[music]
Hey it's me Destin. Welcome back to Smarter Every Day.
I am crossing the street in Atlanta Georgia, you can see the dome in the background
and I'm at Georgia State University and I've got a box of butterfly wings. I'm trying to unravel
a mystery that I uncovered in the rainforest. We discovered that when we dropped
a butterfly and he started to fly off, pixie dust would fly off his wings.
At least that's what I call it. Check it out.
[music]
So to figure out what this is we came to the Petit Science Center here at Georgia State University. We're going to the
biological imaging center. Dr Simmons? Nice to meet you.
- Good to meet you. - I brought you some butterflies. - Oh cool.
(Destin) Ooh so this is where you work huh? - This is where I live. - Let's do it.
- Come on in. - So if you watched the last episode you're aware that these little dust particles are actually
scales coming off the butterfly's wings. What we don't know however is how
are those scales attached to the wing in the first place. Dr Simmons happens to
be an expert microscopist and he's agreed to give us a little lesson in scanning electron
microscopes. So Dr Simmons just drew all this and I'm gonna try
to summarize it. You tell me if I get this wrong OK? - OK.
- OK so we have tungsten up here. We start a flow of electrons here, and as it
comes out we go through what you're calling electromagnetic lenses? - Yes.
- OK and so we vary the beam and then we start to scan that beam across
whatever it is, in this case a butterfly wing. - Butterfly wing.
- Depending on where we are in the scan, we measure how many secondary electrons we get off
the sample, using our electron multiplier?
- It's sort of an electron detector. - And then we run that through some filters and we're able to get
a grey scale image. Is that basically it? - That's basically it. - We are now experts
on scanning electron microscopes. Would you say that?
- Oh yeah. - [laughs] Alright, time for science. Goggle up. Probably the coolest goggles I've ever been given,
not gonna lie. OK here's the question. We have three different types of butterfly wings here,
we have a sunset moth which technically isn't a butterfly. We have a morpho
butterfly wing and then we have a cithaerius. What we're gonna do is Dr Simmons
is gonna use the scanning electron microscope to show us the difference in the wings.
Now what I think is interesting about the cithaerius is that it goes from
a scaled wing to a transparent wing. - The unfortunate thing here is that
this is destructive testing. - It is what it is man. We gotta do it.
[music]
(Destin) On the scanning electron microscope we're gonna be bombarding it with electrons and you're gonna have this huge
charge difference, but the problem is butterfly wings are insulators,
am I saying this right Dr Simmons? - You got it. - Alright. So we have to discharge that
voltage, or I guess it's just potential, we have to discharge that back to ground
and the way we do that is we have gold all over the butterfly wing so that it has a path
to ground. Can you give me a countdown to science? - OK. 3.. 2..
1.. I'm gonna hit start. - Cool.
So that's a gold cloud? - These are golden and palladium
atoms flying around in an ionized argon atmosphere.
-Looks a little different. - Looks a little different. That's got a fairly heavy coat on it.
- So that's gold. - 60% gold, 40% palladium.
(Destin) Alright here we go. It's taken Dr Simmons years of experience
in biology, physics and optics to create.. this.
[music]
Check it out. You can see that these two butterfly scales right next to each other have different textures.
The little holes in the one on the right are less than a micron across.
Now I've heard that butterfly wings are colored by holes in them, so you'd think that the one on the right is colored
right? Well I did a little cross check and I figured out that the ones with the open lattice
structure are actually black. Because SEM uses electrons instead of
light, it can't provide color, so it's common for scientists to create false color images
to help people understand what they're looking at. Check it out again, this time with false color.
