Brought to you by the reinvented two thousand twelve Camray. It's ready. Are you welcome to stuff you should know from house Stuff Works dot com? Hey, and welcome to the podcast. I'm Josh Clark with me as always as Charles W. Chucker's fluttered by Bryant. No, I'm a caterpillar and one day I might be a beautiful butterfly. Yes, you're you're an Olympic coal. Yes, but you're going to be a diamond someday, Chuck. Who's saying that? Uh? Originally it was one of those old guys. That's a good one. Widespread panic. Did they cover that really? Yeah? It was like a nineteen minute version. Yeah, right, it went a little long. You could say, how you doing, Chuck? I'm good. I have freshly shaved my head like you. No, mind's not fresh minds shaggy. Well yeah, but we're both kind of onion heads. Now, you look good where I'm usually not. You look pretty. Thank you? Did you take a series of pictures of yourself? No? Not yet? Okay, that's later. So, Chuck, you've heard about this oil spill, right? Yeah? I had a feeling you might tie this in devastation, uh, dead wildlife, UM, injured economies, Obama's Katrina. Yeah, there's one thing that has been conspicuously absent in my um estimation. Beautiful. Nobody's talking about iridescence. No one's talking about how pretty the oil slick is. It's because it's horribly ugly. It is, unless you stay in at a certain angle and then you're like, oh, this is kind of nice. Actually, yeah, I know what you mean. Yeah, we're headed. We're talking about iridescence in this one because the shimmery color changing quality called iridescence that oils bills feature are in common with something called butterflies, the wings of butterflies. And I can tell you that, Um, twenty four hours ago, I had no idea why a butterfly, the butterfly's wings were iridescent. Now I do. This is why I love episodes like this, because it's here, is why there's no maybe it's kind of like this, or we don't really know, so you and I get the conjecture like jackasses all day long? Right, Um, Instead, it's science has figured out why this happens, and you and I are going to explain it to people. So Chuck, let's do that right. Now, let's talk about why a butterfly's wings are iridescent. Well, there's a couple of reasons they have their their striking color. Iridescence is the main one. But we probably need to go ahead and get pigment and just ordinary color out of the way. Let's pigment, Josh, is uh coloring matter do you find in like cells and tissues? And the deal with pigment is it is the same from every angle. You can get up under it, you can get on top of it and sneak it behind it, you can get all up on that, that all up in it, but it always looks the same. Right. That's just called that's what they call it ordinary color. And the reason why is any given pigment um will absorb all colors except one, say, right, like chlorophyll. Sure, chlorophyll absorbs all colors except green, which it reflects, which causes something to look green like a plant a plant, sure is one. Melanine tends to absorb everything but yellow, giving things a brownish color. Right. Well, yeah, and that's albine is um. That means you have no melanin, right, You're lacking a pigment. Same with paints, right. These are all just pigments. These things don't inherently have a color. They just absorb certain colors and reflect others back. Yeah, it's pretty standard stuff. Did you know redheads um have they think they have an additional um iron based pigment their color. Interesting, they're freak issue poor ginger kids. Man, they are really taking I love redhead stuf, do you well? I mean, okay, yeah, Actually I just like the red, like really red headed people is kind of cool looking to me. I'll just go and go on record with that, like red or orange, because there's a big difference. Man, I'm not talking strawberry blond. I'm talking like really really redheads, shocking red, shocking ginger redheads. You like staring at them? I do? Okay, Um, don't stare too hard, okay. Freaks people blind? Alright. So that's that's pigments. They're pretty standard. One can argue boring stuff, right. Pigments don't give anything iridescence now, they just reflect light. And you know that's that iridescence is uh this kind of super spectacular um reflection of color, almost shimmery. Yes, that changes, Actually the color changes if you move, so your descence is generally relegated to the observer. Depending on where you're standing, that will change the color, how spectacular color is and um again we know why, especially when it comes to butterfly wings right, or you know we should mention just a couple of others before we move on, like the Japanese beetle that green on the wings, Yes, your descent, mother of pearl, seashells, some fish scales and like bubbles, peacock feathers. Pa, Well that's a huge one. Did I tell you that there's a peacock in our neighborhood. No. I was walking with Emily the other day walking the dogs the other morning and we looked up. We heard this weird sound. It sounds like hell yeah. I thought someone was crying for help. And I looked up and literally at the apex of this roof of this house was a full on peacock standing there weird loose or did they keep it in the backyard keep peak? Yeah, the guy has two peacocks because the neighbor. The neighbor was out and I was looking at Yeah, he's got peacocks. I was like, that's staring at it like it was a full on redhead. I was, and I said that's sort of weird, and he went yeah and loud yeah, but so hell yeah yeah. But it was iridescent and it was fascinating. They are they're gorgeous and actually peacock feathers led to um the investigation of iridescence and Newton. Eventually Thomas Boyle was the one who went catching that's the way it happens. So we were talking about Robert Boyle. Sorry, Robert Boyle, thanks, one of the Boil brothers exactly. Um. We were talking about how pigments reflect just one color, right, Transparent objects have the ability to reflect all colors, right, um. With an oil slick with a bubble, you have two surfaces, right you have we'll talk about a bubble. We'll talk about the oil slick. The oil slick is oil floating on water, right, yes, um, you have. So you have the the top film of the oil