– A portion of this video
is sponsored by Google. More on that later. Here on Smarter Every Day, I like to explore things and I like to figure them out for myself. And there’s one thing that
you can do with the internet that’s really cool, you can just go find knowledge
wherever you want it. But what I like to do is
figure things out for myself. That’s like the sweet
spot between the unknown and knowledge, right? That discovery exploration phase. That’s what this video is. A couple of weeks ago, my buddy sent me this video of him moving his hand over
some grass in his backyard, and these little seeds were
exploding all over the place. Now, I’ve heard of grass that does this but I had no idea how it works. And I resisted the temptation
to go search for it, I just wanna figure it out for myself. Now, what I want you to do is I want you to resist the temptation to just fast forward to the slowmo, I want you to go along
on the trek with me and explore how this is working and realize that along the way I’m going to say things that are WRONG. So, let’s go explore, backyard grass seeds exploding
with a high-speed camera and let’s see if we can
learn something together. Well, first of all, I want to show you
this guy’s azaleas. Look at these. They’re awesome. They smell like a really pretty grandma, if that makes any sense. If your hand goes over it, I don’t even know if you
can see this on video because it’s happening so fast, but if this grass is
mechanically disturbed in any way it explodes and it throws grass seeds up. And I think it’s too fast for this camera which means we’re gonna
have to look at this with the slowmo camera. So, I think what we’re gonna do is we’re gonna start
with a wide angle lens, and we’re gonna try to find out at what point on the grass
stem the seed is shooting from. And then after that, we’ll
go to some macro lenses and we’ll try to hone in
on exactly what’s happening and eventually find out the
mechanism for ejecting the seed. But let’s try this. (whooshing) Okay. I don’t know if seeds flew off or not, but we’re gonna look at that. (Snappiing seed sounds) (Soundscape of distant popping popcorn) (Pop) Oh, okay. Oh, it’s coming up from the tassels. We at least know the region of the grass that is happening in. We have figured out that the seeds are blasting out the top of the grass. We’ve figured out that
my hand is in the way. We’re also gonna transition
from the 35 millimeter lens to the 85 millimeter lens, which should give us a tighter shot and we should be able to
walk in on this thing better. Okay. I’m gonna try to trigger
the grass from the back and trigger the camera from here. So here we go. (curious sounding music) Okay. Let’s see what we have. It’s so silly but my heart is
beating fast over grass seeds. (curious piano music) It’s at the base of where the
tassel meets the main stalk. I think I’m running the camera too fast, I can slow it down, I can let more light in and I can get a deeper depth of field because I’m struggling with
stuff in and out of focus. (camera fans whooshing) Okay. (pop!) I’m not framing it well, and the problem is they’re
flying into the field of view and out of the field of view, so they’re in focus for a
very short amount of time. It is literally easier to
film missiles and rockets than these grass seeds. Okay. This just got serious. I had to go get a light. (camera whooshing) All right, we’ll see. (POP!) AAAWWWW (Excitement Intensifies) (POP!) Oh, it’s out of focus it
all comes from one shot. Okay. If I can find that, I
can figure out how to do this. We are getting close and I’m EXCITED. This is a fast event. That was 10,000 frames per second! This is a really, really fast thing. Okay. We are homing in on this thing. All right. So obviously I don’t know what I’m doing. I don’t know what triggered,
I’m looking at that, and I’m looking at this and
I don’t know what happened. We gotta get this. I’m gonna touch that. OH, MAN! It’s a reverse banana peel slap bracelet. (Destin laughing) (wheezing) Okay. This is how I think it’s working. You got a slap bracelet, right? These are awesome. You had ’em when you
were kids, really fun. And these slap bracelets are kind of on the side of the banana. I know this is ridiculous but this is what I think is happening. So if you were to connect up
at the top of the banana here and you were to activate
that slap bracelet somehow on both sides. See if I can do this, check that out. It’s pretty cool. The slap bracelets roll up, and then they fling the
seeds off when they go. That seems to be what’s happening here. It turns out this plant is well described in the scientific literature:
Arabidopsis thaliana. I think is what we’re dealing with. In fact, I found this
really cool document, “Morphomechanical Innovation
Drives Explosive Seed Dispersal” and it’s really, really fun. So anyway, slap bracelet banana. Once I understood the geometry
of what was going on here, I could really focus in on it and make some really serious observations. I started by trying to vibrate the grass, and then eventually I
