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Creature Feature: The Physics of Animal Color · Daniel and Kelly’s Extraordinary Universe

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Speaker 1: Welcome to Creature, feature production of I Heart Radio. I'm
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Speaker 1: your host of Many Parasites, Katie Golden. I studied psychology
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Speaker 1: and evolutionary biology, and today on the show we're talking
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Speaker 1: about all the beautiful colors and nature. Blues and greens
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Speaker 1: and reds and browns and purples and ultra violet. There
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Speaker 1: are so many colors in the annual Kingdom and in
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Speaker 1: the natural world. But it is really interesting how these
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Speaker 1: colors are actually produced, and it's not always straightforward, and
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Speaker 1: in fact, what we see with our human eyeballs may
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Speaker 1: not be what other animals see with their incredible eyeballs.
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Speaker 1: Discover this and more as we answer the age old
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Speaker 1: question is there a berry that's so incredibly blue it's
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Speaker 1: just gonna trick you into doing its dirty work? Joining
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Speaker 1: me today is friend of the podcast who I have
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Speaker 1: been on his podcast quite a bit. Post of the
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Speaker 1: Amazing Physics podcast Daniel and Jorge explain the Universe and
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Speaker 1: particle physicist Daniel whiteson Welcome. Hello, Hello, very glad to
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Speaker 1: be here. Although I can't boast to be host to
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Speaker 1: any parasites as far as I know, as far as
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Speaker 1: you know, although you probably have some demodecs parasites on
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Speaker 1: your eyelashes, as do most people. I contain multitudes. I
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Speaker 1: suppose little societies living on our eyelashes. Is there anything
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Speaker 1: cuter than that? Well, me and my little societies are
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Speaker 1: very excited to be here to talk to you about
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Speaker 1: colors in the natural world. Yes, so I thought this
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Speaker 1: would be right up your alley, because we are talking
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Speaker 1: about the physics of colors in nature. Because you know,
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Speaker 1: when you see a color, it feels pretty straightforward that
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Speaker 1: thing is just somehow painted that color. But it is
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Speaker 1: actually much more complex how it works in nature. Things
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Speaker 1: aren't just kind of painted with a paintbrush. And in fact,
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Speaker 1: there are some incredible ways that colors present themselves, in
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Speaker 1: incredible ways that animals will perceive these colors like an
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Speaker 1: entirely hidden secret world that we never really knew about
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Speaker 1: until researchers started investigating it. So first we will go
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Speaker 1: over how color exists in living organisms. So this is
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Speaker 1: an animals and plants, even fungi. There are a few
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Speaker 1: ways that color occurs. So when you think of color
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Speaker 1: in the natural Kingdom, Daniel, what what do you think of? Like,
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Speaker 1: what is sort of the first thing that comes to mind.
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Speaker 1: I think of the incredible colors of flowers and the
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Speaker 1: incredible colors of insects and words, and I wonder why
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Speaker 1: they're there and whether those animals see them the same
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Speaker 1: way we do. You know. I wonder why we live
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Speaker 1: in a world that we find beautiful, if we could
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Speaker 1: have evolved in a world that we found like boring
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Speaker 1: and drab, or if we just sort of naturally react
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Speaker 1: to any world we discover with amazement and satisfaction. Yeah,
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Speaker 1: this is what's so interesting to me, because I think
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Speaker 1: one tempting thing to think is that humans are the
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Speaker 1: only animals capable of appreciating beauty and color in the world,
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Speaker 1: that we're the only ones who, you know, really enjoy
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Speaker 1: the site of a flower. But as we'll talk about,
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Speaker 1: that may not really be true that we One of
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Speaker 1: the things that we may share with many other animals
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Speaker 1: is their dependence on color, their appreciation for it, and
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Speaker 1: how that beauty of the world serves a very important
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Speaker 1: function for for organism survive all. So, there are two
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Speaker 1: main types of color in the animal kingdom, pigments and
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Speaker 1: structural coloration. So pigments. Pigmentation is pretty straightforward and probably
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Speaker 1: what you think of when you think of something that
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Speaker 1: has some color to it. So pigments are substances produced
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Speaker 1: by cells that will absorb certain certain wavelengths of light.
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Speaker 1: The light that is not absorbed is reflected back to
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Speaker 1: your eyes. So that's how you see something that is pigmented,
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Speaker 1: how you see that color. So pigments can be found
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Speaker 1: in nearly every organism, from flowers to birds, to fish,
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Speaker 1: to mammals to fungi. It's everywhere in the animal kingdom,
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Speaker 1: and that is typically what gives things their color. And
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Speaker 1: you say that simplistic, but actually aren't there several fascinating
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Speaker 1: levels of signs there? I mean, as the physical is here,
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Speaker 1: it amazes me to think about, like the microscopic process
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Speaker 1: that happens when your eyes sees red. I remember as
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Speaker 1: a kid thinking about, like what is red about that light?
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Speaker 1: Is the light itself? Red is happening in my head?
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Speaker 1: That makes me feel red? Did somebody else see red
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Speaker 1: the same way? There's a whole lot of really fascinating
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Speaker 1: questions there. Yeah. Absolutely, it's really interesting too to think
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Speaker 1: about how something that is a certain color, like something
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Speaker 1: that is red, it's actually that is it is rejecting
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Speaker 1: the red wavelength that is the one color that is
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Speaker 1: not there is red, because that red is reflecting back
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Speaker 1: at you and that's why you see it as red.
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Speaker 1: But it's actually absorbing the other wavelengths of light. So
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Speaker 1: like in a strange kind of way, the only color
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Speaker 1: that it isn't isn't part of it is the color
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Speaker 1: that you see. Yeah, And I think for a long time,
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Speaker 1: people didn't know how vision worked. They didn't understand whether
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Speaker 1: light was being bounced off of things and hitting your eye.
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Speaker 1: And for a long time people were wondering if your
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Speaker 1: eyeball actually shot out rays which then bounced off something
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Speaker 1: like sampling it and came back to your eye. You know,
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Speaker 1: back before we understood how light worked, people have to
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Speaker 1: think about all sorts of crazy ideas. But I think
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Speaker 1: it's really cool to think about the actual photons. Like
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Speaker 1: if a photon hits your eye and you see it
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Speaker 1: as blue, or another one hits your eye and you
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Speaker 1: see it as red. And what's the actual difference in
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Speaker 1: the photons? As you said, it's the wavelength, it's how
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Speaker 1: fast they wiggle. They all travel the same speed, but
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Speaker 1: they have different speeds at which they wiggle, so they
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Speaker 1: have different wavelengths. But you know, there's an infinite spectrum
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Speaker 1: of wavelengths, like a photon can have any wavelength of
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Speaker 1: light that just changes how much energy it has. But
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Speaker 1: how you see it, whether it's blue or red or green,
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Speaker 1: that's just is how your brain is interpreting it inside
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Speaker 1: your head. Yeah, that's really interesting to me because there
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Speaker 1: really is. When you think about it, it's there aren't
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Speaker 1: distinct colors, right, There aren't just a certain number of
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Speaker 1: distinct colors. There is likely sort of infinite gradient of colorations,
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Speaker 1: but we can only maybe distinguish a small fraction of
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Speaker 1: those colors that we see because of the limitations of
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Speaker 1: our our eyeballs, which, even though I'm saying limitations are
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Speaker 1: eyeballs are one of the most incredibly complex organ in
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Speaker 1: our bodies. And it's really interesting. It is really fascinating.