slick. Lights passing through all the sums bouncing back, which you will see right with your um, and some can make it to the water beneath the stuff that passes through the top film and then can be reflected back and can be reflected back right now, if the light that's reflected from the top is also reflected from the bottom if they're in sync, if the phases match up, right, and it phases the position of the trough and the crest. Because remember light exists on a wavelength, right, so picture it is like a regular wave or like a roller coaster if you're a little more simple, and like you said, if they match up as if they were on top of each other, then you're gonna get your deskce right. So Chuck, follow me on this one to the ends of the Earth. Alright, So go beep boop beep. Okay. So the beep that's a crest, and then the boop that's a trough off trough. Okay, so start going beep boop beepoop. So and this is this is Chuck being a wave of light, a wavelength of light, right um reflecting. He's just reflected the moment he starts. He's reflected off the surface of a transparent object. Bee booepoo. Right. Okay. So now I'm like coming in and I'm going to come in and start after I've just reflected off the bottom surface of say an oil slick, right, all right, So you want me to do this again, So Chuck has already reflected off the top surface. I made it through the bottom surface, and now I'm reflecting awful. Okay, so boo boo. Now let's say I come in and like halftime beepoo beep beep. It's all screwed up. That sounds awful. It does sound awful, and in when you're speaking of light, it sounds like this, right, nothing, they cancel each other out. But if I can't, if if my phase is equal to yours, but say a full measure behind, it sounds like this, go ahead, bee boop bee boo bee boop beep boopy. Right, So it sounded nice. It sounded louder. It didn't sound nice, but it sounded louder. It wasn't all discordant, right, So what just happened was we amplified the beat boop right, right, yeah, yeah, exactly. This is called um what is it? Constructive interference? That's right, and that's I don't want to say good and bad, because it's really scientists would say it is neither good nor bad. But I'm gonna say that's the good kind because that's what gives you iridescence. The bad kind would be destructive interference, and that, like you said, that cancels each other out, making something like less not less iridescent, not iridescent at all. Right, So that's it close, that's not entirely it, right because consider this chuck light. Light as we see it exists on a spectrum. Right. So, Um, on one hand, you have about a wavelength of four nimes violet light. On the other end of the spectrum that we can see is red light, which is has a wavelength about seven nimes. Right, okay, Um, if you go a little beyond the violet, you get bluer than blue a k A ultra violet, which we all love. Right. If you go beyond the red, uh, you have redder than red or infrared. Right. We can't see either of those, but we can't see within that spectrum for violet to red. And it's based on wavelength, if we um, if you take white light right like sunlight, and you put it, if you projected onto a transparent object, all of the colors. Remember the Pink Floyd Dark Side of the Moon album cover. Of course, it's white light going into a prism and then coming out in its separate forms, in all its psychedelic glory. Right now, imagine that that's static, Like it's it's not changing position. If you are shooting a beam of white light onto a bubble, depending on where you stand, the angle of reflection, right of refraction, I'm sorry, Um, depends on what color you're going to see. So if you move across your angle, you're going to see a different color. And hence this explains the color changing of iridescence. Right. So, like, you know, have you ever seen the big bubble wines where they can both the really huge bubbles the huge bubbles. Uh, if you ever do that, do a little experiment and look at it from different angles, jump around, walk around, and you're gonna see some color change. Have you ever seen a bubble pop in SloMo? That Super SloMo? No, but isn't wasn't that an episode of that one show Time Work? Yeah? Yeah, the Discovery Show. It is super cool, dude. If you look at it in slow motion, you like would pop the bubble, and you know, when you see it in regular motion, it looks like it just pops in a big burst, But from where you touch it spreads and an arc all around the whole thing, and you see it slowly popping as it goes around. It's just really cool. Nice. It's neither here nor there though, but it's still pretty like you're a descence. Right. So what we have now is um if if that if light from white light uh hits a transparent object, and it's a multilayered transparent objects, say like oil on type of water, or one side of a bubble and the bottom side of the bubble, some light's gonna reflect off, some's gonna make it through the bottom. Some of that will reflect off, most will will go through. But if the light from the bottom and the top are in phase with one another, in an even phase, right, separated by one two, three four five wave links rather than you know, one point three five wavelengths, they'll be in phase and they'll amplify each other. If it's white light, then we're going to see, depending on our ang goal all the colors of the rainbow. You're in this iridescent state, right. Okay, So what does this have to do with butterfly wings? I'll tell you, buddy. Okay. Butterfly wings are transparent, and the deal is why they look so striking compared to let's say, a bubble, which is pretty but not as striking as a butterfly. It's because there are many, many more layers stacked on top of each other that the light has to go through. When all those are in phase, you get like super iridescence. Right. So with a with a bubble, you have two chances right at the top and the bottom two lousy chances. Right. With a butterfly wing, the the cuticle of the scale of a butterfly wing, say, has maybe a dozen So every every beam of light, every wavelength of light has you know, a dozen chances to reflect back, say half of those are in phase. Yeah, and also depending on how because the surfaces. Um, if