- It is Laminar Flow day
and you know this about me, I love Laminar Flow. There's a cool video on Smarter Every Day that talks about how Laminar Flow works but we're doing what I call
today, Ultra Laminar Flow! It's not really called
that, I just made this sign to try to make it a thing. But, check this out! We're gonna look at something
called Taylor-Couette Flow. My man here, Maurice Couette, French guy. He came up with a device, so you could quantify the viscosity of a fluid, by a cylinder rotating on the inside of another
cylinder, it's really cool work. My dude here, Sir Taylor, he
expanded on Couette's work and he measured stability
inside Couette Flow. So you combine the two, you
get Taylor-Couette Flow. What we're gonna look
at today, if it works, I really want this to work,
I've been wanting to do this experiment for a long
time, we're gonna look at ultra low Reynolds Number's
Flow, and hopefully, hopefully, we get reversible flow. Let's do this. First things first, we've
gotta fill up the tank. This is corn syrup, which
is a very viscous fluid. Here we go, it's gonna take quite a while, this is a lot of corn syrup. Liquid rope coiling effect. We should revisit that. That's a topic for another video. Okay, here's the magic
of Taylor-Couette Flow. You have something called a
no slip boundary condition. So on this inner cylinder here, the corn syrup wants to stick to it, and on the outer cylinder,
it also wants to stick there. So, if I'm rotating that inner cylinder, what's happening is it will
try to move along with it. So if we were to draw a
line across the gap there and we were to rotate it, the inner cylinder would pull
(bright guitar music) along the inner corn syrup, and the outer corn syrup would stay there. And so what would happen
is, you would create this spiral pattern. In fact, if you look down through there, you can kinda see it
happening in the clear fluid. So what we're gonna do is, we're gonna put this colored corn syrup in there, and because we have so such
a low Reynolds Number here, that's Laminar Flow, and it
should, should, be reversible. Okay, so as I put this color in here, I wanna recommend something. What you're about to see
is absolutely incredible and you're only gonna get
to unwrap this present once. So if you would, please trust me and don't fast forward this video. In order to fully appreciate
what you're about to see, you need to watch it unfold in real time. Okay, here we go. We're gonna go for seven rotations, everything I've seen on
the internet does five. And, go. So you should see the
spiral start to happen. (bright guitar music) One. Two. I see the spirals. Three. Is your heart pounding? - [Trent] That is amazing. - Can you see the spirals in there? - [Trent] Yeah. Four, it's like making
candy cane lookin' things. I don't think it's linear. Like, I think the gradient of the flow across the entire thing. - [Trent] Dude, that is beautiful man. - Is this six? - I think it's seven.
- I think it's six, I don't know. (laughs) Got so excited! Oh dude. Look at that. It's like a marble. Can you see it? Focus further down in there, seven! Okay, here we go. Seven, it looks like it's
completely just all mixed up. Oh man, it looks like you could never get that back together. Okay, here we go. This should work. Reversible Flow. Ultra Laminar Flow, Taylor-Couette. We'll see what you got boys. You ready? Here we go.
(upbeat music) I'm nervous it's not gonna work. Oh golly. (video fast forwarding tone) We should have four spirals after this. (video fast forwarding tone) I have lost count because
(laughs) I'm so excited. I think it's coming up on five. That's five. Get in there tight, it's
about to start getting crazy. We got two more. Come on baby, I'm so worried
that the red and the blue are gonna mix because they were very, very close to each other, like radially. Six, okay. This should be it. Please work. I want you to work so bad. Is it working? Did it work? - [Trent] I think so. - Yes! (laughs) That's awesome. So it worked. Oh, you can see shear thinning in there. Okay, look, the, can I see that? So the, the different
levels of, look at that. So if you get way down in there, look. You see all those striations, that happens because of the way we were mixing it. It looks like different layers
sheared at different rates. So we had different
viscosities at different times and so we get this striated pattern. But we did it! My boys! My boys, what ya got? Taylor and Couette. Hi-five, yeah, yeah! What do you do when you do the thing you've always wanted to do? I don't know what to do. Do we go the other way? Let's do it.