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Speaker 1: And I remember as a kid wondering if colors are
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Speaker 1: just in my head, if my mind is sort of
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Speaker 1: painting red inside my mind's eye when that photon hits,
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Speaker 1: could my mind come up with a new color? Could
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Speaker 1: I invent some new color that hasn't wasn't inspired by
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Speaker 1: something I saw, wasn't like, you know, the color of
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Speaker 1: a bees butt, or something, um, but I never managed
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Speaker 1: to do it. Maybe I'm just not creative enough. I
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Speaker 1: tried to do that too. I tried to think of
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Speaker 1: a new color, and I never really could. But we will,
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Speaker 1: you know later. I'm so excited to talk about this
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Speaker 1: because we will talk about some people who may actually
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Speaker 1: be able to see color that doesn't really exist for
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Speaker 1: other people. And yes, in short, basically all of our experience,
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Speaker 1: right from touch to taste to color, is happening inside
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Speaker 1: of our brains. So it is an interpretation of these
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Speaker 1: photons that wiggle at a certain wavelength and then they
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Speaker 1: hit the back of our eye, and then they hit
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Speaker 1: these photoreceptor cells and will sort of, if you think
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Speaker 1: about it, kind of like tickle certain cells, Like certain
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Speaker 1: wavelengths are able to create sort of a domino effect
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Speaker 1: for certain cells, and then that will be sent to
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Speaker 1: the brain via a bundle of nerves and then that
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Speaker 1: is what creates the color. And it's just it's like
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Speaker 1: the most intricate Rube Goldberg device uh at work there
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Speaker 1: every time you see any kind of color, and it's
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Speaker 1: so helpful, right, And imagine if you couldn't see color
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Speaker 1: in the world, to be so much information out there
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Speaker 1: about the universe that you would just be missing. And
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Speaker 1: as you said earlier, there's lots of different wavelengths of
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Speaker 1: light that we don't see, which means there's a huge
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Speaker 1: amount of information about the universe that's out there that
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Speaker 1: we are just blind to. That's that's exactly right. And uh, yeah,
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Speaker 1: as we'll talk about really soon, there are animals that
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Speaker 1: can actually tap into that secret universe of colors that
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Speaker 1: we can only kind of conceive of. Yes, so even
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Speaker 1: though pigments are relatively straightforward, as we've talked about it is,
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Speaker 1: it's still an extremely complex, fascinating process that happens with
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Speaker 1: those So so, yes, they they are essentially their substances
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Speaker 1: produced by cells that will absorb wavelengths, and that the
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Speaker 1: wavelengths that they do not absorb, they reflect back out
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Speaker 1: and those hit our eye and we see that color.
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Speaker 1: But there's an there's a second type of coloration in
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Speaker 1: the animal world, in the natural world called structural coloration.
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Speaker 1: So these are microscopic structures that instead of absorbing light,
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Speaker 1: they will bend, refract or reflect light, causing certain wavelength
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Speaker 1: to separate and hit the eye. So they kind of
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Speaker 1: they scatter light rather than absorbing certain wavelengths. This is
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Speaker 1: super cool also because it's physics at work again. Right,
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Speaker 1: if you're familiar with a prism, then you know that
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Speaker 1: when white light hits it, white light being a mixture
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Speaker 1: of many different colors, that the different parts of that
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Speaker 1: white light bend at different angles because of their different frequencies.
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Speaker 1: This is something like that Newton demonstrated hundreds of years ago.
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Speaker 1: So it's pretty awesome that the natural world is like
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Speaker 1: scattering tiny prisms all over surfaces to change its color.
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Speaker 1: That's amazing. How do they do that sort of microscopically?
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Speaker 1: Are they actually like little prisms? Yeah? Yeah they are.
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Speaker 1: I mean think I think the Pink Floyd logo with
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Speaker 1: that it's pink Floyd. Right, you're gonna ask the physicist
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Speaker 1: for your pop science. Sorry, you're gonna ask the physicist
10:58
Speaker 1: for your pop culture references. So you know that prism
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Speaker 1: will scatter light, and that is exactly right. They basically
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Speaker 1: have these tiny prisms. So these are common in things
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Speaker 1: like bird feathers or butterfly scales on their wings. So
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Speaker 1: have you ever seen like a morpho butterfly? I have
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Speaker 1: no idea what that is. It's this beautiful butterfly that
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Speaker 1: has this iridescent, bright, bright blue coloration on its wings,
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Speaker 1: and it's such a bright blue it looks like it's shimmering.
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Speaker 1: And it makes me think that these butterflies are maybe
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Speaker 1: where people got the idea of things like fairies or magic,
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Speaker 1: because it looks absurdly magical. So I'm a little confused
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Speaker 1: about how these structural things work, Like doesn't the color
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Speaker 1: of it then depend on the angle of it? Like,
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Speaker 1: is that why it's shimmering because if it turns a
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Speaker 1: little bit, the prisms are shooting red light in your
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Speaker 1: eye instead of yellow light or blue light. Yeah, that's right.
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Speaker 1: So some of these structures are such that they will
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Speaker 1: result in something like a predominantly blue wavelength because they're
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Speaker 1: structured that they basically amplify the blue wavelength through these
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Speaker 1: tiny prisms. But there are some of these prisms that
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Speaker 1: will result in an entire rainbow, and that color will
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Speaker 1: shift depending on the angle of your eye, the angle
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Speaker 1: at which you look at this organism. So there are actually, uh,
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Speaker 1: there are actually snakes that have these iridescent colors in
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Speaker 1: their scales that they look like a rainbow because they
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Speaker 1: are essentially these tiny prisms that are scattering light, and
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Speaker 1: you'll see the entire gradient through their scales, and it's
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Speaker 1: it's quite beautiful. You can actually see up somewhat even
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Speaker 1: with the common crow, where their feathers, these micro structures
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Speaker 1: on their feathers will basically scatter the light such that
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Speaker 1: you can see all of these different hues beyond just
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Speaker 1: the black of their feathers. You can see these other
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Speaker 1: hues of light if you view them at a certain angle.
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Speaker 1: That's right. Crows are awesome. They don't get enough love
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Speaker 1: I think from bird enthusiasts and from the population in general.
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Speaker 1: They're super smart. And they're not just black exactly, they're
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Speaker 1: like shimmering black. But what's the sort of history of that, Like,
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Speaker 1: have these different mechanisms for color pigmentation and structural did
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Speaker 1: they split off evolutionarily at some point? Are they totally
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Speaker 1: different ways to get color? Are they related to each other?
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Speaker 1: I would say that they are somewhat interwoven, because you
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Speaker 1: can have an animal that has both pigmentation and structural coloration,
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Speaker 1: So I think they're they basically worked together. So while
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Speaker 1: some some animals may not have a structural coloration too much,
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Speaker 1: or or maybe rely mostly on structural coloration instead of pigmentation.
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Speaker 1: You'll have many animals that will actually have both a
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Speaker 1: lot of birds, a lot of reptiles will have both
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Speaker 1: structural coloration as well as pigmentation and humans. In humans,
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Speaker 1: we mostly rely on pigmentation in terms of the coloration
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Speaker 1: for our skin and for our eyes and hair. But yeah,
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Speaker 1: and in a lot of other animals, you'll have this
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Speaker 1: really cool confluence of both of these. And I would
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Speaker 1: say that they probably I think that they're they would
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Speaker 1: probably in evolve in the pretty interleaved way because of
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Speaker 1: so there are some really interesting ways you can see this.
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Speaker 1: So in terms of the production of pigmentation in humans,
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Speaker 1: it is melanin produced by our melanna sites, and so
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Speaker 1: melano sites are a type of cell that produced the
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Speaker 1: color in our skin and our hair in our eyes.
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Speaker 1: But not all animals actually use melanno sites. They use chromatophores.
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Speaker 1: So chromatophores are the pigment producing cells of things like cephalopods,
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Speaker 1: so those are octopus, squid, cuttlefish. Chromatophores are also present
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Speaker 1: in reptiles, fish, amphibians, and more. And chromatophores have some
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Speaker 1: really interesting properties, and that is that they can use
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Speaker 1: both pigment and structural coloration, and in some of these
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Speaker 1: animals they can actually be dynamics. So most chromatophores just
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Speaker 1: simply produce a pigment and create color that way, but
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Speaker 1: some chromatophores will use structural coloration to produce hues by
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Speaker 1: scattering light that creates a very very vibrant version of
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Speaker 1: this color that to otherwise not be produced just by pigmentations.
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Speaker 1: So this can be seen in things like the bright
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Speaker 1: blue stripes of a zebra fish. Have you. They're actually
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Speaker 1: a very popular little aquarium fish. They're also called blue danios,
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Speaker 1: but they're these little, just little slips of fish, and
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Speaker 1: then they have these blue stripes and those blue are
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Speaker 1: these bright bright blue. It's hard to describe it without
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Speaker 1: seeing them in person, but it's similar to the morpho butterfly.
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Speaker 1: Where's that shimmery, shiny, bright blue. And that is a
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Speaker 1: result of both pigmentation and structural coloration that like amplifies
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Speaker 1: that blue. And like I was mentioning earlier, there are
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Speaker 1: those rainbow iridescent hues of the sunbeam snake that they
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Speaker 1: actually use guanting crystals in their cell structure to scatter light,
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Speaker 1: which is kind of amazing. It's this snake that has
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Speaker 1: these beautiful crystals that will amplify light and scatter it
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Speaker 1: so that you see these rainbow hues and chromatophores in
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Speaker 1: addition to both being able to produce structural and pigmentation,
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Speaker 1: can alter their shape and alter what pigment they are
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Speaker 1: producing in order to rapidly change color, which you see
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Speaker 1: in things like octopus, octopuses, and cuttle fish, and you
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Speaker 1: can also see it in things like chameleons. So yeah,
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Speaker 1: it is. It's you can see this incredible example of
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Speaker 1: how uh, pigmentation and structural coloration can work together to
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Speaker 1: create mind blowing colors in the natural world. And do
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Speaker 1: all these different creators use it for the same purpose.
