates and changes.
Starting point is 00:06:42 And it can either be something that moves, like how an ocean wave moves, or it can be a standing wave, which is like plucking a guitar string that stays in place. And what does the propagating part of that mean? It means that, like, the wave waves. It goes? I'm making a hand motion. That's kind of what I thought. The propagating means that the wave moves somewhere.
Starting point is 00:07:04 So, like, in the way that sound waves travel through air or radiation travels. Or you can see ocean waves move. Thank you, Hank's computer ghost. Do you have anything else to add? The computer ghost just wants to say, boom. Oh, good Lord. It's time to find out the etymology of the word wave. The computer just wants to say, boom. Oh, good Lord. It's time to find out the etymology of the word wave.
Starting point is 00:07:33 I thought it was going to be another one of the, like, we looked at a thing and it was like, oh, wave. But it seems like multiple words converged into wave. So there's wave, the noun, which came from water. Old High German, wag. Old Frisian, wag. Old Norse, wager, which came from water. Old High German, wag. Old Frisian, wag. Old Norse, wager, which means water in motion or wave. And so like the noun of a wave, we were like, ah, there is a wave. But the verb wave came from moving back and forth or to weave. So like in the way that you wave your hand,
Starting point is 00:08:04 you're like weaving your hand in the air and so you're moving your hand to and fro and then they i guess they looked at the ocean and were like huh that kind of moves to and fro as well so let's uh let's they were thinning out the english language a little bit they were pruning well weird that's like that's pretty cool i like that and now that and now that we know all of that, thank you, Sari, for doing a lot of the heavy lifting for this episode. That means it's time to move on to the quiz portion of our show. This week, it's time to play Truth or Fail.
Starting point is 00:08:37 The most famous supersonic commercial airplane was the Concorde. And that Concorde and all supersonic things go faster than the speed that waves travel through air on our planet. And the Concorde began flying in the 1970s and it reached speeds of up to 1,350 miles per hour. And it was retired in 2003. Now there are some people who are trying to make supersonic aircraft happen again. But as a supersonic aircraft approaches the speed of sound, it creates abrupt changes in the air around it, which creates shockwaves that are audible as sonic booms. And supersonic commercial flights like the Concorde operated for a long time,
Starting point is 00:09:17 but they mostly flew over the ocean. And they didn't really take off in the U.S. from like, you know, flying to New York or to Los Angeles or something. But it's not for lack of trying. In the 1960s, the FAA ran an experiment on the effects of hypersonic flight that ultimately doomed supersonic commercial flight in the U.S., at least for now. The following are descriptions of three experiments. One of them is real. Number one, the FAA had several supersonic flights take off every day for six
Starting point is 00:09:46 months over Oklahoma City, Oklahoma, to test the local residents' willingness to put up with regular sonic booms. And when residents complained about the stress of the noise and damage to their homes, public opinion began to shift against supersonic flights. Or experiment number two, to study the effect of hypersonic flight on the weather, the FAA flew a commercial prototype as many times as they could in a day before the shockwaves began to affect local cloud formations in Seattle, Washington,
Starting point is 00:10:16 with a maximum of three flights per day when you could fly. So there were some days when they decided they couldn't fly. And the aircraft was deemed economically unviable for widespread commercial use. Or, experiment number three, during the fall, the FAA set up flights in Trenton, New Jersey to assess the effect of sonic booms on local geese population
Starting point is 00:10:38 as they migrated south for the winter. While ornithologists reported that no geese were struck and killed by the planes, the birds did, however, have difficulty navigating, which they attributed, the scientists, not the birds, to sonic booms interfering with signals that the birds needed to navigate. So was it we tested the people of Oklahoma City to see if they could handle the sonic booms? Or two, we tested the people of Seattle
Starting point is 00:11:00 to see how they felt about the extra clouds that were created? Or three, we tested the geese of Trenton, New Jersey to see how they were affected by the sonic booms. It made more clouds? It made more clouds, yes. Which in Seattle, you wouldn't think possible. But like when you only got like 10 sunny days a year. It clears up.
Starting point is 00:11:20 That's the great myth of Seattle is that it's gloomy all the time. That's what they tell people to stay away. I lived there as well. that it's gloomy all the time. That's what they tell people to stay away. I lived there as well, and it's gloomy all the time. It rains so much. I know everybody's like, you can't have an umbrella. What are you, a loser? Oh, yeah, you can't carry an umbrella.
