Radiolab - Colors

Episode Date: May 21, 2012

Our world is saturated in color, from soft hues to violent stains. How does something so intangible pack such a visceral punch? This hour, in the name of science and poetry, Jad and Robert tear the rainbow to pieces.  

Wait, you're listening. Okay. All right. All right. You're listening to Radio Lab. Radio Lab. From W. N. Y. C.

See? Yeah. And NPR. And I assume we're live on the air now. We don't do live. Have you guys ever talked to each other? I don't think so, no. Oh, so this is Chadaboon-Rod.

Well, hi. This is Jim Glick. Hi. How are you? Fine. How are you? Pretty good. Rainbows, rainbows. Okay, so we're going to start today with author James Glick. As I recall, you wanted to talk about Isaac Newton.

That's right. We did call him to talk about Isaac Newton, but more specifically, colors. All right. Isaac Newton, he's 23 years old. 1665. And he's home for the holidays. No, there's no holiday. He's home for the plague. There was actually a plague. They sent everybody home from school. In any case, he's in his room, famously solving all these mysteries of the world. And one of the questions that he thinks about during this break is... What are colors? Where do they come from?

Like, when I see the color red, is that red, is it inside my head or is it something that exists sort of out there in the world? Is the light without or is the light within? Hmm. So he pokes a knife into his eye. What do you mean? Here's what Newton wrote in his notebook. I took a bodkin, put it betwixt my eye in the bone, as near to the back side of my eye as

I could. Oh. And pressing my eye with the end of it, it appeared several white, dark, and colored circles. Did that lead him to some conclusion about where the spots live, whether they're outside or inside? No. This didn't get them very far. Because seeing spots when you poke your eye doesn't tell you much about what color is.

But what he did next. Did. And this one he's a little more famous for. He got himself a prism, which is just a bit of glass shaped like a pyramid. It wasn't so easy for him to get his hands on a prism, but he did. Then he shut his blind, so the room was totally dark. But he poked a little hole in one of the blinds. And then he waited.

The sun had to be at just the right angle. And he waited. And when the sun got to just the right spot, a ray of light shot through the room. Newton immediately stuck his prism into the light, and the light shattered. and became a rainbow on the wall. Or in Newton's own words,

A coloured image of the sun. Now that's gorgeous, isn't it? A coloured image of the sun. That's Victoria Finley. She wrote a book about colour, and she says, the thing to understand about this experiment is that at the time,

people believed that white light... It was given by God or given by this amazing thing called nature. The light from the sun was sort of holy. Yeah. If there was anything that was pure, it was white. So when the prism did the rainbow thing, which people knew prisms did, they just figured...

The colors are in there in the glass. In other words, that rainbow had nothing to do with the light itself. That was just the prism. Adding some kind of impurities to the light. Oh, wow. I hadn't thought of the possibility that the prism is muddying the light. It's polluting the light. How do you know that the prism isn't generating these colors?

Yeah. So he got a second prism, and this was the trick. While the first prism was still making that rainbow on the wall, he moved a few feet away, and he held up a second prism in the blue area to see what would happen to the blue light. Would the prism add more colors to the blue light? Or would it be transformed in some other way? And what he found was, nothing happens.

It remains blue. So he thought, hmm, if the blue light isn't getting muddied by the prism, then maybe the prism wasn't muddying the white light to begin with maybe that rainbow of colors was actually coming from inside the white light. He inferred that the first prism is dividing light into its constituent parts. Which means that the white light we see around us is actually constituted of all of these colors. The colors were in the light. They are the light.

He had his answer. Light is a physical thing in the physical world. You can tweak it, test it, study it. This was the beginning of everything we know about light today. Which Newton put us on the road toward finding. that ultraviolet rays, x-rays, radio waves are all different energies of light. And colors are just energies within that little sliver that we can see. And that has led to our understanding of the greenhouse effect,

knowing what stars are made of, even the age of our own universe. But not everybody was pleased by this. Well, a little bit later, John Keats, a romantic poet, was really crossed with him in a poem, because they said he'd reduced, removed all the poetry of the rainbow. And the real challenge to Newton's view of color, one that would really stick, oddly enough, it did come from a poet, not Keats, but the poet named Goethe. Yeah, here's this German romantic poet.

That is author Joan O'Leary. Regular with us, who writes about this kind of thing, and always wonderfully. One day he is walking in the park, and he spots these yellow crocuses, and he looks at the yellow crocuses and admires their petals. It's early spring, and they're blooming. And then it quickly turns away. And in an instant, he suddenly sees... This dash of violet crossed his eyes.

He still sees the shape of the flower, but now it's violet. It's the opposite of yellow. He hadn't rubbed his eye. He hadn't stuck a needle in it. And yet, there it was. Seemed just as real. As real as the yellow croakers. And yet he knew it wasn't real.

It came from inside his mind. And it was something, you know, we've all hallucinated colors. You can press on your eyeball or close your eyes and you see this riot of fireworks. But for Gerta, that simple observation leads him to think that maybe color isn't simply about the external universe and maybe our perception of colors began in the world,

but maybe it was finished inside the mind. And today, hundreds of years later, this is still an open question. A scientist can say color has an objective reality, but the colors we see are tricks of the imagination. And there is no perfect. objective view of color. Personally, I like to

keep both of those opinions in mind at the same time. Me too. Me three. Well, lucky for us, we're going to do a whole show of this. You don't say. I'm Jeddye Boomerant. I'm Robert Trulwich.

This is Radio Lab, and today... It's all about color. Yes. Where is color? Is it in? Is it out? That's the question. Yeah, we're going to explore that question through the eyes of a butterfly.