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Speaker 1: I have a sort of simplistic understanding that sometimes birds
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Speaker 1: uses for like sexual selection, or flowers use it to
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Speaker 1: attract bees for example. Are the structural elements always using
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Speaker 1: the same way as the pigments or there a huge
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Speaker 1: variety in why these creators spend this energy to make
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Speaker 1: these amazing little structures. There is a huge variety of
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Speaker 1: purpose for these colors, So you're right, Like in birds,
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Speaker 1: often the coloration of birds comes down to looking pretty
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Speaker 1: for the opposite sex, for the male birds trying to
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Speaker 1: look very pretty for the females. There are a few
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Speaker 1: species where it's more equal, where both the females and
18:25
Speaker 1: males are trying to look their prettiest. But in a
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Speaker 1: lot of animals, coloration can have many different uses, so
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Speaker 1: uh and chromatophores, because of how dynamic they are, actually
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Speaker 1: really illustrate this beautifully. So in octopuses or color cuttlefish,
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Speaker 1: you actually see that dynamic color shifting of their chromatophores
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Speaker 1: being used for things like camouflage or even like disruptive
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Speaker 1: coloration to evade predators. So they can use it both
18:58
Speaker 1: to be able to hunt to sneak up on their
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Speaker 1: prey or to evade predators and use these kind of
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Speaker 1: distracting colors. Sometimes they'll even have these pulsating colors that
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Speaker 1: is thought to have sort of this disruptive effect at
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Speaker 1: confusing predators about the direction that the the octopus or
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Speaker 1: cuttle fish is going so that they can escape. But
19:20
Speaker 1: in things like the sunbeam snake that has that beautiful
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Speaker 1: rainbow hue, it's actually not exactly known why they have
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Speaker 1: it because they don't seem to really rely on site
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Speaker 1: that much. They're mostly nocturnal, and so one of the
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Speaker 1: ideas is that that is just sort of a byproduct
19:41
Speaker 1: of the structure of their scales, which may have some
19:45
Speaker 1: other use like conservation of heat energy making, because they
19:51
Speaker 1: are they are quote unquote cold blooded, just meaning that
19:54
Speaker 1: they use their environment for thermal regulation to make sure
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Speaker 1: that they maintain a good would uh homeostasis of their
20:03
Speaker 1: body temperature and so being able to have a structure
20:08
Speaker 1: on your skin, the structures on their scales that may
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Speaker 1: help them mediate how much light, how much of the
20:16
Speaker 1: heat from light is sort of reaching their bodies or
20:19
Speaker 1: not that may be beneficial to them. That's still actually
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Speaker 1: being studied though it's not quite known why they are
20:25
Speaker 1: these beautiful colors, but there's a there's a good chance
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Speaker 1: that it has nothing to do with how pretty it looks,
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Speaker 1: and they may not even really see these colors, but
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Speaker 1: that it has it's just a byproduct of the structure
20:37
Speaker 1: of their scales that has some other benefit for them. Wow,
20:41
Speaker 1: so they could be like accidentally glamorous. How incredibly, how
20:47
Speaker 1: incredibly amazing they look, Yeah, exactly, And of course there
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Speaker 1: are other types of structural coloration that we see that
20:57
Speaker 1: don't even use chromatophores like I was described. So that's
21:01
Speaker 1: the case for butterfly scales, where it's just basically these
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Speaker 1: these chunky scales that use diffraction grating to produce colors.
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Speaker 1: So when light hits them, they diffract the light through
21:15
Speaker 1: these microscopic slits like a physics experiment. That's amazing. That's
21:19
Speaker 1: like a whole other way to use light to look different.
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Speaker 1: It's incredible. Yeah, So essentially, like the light goes through
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Speaker 1: these tiny slits and then it comes out as this.
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Speaker 1: I'm actually going to struggle more to explain this than
21:39
Speaker 1: I imagine you might be able to explain it. But like,
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Speaker 1: how so how does It's kind of similar to like
21:44
Speaker 1: the slit experiment, right, the double slit experiment. What happens
21:47
Speaker 1: when light goes through a really narrow passage is essentially
21:50
Speaker 1: that passage becomes like a little source sort of like
21:52
Speaker 1: light is emitted from a little slit itself. That if
21:55
Speaker 1: you have lots of little slits near each other, and
21:58
Speaker 1: you have all these different sources, so now if your
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Speaker 1: eyeball is a certain distance away from all of those slits,
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Speaker 1: then some of those add up and some of those
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Speaker 1: cancel out and so you get these interference effects, like
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Speaker 1: the number of wavelengths the light has to travel from
22:12
Speaker 1: one slit and from another slit might be an equal
22:14
Speaker 1: number of wavelengths, in which case they add up, or
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Speaker 1: they could be off by a half wavelength, which means
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Speaker 1: that one is wiggling up at the same time the
22:21
Speaker 1: other one is wiggling down, and so they cancel out.
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Speaker 1: So you can get these amazing interference patterns from these
22:27
Speaker 1: diffraction gratings. And it's dependent also on the wavelength, so
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Speaker 1: you'll see interference in red, in other places you'll see
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Speaker 1: non interference in blue. And so it's another way, sort
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Speaker 1: of like a prism in that it's bending the light
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Speaker 1: and creating effects that depend on the wavelength. Yeah, I
22:44
Speaker 1: love that. That's that is so cool that essentially, if
22:48
Speaker 1: you want to look at a teeny tiny physics experiment,
22:52
Speaker 1: you can look on the wings of most butterflies. So
22:56
Speaker 1: when you're talking about interference, there can also be constructive
22:59
Speaker 1: interference right where two wavelengths are adding up. Yeah. Absolutely,
23:03
Speaker 1: If the wavelengths are an integer number apart, like if
23:06
Speaker 1: it's wiggled nine times and another photon is wiggled ten times,
23:10
Speaker 1: then they're sort of in the same place in their wave,
23:12
Speaker 1: and so they add up. It's just like waves in
23:15
Speaker 1: the ocean. You know, if two waves hit you at
23:17
Speaker 1: the same time and they're both like pushing up, then
23:19
Speaker 1: you're gonna get two pushes up. It's gonna be really dramatic.
23:22
Speaker 1: So absolutely you can have constructive interference as well as
23:25
Speaker 1: destructive if they're pushing in different directions. Well, constructive interference
23:30
Speaker 1: is the reason behind the brightest blue found in any
23:35
Speaker 1: living tissue in the world, which is produced by the
23:38
Speaker 1: marble berry, which is a plant, which we don't We
23:42
Speaker 1: don't often talk about plants on this show, but when
23:44
Speaker 1: we do, they are absolutely incredible, and the marble berry
23:48
Speaker 1: is a blindingly blue berry. Now, you can look this
23:52
Speaker 1: up online and I'll certainly have a picture of it
23:54
Speaker 1: in the show notes. But a photograph is not going
23:57
Speaker 1: to do it justice because it's not going to capture
24:00
Speaker 1: that blue light like your eyeballs can. And it won't
24:03
Speaker 1: also translate the way that this these shimmer because it's
24:08
Speaker 1: structural coloration. It does depend on the angle, so you'll
24:12
Speaker 1: have this like purplely blue shimmery so bright it might
24:18
Speaker 1: actually hurt your eyes a little bit. So this is
24:22
Speaker 1: a leafy flowering plant from southern Africa. Its berries are
24:26
Speaker 1: shockingly blue due to the mirror like cell structure on
24:30
Speaker 1: their surface and crystalline structure underneath of spiraling cellulose. And
24:37
Speaker 1: what it does is it allows for a huge amount
24:40
Speaker 1: of light to be narrowed and reflected, and it amplifies
24:44
Speaker 1: the blue wavelengths especially, and it hits your eye just
24:48
Speaker 1: with this flood of super super blue in this constructive interference. Well,
24:55
Speaker 1: I don't know if I believe that these things are
24:56
Speaker 1: the bluest things in nature. Pretty sure that after an
24:59
Speaker 1: entire blueberry pie one time, that my insides were the
25:02
Speaker 1: bluest thing in nature based on you know what came
25:05
Speaker 1: out later. But I'm wondering, are these berries blue just
25:09
Speaker 1: in the skin or is their flesh also blue? Because
25:11
Speaker 1: blueberries are mostly blue in the skin. When you bite inside,
25:14
Speaker 1: they're sort of like faintly transparent. Are these guys just
25:17
Speaker 1: in the skin or blue all the way through? That's
25:20
Speaker 1: a really good question. My sense was that it is
25:23
Speaker 1: mostly in the skin, because what is interesting about these
25:29
Speaker 1: is that blue coloration is not an it is not
25:35
Speaker 1: an honest indicator of them being delicious nutritious berries. They
25:40
Speaker 1: do not have any nutritional value. They're not strictly speaking edible.