Starting point is 00:11:35 You're a wimp if you carry an umbrella. You are not. Why? It rains all the time. I know you wear a raincoat. That's it. People in New York carry umbrellas. It rains a lot there, too.
Starting point is 00:11:43 Get over yourself, Seattle. Okay, well, I don't think, ugh, I don't know. The goose one, on the one hand, I feel like nobody would give a shit about a bunch of geese. People give so much shits about geese. Yeah. We have laws in the U.S. that are like, you can't. Right. That's what I was going to say.
Starting point is 00:12:01 I feel like enough people would go in front of Congress and be like, these geese are in trouble, that Congress would be like, oh, fine. I think sometimes scientists think more about geese and wildlife than people. Depends on what the study is. The geese seems more likely than asking the residents of Oklahoma City to me. You think so? Yeah, I just can't imagine them being, like, I think they would just let them have it. I guess so, yeah. Like, to ground something that could be commercially viable and make people a lot of money.
Starting point is 00:12:29 Seems like, you know, if there's a lot of money involved, eventually the geese become less important. It's true. Yeah. But people are also unimportant in that metric. So I don't know. Yeah. This is this has always led me astray, but I'm going to stick with my guns. I've never heard of the Seattle thing.
Starting point is 00:12:48 And I feel like my dad or one of my grandparents would have freaking complained about it to me. Be like, did you know there were these sonic booms causing extra rain? That seems like it would come up as like on Jeopardy or as a Snapple fact or something, you know? Yeah. that seems like it would come up as like on jeopardy or as a snapple fact or something you know yeah like in the way that i know i was gonna say that i know things about macklemore the only thing i know about macklemore is that he comes from seattle uh okay then i was like i know seattle things but right uh well i think i'm gonna go with the goose thing i do think enough people could raise a stink about geese okay i was gonna go with the goose i'm gonna go with the goose thing i do think enough people could raise a stink about geese okay i was gonna go with the goose i'm gonna go with the goose thing too uh we have a goose and we have a goose and i don't know what happened but it seems like you forgot the actual answer existed at all
Starting point is 00:13:36 which is the people of oklahoma city oh so we've got got a bunch of losers in the room, except for me. But yeah, so it turns out that people are very resistant to the idea of having lots of explosions all day long. Sure. Yeah. But also, they had to live through up to eight sonic booms every day. And also, my favorite part of this is that the experiment was called Operation Bongo 2. It's possible because it is a Roman numeral 2 that it was actually called Operation Bongo the 2nd. I think it's probably Operation Bongo 2, but I'd prefer it be called Operation Bongo II. Now, the reason they did this is because there was an Air Force base nearby and like 25% of the jobs in Oklahoma City at that time were in aircraft manufacturing. So like it's the place in America where people are most likely to be in favor of new kinds of airplanes.
Starting point is 00:14:40 But within the first week, there were 655 complaints. By the end of the experiment, there were 15,000 formal complaints sent to the air force and the faa and they included uh broken china broken mirrors for which people were reimbursed and while people did complain 75 percent of the people responding to a survey about their experiments said that they could learn to live with eight sonic booms per day. Oh, come on. But there was a guy who was quoted in the New York Times about the tests and said, maybe you could get from here to New York in an hour,
Starting point is 00:15:12 but I don't want to live that fast. Oh, cool guy. Yeah. Do they still fly the Concorde at all? No, no, the Concorde has been totally retired. That's what I thought. Ultimately, it turns out. It'll stop eventually, I promise. Ultimately, it turns out that it's better to just like,
Starting point is 00:15:36 like if you have a bunch of money, it's better to like sit around and get taken care of for eight hours than it is to get to London reallyondon really fast that makes sense i guess yeah can i ask a question that might be too complicated to answer wow why does a sonic boom why is it happened i'll try the basics the basics is that like the jet is making a noise but the jet is pushing through the the wave front of the noise so all of the noise as a plane is traveling faster and faster, that sort of Doppler effect is making it so that all of the noise that's coming from the engines and going forward is getting compressed into a more and more compressed area
Starting point is 00:16:19 because it's like the noise is happening and these are actual physical waves in the air. So the noise is happening, but they're getting pushed into a smaller and smaller physical space. And then eventually when you break the speed of sound, that wave front of really compressed sound waves like breaks apart and get like, there's just a lot of, a lot of turbulence that occurs because of that. And that is just that, that becomes a very loud noise.