In the killing fields of Cambodia. With a woman who may see colors, the rest of us can only dream of. And we'll go back to a time when the sea apparently looked like dark red wine. Stick us in your air holes because we're about to get colorful. And by the way, before we get rolling, let's just want to say, we did something kind of different for us while making this hour. We put out this call to a bunch of musicians, solo artists, bands, to send us their favorite color songs, their own interpretations of their favorite color songs.

song. We got an amazing response. So throughout this hour, you're going to hear color songs of various kinds woven into some of the pieces, between the pieces. Those songs, by the way, we have plans for. Yeah, big plans. You can go to our website, RadioLab.org, to get a full list of the songs. And thank you, by the way, everybody who sent those songs in. Absolutely. Okay, so should we go? Yes. So to get things going... Hey, here he's here. Here he is. Not long after we talk to Jim Glick about Sir Isaac Newton, we talked to a neuroscientist by the name of Mark Changese. I'm going to chew grapes if that's all right with you. Who had written a book about color? Would you like some grapes? No thing. And we threw the question

at him. So one of the sort of debates that became interesting to us is this, where is the color? Is it out there? I mean, is this grape that I'm holding right now? Is it red for everything? A bee, a whale? I mean, does it exist in a way that you could pin down and say it's outside me or does it only get to be red when it gets in my head? Well, you can, another more severe way to ask this, and I ask this whenever I'm giving talks, is just, would aliens see it as red? Yeah, would aliens see it as red? Right, and the answer is almost surely no.

Truth is, says Mark, even your dog wouldn't see it as red. Your dog has color vision. It has blue, yellow, and black, white. Really? Yes. So what would the world look like to a dog? I mean, if you've ever known a guy who's colorblind and 10% of men are colorblind, that's roughly what it's like. Well, here's a question. If a dog and a human and a crow were to be staring at a rainbow, would they be seeing very different things? Yes.

Now, this question that Robert just kind of tossed out during an interview, like about how different creatures would see the rainbow, this ended up taking us down a little wormhole. And we ended up actually getting a choir to help us illustrate what we've looked at. But just to set a baseline, your normal rainbow goes like this, starting bottom up. Red, orange, yellow, green, blue, violet, Roy G. Biv. Roy G. Biff. Yeah, I don't know why people put the eye in there, but that's it. If you didn't have the indigo, you couldn't say it, though. It would be Roy G. Biv. That's why you need the eye, I think, is to say the Roy G. Bivv. That, by the way, is Tom Cronin?

I'm what's called a visual ecologist. Mark suggested we give him a call. He told us that humans see seven colors in the rainbow. In the case of the dog. Very different rainbow. It's going to start off blue. He'll be able to see blue just fine. So it would see a rainbow starting with blue. Same blue we see.

And then grading off into green. Same green as us. And then disappearing. The rainbow would end there with a tiny bit of yellow thrown in. That's it? Yeah, so the rainbow will only be about half as thick as ours. Wow. That's a sucky rainbow, dog.

Yeah. That's why when God promised that he would never deliver another daylures that he gave up He made the promise in a rainbow. The dog's just for totally unimpressed. And what is it about the dog eye that makes it see this way? It doesn't have red sensitive photoreceptors, no red sensitive cones. The weird thing is that the difference between dogs and us, cone-wise, is just one. They have cones tuned to blue and green, so do we.

But we have this one extra. Red, which doesn't really seem like a big difference. I mean, it's just one cone. But... To have three is so much better than two. That's Jay Knight's vision scientist. I'm Jay! Because of this kind of multiplicative thing.

Red can get mixed with blue. Which makes purple. Or red can get mixed with yellow. To make orange. And green to mix with blue. To get teal or turquoise. And that's how we get about 100 different shades of color that we can see. So by adding one photopigment,

instead of adding just one more color, you actually add about 98 colors or so. All right, let's move on. So now we have a crow, unless you'd like to change the bird. Well, the crow is not so interesting because it's pretty much like us. Oh. So let's take something like a sparrow. All right.

Because sparrows have ultraviolet vision. What do they see? So they see the rainbow starts before our rainbow starts, where we just see sky. It would see an ultraviolet color. And then it would see the violet. And it would see the blue. And the greens and the oranges. the yellow first and the orange

and then the red and probably would see further into the red than us because they have a more red sensitive red receptor than we have. So we'd see a much broader rainbow. It would start earlier

and it would end later. So should we assume that we've now that the sparrow is the champion? That's as high as it gets. If you're talking about vertebrates, no, I'm talking about anything that has a heart

and a mind in a bit. Once you leave the vertebrates, then all bets are off. You've got many animals have much better color vision than the vertebrates. Oh, really? Like what? Butterflies are a great example. Butterflies have five or six kinds of color receptors. We only have three, remember.

Butterflies see more colors than we do? Yeah. So if a butterfly were looking at a rainbow. I never thought we did here. Well, they do, I'm sure. I mean, butterflies are out there when the rainbows are out. But we see colors we have no names for between the birds. blues and the greens and the greens and the yellows.

So it would go from ultraviolet. It would see that. Yep. Then it would see violet. And then blue. And then blue, blue, green. Yep. And green, green, blue-bluey or whatever.

Right. And then orange and red and all that. Yeah. They have very complicated eyes. Huh. Okay, so just to recap. All right. Here's the dog.

Here's us, humans. Now the sparrow. A little bit more bass, a little bit more high-end, so to speak. And finally, the butterfly. Which is, you know, not so far above the sparrow, but it's got more mids in there. So I'm now thinking butterflies get the crown. Yeah, but then if you go under coral reefs, you come across these animals called mantis shrimps. What are they called meta?

Like a praying mantis. Oh, mantis shrimp. The shrimp catches prey using an arm like a praying metas has. Oh. Manish shrimps are mostly pretty small about the size. of a finger, some get to be as big as your forearm. They're big, big animals. I'm actually looking this up right here.

Oh my god, they're so colorful. No, they are colorful though. Here, look at this. Oh my god, they're just like a... It's like they're electric colored. Yeah, they're like turquoise or something. Iridescent. And their eyes are like little cartoon eyes.