25:44
Speaker 1: They don't I don't think they would make you sick, really,
25:48
Speaker 1: but they don't taste good. They're not really good for you.
25:51
Speaker 1: But birds love them. And the reason they love them
25:56
Speaker 1: is a bird is going to be very easily wooed
25:59
Speaker 1: by some pretty and colorful uh. The birds will try
26:03
Speaker 1: to eat them or even decorate their nests with them
26:07
Speaker 1: because they are just so so blue, so shiny, so shimmery,
26:12
Speaker 1: just like humans. Essentially, these birds just love these berries
26:16
Speaker 1: because they're pretty and they want they want to have them,
26:19
Speaker 1: and so the berries don't have to waste resources making
26:23
Speaker 1: themselves nutritious. They're just so shiny and pretty that birds
26:27
Speaker 1: will distribute them. They will disperse them and try to
26:30
Speaker 1: eat them, despite them not being nutritional at all. They'll
26:33
Speaker 1: put them in their nests. And this plant then sneakily
26:36
Speaker 1: finds a way to have itself distributed just through sheer
26:41
Speaker 1: beauty and no actual intrinsic value. Oh man, I feel
26:46
Speaker 1: bad for the birds. I feel bad for the birds.
26:48
Speaker 1: They're getting like conned by a dumb berry. It happens
26:53
Speaker 1: more often than you would think we're a plant outwits
26:55
Speaker 1: an animal. The day that happens to me, I'm gonna
27:01
Speaker 1: resign my job here as a professor. How smarted by
27:04
Speaker 1: a unless it's a slime mold that here. Those are
27:07
Speaker 1: pretty smart. So we've talked about some of the incredible
27:20
Speaker 1: ways that you can see color in the natural world.
27:23
Speaker 1: You have pigments which can produce amazing colors, like the
27:28
Speaker 1: color of of our eyes, of our hair, and our
27:31
Speaker 1: skin is through pigmentation. But there's also structural coloration which
27:35
Speaker 1: can happen in a variety of ways, where basically it
27:39
Speaker 1: is a structure that is manipulating the light's wavelength so
27:44
Speaker 1: that it can scatter, it can amplify it, it can
27:47
Speaker 1: cancel it out, and that can result in everything from
27:50
Speaker 1: the bluest blue you've ever seen to a shimmery rainbow.
27:55
Speaker 1: One thing is interesting is that as beautiful as the
27:58
Speaker 1: world is to our eyes, it looks radically different to
28:03
Speaker 1: other animals, and other animals will experience the world in
28:08
Speaker 1: such different ways that it may even be hard for
28:12
Speaker 1: us to imagine exactly what is going on, because, of course,
28:15
Speaker 1: we cannot read the mind of an animal. We can
28:18
Speaker 1: only look at their eye and look at their brain
28:21
Speaker 1: and kind of try to piece together what maybe their experiences.
28:27
Speaker 1: We can't even understand what another human is experiencing when
28:30
Speaker 1: they look at the world and they have basically the
28:32
Speaker 1: same biology, right, I don't know that your red is
28:35
Speaker 1: my red and your blue is my blue, And so
28:38
Speaker 1: to me, it seems like philosophically impossible to imagine what
28:41
Speaker 1: an octopus or a rat or a fly might be
28:44
Speaker 1: experiencing about the world. Yeah, this say, is What is
28:47
Speaker 1: so mind blowing for me is that, Yeah, I can't
28:51
Speaker 1: even trust that you, Daniel, sees the same world that
28:56
Speaker 1: I see. Like, we already know that a lot of
28:59
Speaker 1: people definitely don't see color in the same way that
29:03
Speaker 1: others do because there are varying degrees of color blindness.
29:08
Speaker 1: And it is also hard for me to imagine that
29:12
Speaker 1: everyone's experience of color is going to be exactly the same,
29:16
Speaker 1: because of course all of our eyes are going to
29:18
Speaker 1: be different and our brains are going to be different. So, yeah,
29:22
Speaker 1: it is. It is really interesting, And there are experiments,
29:26
Speaker 1: psychological experiments that show that people can differ in like
29:30
Speaker 1: how many colors they can distinguish between, And I think
29:34
Speaker 1: it mostly comes down to practice, so like you can
29:38
Speaker 1: actually practice and become better at distinguishing between different colors. Uh.
29:43
Speaker 1: And if but if you're unpracticed, something that is a
29:47
Speaker 1: different color from another thing may look like the same
29:50
Speaker 1: color to you. I guess that's because a lot of
29:53
Speaker 1: it's happening sort of in software in your brain, and
29:56
Speaker 1: so you can improve that by practicing. I love the
29:59
Speaker 1: way the world looks, you know. I love the purples
30:01
Speaker 1: and the reds and the blues and all the greens.
30:02
Speaker 1: And I feel bad if people aren't like experiencing the
30:05
Speaker 1: same incredible world that I'm enjoying. And then I realized,
30:08
Speaker 1: hold on a second, maybe everybody else out there has
30:11
Speaker 1: an even more amazing world, and like the way I'm
30:13
Speaker 1: experiencing it is like, you know, a thin shadow of
30:16
Speaker 1: the true beauty of the world. And then I feel
30:18
Speaker 1: frustrated because we're like all trapped inside our brains that
30:21
Speaker 1: are painting these worlds for us. Yeah, I mean one
30:25
Speaker 1: interesting example of how we may not recognize, like we
30:29
Speaker 1: may think that our way of seeing the world is
30:31
Speaker 1: the best because we get to see all these pretty colors,
30:33
Speaker 1: but even when there's an animal that may not have
30:36
Speaker 1: the same kinds of structures that we do in our
30:39
Speaker 1: eyes and our brain, they may still have a really
30:41
Speaker 1: interesting way of perceiving the world we just don't know.
30:45
Speaker 1: And a great example of this is the octopus. So
30:50
Speaker 1: octopus is of course we talked about earlier, for having
30:53
Speaker 1: those incredible chromatophores that not only produce pigment, but can
30:58
Speaker 1: actually change their shape and can change what kinds of
31:01
Speaker 1: pigments they produce in order to create this rapid change
31:05
Speaker 1: in color, and they can use that for things like camouflage.
31:10
Speaker 1: There's even been there is a guy who kept an
31:13
Speaker 1: octopus in his living room and he got to watch
31:17
Speaker 1: this octopus as it was sleeping, and as it was sleeping,
31:20
Speaker 1: it's it would kind of flicker and its colors would change,
31:23
Speaker 1: possibly indicating that it was dreaming. And so the octopuses
31:28
Speaker 1: have these wildly amazing colorful lives, and yet they don't
31:33
Speaker 1: have color detecting cones, those little photo receptors that are
31:38
Speaker 1: on our retinas. They only have one type of photoreceptor cell.
31:44
Speaker 1: And so the thought was, these poor octopuses, they are
31:48
Speaker 1: so colorful, and yet they can't perceive color because they
31:52
Speaker 1: don't have cones like humans do. So they might be
31:56
Speaker 1: producing color on their skins but not observing it any
32:00
Speaker 1: each other. I always thought that maybe occupied were using
32:02
Speaker 1: that as a way to communicate, like a visual, colorful language. Well,
32:07
Speaker 1: octopuses are really interesting because as intelligent as they are
32:11
Speaker 1: and as spectacular as they are, they're not that social.
32:15
Speaker 1: They have very limited social interactions. And when they are social,
32:20
Speaker 1: they do seem to have some changes in their coloration,
32:25
Speaker 1: but not much is known how they use that for
32:29
Speaker 1: communication because they're they are very shy, even with each other,
32:34
Speaker 1: and so their social lives are very limited and we
32:37
Speaker 1: don't observe them too often. That doesn't mean that they
32:40
Speaker 1: don't use that coloration to communicate, but it's just so
32:43
Speaker 1: such a rare event that we have researchers struggle to
32:48
Speaker 1: actually understand what language they are speaking with this coloration.
32:53
Speaker 1: But while it may be that they can't see color
32:56
Speaker 1: because they don't have cones, they may yet be able
33:00
Speaker 1: to see color because they have a very strange wide
33:06
Speaker 1: pupil and you've probably seen that it's this like sort
33:09
Speaker 1: of wobbly wide you shaped pupil, and the this wide
33:15
Speaker 1: pupil actually scatters light as it enters the eye, which
33:21
Speaker 1: means that it would hit the back of the eye
33:23
Speaker 1: the retina at different focal points. So there is a
33:28
Speaker 1: theory that potentially these octopuses are able to see color
33:33
Speaker 1: based on the difference of blur and what it sees.