you look at a butterfly cuticle, it looks kind of like a Christmas tree, right, so there's like a it looks like a Christmas tree, basically like a lego Christmas tree. Will say, but the scales, actually I'm out the scales. Yeah, yeah, the scale cuticles that make up the scales. Yeah, that's kitan. That's the same thing we have in like our hair, it's protein in our fingernails. Nice okay, sorry, Um, So as it goes down the tree, you know, they get wider, These surfaces get wider, and each one can can bounce light back off, but they're spaced evenly. So let's say that the space in between is two d nanimeters and blue light is four hundred nanometers in wavelength. Since the two hundred is half of four hundred, it's going to give blue light a better chance to reflect back in phase, which is why I stay on like the blue morphoe butterfly, which has a space of two between the scales. The space and the scales appears so blue because blue has a likelier chance of reflecting back in phase and being amplifying in this iridescent manner, and the morpho doesn't that actually venture into ultra the ultra violet spectrum? Yeah, remember the angle. Yeah, so if you're looking, let's say, at the right is red and at the left is violet. If you move too far to the left, everything's gone because you've moved out of the visible spectrum of light. And now what you're seeing is the brown pigment, but who can see it is the butterfly. Yeah, the monarchs are actually in their migration, their huge migration every year. They use ultra violet markings. Uh, ultra violet um light for guide posts basically, right, Yes, they do, and uh it Also the other effect or the other reason, um that you have this iridescence and on the scales is it soaks up heat because butterflies are cold blooded, so they rely on like the sun to be able to function. So the fact that they're soaking up this heat from the sun allows them to fly, right, which is pretty cool. And we also remember pigment, don't forget still plays a role in this too, right, So if you have if you have a butterfly scale that's um constructed, contains chlorophyll, so you have um a green pigment. Yes, let's go with blue. Okay, Now let's go with yellow. Okay, say say it's a butterfly scale. It's constructive melanin. So you have yellow already, which it's reflecting back yellow and monochromatic blue light. It's going to it's going to appear to us as green because color mixing still has has an effect, right, So pigment structural color green. Can we talk about the wings for a second too, because I know people are going to write in and say that's really cool, but is it true that butterflies will die if you touch their wings? Sort of not completely? You can touch a butterfly wing. Like, if you've ever touched a butterfly wing, you'll notice you have like powder on your hands. Yeah, those are the scales. Those are the scales. They are that fine that they kind of disintegrate into powder. And in theory, you can touch a butterfly wing without killing them, but if you break it. They have little veins. They're all connected by little veins, So essentially, if you disconnect the veins from the fore wing and the hind wing, that's when the butterfly is gonna die. And they're so tender that it's really easy to happen. So in effect, you probably will kill a butterfly if you mess with their wings, but if you just happen to graze against it, maybe not. No need to squish it after just such a slight intrusion, right, Yeah, And moss, I think get a bum wrap because they're not as pretty. Yeah, because they're mainly mel what what was it, melitan, melanin melanin mainly like brown and yellow, black and white. And they also have a frenulum, which is a spine, and butterflies don't have that. Right. Also, moths tend to be fatter and fly at dusk or at night. Well, yeah, and that's why butterflies get all the credit, because you're out on a nice spring day in the garden and butterflies were everywhere, and then at night you're hanging out by the porch and you're freaked out by the moths everywhere, like going towards the light. Well not only that, um, there's there. The structure of a moth's wing is very, very similar to the structure of butterflies transparent filmy scales. For some reason, I guess it's because they do fly at night. They are not iridescent. They don't appear iridescent, although they would in sunlight. But they're part of the same family scientifically, big happy family. Yeah, what was the family? Uh, Lepidoptera? Was that lepidoptera? Lipidoptera. There's like a hundred and fifty thousand varieties within that family and lepidoptera I means scaled wings boom. Yeah, it's a great place to finish, don't you think? Sure? You got to we recap Oh, I don't think so. The party we explained it, well, I think so, all right, because I feel more confused than I did before. Well, you brought sound into it, but I thought that was a very clever way to go about it. Well, thanks a lot. If you want to learn more about butterfly wings and they're striking colors, type in butterflies striking colors in the handy search bar, how stuff works dot Com brings up a pretty cool article by Jennifer Horton. Hey, Chuck, chucks me from the future. The future are idiot. Past seals have no idea whe're doing this right now, right, but we do because we're from the future, indeed, and you know what we're here to do, don't you. We're interrupting our podcast for a reason. T Shirt Winners announced. This is one of the if you were a winner that you were guaranteed I mentioned on the show, and this fulfills that application. Yes, this is um. We've got the lawyers behind us that their briefcases in bullwhips, right, yes, and uh, Chuck, we picked five. I'm glad we picked five because we had like more than seventy jries, right. I wanted to pick ten. I wanted to pick twenty three. Um, and we actually did have like a top twenty three at one point and finally whittled it down time and time again, and we came up with the five winners and they're announced on the blog. There's an image gallery on how Stuff Works. You can go onto our blogs at how stuff works dot com and look for the blog post entitled we Got your T shirt. We got your stuff you should Know T shirt