Starting point is 00:16:45 So there were some grains of truth here. The geese, not a thing, but in 1997, there was some thought that there was this like homing pigeon race and they had, the pigeons had to go over some of the same area that the Concord was going over. And it seemed like they lost a lot more pigeons that year. They just like didn't arrive they didn't die they just like got confused and didn't go to the right place and the ones that
Starting point is 00:17:09 did arrive arrived more slowly than usual so that but that to me is like there's not a lot of strong data on that one yeah and then as far as cloudiness that was just made up though there there is like a sort of very special cloud that can form in the very low pressure areas. When there is a sonic boom happening, when there's hypersonic travel happening, because the, as the, as the air creates this vacuum,
Starting point is 00:17:33 it condenses a bunch of water. Wow. All right. So that means we're going into the break with a zero, zero tie after the break, it'll be time for the Fact Off. Welcome back, everybody. It's time for the Fact Off. Our panelists have brought science facts to present to me in an attempt to blow my mind. After they have presented all their facts, I will judge them and award Hank Bucks any way I see fit.
Starting point is 00:18:16 To decide who goes first, I have a trivia question for you. Tsunamis are a series of waves generated by the displacement of a lot of water, usually by earthquakes or volcanic eruptions. And the Circumpacific Belt, also known as the Ring of Fire, is a loop around the Pacific Ocean famous for earthquakes and active volcanoes. What percentage of tsunamis occur within the Pacific's Ring of Fire? I mean, I'm just going to say 100%. Oh. It seems like tsunamis only happen in one very, like a very specific part of the world.
Starting point is 00:18:50 100% is unusual in nature. You don't tend to get 100%. Well, 100% of clouds are in the sky, Hank, so, you know. Well, fog is a cloud. Oh, no. Oh, no. there's probably clouds underground somewhere too huh yeah underground clouds also there's hey the uh there are some stadiums that have clouds in them because they're so big is that the sky it's not the sky if it's in a stadium
Starting point is 00:19:20 well is the sky anything that's not the ground yeah it is the sky anything that's not the ground? Yeah, it is. Is the sky anything that is not the ground? Do I have sky in my mouth? Uh-huh. That's like the next you have stardust within you. You have sky in your mouth. Eat the sky, bitches! Just wake up every morning and just eat the sky. Take a bite out of the sky.
Starting point is 00:19:46 Well, Sarah, you can go ahead and say 99% and win. Oh, I want it to be a, I want it to be a, I want you to do math. Uh,
Starting point is 00:19:53 I'm going to say 75%. Well, Sarah, not only wins, but was exactly correct. I mean, not exactly, but like to two significant figures,
Starting point is 00:20:04 you were exactly correct. 75.000. How does anyone live without understanding significant figures? It sounds very hard to me. Sam? What is it? I just wanted to know, how do you get by? How do you get by without-
Starting point is 00:20:23 It seems like I'm doing fine, but there could be something I'm missing that I didn't know about until just now. You live a little less precisely, a little bit more like that guy in Oklahoma who doesn't want to be fast. Oh, sorry. It was about 80%.
Starting point is 00:20:37 Sorry. Where do I get 75% from? Oh, it is estimated that the Ring of Fire is home to 75% of the world's active volcanoes. Oh. And it's responsible for about 90% of the world's earthquakes, 80% of the tsunamis. You know. Sorry, Sari.
Starting point is 00:20:55 Volcano, tsunami, potato, potato. I led you astray. It's too complicated to edit any of that out, so it's just staying in. Definitely leave it in, especially because we got to talk about precision because everybody loves significant figures. And be mean to me. So two things you guys like to do. And the audience loves it too.
Starting point is 00:21:16 Sari, who do you want to go first? Well, I'll go first and pull off the bandaid. The roughed grouse is a... Sorry, go again. Thank you, computer ghost. The ruffed grouse is a chunky, one-ish pound, ground-dwelling bird that has evolved to camouflage with bark and fallen leaves.