33:38
Speaker 1: So if it's hitting the eye at these different focal lengths,
33:41
Speaker 1: for us, we would see that as sort of a
33:43
Speaker 1: blurry nous Like you know, if you have something really close,
33:46
Speaker 1: like a hand really close to your face and you
33:48
Speaker 1: look at it, it's it's blurry. It doesn't look quite right,
33:51
Speaker 1: or things sort of in the corner of your eyes
33:54
Speaker 1: are sort of blurred, they're not fully defined. That is
33:57
Speaker 1: just raw information, right, that we're seeing that as blurry,
34:01
Speaker 1: and it's our brain's interpretation of that information. But it's
34:05
Speaker 1: absolutely possible that the octopus is using the difference in
34:11
Speaker 1: blur results as a result of the different wavelengths of
34:14
Speaker 1: the colors hitting the eye at different focal points and
34:17
Speaker 1: interpreting that as color. Wow, that's sort of incredible. What
34:24
Speaker 1: do you think is sort of the forefront or the
34:25
Speaker 1: goal of this research. Do we need to like dig
34:28
Speaker 1: into the octopus brain to understand how it's taking this
34:31
Speaker 1: information and entangling it and experiencing it. Is it ever
34:34
Speaker 1: really going to be possible to do science about what,
34:38
Speaker 1: in the end is sort of a subjective experience. That's
34:41
Speaker 1: a really good question. I mean, personally, I find octopus
34:45
Speaker 1: is one of the most fascinating animals in the world
34:48
Speaker 1: because they have evolved completely, almost completely independently from humans
34:56
Speaker 1: and mammals and most other animals in the world. Uh,
35:00
Speaker 1: And yet they have two eyes and a brain, and
35:05
Speaker 1: they seem to have a certain amount of intelligence that
35:09
Speaker 1: we can kind of understand. They seem to have a
35:11
Speaker 1: playfulness of curiosity, and so they're the closest thing we
35:15
Speaker 1: have to an alien that we can interact with. And
35:20
Speaker 1: while I don't know other researchers could ever really be
35:25
Speaker 1: able to fully understand what their subjective experiences, studying these
35:31
Speaker 1: octopuses and understanding as much as we can about their experience,
35:36
Speaker 1: I think maybe the closest thing we could get to
35:39
Speaker 1: studying intelligent alien life and a clue to like what
35:44
Speaker 1: life might look like on other planets, because their evolutionary
35:49
Speaker 1: journey was so wildly different from our own in such
35:53
Speaker 1: a different environment. And of course they're a fun playground
35:56
Speaker 1: for science fiction authors. I've read many awesome science fiction,
35:59
Speaker 1: but imagining intelligent octopi or their equivalent from alien world,
36:05
Speaker 1: it's really fun to think about it into experience. But
36:08
Speaker 1: it's funny that you call them basically like aliens. I mean,
36:11
Speaker 1: maybe they would think of themselves as you know, earthlings,
36:14
Speaker 1: and we are the aliens, right, it's all relative. I mean,
36:17
Speaker 1: if you've seen there's that document My Octopus Teacher, and
36:21
Speaker 1: in a way, it really does seem like they see
36:23
Speaker 1: us as a curious alien because this diver who would
36:29
Speaker 1: very very carefully and slowly interact with this octopus, the
36:33
Speaker 1: octopus seemed to take a real curiosity in him. And
36:37
Speaker 1: there there are a lot of instances of octopus as
36:39
Speaker 1: being curious about humans, or at least seeming to display
36:45
Speaker 1: curiosity rather than simply fear, which I find so interesting.
36:49
Speaker 1: I mean, they are really really mysterious and interesting animals.
36:54
Speaker 1: And the last time we were related to an octopus
36:58
Speaker 1: was when everything was basically a tiny nema toad like
37:03
Speaker 1: worm with just the bare essentials to be able to function,
37:07
Speaker 1: which I just I find that so interesting and also
37:10
Speaker 1: kind of encouraging because it makes me think that you know,
37:14
Speaker 1: given enough evolutionary pressures, it is possible to repeatedly create
37:21
Speaker 1: organisms that have a curiosity around the world and are
37:26
Speaker 1: really interesting and maybe are capable of being observers of
37:31
Speaker 1: their environment, just like humans are. It is amazing that
37:35
Speaker 1: they evolved their intelligence sort of separately, and it is
37:39
Speaker 1: hopeful that if independently evolved intelligence finds us curious rather
37:43
Speaker 1: than like disgusting and squishable, that maybe aliens when they
37:47
Speaker 1: arrive will also find us worth talking to. I, for one,
37:51
Speaker 1: would love to hug like a big octopus alien that
37:54
Speaker 1: would just that would be wonderful. So octopuses are not
37:58
Speaker 1: the only animals that have a very different subjective experience
38:03
Speaker 1: when it comes to color. There are a lot of
38:06
Speaker 1: animals that can see UV light, so ultra violet light,
38:11
Speaker 1: and so how they pursue the world is going to
38:13
Speaker 1: be very different from us, and these are There are
38:16
Speaker 1: a lot of animals, and we're discovering more and more
38:19
Speaker 1: almost every day who can see UV lights. So butterflies, bees, birds, bats,
38:25
Speaker 1: and other pollinators can see UV light for pretty obvious reasons,
38:31
Speaker 1: because flowers have UV light patterns on their petals and
38:36
Speaker 1: they use these like landing strips for the pollinators to
38:40
Speaker 1: come like a big eat at Joe's sign neon sign
38:44
Speaker 1: telling these pollinators, come on, come here, get your nectar.
38:47
Speaker 1: And while you're at it, why don't you pick up
38:49
Speaker 1: some pollen and transfer it to my neighbor so we
38:51
Speaker 1: can get some cross pollination going. I'm glad to see
38:56
Speaker 1: that kind of interaction facilitated in the natural world. M
39:00
Speaker 1: And some flowers. Remember we talked about structural coloration, those
39:06
Speaker 1: like little miniature prisms or slits that will bend light
39:11
Speaker 1: in certain ways. Some flowers will use structural coloration to
39:15
Speaker 1: create a blue and UV halo that is typically not
39:20
Speaker 1: visible to humans but stands out like a hologram two
39:24
Speaker 1: bees telling them that, like a flower is only tin
39:27
Speaker 1: wing beats away. So these flowers have cracked holographic advertisement
39:33
Speaker 1: before humans have, because I was promised when I was
39:36
Speaker 1: a kid sort of a cyberpunk future where you would
39:39
Speaker 1: have these holograms advertising soda to you, but that didn't happen.
39:43
Speaker 1: But these flowers have managed to do that, but we
39:47
Speaker 1: can't see it. Only bees and other UV light detecting
39:50
Speaker 1: animals can see those kinds of beautiful displays. Wow. And
39:54
Speaker 1: bees also basically get jet packs also, so they're living
39:57
Speaker 1: in the future. And we're stuck here in the present.
40:00
Speaker 1: That's how do we know? But how do we know
40:02
Speaker 1: what bees can see? Like if people dissected be eyeballs
40:06
Speaker 1: to understand what they're sensitive to, or put little recorders
40:09
Speaker 1: in b brains. It's both, uh, the It's both that
40:14
Speaker 1: we can see the structure of the b eyeball so
40:16
Speaker 1: we know UV light can pass through, but also behavioral experiments,
40:22
Speaker 1: so seeing that bees will go towards UV light when
40:27
Speaker 1: no other coloration or light is present, that we can
40:31
Speaker 1: see that they can see these light patterns and they
40:34
Speaker 1: respond to it. So in an experimental settings, they will
40:37
Speaker 1: respond to UV light patterns that we we recreate artificially,
40:42
Speaker 1: so we we can test both their behavior and the
40:46
Speaker 1: structure of their eyeball to show that it is physically
40:49
Speaker 1: possible for them to see UV light. You can figure
40:52
Speaker 1: it out by both combining the behavioral studies with the
40:56
Speaker 1: anatomical properties of their eyes. What it's like to be
41:00
Speaker 1: a bee. But what's so interesting is it it makes
41:05
Speaker 1: sense from an evolutionary standpoint that bees and birds and
41:09
Speaker 1: even bats can see UV light because they're pollinators. But
41:14
Speaker 1: research is showing that more and more animals can see
41:17
Speaker 1: UV light than we may have previously thought. So there's
41:21
Speaker 1: some evidence that based on the structure of many mammalian lenses,
41:26
Speaker 1: so that clear uh structure just sitting right on top
41:31
Speaker 1: of your eye that helps shape the light as it
41:34
Speaker 1: goes into your eye. Um U V light is able
41:38
Speaker 1: to make it past that lens and hit the retina,
41:41
Speaker 1: and so it is likely that their rods and cones
41:45
Speaker 1: are able to detect UV light and humans. In most humans,
41:51
Speaker 1: that lens will actually absorb the UV light and so
41:55
Speaker 1: because it absorbs that UV light, it never actually manages
41:59
Speaker 1: to hit our photoreceptor cells and so we don't detect it.