contest winners right here, uh, and that'll take you into the site to check them out. You can also get the shirts on the Discovery channel store right yeah, there for sale. Yeah. You just go onto the I Think store dot Discovery dot com and do a search for stuff you Should Know and it brings up all five of these magnificent T shirts. Right. So, the names of the winning designers, the five brilliant individual human beings who created these amazing designs, right, Their names are what chuck Well first, these are in no particular order. By the way, Um, we have Peter Feek or fight Or We've been debating endlessly and he did a really cool design of this old school microphone and it's sort of logo looking. It makes us look like we're really pros. Yeah, I call it hot Mike Hot Mike, Yeah, I like it. Uh. And then of course there's Suki Anderson. Yeah, out of Kentucky, I believe, I think, and she made what I think is the coolest picture I've ever seen in my life. Yeah, it's the baby with the fly on its forehead. Yes, and don't worry. Yeah. I said on the blog that it's it's unsettling and comforting at the same time, and it's very hard to achieve. Agreed. So that was one of our favorite ones. And then we went with Brad Wilson's brain design, which is awesome. Yeah, we got a lot of brain designs, so you guys were thinking along the same lines, which means you're all smart and cool. And that was the brain as as a representation of our show is really, I think, pretty cool, and this was what we thought looked best on a T shirt. Brad nailed it. Yeah, he nailed it definitely. Uh. Matt Stevenson came up with what I've dubbed the wood cut parade right right, Our fans are gonna love this one. Yeah. It's a it's a series of medieval characters I would say, skeleton, bishop, a monk, a jester, um and they are carrying banners let's say s y s K. They're leading the parade. The stuff you should know parade from medieval times. Yeah, and I said on the site it looks like a paraded one to hide behind a tree and watch. It's awesome. It's very cool. And then lastly, Chuck, I'm going to leave this one to you because I can't pronounce this guy's last name. Yes, we have Scott y A C y s h Y, and I'm gonna say, yeah, yeah, yakin ya kishin, Scott, whatever your last name, let's try that one to Scott Yukishan if that is you. You are one heck of a designer, my friend. And you did the very cool caricature of Josh and I and from our mouths and balloons. You have different caricatures of different episodes and so much camaraderie between us. You know, we just look like we are having a heck of a time gaining the podcast as a sixties illustration. It's very cool. One of my favorite ones to super awesome. So Scott, Matt, Brad, Suky, Peter, thank you very much to all of you guys, uh and thank you to everybody who sent in. From something created in rich text format to something that was obviously made by a professional graphic designer, we appreciate all of you, guys, and thank you very much for taking the time to lend us your brains and creativity. That's awesome that we were blown away. It was very cool. You're all very talented. Okay, and now let's go back to our stupid um selves from the past. I predict that it's going I'm gonna say some assin I thing about the handy search bar. Watched. Uh that means since I said handy searchbar, Chuck, are you ready for this? Listener mail, Josh, I'm just gonna call this, uh stuff you should know educating prisoner of America. I like this one. This is a good one. Well, prisoners of Virginia. At least, right which is in America? Isn't it still it's a commonwealth. I don't know if it counts. Oh, that's right, weirdos. All right, This from Maria in Amelia, Virginia. I guess you have a prison there. Hi, guys, I thought you might be interested to know that I use your podcasts as a resource to teach writing to inmate students. I'm a G. E. D. Teacher at a men's president in Virginia. Writing is one of the weakest skills for my students, and many of them never learned to write as far as secondary school. Uh, and they were afraid to write as adults, so they're sort of illiterate or completely illiterate in some cases. Well, I mean, think about it, Chuck, WoT is writing if not a series of choices of what you're going to share with people, it can be very intimidating. I burned your podcast to a c D and replay one in class because we don't have internet for obvious reasons. The men listen to your podcast, they take notes, and then they must write an article based on what we said. They practice writing sentence is and paragraphs in this way. The subject matter is of interest to them, some more than others. I'm afraid to play the moonshine one as much as I would like to. I know they would be interested even if I skipped the parts where you make the still and give the general recipe. So she won't do that, because you know they'll build a moonshine still. I'll bet they already know how the menhorns. Yeah, I think so. Uh. Some of these guys have been down a long long time, so they appreciate something to think about that isn't about sentencing and parole hearings. Thank you for your material. My family and I enjoy the podcast and they do a real service to people. So we are actually educating prisoners of a mayor. I know. That's awesome. So if you guys are in prison right now, if you're in the in the pokey in the who scale and you're listening now, we just want to say good luck. You can turn your life around, do your hard time, come out a better person, don't do crimes again, and get your g E D. And you know, get a get a job, and and good luck to you. That's what I say. And remember when you make a decision writing, don't look back. Really such your advice. Yeah, that is my advice. Actually, all right, you can always write something else. That's a good point. Yeah, if you want to let us know how we are changing the world for the better with this podcast, and it's an email to stuff podcast at how stuff works dot com for more on this and thousands of other topics, does it how stuff works dot com. Want more how stuff works, check out our blogs on the house stuff works dot com home page. Brought to you by the Reinvented two thousand twelve camera. It's ready. Are you