Starting point is 00:21:35 It's also called a partridge and is a common bird targeted by hunters. And unlike birds that use complicated songs to communicate with each other, ruffed grouse are pretty vocally silent. They have a couple quiet alarm type calls when there's danger afoot or to get the attention of babies. And like I said, they're camouflaged to be grayish brownish
Starting point is 00:21:54 and don't have flashy colors to woo each other either. So their mating routines involve some very weird sound waves. When males are trying to attract a mate, they make a loud noise with their wings, like lawnmower motor struggling to start loud. They hop on a log that becomes a sort of home base for the rest of their life. So big decision there. And then rotate and flap their wings so fast, like 50 times in eight to 10-ish seconds, that they create little sonic booms, in 8 to 10-ish seconds that they create little sonic booms, basically pushing the air molecules aside so fast in the way that a plane would, faster than the speed of sound, that they form small shock waves. These little sonic booms echo out for a quarter of a mile or more,
Starting point is 00:22:38 so not quite as explosive as the thunderclap of an aircraft, but it can still be quite confusing in the middle of the woods. These intense wing flaps take a ton of energy to do, but it's worth it because of passing on their genes. And while these low sounds are clear mating signals to other grouse and easily hearable by humans, it's thought that they're either too low frequency or difficult to pinpoint to attract their non-human predators like owls. So even though these waves are super loud with a high amplitude, the frequency, the low wavelength of the roughed grouse sounds could keep them safe. And I have a sound to share with you so that you can listen to it. Yes, we have a clip and it was recorded by Nathaniel H. Taylor and comes to us courtesy of the Cornell Lab of Ornithology's Macaulay Library.
Starting point is 00:23:38 He's just going absolutely ham. That was nice. That's kind of relaxing. This is a question I thought up about crickets the other day. Crickets would be making sound and then you'd be like, ah, I like to eat crickets. I'm going to go to where the cricket sound is and eat it. Is it the same deal where
Starting point is 00:23:54 they're just making a sound that you can't, that things that would eat them can't really find? That is my guess. I know that it's very hard to find a cricket. It tends to be that that noise is difficult to locate in my experience. But I am a human, not a snake or a lizard or a bird. Yeah.
Starting point is 00:24:10 Allpestprose.com says, most predators are active during daylight hours, which is why crickets chirp at night. And then if they feel slight vibrations in the air, then they go quiet. So maybe the predators can't hear the chirps, but they're just like, gotta be quiet now. All right. Sam, what do you got for us? Great bird, Sari, by the way. So now I'm going to try to talk about how reflections work
Starting point is 00:24:39 and we'll see if I understood correctly how they worked. So in waves, maybe any kind of wave i don't know sound wave and light wave is what i'm talking about bounce off the surface they bounce at the angle that they hit the surface so when you look in a mirror you see your own face because the light waves are bouncing off your face into the mirror then back into your eyes is that how a mirror works yeah then when you look in a mirror at an angle, you see stuff way over there because it's hitting it at an angle and then bouncing into your eyes. Cool. So sound and light both do the same thing, basically.
Starting point is 00:25:12 If you are able, though, to break the laws of reflection and make waves bounce off at specific angles instead of the angle they hit an object, you could divert sound and light in all kinds of crazy ways and do stuff like maybe make things perfectly silent or perfectly invisible. And because perfect invisibility and perfect silence are both very cool and very useful, mostly maybe for like the military, but hopefully for other reasons too, there are lots of researchers working on how to make that happen. So there's one way I read about that was kind of wild sounding. Researchers set up a maze for sound waves and they shot a sound wave through it. And inside the maze, there were tons of tiny speakers that would shoot other sound out and literally smack into the sound wave and make it like go through this maze and it would redirect the sound wave. And it would come out the