42:04
Speaker 1: But uh. It has also been reported that people who
42:10
Speaker 1: were either born without a lens or have had their
42:13
Speaker 1: lens removed for medical reasons, like for cataracts surgery, can
42:18
Speaker 1: actually see U V light. What how's that possible? Really? Yeah? Yeah,
42:24
Speaker 1: So there are a variety of surgeries that are done
42:27
Speaker 1: on the eye to correct for issues things like cataracts.
42:31
Speaker 1: And so once that lens is removed, it's actually replaced
42:35
Speaker 1: with an artificial lens again so that you can focus
42:38
Speaker 1: that light, because without the lens the things would be
42:41
Speaker 1: too blurry. It helps focus the eye to the back
42:44
Speaker 1: of your retina, But that artificial lens actually doesn't necessarily
42:49
Speaker 1: absorb UV light. It can pass through and hit the
42:54
Speaker 1: retina because it's litting UV light through. It allows people
42:59
Speaker 1: to both focus saw on an object and also see
43:02
Speaker 1: u V light, And so people with their lens removed
43:07
Speaker 1: and replaced will report UV light as looking like this
43:11
Speaker 1: kind of white violet hue, like a a really oddly
43:16
Speaker 1: bright violet. And it's one of those things where I
43:20
Speaker 1: can try to imagine what that's gonna look like, but
43:23
Speaker 1: you can't really even with a human being, you can
43:26
Speaker 1: report to you, this is what I see. You can
43:29
Speaker 1: still only kind of like imagine what that's like. You
43:32
Speaker 1: can't ever actually experience it. Because they're trying to describe
43:35
Speaker 1: one color in terms of other colors, but it seems
43:38
Speaker 1: fundamentally impossible, Like how could you describe red in terms
43:42
Speaker 1: of blue and green? It's not like some combination of them.
43:46
Speaker 1: It's like describing something totally different. It's sort of like
43:49
Speaker 1: you know, eating a new fruit and then describing it like, oh,
43:51
Speaker 1: it's a little bit like an apple mixed with a kiwi.
43:54
Speaker 1: It's never going to really capture it right exactly and
43:57
Speaker 1: it's so it is probably really tricky for people who
44:01
Speaker 1: see this to be able to describe it, just as
44:04
Speaker 1: it's hard for us to those of us who cannot
44:06
Speaker 1: see UV light cannot really imagine what it's like. Uh
44:12
Speaker 1: so this is this is a fun one. Now. I'm
44:14
Speaker 1: not an art historian, but there is a historical theory
44:19
Speaker 1: that Claude Monet's paintings became much more blue and violet
44:24
Speaker 1: later in life because he had cataract surgery and his
44:28
Speaker 1: left islands was removed, which allowed him to see UV light.
44:35
Speaker 1: And so it's possible that he was not just painting
44:39
Speaker 1: these bright, bright blues and bright violets because he liked
44:43
Speaker 1: these colors, but because he was actually seeing more and
44:45
Speaker 1: more of these colors or this UV color that we
44:49
Speaker 1: can only imagine how it looked like, and trying to
44:52
Speaker 1: represent it in his paintings. Wow, he wasn't just a genius.
44:57
Speaker 1: He was an ultra violet genius. It's like extra good.
45:00
Speaker 1: I want to be an ultra violet physicist. I just
45:04
Speaker 1: I love. I love how researchers can as we make
45:10
Speaker 1: scientific discoveries today, it can impact how we see our history,
45:14
Speaker 1: Like we can see this whole new context for someone
45:18
Speaker 1: famous like Claude Monet in his life and what he
45:21
Speaker 1: may have gone through. It is amazing how we can
45:24
Speaker 1: understand more about what happened in history given our theories now,
45:28
Speaker 1: Like I don't know if you know the whole story
45:29
Speaker 1: about the camera, about the camera obscura and how influenced
45:33
Speaker 1: painting and understanding of like depth and how to paint
45:36
Speaker 1: depth and painting. It's really fascinating to sort of unravel
45:39
Speaker 1: that we might understand more than the folks actually at
45:42
Speaker 1: that time did about what they were doing. Yeah, it
45:46
Speaker 1: is so interesting. It's like piecing this puzzle together backwards
45:51
Speaker 1: as human society. And another interesting way that this UV
45:57
Speaker 1: research can help us understand the world is it may
46:01
Speaker 1: help us understand our impact on animals. So, um, power
46:06
Speaker 1: lines typically look pretty boring to us, maybe unless they
46:10
Speaker 1: explode and like a you know, transformer explodes and then
46:13
Speaker 1: you you you do get to see an interesting and
46:16
Speaker 1: very dangerous light show. But two animals that can see
46:21
Speaker 1: UV light, power lines are horrifying looking all the time.
46:25
Speaker 1: So the UV light that power lines emit look like
46:28
Speaker 1: a violet blazing corona. And there is the thought that
46:34
Speaker 1: this might actually frighten migratory birds who see this don't
46:39
Speaker 1: know what the heck is going on, and so go
46:41
Speaker 1: out of their way to avoid these power lines. Uh.
46:45
Speaker 1: And so there are so many, so many like man
46:48
Speaker 1: made things that we may see as a somewhat innocuous thing,
46:53
Speaker 1: but then to an animal it is this terrifying, strange,
46:58
Speaker 1: alien intrusion, and in their normal lives that is really amazing.
47:04
Speaker 1: While these birds are basically seeing special effects, and we
47:07
Speaker 1: of course are always emitting e m radiation in lots
47:10
Speaker 1: of frequencies that we can't see. You know, radio for example,
47:14
Speaker 1: in cell communications, these are all electromagnetic radiation. They're basically
47:18
Speaker 1: just photons of different wavelengths that we can't see. So
47:22
Speaker 1: if you could see radio waves, if you could see microwaves,
47:26
Speaker 1: if you could see the frequencies for cell phones, then
47:29
Speaker 1: the world would look crazy to you around big cities
47:32
Speaker 1: and be all these intense lights flashing around all of
47:35
Speaker 1: the time. I wonder if there are animals out there
47:38
Speaker 1: that can't observe that. So we've talked about how you
47:49
Speaker 1: can even have color in the natural world through pigmentation,
47:53
Speaker 1: through structural coloration, through these incredible little microscopic structures that
47:59
Speaker 1: bend in manpulate light. And we've talked about how other
48:03
Speaker 1: animals will have these different ways of viewing the world.
48:07
Speaker 1: Animals who can see UV light, and it just looks
48:10
Speaker 1: like an entirely different amazing world than what we humans have,
48:15
Speaker 1: unless humans have some modification done to their eye where
48:20
Speaker 1: the lens is removed, in which case maybe humans can
48:24
Speaker 1: see UV light. But now we're going to talk about
48:27
Speaker 1: how humans can modify animals to make them exhibit amazing
48:36
Speaker 1: colors and amazing u V glow using things called quantum dots.
48:42
Speaker 1: So researchers who are always i think, trying to win
48:47
Speaker 1: award for most science fiction like experiment fed silkworms quantum
48:54
Speaker 1: dots which cause them to glow red under UV light.
48:59
Speaker 1: And these quantum dots are nanoscale crystals and are subject
49:06
Speaker 1: to quantum effects, and the size of the particle can
49:10
Speaker 1: determine which wavelength of light it will emit. And at
49:14
Speaker 1: this point I'm going to hand things over to you, Daniel,
49:17
Speaker 1: because I am sure you can give a much better
49:20
Speaker 1: explanation of quantum dots than I could hope to do
49:24
Speaker 1: unless I just open up Wikipedia and start reading it. Well,
49:28
Speaker 1: first of all, I want to advise your listeners not
49:31
Speaker 1: to eat a spoonful of quantum dots. Really not a
49:34
Speaker 1: great idea, and I feel bad for those poor worms,
49:36
Speaker 1: you know, subjectly to that experiment, but I hope they've
49:39
Speaker 1: got some awesome superpowers. Quantum dots really are awesome. They're
49:43
Speaker 1: sort of like an engineered atom. You know, you were
49:46
Speaker 1: talking earlier about pigments and why some of them are
49:48
Speaker 1: blue and some of them are red, and microscopically, that's
49:51
Speaker 1: because the atoms that make up those pigments have quantized
49:55
Speaker 1: energy levels. The electrons that are whizzing around the nuclei.