(bright guitar music) Okay, so this is an awesome
fluid mechanics demonstration. But for me, there's a
metaphor to all this. Sometimes it feels like life is turbulent, like everything is jumbled
up and there's no way you're ever gonna get things set straight. But I believe, if you
slowly and methodically think about the way you got
yourself into the situation and start thinking about how
to get out of that situation, and take slow, deliberate
steps, hopefully, hopefully, I know it's not possible for everyone, something that looks
like, is a complete mess and it'll never be set
straight, hopefully, one day, you will actually be able
to get out of the situation. But, it requires patience
and deliberate thinking to get it all straightened out. Anyway, I wanted to tell you about a book that makes me think about
this principal for life. I'll do that now.
(beep) Okay, this episode of Smarter Every Day, was sponsored by Audible. As you know, Audible is a great
way to listen to audio books and I spend the bulk of my time on the go and it is a way for me
to reclaim that time in order to learn. So you can get an audio book by going to audible.com/smarter, or texting the word, Smarter, to 500-500. The book I wanna talk to you today about is called the Sun Does
Shine, by Anthony Ray Hinton, who was wrongly convicted of murder and served on death row for decades. Anthony Ray Hinton is an amazing writer and it's told from his perspective from many years living on death row. This has changed the
way I look at the world and I want you to listen to this book. I gotta go to the airport. (thudding) All right, let's go. My wife books my seats. Thank you very much wife. (engine roaring) - [Anthony Ray Hinton]
If I could put my heart in the judges heart, he
would know I didn't do it. - So one thing I really like about the app is you can click this little
Clip button right here and you can add a note in the book and you can go back and listen to it later and you can bring back all
those thoughts and memories and think more deeply
about the subject at hand. It's a really cool feature. (engine humming) You can get a free audio book
and two Audible originals by going to audible.com/smarter or texting the word, Smarter, to 500-500. You're gonna enjoy audio books. I get smarter when I travel. This is time that feels
that I'm kinda wasting it, but when you're listening to
audio books, you get smarter. So, again, text Smarter to 500-500 or go to audible.com/smarter.
(beep) If you wanna see just the tripod shot, and that being sped up,
go check out that video I'm putting over on the second channel. I think you'll like that. Thank you if you decided to
actually watch this video and learn about these principals with me, instead of just watching
a GIF on the internet and not, like, diving into the
science of what's going on. So thank you. If you're interested in
subscribing to Smarter Every Day, like if you feel like this
kinda content earns it, then thanks, that'd be awesome. Feel free to ring the bell,
if that's what you're into. If you're not into that, no big deal, but I'm just happy that you're here. Thanks for doing this with me. Let's do it one more time, and, boom, (laughs) that's awesome. Dude, that works well!
Did Destin lose count? I think he lost count. Because he's a big kid.
Wise move, putting "Smarter Every Day" on the cylinder. That way, if someone does make a GIF of it, you'll still get some visual credit anyway.
That was awesome and so are you!! Thanks u/MrPennywhisle!!
Who said you can't unmix paint? SCIENCE.
/u/MrPennywhistle
Dictionary.com says you managed to pronounce Couette correctly, but for Sir Geoffrey Taylor he would be referred to as Sir Geoffrey never Sir Taylor.
Awesome video!
I was thinking the striations might be partly due to the slightly different rotational speeds and jittery movements. Would be interesting to see if hooking it up to a motor and run at a constant speed might eliminate this effect.
How is this also laminar flow? It's not going unidirectionally - just seems like a totally different genre than the fountains?
So I just watched the BTS on the second channel where you went 12 turns and back. Now I want to know where the limit is. How many turns until it breaks down and doesn't come back? Also, what variables would have an effect on that limit? Speed of rotation? Jittery vs smooth movement? Position of the dye between the inner and outer cylinders? So many questions...
This was a great video. That said, I have an off topic question. It's very common for YTers to flash text on the screen long enough to see it but not long enough to read it. This is especially difficult on mobile where you have to fight with the pause button and slider to read it.
Why do people do this? It's really not user-friendly and kind of a dick move. The only reason I can think of is that they earn more money or the video becomes more popular the longer you spend engaging with it. Destin did it 3x by count in this video.
So what is the purpose of this editing choice?