Brought to you by the reinvented two thousand twelve Camray. It's ready. Are you welcome to stuff you should know from house Stuff Works dot com? Hey, and welcome to the podcast. I'm Josh Clark with me as always as Charles W. Chucker's fluttered by Bryant. No, I'm a caterpillar and one day I might be a beautiful butterfly. Yes, you're you're an Olympic coal. Yes, but you're going to be a diamond someday, Chuck. Who's saying that? Uh? Originally it was one of those old guys. That's a good one. Widespread panic. Did they cover that really? Yeah? It was like a nineteen minute version. Yeah, right, it went a little long. You could say, how you doing, Chuck? I'm good. I have freshly shaved my head like you. No, mind's not fresh minds shaggy. Well yeah, but we're both kind of onion heads. Now, you look good where I'm usually not. You look pretty. Thank you? Did you take a series of pictures of yourself? No? Not yet? Okay, that's later. So, Chuck, you've heard about this oil spill, right? Yeah? I had a feeling you might tie this in devastation, uh, dead wildlife, UM, injured economies, Obama's Katrina. Yeah, there's one thing that has been conspicuously absent in my um estimation. Beautiful. Nobody's talking about iridescence. No one's talking about how pretty the oil slick is. It's because it's horribly ugly. It is, unless you stay in at a certain angle and then you're like, oh, this is kind of nice. Actually, yeah, I know what you mean. Yeah, we're headed. We're talking about iridescence in this one because the shimmery color changing quality called iridescence that oils bills feature are in common with something called butterflies, the wings of butterflies. And I can tell you that, Um, twenty four hours ago, I had no idea why a butterfly, the butterfly's wings were iridescent. Now I do. This is why I love episodes like this, because it's here, is why there's no maybe it's kind of like this, or we don't really know, so you and I get the conjecture like jackasses all day long? Right, Um, Instead, it's science has figured out why this happens, and you and I are going to explain it to people. So Chuck, let's do that right. Now, let's talk about why a butterfly's wings are iridescent. Well, there's a couple of reasons they have their their striking color. Iridescence is the main one. But we probably need to go ahead and get pigment and just ordinary color out of the way. Let's pigment, Josh, is uh coloring matter do you find in like cells and tissues? And the deal with pigment is it is the same from every angle. You can get up under it, you can get on top of it and sneak it behind it, you can get all up on that, that all up in it, but it always looks the same. Right. That's just called that's what they call it ordinary color. And the reason why is any given pigment um will absorb all colors except one, say, right, like chlorophyll. Sure, chlorophyll absorbs all colors except green, which it reflects, which causes something to look green like a plant a plant, sure is one. Melanine tends to absorb everything but yellow, giving things a brownish color. Right. Well, yeah, and that's albine is um. That means you have no melanin, right, You're lacking a pigment. Same with paints, right. These are all just pigments. These things don't inherently have a color. They just absorb certain colors and reflect others back. Yeah, it's pretty standard stuff. Did you know redheads um have they think they have an additional um iron based pigment their color. Interesting, they're freak issue poor ginger kids. Man, they are really taking I love redhead stuf, do you well? I mean, okay, yeah, Actually I just like the red, like really red headed people is kind of cool looking to me. I'll just go and go on record with that, like red or orange, because there's a big difference. Man, I'm not talking strawberry blond. I'm talking like really really redheads, shocking red, shocking ginger redheads. You like staring at them? I do? Okay, Um, don't stare too hard, okay. Freaks people blind? Alright. So that's that's pigments. They're pretty standard. One can argue boring stuff, right. Pigments don't give anything iridescence now, they just reflect light. And you know that's that iridescence is uh this kind of super spectacular um reflection of color, almost shimmery. Yes, that changes, Actually the color changes if you move, so your descence is generally relegated to the observer. Depending on where you're standing, that will change the color, how spectacular color is and um again we know why, especially when it comes to butterfly wings right, or you know we should mention just a couple of others before we move on, like the Japanese beetle that green on the wings, Yes, your descent, mother of pearl, seashells, some fish scales and like bubbles, peacock feathers. Pa, Well that's a huge one. Did I tell you that there's a peacock in our neighborhood. No. I was walking with Emily the other day walking the dogs the other morning and we looked up. We heard this weird sound. It sounds like hell yeah. I thought someone was crying for help. And I looked up and literally at the apex of this roof of this house was a full on peacock standing there weird loose or did they keep it in the backyard keep peak? Yeah, the guy has two peacocks because the neighbor. The neighbor was out and I was looking at Yeah, he's got peacocks. I was like, that's staring at it like it was a full on redhead. I was, and I said that's sort of weird, and he went yeah and loud yeah, but so hell yeah yeah. But it was iridescent and it was fascinating. They are they're gorgeous and actually peacock feathers led to um the investigation of iridescence and Newton. Eventually Thomas Boyle was the one who went catching that's the way it happens. So we were talking about Robert Boyle. Sorry, Robert Boyle, thanks, one of the Boil brothers exactly. Um. We were talking about how pigments reflect just one color, right, Transparent objects have the ability to reflect all colors, right, um. With an oil slick with a bubble, you have two surfaces, right you have we'll talk about a bubble. We'll talk about the oil slick. The oil slick is oil floating on water, right, yes, um, you have. So you have the the top film of the oil