49:59
Speaker 1: They can't just have an the arbitrary energy. There's like
50:01
Speaker 1: a ladder of allowed energies, and when the electron goes
50:04
Speaker 1: down one step, it gives off that much energy in
50:08
Speaker 1: terms of a photon. So the spacing of that ladder
50:11
Speaker 1: determines the photons that an atom can emit, and that's
50:14
Speaker 1: why some emit blue and some emit red. That's really awesome,
50:17
Speaker 1: But it would be cool to like engineer your own
50:19
Speaker 1: to say, oh, I want this specific set of ladder,
50:22
Speaker 1: so I get these colors. I want this ladder so
50:24
Speaker 1: I get those colors. It's pretty hard to do with
50:26
Speaker 1: atoms because they're kind of finicky and tiny and annoying,
50:29
Speaker 1: and you need like magnetic fields and lasers and weird
50:33
Speaker 1: vacuum chambers to manipulate them. So people have figured out
50:36
Speaker 1: a way to sort of engineer different energy levels using
50:40
Speaker 1: quantum dots, which, as you say, are basically tiny little
50:43
Speaker 1: crystals of semiconductors. So my conductors sit right between an
50:48
Speaker 1: insulator that doesn't conduct electricity and a conductor or like
50:51
Speaker 1: a metal where electrons just flow free, and so electrons
50:55
Speaker 1: sort of flow free, and if you make them small enough,
50:58
Speaker 1: then they get weird quantum effects. Quantum effects usually come
51:01
Speaker 1: from confinement, from requiring an electron to be like bound
51:05
Speaker 1: to an atom or stuck in a little hole somewhere.
51:08
Speaker 1: And so they can like put ingredients in this solution
51:11
Speaker 1: and heat them up and then have them form these
51:13
Speaker 1: tiny little micro crystals that can do sort of amazing things,
51:17
Speaker 1: And there's potentially really incredible, like science fiction like applications
51:21
Speaker 1: for these things, you know, incredible displays or solar cells
51:25
Speaker 1: or super tiny electronics. You know, printing like with a
51:29
Speaker 1: laser printer, um printing like with a laser printer, electronic
51:33
Speaker 1: circuits made out of quantum dots. It's going to be
51:36
Speaker 1: pretty awesome. That all sounds cool, But what if we
51:39
Speaker 1: feed these to a bunch of larvae. Well, I suggest
51:44
Speaker 1: that you get the larvae to sign off first, you know,
51:47
Speaker 1: sign the way their rights so they don't sue you
51:49
Speaker 1: when they start to glow weird colors. I've never seen
51:52
Speaker 1: a larvae try to hold a pencil, but I'm sure
51:54
Speaker 1: it's it's pretty adorable and awkward. And you might have
51:57
Speaker 1: seen quantum dots in real life because they're all already
52:00
Speaker 1: in televisions Like quantum dot televisions have been around since
52:04
Speaker 1: two thousand fifteen. Wow, I mean my TV is pretty cheap,
52:08
Speaker 1: so I kind of doubt it. But that is really
52:11
Speaker 1: really cool. So when these quantum dots, so the ones
52:14
Speaker 1: that are fed to these silkworms are like six nanometers,
52:18
Speaker 1: which I guess is the magic size for the red
52:21
Speaker 1: emitting quantum dots. They're hit with UV light and this
52:27
Speaker 1: will cause them to glow red. Now why why do
52:30
Speaker 1: you need that UV light to see that red glow? So,
52:34
Speaker 1: just like with any sort of material, you can absorb
52:37
Speaker 1: it some frequencies and emit it some frequencies, and some
52:40
Speaker 1: materials like to emit in different frequencies than they absorb,
52:44
Speaker 1: so they take an energy and then they sort of
52:46
Speaker 1: like down shifted to a lower wavelength and then emit.
52:49
Speaker 1: So I don't know the details here, but I'm imagining
52:52
Speaker 1: that's what's happening that they sort of but I'm imagining
52:54
Speaker 1: that's what's happening. They sort of wavelength down shifting, So
52:58
Speaker 1: you send in UV photons, which are very high energy,
53:01
Speaker 1: and then it bounces around inside the material for a
53:03
Speaker 1: little while and then emits as a red photon. Yeah,
53:06
Speaker 1: and that would actually be the same or similar mechanism
53:10
Speaker 1: as biofluorescence, where you can hit an living organism with
53:16
Speaker 1: some UV light and they fluoresce under that UV light,
53:20
Speaker 1: which is different from bioluminescence because the bioluminescence it's actually
53:24
Speaker 1: a light created by a chemical reaction that produces light,
53:28
Speaker 1: whereas with biofluorescence, they're actually taking in UV light and
53:33
Speaker 1: re emitting it at a different sort of energy level.
53:36
Speaker 1: Which it sounds like that's sort of what's happening with
53:39
Speaker 1: these quantum dots. And now I'm terrified that your listeners
53:42
Speaker 1: are going to take laser pointers and shoot them at
53:44
Speaker 1: all sorts of creators hoping that they'll glow crazy colors.
53:47
Speaker 1: Please don't do that. People don't do that. But also
53:50
Speaker 1: that is what researchers are doing. They're collecting like roadkill
53:54
Speaker 1: of variety of animals, and just whenever they find a specimen,
53:58
Speaker 1: they like try to see if it glows under UV light,
54:02
Speaker 1: because they keep discovering all these different animals, especially marsupials
54:06
Speaker 1: for some strange reason, actually glow under UV light and
54:12
Speaker 1: we don't know why, and so it is that is
54:15
Speaker 1: you joke, but there are researchers doing exactly that, Like
54:18
Speaker 1: they'll find a dead specimen and just sort of see
54:21
Speaker 1: if it glows. Well, what a job, corpses with lasers
54:27
Speaker 1: and see what happens? I collect road kill and bring
54:31
Speaker 1: it back to my laboratory. Yeah, it's it is really interesting.
54:35
Speaker 1: And so we're essentially turning these silkworms into biofluorescent animals,
54:42
Speaker 1: except that we are, they're sort of artificially biofluorescence. So
54:46
Speaker 1: by being fed these quantum dots that glow red under
54:50
Speaker 1: UV light, not only did the silkworms glow red, but
54:55
Speaker 1: so did their silk, their cocoons, and the adult moth
55:00
Speaker 1: bodies after metamorphosis, so they really are what they eat,
55:05
Speaker 1: like they eat quantum dots, and so their whole world
55:08
Speaker 1: becomes quantum dots and they retain that. And because the
55:13
Speaker 1: silk is probably is made out of you know, the
55:17
Speaker 1: food that they eat and expressed and turned into silk,
55:21
Speaker 1: of course the silk then is going to also glow red,
55:24
Speaker 1: and so will their cocoons. And after they go through metamorphosis,
55:28
Speaker 1: their adult bodies glowed red and even their eggs were fluorescent.
55:34
Speaker 1: But it finally ended with the second generations of silkworms born,
55:39
Speaker 1: they no longer glowed. Uh so it only lasted for
55:44
Speaker 1: the initial silkworms lifespan. But the fact that it was
55:49
Speaker 1: able to produce all of these effects be retained in
55:52
Speaker 1: its silk and its cocoon after metamorphosis, it is pretty interesting.
55:57
Speaker 1: It's a very pervasive way to just by feeding this
56:01
Speaker 1: animal without actually tampering with its genetics, directly turning it
56:05
Speaker 1: into a biofluorescent animal. That's pretty awesome. And it makes
56:10
Speaker 1: quantum silk out of which you can leave like quantum shirts.
56:14
Speaker 1: That sounds pretty cool. You know, people put quantum and
56:16
Speaker 1: everything in these days, but in this case, it might
56:18
Speaker 1: actually be justified. Now you mentioned that you typically don't
56:22
Speaker 1: want to eat these quantum dots. Now why is that?
56:26
Speaker 1: Oh man, these quantum dots are made out of crazy stuff.
56:28
Speaker 1: You know, the kind of materials you need to make
56:31
Speaker 1: semiconductors can be like weird heavy metals, you know, germanium
56:36
Speaker 1: and all sorts of craziest stuff. You definitely do not
56:38
Speaker 1: want to be consuming these things. Yeah, I think that
56:41
Speaker 1: in this case, for these silkworms, I believe I read
56:45
Speaker 1: they derived it from some material that was similar to
56:48
Speaker 1: the mulberry leaves that they would eat naturally. So I
56:52
Speaker 1: don't think it was hurting these uh, these silkworms. But yeah,
56:57
Speaker 1: don't like go down to your nearest hard where a store,
57:00
Speaker 1: pick up some quantum dots and just chug them, because
57:03
Speaker 1: that's not going to be that's not going to be great.
57:07
Speaker 1: Ask you a doctor before eating cadmium. But I do.
57:11
Speaker 1: I I again, I feel somewhat like these these invertebrates
57:16
Speaker 1: are getting to live cyberpunk future whereas we are not.