They're gigantic. Yeah, they have two really big eyes right on the front. And you said that dogs have two cones, we have three... How much does the butterfly have again? Butterfly has five. depends on the butterfly. Manistrams have 16. 16?

Oh, my God. 16 kinds of receptors. What would the rainbow look like to them? Could they even see it? Manus shrimp would see the rainbow fine because they live in very shallow water, and so the water is pretty clear, almost like air. They would start the rainbow way, way, way inside where we see violet. They would see an extraordinarily deep ultraviolet.

And then they would go on through several kinds of ultraviolet, probably five or six kinds of ultraviolet. And then they would get to violet, which is now they're reaching our colors, and go through violet and violet blue and blue and blue-green. Where they have those green-green, blue-blue-blue-blues as well? Yep. And then they would go out and do the reds.

So they would be about as red as us when they got to the red end. But only in the reds? Yeah. What a rainbow that must be. Yeah. They have the most complicated visual system of any animals by a factor of two or more. Wait, wait, but he said any.

Do you mean that unequivocally, any? Yeah, no other animal that we know of has a visual system within 50% as complicated. All right, Mantis. But, you know, on the other hand, their brains are tiny, so who knows what it turns into. So they may not have the ability to perceive the beauty of the rainbow in the way they... No, I don't, I don't, no, they're banish streams are into violence. They're not really into beauty. They go around and kill things.

I mean, really, that's what they do. That's one reason they're so fascinating. They love to go around and kill things. What do they kill? Crabbs, other manish shrimps, shrimps, octopuses. They'll kill octopuses? Yeah, small ones. A good-sized manish shrimp can break the wall of an aquarium.

Well, really? Yeah, there's ones in California that can break aquarium walls if they hit it hard. Oh, my God. So you have a pugnacious Mohammed Ali sea-going animal with incredibly great visual sense. Special thanks to Jim Briggs, our engineer, for the choir session, which was a blast. To Mark Shangizi for setting us off in this direction. To Michael Kirshner and the Young New Yorker's Chorus. And John McLeay and the Grace Church Choral Society, and those folks from the collegiate corral,

Medesoff choirs who joined us. And to Alex Ambrose of WQXR for getting everybody together. Thank you, thank you, thank you. Okay, a very quick update. Since we aired this broadcast, the mystery of the mantis shrimp, has just gotten deeper. As we mentioned, they don't seem to gaze at sunsets or rainbows. We now think that maybe they use colors as kind of triggers for particular actions.

One color says, fight. Another color they eat. Another color says sex. They still have the best eyes in the world. But what they're doing with those eyes is a bigger mystery now than ever. Start of message. Hi, this is Tom Cronin. Hello, this is Jay Knight.

Radio Lab is supported in March and and the Alfred P. Sloan Foundation Alfred P Sloan Foundation enhancing public understanding of science science and technology in the modern world More information about Sloan at www.sloan

sloan.org This is James Glick. Radio Lab is produced by WNYC and screwed by NPR. Okay, hope that's good enough for you. Bye. Hey, I'm Jeddab. I'm Robert Krillwich. This is Radio Lab, and today we're talking about color. Okay. And that actually

brings us back to Jay Knights. I'm a professor of ophthalmology, University of Washington, Seattle. Jay has actually spent his entire career trying to get creatures to see colors that they normally can't see. Well, yeah. And he started, this is kind of an interesting story, by taking some colorblind monkeys who couldn't see red. They have blue cones, green cones, but no red cones. Which is not unlike a lot of human males. In any case, he had these monkeys and was able to take the human gene for the red cone, rabbit and a virus, inject it into the monkey's eyes, and bam, the monkeys suddenly had red cones. Yeah. So it had blue, green and red. Was this like Lasix?

It was just like a 10-minute outpatient situation for the monkeys? I would say close. Close to LASIC. Could they then now see red? Well, every single morning before they get their breakfast, they have to do their color vision test. So he'd sit each monkey at a computer. We had a touch screen. And the screen looks totally gray.

But in that field of gray, he adds a little red blob. Right. Now here's the key. We use grape juice as the reinforcement. For the monkeys. But the game is... You have to touch the blob before you get your juice. So before the surgery, they weren't seeing any blobs, and they weren't getting any juice.

Because all they could see was gray. So a little red blob could be right there in front of them. and they'd never see it. And the morning after their LASIX color booster shot. Okay. Touched if you see it. They still couldn't see it. Day after day, they would do their test.

And every day they would fail. Every day they would fail. No blob. No juice. But it's fun for them. They get out of their cage and they talk to their friends. Did you fail? Yeah, I fail.

I fail. You fail. Another day, another fail. Until one morning, after about 20 weeks, Jay woke up the monkeys, gave them the test, and they began to not fail. Really? If you watched a video of this,

it actually looks like the monkey is like, Wow, you know, I'm not having any failures. And check out this dot. Look at this thing. Check it out. So I did get some sense that they felt like that their life had improved. Now, if this works so well with the monkeys, couldn't you take a colorblind human and give them back the thing they're missing? Absolutely.

We could cure colorblindness in a human with exactly this technique. Really? The only thing that we have to do is convince the FDA that the risks are low enough and the benefit is high enough that it would be something we could do in people. You've never tried it? No, we've never tried it. Although I get a lot of emails that say, I don't care what the risks are. I've even had offers. How about if I come to your laboratory and you don't tell anybody late at night

and you give me the shot in the eye and we won't tell anyone? Which brings us back to our original question. If you can take a colorblind human and give them normal color vision, could you take a normal color sear and boost them to make them a little more shrimpy? Well, yes, yeah. He said, sure, why not? But then there's the whole FDA thing. But here's the real surprise.

Jay says there are some people who are already a little bit mantis shrimp-like. There are color mutants, if I may call them that, in the nicest possible way, among us. Or they're out there in theory. Okay, so here's the deal. The genes for the cones in our eyes that see color, you know, the red, green, blue cones. They're on the X chromosome. Now men, as we know, only have one of those. Women have two X chromosomes.