slick. Lights passing through all the sums bouncing back, which you will see right with your um, and some can make it to the water beneath the stuff that passes through the top film and then can be reflected back and can be reflected back right now, if the light that's reflected from the top is also reflected from the bottom if they're in sync, if the phases match up, right, and it phases the position of the trough and the crest. Because remember light exists on a wavelength, right, so picture it is like a regular wave or like a roller coaster if you're a little more simple, and like you said, if they match up as if they were on top of each other, then you're gonna get your deskce right. So Chuck, follow me on this one to the ends of the Earth. Alright, So go beep boop beep. Okay. So the beep that's a crest, and then the boop that's a trough off trough. Okay, so start going beep boop beepoop. So and this is this is Chuck being a wave of light, a wavelength of light, right um reflecting. He's just reflected the moment he starts. He's reflected off the surface of a transparent object. Bee booepoo. Right. Okay. So now I'm like coming in and I'm going to come in and start after I've just reflected off the bottom surface of say an oil slick, right, all right, So you want me to do this again, So Chuck has already reflected off the top surface. I made it through the bottom surface, and now I'm reflecting awful. Okay, so boo boo. Now let's say I come in and like halftime beepoo beep beep. It's all screwed up. That sounds awful. It does sound awful, and in when you're speaking of light, it sounds like this, right, nothing, they cancel each other out. But if I can't, if if my phase is equal to yours, but say a full measure behind, it sounds like this, go ahead, bee boop bee boo bee boop beep boopy. Right, So it sounded nice. It sounded louder. It didn't sound nice, but it sounded louder. It wasn't all discordant, right, So what just happened was we amplified the beat boop right, right, yeah, yeah, exactly. This is called um what is it? Constructive interference? That's right, and that's I don't want to say good and bad, because it's really scientists would say it is neither good nor bad. But I'm gonna say that's the good kind because that's what gives you iridescence. The bad kind would be destructive interference, and that, like you said, that cancels each other out, making something like less not less iridescent, not iridescent at all. Right, So that's it close, that's not entirely it, right because consider this chuck light. Light as we see it exists on a spectrum. Right. So, Um, on one hand, you have about a wavelength of four nimes violet light. On the other end of the spectrum that we can see is red light, which is has a wavelength about seven nimes. Right, okay, Um, if you go a little beyond the violet, you get bluer than blue a k A ultra violet, which we all love. Right. If you go beyond the red, uh, you have redder than red or infrared. Right. We can't see either of those, but we can't see within that spectrum for violet to red. And it's based on wavelength, if we um, if you take white light right like sunlight, and you put it, if you projected onto a transparent object, all of the colors. Remember the Pink Floyd Dark Side of the Moon album cover. Of course, it's white light going into a prism and then coming out in its separate forms, in all its psychedelic glory. Right now, imagine that that's static, Like it's it's not changing position. If you are shooting a beam of white light onto a bubble, depending on where you stand, the angle of reflection, right of refraction, I'm sorry, Um, depends on what color you're going to see. So if you move across your angle, you're going to see a different color. And hence this explains the color changing of iridescence. Right. So, like, you know, have you ever seen the big bubble wines where they can both the really huge bubbles the huge bubbles. Uh, if you ever do that, do a little experiment and look at it from different angles, jump around, walk around, and you're gonna see some color change. Have you ever seen a bubble pop in SloMo? That Super SloMo? No, but isn't wasn't that an episode of that one show Time Work? Yeah? Yeah, the Discovery Show. It is super cool, dude. If you look at it in slow motion, you like would pop the bubble, and you know, when you see it in regular motion, it looks like it just pops in a big burst, But from where you touch it spreads and an arc all around the whole thing, and you see it slowly popping as it goes around. It's just really cool. Nice. It's neither here nor there though, but it's still pretty like you're a descence. Right. So what we have now is um if if that if light from white light uh hits a transparent object, and it's a multilayered transparent objects, say like oil on type of water, or one side of a bubble and the bottom side of the bubble, some light's gonna reflect off, some's gonna make it through the bottom. Some of that will reflect off, most will will go through. But if the light from the bottom and the top are in phase with one another, in an even phase, right, separated by one two, three four five wave links rather than you know, one point three five wavelengths, they'll be in phase and they'll amplify each other. If it's white light, then we're going to see, depending on our ang goal all the colors of the rainbow. You're in this iridescent state, right. Okay, So what does this have to do with butterfly wings? I'll tell you, buddy. Okay. Butterfly wings are transparent, and the deal is why they look so striking compared to let's say, a bubble, which is pretty but not as striking as a butterfly. It's because there are many, many more layers stacked on top of each other that the light has to go through. When all those are in phase, you get like super iridescence. Right. So with a with a bubble, you have two chances right at the top and the bottom two lousy chances. Right. With a butterfly wing, the the cuticle of the scale of a butterfly wing, say, has maybe a dozen So every every beam of light, every wavelength of light has you know, a dozen chances to reflect back, say half of those are in phase. Yeah, and also depending on how because the surfaces. Um, if