OK Let's look at the morpho. You can see that the tops of the wings are blue, but the bottom has some kind of
brownish-tan color. If we scan it we can see that these tan scales have small holes
in them but the blue scales have some kind of ridge in them. Now if we measure the width of these
ridges it turns out that it's at the exact same wavelength as yellow light. White light
minus yellow light is equal to blue light, so somehow
these ridges are removing the yellow light and making the wing look blue. If we were to take this scale
and cut it right here and go look along those ridges, kind of like we're looking through a canyon,
you would see a baffled nanostructure that's amazing. As white light
comes in, this nanostructure is the perfect size to interact with the
wavelength of visible light and strip out the yellow. That leaves blue left
and that's where the morpho gets its color. On this goliath birdwing butterfly
those baffled nanostructures strip out the red and the blue which leaves you with
green. After thinking about this I realized that if I were to somehow fill up these baffles
so that they couldn't interact with the light, I should be able to see the pigment of the wing as it really
is, instead of this pseudocolor. So here we go. When I coat the wings with
isoproponol you can see that the wing loses its irradiance because these nanostructures fill up.
But as soon as it evaporates off, these brilliant colors return. So there you have it.
Butterflies use nanotechnology to lie about their color.
But we still haven't answered our question. How are these scales attached to the wing?
Like this. It's almost as if someone deliberately planted trees in a
nice evenly spaced row. I think it's beautiful. Through normal wear and tear,
even aerodynamic drag along the wings, these scales are somehow plucked out of these roots
leaving these hollow stumps. So every time you rub a butterfly wing that's what you're doing.
You remember that cethaerius I was talking about right? It's got scales on one side and it gradually
fades to a transparent wing. So I took some photos under my microscope to figure out
exactly what colors we should use for the false color, and I discovered that not only are there scales
but there appears to be some type of hairs. When I took this to Dr Simmons I learned two things.
Number one, I know the color of the scales are pink because I took a picture of it,
but they have those hole structures like we saw earlier. That's weird. So it looks like there's
actually pigment involved. And number two, the hairs are not hairs.
I mean look at this thing. That is crazy. What is going on and why?
I mean there's a nanostructure but it doesn't appear to be an optically driven
phenomenon because this is on a transparent part of the wing. Why would the butterfly need
this? I mean, the information required to build something like this
and the energy that goes into something like this is incredible. So why does he need it?
For just a second, let's all agree on this. Something as simple
as a butterfly contains complicated mysteries that you and I will never understand.
And that.. that's beautiful.
Wow. That's awesome.
So thank you very much for your time. A video like this is very hard to put together and often it requires
a lot of people, like Dr Simmons for example, genius.
There is also Larom who colorized all the SEM images, which are on the Facebook page
if you'd like to download them yourself. Also Henry from Minute Physics. He took the time to make that
zoom animation for me. I couldn'ta done that myself, that was great. Gordon wrote the music,
just a lot of people. But probably most importantly is audible.com,
because they provide money for me to do things like
drive to Atlanta, so they are sponsoring Smarter Every Day. So if you would consider
helping audible.com like Smarter Every Day by downloading
a free audio book, go to audible.com/smarter, check out all their titles
there's like 100,000 of them. I was looking at one right now, The Shark's Paintbrush:
Biomimicry and how nature is inspiring innovation. There's some biomimicry
stuff here I'm gonna talk about in the next episode that I think you'll like, but anyway more importantly
go check out audible.com/smarter, consider downloading a book, that helps
Smarter Every Day out. You're smart people, you know what's going on here. Anyway, I'm Destin
you're getting Smarter Every Day. Thanks for your time. Have a good one.
(Destin) Did she not just say she wanted to be on the video?
- You want to get the maximum likes, you need to put me on your video. - Really? You have no idea.
There's nothing on this little caterpillar that looks even remotely
like a butterfly scale, but somehow he gels, inside
of his cocoon and his pupa, and he creates nanostructures.
Oh, he's moving. So here he is...
Oop! [laugh]
(Destin) What are you drawing down there? - The butterfly's scales.
- Where are the scales at? - On the wing. - How do you know that?
- Because you're making a video. - [laughs]
(Destin) Right now? - Yes.
[laughs] Alright, so obviously I get maximum likes now because
"Princess" is in the video right? - Byeee! - Byee!
[ Captions by Andrew Jackson ] captionsbyandrew.wordpress.com
Captioning in different languages welcome. Please contact Destin if you can help.