Which means that women have two sets of these cone-making genes. Normally, one set is just a spare. It's not used, but still they've got two sets. And so someone said, aha. It is theoretically possible that in some women, this spare set of genes might mix up, turn on, morph into a whole new cone, a fourth cone. We're going to call it the yellow cone.

So if people with normal color vision are trichromats, because we've got three cones. woman like that would be a tetragramat. So altogether she'd have a blue cone, a green cone, a yellow cone, and a red cone. But she wouldn't just see more yellow. This new yellow would mix with the red and the blue and the green to create thousands, maybe millions of more shades of color. This amazing, the technicolor is not the right word.

It's whatever would be the next kind of color that would be even more super duper. This was just a thought experiment? Yeah, but... Jay actually figured out a way to test for this. We can look in people's blood, and I can say this woman has the genes for blue cones, green cones, yellow cones, red cones. You can do a DNA test, really.

Yeah. So, he started doing blood tests, and he found this one woman. She worked at the same place we did. Crazily enough? At the university. He looked at her DNA, and he saw the gene for the fourth coat. Yeah. Wow.

So did she see in Super... Technicolor or how would you even know? That was a problem. And so we thought of an experiment in order to be able to see whether or not she had this extra dimension of color vision. He was able to produce these two yellow lights that to us, you know, trichromats, normal trichromats, look totally identical. We're colorblind to that difference.

But to a tetachromat, a woman with this fourth cone, they would look totally different. Yeah. So they brought her in. I said, okay, here it is. Do you see these as different? And she said, no. I don't see them. There's any different.

No. But the story doesn't end there. Good. Jay told us about a colleague of his in England. She's at Newcastle named Gabrielle Jordan, and she apparently found eight of these women with the extra cone. And out of those eight? Seven of those women behaved exactly like the person that I had tested.

Couldn't see the difference. But one of them took one look at those two. two yellows and said? No, they look totally different to me. Oh, one of these women saw it as different. So one of them had the cone but you could use it, and the others had the cone but couldn't use it?

Yep. So why is that? Yeah, why? Well, this is the part, if you'd like, I could tell you what my theory is of what's going on. Yeah. So I think that if Jay says, let's just imagine you grow up in a world without color,

completely and totally a black and white world. houses would be painted black and white. Printers would only print in black and white. Even the TV. They would just have black and white TV. Women's makeup would be just, you know, either dark or light. So it wouldn't make any difference if you had color vision because you would never use that color vision.

There'd be no words for color. Now, just to make it interesting, let's imagine one day a bright red apple plops into your world. How would you react to it? Would you see it, you think? Well, so that's a very good question. Maybe, says Jay, even though you have the ability to see that red apple, if you've never had a chance to use that ability to practice, it may just lay dormant. And that, he thinks, might be what happens to women living with the extra cone in our world.

They're very rarely subjected to colors that would stimulate their extra kind of cone differently. So you're saying those other colors just aren't around enough for those? Yeah. Everything that we make is based on the fact that humans are trichromatic. The television only has three colors. Our color printers have three different colors. There's nothing out there that we make artificially that a tetragramatic could see. But Jay says maybe. Some women, because they're just more aware or because of the job that they do. Maybe someone who works with color all the time, like a florist or a painter. Little by little. Because they're paying such close attention. their brain would learn to see that difference.

So naturally, we wanted to find one of these mythic ladies. Well, I hope they're not mythic, maybe. The reason I say that is because we tried to find that one woman that he mentioned, you know, the one out of eight. Yeah. And we had a really hard time, and we began to doubt that she even existed. And then we began to look online, and you see all these websites saying, are you a tetachromat?

Contact us, contact us. Everybody is searching for these women, and we began to feel like we were chasing unicorns a little bit. But then our producer Tim Howard claimed that he had found one. Yeah, you are. Turn right on Sarah Street. He'd been in touch with Jay. Jay told him that he tested a woman, determined that she had the fourth cone,

and this woman was an interior designer. Oh. But Jay had not yet determined whether she could use her fourth cone, so we sent Tim to Pittsburgh where she lives to see what he could find out. Hey, how are you? Hi, I'm Susan Hogan. mother of three and an interior designer. What if she like?

She's great. You have a jukebox. Really? You want me to play something? How about number 307? It just seems appropriate because it's about color. White or shade of hair. She told me a lot about how she uses color in her work.

You see the different colors of paint? Because she thinks a lot about it in terms of painting walls. I know the way the sun is oriented in a room. Each wall will look a different color, even though. In any case, here was my plan. I'd ordered this test before I went to Pittsburgh that Jay had suggested I'd get it. All right, open it, open it, open. It involved these little pieces of brown fabric.

Okay. They all look identical. They look strikingly the same to me. Yeah, Lynn, Brenna, me, Soren. Those are completely indistinguishable. Couldn't see a difference. Do they all look the same to you guys? Yes.

But I'm assuming they're actually not all the same. That's the trick. Jay said, if you show them to a real tetrachromat, They're going to be able to see these subtle differences that, you know, you and I can't see. And back to Pittsburgh. So how about we head over toward that tree? Is that that look like me? I'm going to take my shoes off because it'll be much more fun.

We ended up doing the test in a nearby park. We're going to do a bunch of these, if you don't mind. In the first trial, I took out three of the swatches, two that were exactly the same and one that was supposedly different. And when you took it out, could you see the difference? No, no. So I go behind the tree. and I whisper into the mic, number. I hope you couldn't hear me.

No, thank you. I'll let you take a look. She steps back from the swatches, gives it a look for a moment, and then she says... Number three. Third one is different. Looks more neutral, less red

than one and two on the left. One for one. Luck. So I went behind the tree. I changed up the swatches so that now the middle swatches, so that now the middle swatch was the odd one out. And same deal, ready set, go.

Easy. Which number looks different? The middle one. Number two. Mm-hmm. You're right. Really? Yeah.