you look at a butterfly cuticle, it looks kind of like a Christmas tree, right, so there's like a it looks like a Christmas tree, basically like a lego Christmas tree. Will say, but the scales, actually I'm out the scales. Yeah, yeah, the scale cuticles that make up the scales. Yeah, that's kitan. That's the same thing we have in like our hair, it's protein in our fingernails. Nice okay, sorry, Um, So as it goes down the tree, you know, they get wider, These surfaces get wider, and each one can can bounce light back off, but they're spaced evenly. So let's say that the space in between is two d nanimeters and blue light is four hundred nanometers in wavelength. Since the two hundred is half of four hundred, it's going to give blue light a better chance to reflect back in phase, which is why I stay on like the blue morphoe butterfly, which has a space of two between the scales. The space and the scales appears so blue because blue has a likelier chance of reflecting back in phase and being amplifying in this iridescent manner, and the morpho doesn't that actually venture into ultra the ultra violet spectrum? Yeah, remember the angle. Yeah, so if you're looking, let's say, at the right is red and at the left is violet. If you move too far to the left, everything's gone because you've moved out of the visible spectrum of light. And now what you're seeing is the brown pigment, but who can see it is the butterfly. Yeah, the monarchs are actually in their migration, their huge migration every year. They use ultra violet markings. Uh, ultra violet um light for guide posts basically, right, Yes, they do, and uh it Also the other effect or the other reason, um that you have this iridescence and on the scales is it soaks up heat because butterflies are cold blooded, so they rely on like the sun to be able to function. So the fact that they're soaking up this heat from the sun allows them to fly, right, which is pretty cool. And we also remember pigment, don't forget still plays a role in this too, right, So if you have if you have a butterfly scale that's um constructed, contains chlorophyll, so you have um a green pigment. Yes, let's go with blue. Okay, Now let's go with yellow. Okay, say say it's a butterfly scale. It's constructive melanin. So you have yellow already, which it's reflecting back yellow and monochromatic blue light. It's going to it's going to appear to us as green because color mixing still has has an effect, right, So pigment structural color green. Can we talk about the wings for a second too, because I know people are going to write in and say that's really cool, but is it true that butterflies will die if you touch their wings? Sort of not completely? You can touch a butterfly wing. Like, if you've ever touched a butterfly wing, you'll notice you have like powder on your hands. Yeah, those are the scales. Those are the scales. They are that fine that they kind of disintegrate into powder. And in theory, you can touch a butterfly wing without killing them, but if you break it. They have little veins. They're all connected by little veins, So essentially, if you disconnect the veins from the fore wing and the hind wing, that's when the butterfly is gonna die. And they're so tender that it's really easy to happen. So in effect, you probably will kill a butterfly if you mess with their wings, but if you just happen to graze against it, maybe not. No need to squish it after just such a slight intrusion, right, Yeah, And moss, I think get a bum wrap because they're not as pretty. Yeah, because they're mainly mel what what was it, melitan, melanin melanin mainly like brown and yellow, black and white. And they also have a frenulum, which is a spine, and butterflies don't have that. Right. Also, moths tend to be fatter and fly at dusk or at night. Well, yeah, and that's why butterflies get all the credit, because you're out on a nice spring day in the garden and butterflies were everywhere, and then at night you're hanging out by the porch and you're freaked out by the moths everywhere, like going towards the light. Well not only that, um, there's there. The structure of a moth's wing is very, very similar to the structure of butterflies transparent filmy scales. For some reason, I guess it's because they do fly at night. They are not iridescent. They don't appear iridescent, although they would in sunlight. But they're part of the same family scientifically, big happy family. Yeah, what was the family? Uh, Lepidoptera? Was that lepidoptera? Lipidoptera. There's like a hundred and fifty thousand varieties within that family and lepidoptera I means scaled wings boom. Yeah, it's a great place to finish, don't you think? Sure? You got to we recap Oh, I don't think so. The party we explained it, well, I think so, all right, because I feel more confused than I did before. Well, you brought sound into it, but I thought that was a very clever way to go about it. Well, thanks a lot. If you want to learn more about butterfly wings and they're striking colors, type in butterflies striking colors in the handy search bar, how stuff works dot Com brings up a pretty cool article by Jennifer Horton. Hey, Chuck, chucks me from the future. The future are idiot. Past seals have no idea whe're doing this right now, right, but we do because we're from the future, indeed, and you know what we're here to do, don't you. We're interrupting our podcast for a reason. T Shirt Winners announced. This is one of the if you were a winner that you were guaranteed I mentioned on the show, and this fulfills that application. Yes, this is um. We've got the lawyers behind us that their briefcases in bullwhips, right, yes, and uh, Chuck, we picked five. I'm glad we picked five because we had like more than seventy jries, right. I wanted to pick ten. I wanted to pick twenty three. Um, and we actually did have like a top twenty three at one point and finally whittled it down time and time again, and we came up with the five winners and they're announced on the blog. There's an image gallery on how Stuff Works. You can go onto our blogs at how stuff works dot com and look for the blog post entitled we Got your T shirt. We got your stuff you should Know T shirt