settled on using my knife to trigger it in various ways. Sometimes I would cut the stem, and other times I would try to tap it. But eventually I settled
on using the pretty azaleas as a backdrop to make the shot
as pretty as I could make it. (Acoustic Guitar Music) Shut up!? The seeds are sticking
to it as it’s rotating. And then as it curls
in tighter and tighter the rotational velocity… Oh, my goodness! It does the figure skater thing. It starts wide as it curls
up tighter and tighter, the radius gets smaller and smaller, angular acceleration goes through the roof which disconnects it from the pea pod. We understand! (Fist Pump) (guitar music) There’s all kinds of crazy
stuff going on in this footage when you look closer. When I looked at this one
particular macro shot again, I realized that there were a
few small red bugs on the pod when it exploded, and one of
those little ones were flying. (guitar music) I decided to measure the
length of one of the pods with some calipers and
use it as a fiducial or a reference measurement
to calculate the velocity of each seed as they’re being thrown off. There is so much to see in this data. For example, the location
of the seed within the pod that seems to determine how fast it is. It looks like the first seeds
to launch go the fastest. Furthermore, the direction
that each seed goes seems to be a function of
the stickiness of the seed to the pod curl. If you look as the radius
of the pod tightens, it seems like that helps
it peel the seed away from the inner surface. And because each seed
detaches at a different time the spatial distribution
is all over the place which is a function of the
stickiness and the curl, but all that is good if you’re a plant, you want your seeds to go in
many different directions. All of this feels like
chaos, but it’s not. There’s just a few
simple principles at play that almost randomize
the seed distribution. The design of these little seed pods reveals tremendous mechanical mysteries IF you’re willing to look close enough. All right, I’ve got one more
slowmo shot to show you. But before that, this portion of the video was sponsored by Google. One thing I’m really serious
about here on Smarter Every Day is combating misinformation. In fact, I did the
entire video series here on social media misinformation
and how that affects you. I wanna talk about being
smart and thinking critically when you search for information online. When you use Google to
search for something it’s important that you
do it in a smart way. The Google search function is a tool. And just like any tool,
there’s a smart way to use it. As a part of their civic
online reasoning program, The Stanford History Education Group has identified three
questions to ask yourself when looking for information online. The first question is, who is behind the information? I don’t know if you knew this, but every time you
conduct a search on Google there’s these three
little dots that pop up at every single result. Then if you click those, it’ll expand and give you more information about the website that’s
serving you the information. The second thing to think about when you’re figuring out
who’s behind the information is kind of in YOUR head. Let’s say you wanna learn
about these islands right here in South America. If you were to search
for the term Falklands, you’re gonna get one set of perspectives, but if you use the term Malvinas, which is the Argentinian
term for those islands you’re gonna get a completely
different perspective, because those islands were the subject of a major conflict between
two different groups of people. Think critically about
what you’re searching for in how you conduct the search. And when you get the information think critically about
the results you get. You have to search for
information in a smart way. If Google search is a tool, you’d have to use the tool
well and be smart about it. So, yeah, that’s a really big deal and I’m super passionate about it. So thank you, Google for sponsoring this portion of the video. – Okay. At this point, I have been doing this in the backyard for maybe seven hours. So I want to just for a grand finale step in a big patch of this stuff
and watch it all fly up now that we understand the
minute mechanism at work. So here we go, we’re gonna waste all these at one time… Should be pretty cool. (guitar music) I thought this mechanism
was incredibly clever and I really enjoyed exploring this. So I hope you enjoyed
the path of exploration trying to figure out how
this little thing worked. I’ll leave a link down to that
scientific research paper. It’s fascinating how
this little guy works. I just love it. So please consider subscribing
to Smarter Every Day if you’re into that sort of thing, but if not, I don’t care. I just want you to go outside and look at the world a little bit closer and see all the beauty and
wonder that’s around you. Thank you so much. I’m Destin, you get Smarter
Every Day, have a good one. Bye. Video source: https://www.youtube.com/watch?v=MUaTOoVmg1Q