Wow. Okay. Then I figured I got to make it harder. I switched it up, and I made it so all three are different, and I didn't tell it. All three are different. All three different. Wow. Green, red, less red.

knocking it out of the park. Why didn't I do this well on my SATs, Tim? Wow, you found her. I was sure that she was not going to be. There's no way this test can work. Well, it actually might not have totally worked. Wait, what? Did she start to fail?

There's one little thing I didn't mention. What? I brought along a friend. I'm Jason McCroy. Painter. Landscape. Still life. I thought I try him out as a control.

Oh, because you were thinking, and let's get someone who likes color but is a boy and can't be a tetrochroma. Right. And when we tried the exact same test with him, I mean, these three, they look the same, don't they? To you? No? I see different.

He was amazing. Uh-oh. Every time. The first one on the left, two jumped out immediately. Number one. They all three look different to me. Wow. Was he just as good as Susan?

Yeah. I was a little bit disappointed, I got to say. And there was nowhere where he couldn't do it and she could? No, but I mean, I only had pieces of brown cloth, you know? So it doesn't prove anything, I guess. She still might be a tetragrammat, right? For all I know. And there was this one moment.

I know it doesn't prove anything, but I asked her about the sky. And the sky was just that quintessential sky blue. And she was, I was like, what do you see? And she's like, I see. do you see some of the pink in the blue? See, I see a lot of pink like among the blue. There's red in that blue. She was looking up at a blue sky and seeing red?

Yeah, yeah. Do you see that? No. Oh, I see so much red like up in. And it's kind of a cop-out, but it's just kind of that perfect sky blue. Okay, that's a good. It's just mixed in there. That's cool.

One thing I don't see is any green in the blue. that blue. I just see reds right, especially around the white clouded section. And at that moment, I felt like my sky is boring. I'm so sorry for you. For us. I'm sorry for us. I mean, how do we know that any of this makes sense? You know, that's the fine of it. Yeah. You know we haven't talked about yet. What's that? Where do the colors come from?

You mean like sky colors? No, no, like painterly colors, like marine blue. Oh, like artificial colors. Well, no, they're not. That's the thing. You'd think they come from a factory or something, but originally they came from the earth. And there's one story about color that has haunted me.

for about a year and a half. It's so strange. I don't know if it's true or not, but I mean, I don't know if you... It was in my book, of course, it's true. That's Victoria Finley again. Her book is called Color. And this story starts with, well, a particular kind of goop. It's a color called Gamboges.

It's named after Cambodia, the French word for Cambodia. And it comes from the sap of a tree that grows in the Cambodia, Vietnam, Thailand, border area. And this is a yellow color? Well, it's a yellow color, but... How you get it is really the sticky part. I mean, the way they get it is that they cut a slash in the bark and then hitch up a tube made of bamboo. About the circumference of a quarter?

Yes. And then little droplets of goop come? Little tiny droplets of goo. And they fill up the tube. The same way you get maple syrup or rubber. But they leave it. for a couple of years. Years.

Years. All right, so it's a really slow process. So slow. Drop. That some pretty strange things... Drop. Can happen in that time. What do you mean?

Sap has secrets. Secrets. What secrets? Wait a minute. So, after two long years, the harvesters come back, and each of those tubes, is now full of this quite like plastic. It's sort of it's got that sort of plastic resin-y kind of feel. But that's just the beginning.

The resin makes this incredible transformation, which we actually saw, Sean and I. Hello. Thanks to this guy. My name is George Kramer. I'm a color man. He owns Kramer's pigments in Manhattan, and he sells this gamboche.

It is an important yellow. It's amazing when you use it. We have powdered and the resin for me. When you have a look at it, it's just like this dull, oakry brown color. You can imagine like a ball of ear wax. And you think, oh, that's not very interesting color. The dusky sort of. That's like a really boring color.

But then you put a drop of water on it. Or you grind it up in a bowl. With a little water. When you grind it, it looks like this. Oh. And there it is. Wow. It's a little bit of white.

It's bright. Very bright yellow. It's bright fluorescent yellow. Suddenly it's like, pow! It means it is quite an exciting color. Very, very yellow. I carried one around for ages. I say, have a look at this color.

Look how boring it is. Now put a drop of water on it, showing kids and I was really happy. I even gave it to one kid who was just so delighted, and it was only afterwards that I found out that it's so dangerous. It's dangerous? Why? Why? You get a bad diarrhea. When the guy's... the guys used to chip in the small pieces.

There was actually a time built in for them to visit the toilet at least once an hour. Ian Garrett knows that because he was technical director at this art supply company called Windsor and Newton in England. And here's what really got us interested in all this. Back in the 1980s, Windsor and Newton would get these shipments of Gambos from Cambodia and they would take it to this production room. It's quite a dusty area. Just had a table in there.

Big old table where the workers would set. And then they would have this hammer, put the gambouge pieces on this lump of iron, and then hit it and shatter it into small pieces. Because that's how they make it into a kind of usable, sellable paint. And one day, one of the workers was chipping and scraping at the resin. There they were. They found something in the resin that they didn't expect. They found bullets.

Bullets? Like, in the hunks of resin? Lodged in them, yeah. Sometime in that two-year drip drip process, toward the end probably, as the resin was getting thick, a bullet went whizzing through the air, went flak into the goop, and stayed there. Actually, it wasn't just one bullet. There's a total of about a dozen. And those are just the ones he found lying around the factory.

There were probably many more. They fall into two sorts. There's a very sharp, pointed one about just over an inch long. And then the other type are small sort of barrel shapes, which are about three, quarters of an inch long, about half a dozen of each, and how they got there and what they passed through on the way into the gambou, I'm not sure. What we do know, of course, is that those years in Cambodia were years of war and murder. A million and a half people died there, most of them in the killing fields.