Starting point is 00:26:01 other side having lost none of its energy somehow and yet sounded the same as going in. But this tiny speaker method would require basically lots of tiny speakers to be everywhere on everything that you wanted to soundproof and that gets impractical really fast. So researchers at Duke University came up with a different solution that they called the MetaMirror. And this ain't your father's mirror. So instead of preventing waves from hitting it, like the tiny speaker method, the metamirror has sound hit its surface, but its surface is covered in extremely tiny, intricate grooves that are etched in a way
Starting point is 00:26:36 that mimic the shape of the sound wave. So the grooves are precisely designed to change the direction of the reflection of the sound wave and not absorb any of its energy. So I think they're like little slides or like ramps that the sound waves hit and they physically like are curved to maintain the curvature of the sound wave. So the effect of this is that sound waves can be like directed in any direction the researchers choose
Starting point is 00:27:02 without changing the amplitude or frequency or anything like that of the sound so right now they're all 3d printed pieces of plastic so you can pretty much only shoot them with like one specific sound and have them go one specific direction but they're working on adaptive surfaces so that anything it would hit it and it would automatically know to like change shape to match that sound and bounce it any direction that you wanted it to go. And as far as applications go, you could use metamirrors for noise cancellation and soundproofing, which they're especially good at
Starting point is 00:27:32 because they can be made to absorb certain sounds and bounce others out. So you can make really good speakers that wouldn't have any kind of crackle or anything like that. It would just bounce out all the good sounds and none of the bad sounds. And redirecting sound waves is cool, but this team is also looking into redirecting light waves with metamirrors. So they can't really do it yet, because
Starting point is 00:27:52 they're just 3D printing stuff, and they'd have to be so, so small, I guess, because light waves are way smaller, or like they're tighter. So the grooves have to be way smaller, but if they could come up with an adaptive light-reflecting surface that could redirect light anywhere they wanted to they could potentially make like a perfect cloaking device where you look at something and it would just be completely invisible like with mirrors specifically
Starting point is 00:28:14 i can imagine that being just the weirdest thing to look at uh-huh with sounds i'd be like i could imagine it being useful but with a mirror i i'm just like, wow, if that is actually a thing that would be possible, I can imagine just going insane looking at that thing. I think one of the things they were talking about was they could make a mirror that you'd look in and you wouldn't be able to see yourself, but you could see everything else around you, which would be horrifying. Yeah, not particularly useful, but certainly all of these things are useful for hiding things that the military doesn't want you to see. Really looking forward to the future where I can be literally not trust my senses at all. Yeah.
Starting point is 00:28:54 Well, maybe it'll be fun at like Disney World too. Disney World and the military. Yeah. Pretend to be a vampire. And then also there could be a person around you at any time and you wouldn't know. Yeah. So we have the rough grouse creating tiny sonic booms
Starting point is 00:29:13 as part of their mating routine, which I can barely believe, or the metamirror, which breaks the rules of reflection and could be used to make things invisible or insoundable. Inaudible, I guess is the word for that. No, I like yours better. be used to make things invisible or in soundable inaudible i guess i'm gonna go since you guys are tied i'm gonna call it for sari because i think it is so strange that this grouse which does not let's admit look particularly impressive not really break the speed of sound just for foreplay reasons hell yeah that's great that's i like i'm behind this decision 100 every time you hear a partridge in a pear tree just imagine him just flapping
Starting point is 00:30:00 you know waves is one of those topics that's hard as hell for dumb guys like me so i should you did the smartest guy fact of the pod i know but sometimes that's a problem i need to stick with animals look it needs to be related to a mating ritual or else that's my rule that too yeah all right it's time to ask the science couch where we've got listener questions for our virtual couch of finely honed scientific minds. This one's from at Hannah G at 0913. How do underwater waves work and how did we discover them? Underwater waves. So are we talking about underwater sound waves? I assume. No, not underwater sound waves, like underwater waves that basically look like the waves on the surface.