contest winners right here, uh, and that'll take you into the site to check them out. You can also get the shirts on the Discovery channel store right yeah, there for sale. Yeah. You just go onto the I Think store dot Discovery dot com and do a search for stuff you Should Know and it brings up all five of these magnificent T shirts. Right. So, the names of the winning designers, the five brilliant individual human beings who created these amazing designs, right, Their names are what chuck Well first, these are in no particular order. By the way, Um, we have Peter Feek or fight Or We've been debating endlessly and he did a really cool design of this old school microphone and it's sort of logo looking. It makes us look like we're really pros. Yeah, I call it hot Mike Hot Mike, Yeah, I like it. Uh. And then of course there's Suki Anderson. Yeah, out of Kentucky, I believe, I think, and she made what I think is the coolest picture I've ever seen in my life. Yeah, it's the baby with the fly on its forehead. Yes, and don't worry. Yeah. I said on the blog that it's it's unsettling and comforting at the same time, and it's very hard to achieve. Agreed. So that was one of our favorite ones. And then we went with Brad Wilson's brain design, which is awesome. Yeah, we got a lot of brain designs, so you guys were thinking along the same lines, which means you're all smart and cool. And that was the brain as as a representation of our show is really, I think, pretty cool, and this was what we thought looked best on a T shirt. Brad nailed it. Yeah, he nailed it definitely. Uh. Matt Stevenson came up with what I've dubbed the wood cut parade right right, Our fans are gonna love this one. Yeah. It's a it's a series of medieval characters I would say, skeleton, bishop, a monk, a jester, um and they are carrying banners let's say s y s K. They're leading the parade. The stuff you should know parade from medieval times. Yeah, and I said on the site it looks like a paraded one to hide behind a tree and watch. It's awesome. It's very cool. And then lastly, Chuck, I'm going to leave this one to you because I can't pronounce this guy's last name. Yes, we have Scott y A C y s h Y, and I'm gonna say, yeah, yeah, yakin ya kishin, Scott, whatever your last name, let's try that one to Scott Yukishan if that is you. You are one heck of a designer, my friend. And you did the very cool caricature of Josh and I and from our mouths and balloons. You have different caricatures of different episodes and so much camaraderie between us. You know, we just look like we are having a heck of a time gaining the podcast as a sixties illustration. It's very cool. One of my favorite ones to super awesome. So Scott, Matt, Brad, Suky, Peter, thank you very much to all of you guys, uh and thank you to everybody who sent in. From something created in rich text format to something that was obviously made by a professional graphic designer, we appreciate all of you, guys, and thank you very much for taking the time to lend us your brains and creativity. That's awesome that we were blown away. It was very cool. You're all very talented. Okay, and now let's go back to our stupid um selves from the past. I predict that it's going I'm gonna say some assin I thing about the handy search bar. Watched. Uh that means since I said handy searchbar, Chuck, are you ready for this? Listener mail, Josh, I'm just gonna call this, uh stuff you should know educating prisoner of America. I like this one. This is a good one. Well, prisoners of Virginia. At least, right which is in America? Isn't it still it's a commonwealth. I don't know if it counts. Oh, that's right, weirdos. All right, This from Maria in Amelia, Virginia. I guess you have a prison there. Hi, guys, I thought you might be interested to know that I use your podcasts as a resource to teach writing to inmate students. I'm a G. E. D. Teacher at a men's president in Virginia. Writing is one of the weakest skills for my students, and many of them never learned to write as far as secondary school. Uh, and they were afraid to write as adults, so they're sort of illiterate or completely illiterate in some cases. Well, I mean, think about it, Chuck, WoT is writing if not a series of choices of what you're going to share with people, it can be very intimidating. I burned your podcast to a c D and replay one in class because we don't have internet for obvious reasons. The men listen to your podcast, they take notes, and then they must write an article based on what we said. They practice writing sentence is and paragraphs in this way. The subject matter is of interest to them, some more than others. I'm afraid to play the moonshine one as much as I would like to. I know they would be interested even if I skipped the parts where you make the still and give the general recipe. So she won't do that, because you know they'll build a moonshine still. I'll bet they already know how the menhorns. Yeah, I think so. Uh. Some of these guys have been down a long long time, so they appreciate something to think about that isn't about sentencing and parole hearings. Thank you for your material. My family and I enjoy the podcast and they do a real service to people. So we are actually educating prisoners of a mayor. I know. That's awesome. So if you guys are in prison right now, if you're in the in the pokey in the who scale and you're listening now, we just want to say good luck. You can turn your life around, do your hard time, come out a better person, don't do crimes again, and get your g E D. And you know, get a get a job, and and good luck to you. That's what I say. And remember when you make a decision writing, don't look back. Really such your advice. Yeah, that is my advice. Actually, all right, you can always write something else. That's a good point. Yeah, if you want to let us know how we are changing the world for the better with this podcast, and it's an email to stuff podcast at how stuff works dot com for more on this and thousands of other topics, does it how stuff works dot com. Want more how stuff works, check out our blogs on the house stuff works dot com home page. Brought to you by the Reinvented two thousand twelve camera. It's ready. Are you