And that's the same place where you'd find the gamboes trees. I mean, it's shocking, really, and it, because those were just the random little bamboo tubes hanging on the trees. What happened in that grove? what terrible things happened. The proposition here would be that at some point, maybe because of the famous killing fields, that some 14-year-olds with Kalishnikov rifles

after finishing a series of murders or just shot lots of bullets. They would have just sprayed that grove. In order to get into the little tiny bamboo canisters collecting this gambos, they would have had to have sprayed that entire grove with machine-gun bullets. And in that year or two years, somebody murdered people, I should think. Well, I mean, it's not necessarily a battle scenario. It could have been target practice.

You see these things hanging on the side of a tree. You want to practice your marksmanship. I mean, there is a way in which there's violence in this color. I guess there's violence. It makes me wonder about the... Does it ever give you pause? Does it ever give me what, sorry? Pause?

Pause. Not really. We were too remote. Bought it from a guy in Holland who bought it from an exporter who got it from Lord knows where in Cambodia. But the idea that it could have been attached to that bloodshed, does that bother you at all? Are you saying, do I think it's morally acceptable?

Is that what you're asking me? Yeah. You know, it wasn't Windsor Newton who discovered these things. These things were demanded by customers. You're a hard-hearted man, I feel. I had never thought about it until you pitched it like that. As we kept on talking, Ian made it clear. It wasn't that he hadn't thought about the violence, per se.

It's just that it wasn't like breaking news to him. They sell some pigments that come straight out of hills that are right in the middle of war zones. Okay. Colors are sometimes soaked in blood. That's just how it is. On the other side of the coin, I've made it my career in 40 years to make artists paints

on the basis that people who paint tend not to make war. It's a peaceful occupation. And George Kramer, who runs the paint shop, he was pretty much of the same mind. You could think of it this way. Imagine the first person to ever find this brilliant yellow. maybe 10,000 years ago. He's walking through the forest after it's rained,

and he sees it there on a tree, and he's a maze, so he puts his finger into the yellow, and then dabbs some on his face, and he feels instantly beautiful, like larger than himself. It is about being related to something transcendent. And that says George is the other side of the coin. To an upper high or whatever. Therefore, the ball will be used it

from all sorts of ceremonies. Marriages, feasts, maybe war paint to feel invincible. Any moment he suspects that needed to be pulled out of the ordinary and lift it up. And there you need something

what is bright, something what is beautiful and special. And this yellow gives you something special. It is a perfect yellow. Thank you to Victoria Finley. Her book is called Color,

short and simple. And to Ian Garrett of Windsor and Newton, who did not wither under our withering moral attack. On the contrary. This is Amy Lantinga from Boston, Massachusetts. Radio Lab is supported in part by the Alfred P. Sloan Foundation, enhancing public understanding of science and technology in the modern world. More information about Sloan at www.sloan.org. Blue is a song for...

Hey, I'm Jada Boomrod. I'm Robert Krollwich. This is Radio Lab. We're going to keep going with our show on colors now with a story about, well... The color of the sky. Most beautiful color. Well, I think so.

Except red. Nah. Yeah. It's a story that we find really surprising, frankly. And it comes from our producer Tim Howard. Yes. Hello. Who heard it from...

Do you want to set up who this guy is? So Guy Deutsche. is a linguist and a writer. I came across his book. He tells us one particular story in it that starts in, I think, 1858, with this guy, William Gladstone, who was an incredibly famous politician in England. He was four times prime minister in the second half of the 19th century. Every school kid knows who he is, even now.

But there's one thing that not many people know about Gladstone. Well, he was a homer fanatic. As the soldiers marched, the gleam went dazzling from the magnificent bronze all about through the upper air to the heavens. He was a deeply religious man, and for him the Iliad and Odyssey were almost like a second Bible. Sipping the black blood, the tall shade perceived me and cried out sharply. He read them over and over again throughout his life. So he was into Homer. Yes. And so early on in his career, Gladstone decided.

decided to write the definitive history of Homer. This huge book, actually three books. Thousands of pages. Where he discussed a whole range of issues relating to Homer and his wealth. And here's the thing. As he was reading, doing his research and everything. He made this very strange discovery. That the way Homer talks about color in the Iliad and the Odyssey is extremely odd.

It's odd? Very, very odd. How so? To start with, he uses extremely strange terms for colors of simple objects. The most famous one perhaps is... The wine dark sea. The wine dark sea. It looks like wine.

It looks like wine. Is it possibly like a poetic kind of thing? That's what you would naturally think. But the other thing he calls wine color are oxen. But it's more than just wine. Take the color violet. which to me and probably do you use it. Purple?

Like purple. When Homer uses it. He talks about the sheep. The Cyclops Rams were... And the Cyclops caves is having... A dark violet. Whoa. But that's just fantasy.

I mean... But the other thing that he also says is violet is iron. Iron. Iron. So... Chew on that. How about this one? What is both the color of honey and the color of faces pale with fear?

No idea. If you ask Homer, those are green. Green, honey? He didn't call his forest green. He didn't call his leaves green. It all seems to be wrong. And this was totally puzzling to Gladstone.

Homer was Gladstone's absolute hero. So he found it difficult to understand or accept why someone who was so perceptive would use such defective terms, as Gladstone call it. So he starts going through the Iliad in the Odyssey again page by page, and he counts how many times each color appears. I mean, like, how many times he uses the word black or blue or whatever? Yeah, and it only takes a couple pages for him to notice.

The predominance of black and white. That the term black days, black carrion flies under his black brows. Black, black, black, black, black, black. It occurred about 170 times in both books. White arms, white clav, the white sail on it. It occurred about 100 times. But red? A blood red serpent.

Only clocks in it about 13 times. It's a big drop. Yellow? Dawn in her yellow robe robe. Under 10 times. Green? His teeth chatter in green fear. Also under 10.

And then Gladstone realizes something crazy. The color blue? Um. Zero times. What? There's just no one. that describes the color blue in any of Homer's poems. He does not use the word blue at all?