Starting point is 00:30:46 Oh! Tell me more, Sari, because I know nothing about this. Yeah, we didn't discover them. Me and Hank didn't. Well, I discovered them. Sari Riley discovered them because HannahG0913 asked about them. But actually, they are
Starting point is 00:31:01 very hard to monitor because we don't do a bunch of intense underwater measuring because we don't do a lot of like construction underwater very often or travel underwater. And so we know a lot more and we do a lot more measuring of the atmosphere than we do the deep ocean. And so underwater waves were actually like theoretical and calculated. Like people assumed that because there are different current movements under the water, then there may be waves down there. And then they did a bunch of math and were like, yeah, there are probably waves down there. And then starting around like the last decade or so, it seems like people are actually measuring them and finding regions of the ocean to measure them in. actually measuring them and finding regions of the ocean to measure them in, such as in the Luzon Strait, a body of water that stretches about 200 miles between Taiwan and the Philippines,
Starting point is 00:31:52 where some of the most powerful underwater waves are generated. These waves are called underwater waves or internal waves or internal gravity waves or abyssal waves in various studies. And to my understanding, there were no pictures of them, which makes sense because no one's got like a camera down under the water. If you imagine an ocean wave on the surface, like it comes up and comes down, and the water is interacting with the air. In the way that the water and air are the two different mediums there,
Starting point is 00:32:24 you have to imagine that there is like a saltier chunk of water and a less salty chunk of water or a low temperature chunk of water and a high temperature chunk of water. And for the purpose of your mental image, one can be blue, one can be red. And the blue one is waving, like creating waves through the red one in in the wave motion, which is different than just a current flowing in any direction because it adheres to the properties of a wave as it would exist on the surface of a pond or an ocean. And so it's because of these harsh boundaries
Starting point is 00:33:00 between colder and less cold water and saltier and less salty water that that can be detected instrumentally. And these underwater waves are generated by the same things as surface waves, just that propagate downward, like tides. So gravity pulling on various bodies of water from the moon and then winds below the surface and that propagates downward. And these waves, in addition to other currents that are through the ocean, help with the circulation of sediments and pollution and nutrients throughout the ocean. And it's also, they're a really important piece in climate modeling. And that's why a lot of people are studying them right now, because we know the ocean ends up capturing a lot of the carbon in the atmosphere, but also
Starting point is 00:33:49 just a lot of the heat, like the ocean is a heat sink and it moves the temperature around, moves the heat around. The group of scientists that are interested in hydroengineering or like the movements of the ocean are saying that our global climate models are inaccurate because we haven't entirely captured the underwater waves and like the effect that these really huge, like they reach heights of 170 meters and can travel at a leisurely pace of a few centimeters per second. So there's these like gentle giants propagating throughout the oceans that are moving things around that we don't necessarily always take into account if we assume
Starting point is 00:34:30 that the ocean is either static or just moving along the currents that we already know of. It's a whole new bunch of complications to the ocean. It was already hard enough. Yeah. We continue to find things that we do not know, which is great because before we knew about them, then we definitely couldn't model them.
Starting point is 00:34:48 Yeah. But now that we do, we're like, dang it. Yeah, come on. It'd be better if you just hadn't showed up. Thank you very much. We need to start being able to talk to whales or something. They can be like, just tell us what's going on down there, whales. Yeah, I'm sure they know.
Starting point is 00:35:01 And they can give us the input or what we need to know. Our whale colleague doctor doctor or doctor whale i'm sorry if you want to ask the science couch for your question you can follow us on twitter at scishow tangents where we'll tweet out the topics for upcoming episodes every week thank you to at euphonia 53 at xbree ash and everybody else who tweeted us your questions for this episode if you like this show and you want to help us out, even though it didn't maybe sound like it usually does, it's really easy to do that. First, you can go to
Starting point is 00:35:30 patreon.com slash scishowtangents to become a patron and get access to things like our free newsletter and also bonus episodes. What did we decide the new podcast was called? Peepy Poopoopedia. Yeah, Poopy Peepypedia. Great. Thank you. I'm so glad that you remembered that. I can never forget it.. I'm so glad that you remembered that.
Starting point is 00:35:46 I can never forget it. And I'm sure you're very disappointed that you did. Second, you can leave us a review wherever you listen. That helps us know what you like about the show. It also helps other people know what you like about the show. And finally, if you want to show your love for SciShow Tangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sari Reilly.
Starting point is 00:36:02 And I've been Sam Schultz. SciShow Tangents is created by all of us and produced by Caitlin Hoffmeister and Sam Schultz, who edits a lot of these episodes. Our social media organizer is Paolo Garcia Prieto. Our editorial assistant is Deboki Chakravarti. Our sound design is by Joseph Tuna-Medish. And we couldn't make any of this without our patrons on Patreon.
Starting point is 00:36:18 Thank you! And remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. Many home plumbing systems feature a vent stack. I know mine does. A pipe that connects to the outside to allow gas from our waste,
Starting point is 00:36:56 aka the bad poop smells, to vent outside instead of in our homes. However, this means that on a windy day outside, the air speeds up, which in turn lowers the air pressure in the pipe and pulls on the water in the toilet. So if you want to take a little beach vacation and see some waves, you can just open up your toilet on a windy day and you can maybe possibly see some waves in your very own toilet. That's good because it also answers a question that people often have. Why on earth is my toilet moving? Not a toilet ghost.
Starting point is 00:37:23 That's super weird. Do people ask that? I've never noticed. I don't really sit and look at my toilet ghost that's super weird do people ask that i've never noticed i don't really sit and look at my toilet all that often and consider it

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