57:20
Speaker 1: Because I was thinking as a kid, you know, you
57:22
Speaker 1: would get dippin dots, and so quantum dots sound like
57:26
Speaker 1: a more advanced version of dippin dots where maybe maybe
57:29
Speaker 1: you could have glowing ice cream of the future. And
57:33
Speaker 1: I wanted holograms, but only bees and silkworm get get
57:38
Speaker 1: these futuristic fun treatments. I don't know, I'm imagining quantum
57:42
Speaker 1: ice cream. Quantum ice cream dots is like a bowl
57:45
Speaker 1: full of glowing worms or something. It doesn't sound bad
57:48
Speaker 1: appealing to me. I'm pretty happy with old fashioned ice cream.
57:51
Speaker 1: I don't think we need to upgrade it to quantum
57:53
Speaker 1: ice cream. That doesn't sound like the words of a
57:57
Speaker 1: particle physicist to me. You know, it's all about work
58:03
Speaker 1: life balance, old fashioned, old fashioned dinner and newfangled and
58:09
Speaker 1: newfangled work times, splitting particles at work and having a
58:13
Speaker 1: banana split at home. You go exactly, So before we go,
58:20
Speaker 1: I know, this whole episode has been about a feast
58:23
Speaker 1: for the eyes, but now we are going to have
58:27
Speaker 1: a little dessert for the ears because we're gonna play
58:31
Speaker 1: a game of guess who's squawking the Mystery animal sound game.
58:37
Speaker 1: So every week I play a mystery animal sound and
58:41
Speaker 1: you the listener, and you the guests, try to guess
58:44
Speaker 1: who is making that sound, and sometimes the answer is surprising.
58:51
Speaker 1: So the hint last week was this isn't a cat,
58:56
Speaker 1: it's not a dog, and despite that smell, it's not
59:00
Speaker 1: a skunk. So, Daniel, can you guess who is making
59:06
Speaker 1: that sound? M Well, it didn't sound very happy, so
59:11
Speaker 1: I'm gonna guess some sort of rodent, maybe a squirrel
59:14
Speaker 1: being force fed quantum dots by a researcher that's not
59:18
Speaker 1: very caring about their feelings. You know, there are actually
59:23
Speaker 1: certain flying squirrels that will glow under UV light just naturally.
59:28
Speaker 1: They weren't force fed any quantum dots. But no, you're incorrect.
59:33
Speaker 1: This is not a rodent. It is actually a fox.
59:38
Speaker 1: This is one of the many sounds that a fox makes.
59:43
Speaker 1: This fox in particular is sort of sleepy, sort of
59:47
Speaker 1: relaxed and issuing a gentle little call just to kind
59:52
Speaker 1: of say hello to one of its fox friends that
59:56
Speaker 1: is nearby. Oh it's a cozy, snuggling fox. It's a
1:00:00
Speaker 1: cozy little fox. Yes, Oh, I'm glad. It's a happy sound.
1:00:05
Speaker 1: Maybe it's cozy because it just ate one of those
1:00:08
Speaker 1: quantum glowing squirrels. I don't know, but yes it is.
1:00:12
Speaker 1: It is a relaxed sound from a fox. Foxes have
1:00:16
Speaker 1: a wide variety of calls to express themselves, from mating
1:00:20
Speaker 1: calls to alarm calls, to fighting cackles or play laughter,
1:00:25
Speaker 1: and even these pearl like sounds they can make when
1:00:28
Speaker 1: they're comfortable, or these little like murmurs that are sort
1:00:32
Speaker 1: of like, hey, I'm over here, how are you doing?
1:00:35
Speaker 1: Kind of sounds. As far as I can tell now,
1:00:38
Speaker 1: I don't speak fluent fox, so something may have gotten
1:00:42
Speaker 1: lost in translation. As adorable as foxes are and the
1:00:46
Speaker 1: sounds they make, they are terrible pets and unless you
1:00:51
Speaker 1: are prepared for an undomesticated, incredibly stinky, hyperactive beast, they
1:00:58
Speaker 1: are extremely smelly, which often surprises people because you know,
1:01:04
Speaker 1: we think of a skunk now that makes a bad smell,
1:01:07
Speaker 1: But foxes are really smelly and not eat They won't
1:01:11
Speaker 1: even just kind of like spray you in self defense.
1:01:14
Speaker 1: They are smelly almost all the time because they have
1:01:19
Speaker 1: a number of scent glands, both on their tails or
1:01:22
Speaker 1: near their anus, on their feet and under their chins,
1:01:27
Speaker 1: and these scent glands will excrete a musk, which is
1:01:32
Speaker 1: basically a calling card for the foxes, like leaving a
1:01:35
Speaker 1: little business card in the form of a real stinky smell,
1:01:40
Speaker 1: and their feces and urine is also riddled with this musk,
1:01:45
Speaker 1: so their urine in particular is extremely foul smelling. I
1:01:50
Speaker 1: would never recommend a fox as a pet. Typically, pet
1:01:54
Speaker 1: foxes are only tamed, which means that they are not
1:01:57
Speaker 1: They have not been genetically my defied to be more
1:02:01
Speaker 1: calm in our presence. They have just been raised since
1:02:05
Speaker 1: they were a pup to basically tolerate humans. But yes,
1:02:10
Speaker 1: I just I think the stinkiness alone should be enough
1:02:15
Speaker 1: to ward people off from owning foxes as pets. Wow,
1:02:21
Speaker 1: well you just wow, Well you just answered too deep
1:02:23
Speaker 1: philosophical questions. They're not just the age old question of
1:02:27
Speaker 1: what does the fox say? But also how does the
1:02:30
Speaker 1: fox stink? Pretty badly? Smells pretty bad. I mean they
1:02:35
Speaker 1: have a good sense of smell, but a bad sense
1:02:38
Speaker 1: of taste because of how bad they smell. So onto
1:02:44
Speaker 1: this week's mystery animal sound and the hint is is
1:02:48
Speaker 1: it a helicopter, a jackhammer, a lawn more or something
1:02:52
Speaker 1: from Greek mythology? Daniel, who do you think is squawking? There?
1:03:02
Speaker 1: It sounds to me like fluttering of wings. Is it
1:03:05
Speaker 1: like maybe a super close up microphone to a bee's wings.
1:03:08
Speaker 1: That's an interesting guest. Well, you will find out if
1:03:13
Speaker 1: you're correct on next week's episode of Creature Feature next Wednesday.
1:03:18
Speaker 1: If you out there think you know who was squawking,
1:03:22
Speaker 1: you can write to me a Creature Feature Pod at
1:03:25
Speaker 1: gmail dot com. I'm also on Twitter at Creature Feet Pod.
1:03:28
Speaker 1: That's feteeth. How does something very different? Daniel, thank you
1:03:34
Speaker 1: so much for joining me today. This was a wonderful
1:03:38
Speaker 1: mixture of both biology and physics resulting in a beautiful
1:03:43
Speaker 1: rainbow of amazing animals. Where can people find you are?
1:03:48
Speaker 1: You can find me at our podcast Daniel and Jorge
1:03:51
Speaker 1: Explain the Universe on Twitter at Daniel and Jorge or
1:03:56
Speaker 1: online at www dot Daniel and Jorge dot com. Come
1:03:59
Speaker 1: on over and talk about the physics of the universe
1:04:02
Speaker 1: with us, and I am sometimes on the show when
1:04:05
Speaker 1: Jorge has to step out, or as some people theorize,
1:04:09
Speaker 1: we're simply the same person feed enough quantum dots of
1:04:13
Speaker 1: Jorge and becomes a biologist named Pete. Thank you guys
1:04:19
Speaker 1: so much for listening. If you're enjoying the show and
1:04:22
Speaker 1: you leave a rating and review, I would be so
1:04:25
Speaker 1: very grateful, And I read all the reviews, even the
1:04:29
Speaker 1: reviews saying like, hey, I want to eat quantum dots,
1:04:33
Speaker 1: and then I would say, hey, don't do that. Uh
1:04:36
Speaker 1: if I could respond to the reviews, but I still
1:04:39
Speaker 1: appreciate them and thank you to these space Costlics for
1:04:43
Speaker 1: their super awesome song. Exo Alumina Creature features a production
1:04:47
Speaker 1: of I Heart Radio. For more podcasts like the one
1:04:50
Speaker 1: you Just heard, visit the I Heard Radio app Apple podcast,
1:04:53
Speaker 1: or Hey guess what whereever you listen to your favorite shows,
1:04:56
Speaker 1: I don't. I don't judge you. I do judge you
1:04:58
Speaker 1: if you eat quantum dots, but I won't judge you
1:05:00
Speaker 1: for where you listen to your podcasts. See you next Wednesday.
1:05:06
Speaker 1: M