No blue. No blue. Not even once. Nope. So Gladstone thought, huh, bizarre. And he started looking in other classic Greek texts too. And there, he kept finding all of these strange uses of color. Violet hair and things like that.

And after thinking about this for a long time, Gladstone concluded that Homer was color. but also that all the Greeks were colorblind. He thought all of them were colorblind? Yes, that they saw the world in black and white, maybe with a touch of red. His thought was that they were straining to see these other colors that were kind of just outside of their reach. And then their kid would inherit that effort, or their kid would just be a little bit better. Oh, so that's how we got color.

So Homer Jr. would be able to see a little bit of yellow because Homer tried really hard to see yellow. And then Homer the third would be better than Homer the second. Yeah, and then this would happen again and again every generation down 3,000 years to the present day. It just seemed the only, you know, the only possible explanation. That's ridiculous. It's ridiculous. We know today, of course, I mean, that our color vision goes back probably about 30 million years. You know, to like when we were still in the jungle, climbing trees. Exactly.

Generally, people mocked him. No one took him seriously. So then how do people explain the no blue and Homer thing? Well, here the plot thickens. Ten years after Gladstone's Homer debacle, this other guy... A German Jewish philologist called Lazarus Geiger. Lazarus Geiger. A German-Jewish what?

A philologist, which I thought was a linguist. It basically means he studies ancient texts. He finds pretty much the same kind of weird stuff the Gladstone did, but he finds it not just in ancient Greek texts, but all over the place. Sorry, this one. He looked at the old Icelandic sagas. Ancient Chinese, ancient Vedic hymns, the Bible. And surprise, surprise, what did he find there? No blue.

Even the Bible had no blue? In the original Hebrew, Lechuna and it has no blue. So, where, what's this, what's this room? Right now we're in the public catalog room. I actually went to the New York Public Library and talked to this librarian. Who can speak German? So Envickland Geshechekhter's book.

So the development history of mankind. Wait a second, I know this voice. Really? Yeah, that's my girlfriend. My name is Brooke Watkins and I'm a library. at the New York Public Library. She helped me find some very cool passages in Geiger's book. Let's do it. First, let's do it

in Germain. Geiger has this amazing quotation. Okay, I'm sure. About the Indian Vedic poems. These lera out more of 10,000 verses best... What does that say? These hymns of more than

10,000 lines are brimming with descriptions of the heavens. Scarcely, is there any subject evoked more frequently? The sun and reddening dawn's play of color day and night, cloud and lightning, the air and the ether are unfolded before us, and over and over in splendor and vivid fullness. There's only one thing that no one would ever learn from those ancient songs who do not already know it,

and that is that the sky is blue. It gets weirder. You ready? Yeah. I'm totally ready. All right. Because Geiger then wondered, all right, if there's no blue in any of these old texts, then when did blue come into these languages?

Yeah. So he did this massive analysis to trace when each color term was first introduced to each language. And what he found was... The order at which languages seem to acquire these color terms is not entirely random. First, black and white. Every language has black and white. Then when they get their first color term... Red always comes first.

Always red. After red, it's always yellow. Really? Yeah. And then green. and blue only at the very end. So black, white, red, green, yellow, and then blue? Yeah.

And that's universal? Well, as people discovered more and more languages, they found some exceptions. But a couple of things held, even from Geiger. Out of these colors, red is always first and blue is always last. Why? Well... Why would there be an order at all?

And why would blue always be last? Well, here's where you get to the guessing part. Okay. I thinks it might have to do with a couple of things. First, in Homer's world, you wouldn't have actually been exposed to a lot of blue things. Actually, if you think about it, blue is extremely rare in nature. Blue foods?

No. Blue animals? How about plants? There's a few blue plants. Like what? Flowers that are really blue are extremely rare. A lot of flowers that we think of as blue, they're actually... Artificial flowers.

We made them blue. Genetically, you mean. Yeah. What about blue eyes? Blue eyes at the time were in short supply among the Greeks. But here's where we get to guy's main point. He says you don't really need a word for a color until you can make that color, reliably.

And the reason that red might have been first is that red... It is apparently one of the easiest to produce. You can just take a dried piece of red clay and you can use it as a cram, which is why paints made out of ochre go back something like 60,000 years. And blue? Blue is the hardest of all.

For thousands of years, no one had it. One exception, the Egyptians. The Egyptians. And they, and only they, had their own word for blue. So that's it? That's your answer? Yeah. Like, no blue dyes, no blue words? That's not interesting?

I want more than that. What do you mean more? I don't know, something more to say than just it's about dies. Here you go. As I was calling around, I ran into something that made me think, A little differently about Gladstone's whole theory of colorblindness. Called this guy named Jules Davidov. Professor of Neuropsychology, Lung University.

And a few years back, he got interested in this particular tribe in Namibia called the Hymba. The Hymba. Like many languages in the world, they don't have a different word for blue. You might think of them as like a very poor stand-in for Homer. And to make a long story short, Jules went to Namibia. He sat down with a bunch of members of the Himbab tribe, whipped out a laptop and showed them 12 colored squares. All identical except for one.

And there's actually some really cool video footage of his research assistant doing this. And he asked him, very simply, which one is different? Now, you look at this and you see that 11 of these squares are green. A color we would call green. Very green. The other one is blue. This blue one, it's shouting.

It's like, hey, I'm blue. Over here, I'm blue. It's easy enough for us to do. It's a no-brainer, but the Hymba, who don't have a separate word for blue in their language... They find this distinction a little difficult. When they stare at this screen, they just stare and stare. They don't see the difference to the blue and the green? No.

Well, is there something wrong with their eyes? No, definitely not. We completely rule that out. They don't see color and individual colors differently. But then, wait. It's so easy to say that they're seeing different colors to us. us and they're not. Well, then how does he explain it?

Okay. When we decide to put colors together in a group... And then give those colors a word, like blue. Something happens. He says what happens is that now that there's a category for that thing, the thing in the category jumps out. It gets louder and louder to your eyes. The category actually feeds back on your perception,

so you notice it more. You're saying that having the word for blue unlocks your ability to see blue? I mean, that's how it feels to me, and Jules says... No, it's not quite that. He says without the word, you're still seeing the blue, no matter what. You're just not noticing it. Your eyes are just kind of glossing right over it. So you don't see it?

It's harder to spot, says Jules. Whatever, I don't quite understand that difference. The blue would not jump out and say, high five. the way it does with us. But if it doesn't jump out to that extent, then this is starting to sound very glad, Stony, to me. I mean, maybe he was a little right, because if Homer had no word for blue

and the word somehow enables the blueness of the blue, then maybe his world was less blue than it would be for us. I mean, maybe the blue went through his eyes in the same way, but perhaps didn't get into his mind in the same way. Yeah, blue didn't matter. Wait a second. Do you know where this breaks down? Where?

The sky. I mean, you look up and there's the bluest blue in the world. And it's right there above our heads. It's been there since the dawn of time. So why wouldn't blue matter more? I mean, why wouldn't it be the first color instead of the last? Well, that's what I thought too. And I asked Guy about that.

Yeah, why is the sky blue? Is the first question that you always think? Allegedly the first question that all children ask. Yeah. But I wanted to see how obvious or striking this blueness of the sky is. So I decided to make an experiment. Guy has a very young daughter. About 18 months.

She was learning to speak. What's her name? Alma. I talked a lot about colors with Alma and taught her all the colors, including blue. We would play all these games that dads play with her children. You know, pointing at objects. I would point at a blue object and ask her, what's the color of this? She would say boo.

Boo for blue. Oh, okay. Soon enough, Alma was a total pro. She could identify any color. Show me the red object. Show me the red object. Show me the distance. Right.

The only thing I didn't do, and I asked my wife not to do, was ever mentioned that the sky was blue. That was the setup. So one day, Guy and Elmo were taking a stroll, and they were practicing the colors. What's this tree? What's this? What's this?

And then I pointed at the sky and said, what color is that? And she wouldn't give me any answer. Although she just a second before was happily telling me that something was blue on red or green. She just looked up and looked at me incomprehendingly. Sort of what are you talking about? She thought you were kidding? I think she didn't understand what I was on about.

In retrospect, there was no object there. There was nothing with color for her. You're just pointing into the void, basically. Pointing into nothingness. So she wouldn't say anything. But Guy kept asking every single time they went out. Of course, I would do it only when the sky was blue. and she would never answer.

And this went on for two months. And then finally, she did consent to give me a color name, but it wasn't blue. It was white. For a few times she said white. And then finally, after a month and a half, or two more months, she said blue for the first time. Wow.

But even then it wasn't consistently blue. So then she said once blue, no white, no blue. Did she eventually decide, though? You know what that it is blue? Well, no, she never said it. this way, but eventually when I asked, it became consistently blue, so she just would say blue. Okay. This was for me really the point where I could, you know, convince myself, I could convince at least my heart that the sort of allegedly perfect example of blue is not so perfect.

So, you know, for Homer who, you know, never ever probably saw a blue object except the sky and the sea, never had a dad who sort of went on about and blue objects and asking what the color of the sky was. The fact that he didn't lose sleep over it doesn't seem so strange anymore. You know, it's kind of, now that I've heard this, I'm a little, I'm a little, uh, ruying the, the moment when Alma decided the sky was blue. Let her have whatever color she wants it to be. Doesn't have to be blue. Weirdly then, color is a loss of innocence.

Yeah. It's like having something fixed that for a while is just between you, And your frenzied hearts, you know? And the sky is many colors, truthfully. On the other hand, though, I'm disagreeing with myself now. If we all agree the sky is blue, then that's something we can share. She can share. And then she's in conversation.

And then eventually she'll understand, you know, this kind of blue. Yeah, there aren't blue moons, but you know what one would, you know what it feels like. Oh, yeah. It's not a happy night. lost all his glow The day that I lost you He lost all his glitter The day you said no

And his silver turned to blue Like him I am doubtful That your love is true I don't think it's the most beautiful. I don't think it's the most beautiful color. I just took red just to be contrary. I'm trying to what actually my favorite color is. I don't know.

When you say you love me, then prove it by going out on the slide. Proving your love isn't true. Call me Mr. Blue. I want to thank all the musicians who were so generous to let us use their music this hour and joined in in our covers of the Rainbow Project. You heard Reggie Watts with Rainbow Connection. Barbara Bennery with Over the Rainbow, Lonesome Organist with Green Onions, Nymph with Brown Rice, Yellow Ostrich with Sound and Vision,

Raya Brass Band with Paint It Black, Nico Muley with Big Yellow Taxi, Shearwater with Black is the Color, Eric Freelander with Blue in Green, Marcy Playground with whiter shade of pale. The heap with mellow yellow, tau win with blue, Snowblink, you just heard, with blue moon.

Dan Deacon right here with colors. Busman's Holiday, Mr. Blue. And our very own Tim Howard, aka Soltero, performing Green River. We'll be doing some cool things with these songs for the moment. Visit radiolab.org. Hello Radio Lab, this is Guy Deutsche.

This is Brooke Watkins. This is Jason McCroy. Here's the message. Radio Lab is produced by... I don't know how to pronounce them. Judge Abelrod. Our staff includes Ellen Horn, Thorne Wheeler.

Pat Waters, Tim Howard, Renner Farrell, Len Levy. Dylan Keith, Melissa O'Donnell and Sean Cole. With help from Douglas C. Smith, Brendan Macmillan, and Raphael Ben In. Okay. Special thanks to Sharon Montague. Nick Capodice

I love it Ivan Zimmerman Ayake Judy Jha Winter Woody Raga Gess daughter And Kerber Throdson

Thanks bye End of message