Chladni Figures – random couscous snaps into beautiful patterns

Chladni Figures – random couscous snaps into beautiful patterns


In front of me is a giant metal square and I’m going to use this as a kind of blank piece of graph paper to plot a random distribution of couscous. Okay, here we go. It’s a scatter plot. Okay, now this is a pretty random distribution of couscous but when I take my bow and I play this metal square like an instrument this random distribution will suddenly become decidedly unrandom. Here we go. Okay, this is called a Chladni figure. And there are a few different Chladni figures that [I’m] able to make with this plate and I’ll show you a few more of those later on in the video. Chladni figures were discovered by someone called Ernst Chladni. But although he discovered that you could make these shapes, he wasn’t able to work out the mathematics that describes ‘why the couscous goes where it goes?’ In fact he used sand not couscous, but I found that couscous works a lot better. Uncooked, if you’re going to try this at home. The mathematics of where the couscous goes is actually a really hard problem and most of the work in solving that problem was done by a mathematician called Sophie Germain. Sadly she got almost no recognition while she was alive for her mathematical achievements. Things did get better unfortunately after she died, another famous mathematician gauss declared we must give this woman a posthumous degree. So, things improved a little bit. To work out where the couscous goes Sophie Germain had to work out how the plate moves when it’s bowed and this is a problem of wave dynamics. Wave dynamics is a subject that permeates almost all of physics, so it’s hugely important. The equations that describe the motion of this plate are here or at least these equations describe some of the possible motions of this plate. [If you] put those equations into Excel you start to see some of the structure. Then if you do a 3D plot, here you go, you can really start to see it But if we animate it there we go that is how the plate moves? When you bow it or at least in this particular situation This is what’s happening and you can see the parts of the plate moving And that’s really important if you look at the plate here the parts that are moving Jiggle the couscous around and they move around Until they reach parts of the plate that aren’t moving when they get there they settle and they don’t move [so] the couscous is Marking the places on the plate that aren’t moving you may have seen chladni figures before but you probably saw it with a smaller plate that was being driven by a vibration generator to Produce the different frequencies that produce the different patterns [but] this is how gladney originally did it with a fixed plate and a bow so I’m going to see if I can produce Some more of the patterns the first thing. I need to do is apply my couscous randomization function Okay, here we go nice A Big thank you to the center for life in Newcastle for lending me their chladni plate the sensible life is an amazing Science center run by amazing people [so] go and check it out

100 thoughts on “Chladni Figures – random couscous snaps into beautiful patterns

  1. I've wanted to do this for years. I've only ever seen it done with an electric driver under the plate. Using a bowstring is beautifully simple. I guess I would have known if I had ever bothered to google the experiment.

  2. awesome demonstration! would the patterns have been different if the plate was fixed to the base at different points? i guess so, right? also, do variations on the bow, like thickness, speed or material, also result in variations on the patterns?

  3. and is it possible to do that just by hitting the plate? i figure the vibration caused by the bow must be like continuous hitting, right? what if you hit it strongly, like a bell, so that it keeps vibrating for itself for a while, would that cause patterns? and if so, would the patterns change as the vibration gets weaker?

  4. This experiment seems like a very messy operation, I’m sure you had to hoover a lot of couscous up after and you probably keep finding little bits under the sofa to this day 😂

  5. i like that where the instrument moves thet wil be the center of the antinode and where he puts his finger there will be a node

  6. 3:04 of course. This is the first thing people draw in every place they can. And now looks like it is scientifically proven that it is perfectly natural!
    Who would have thought…

  7. Ok I'm so intrigued… Physics!!!!!…I'm coming.!!!!!
    Me:guys don't stop me …
    Guys:go ahead..
    Me:😧😧

  8. It seems like the higher the pitch, the less of the square that vibrates, leaving a larger area of pattern. We're you increasing the pitch by touching the square and bowing it in certain spots? Iguess what I'm trying to ask is, how do you "play" the square, exactly? 😁

  9. Hi Steve, this is awesome!! If I wanted to do this, what type of metal would I use? Does it have to be a certain thickness?

  10. So someone had to decide to put sand or couscous on a metal plate and play it with a bow to discover this. Kind of a strange thing to do

  11. the beans are arranged exactly where Steve's finger is. And there is always a ratio of 1.618 between the finger ark and the edge of the square 0:33 3:07 3:17 3:28

  12. I get so stupidly excited by this stuff that I sit here, trying to explain it to another person in the room and they're all like, "meh". So I respond with, "well, what about the double slit experiment ? That's a mind-fuck that you can't ignore". Their response?
    Nothing.

  13. 😳🙏🏼HOLY CRAP!!!!!
    I came ALL THE WAY from Insta!!! 🙌🏼🙌🏼🙌🏼🤯
    "Seeing Sounds" I KNEW N.E.R.D. was RIGHT!!!! & I wasn't just REALLY high 4 the first time at 18yrs/old. 😂🤣👏🏼
    AMAZING!!!!!!💯

  14. You could attach ECG to a synaptic sound receptor code computer to read the shape for a thought and store profile pattern mind reader

  15. Hello, at 1:56, what branch of maths would I need to read up on to fully understand and manipulate the equations? I know they are just trignonometric relations, and that looks like a matrix, but does that particular form come under multivariable calculus or something? Sorry for dumb question, when you don't know what you don't know, its hard to formulate an intelligent question to find out what you need to know! No, no, no na no no, THERES NO LIMIT etc

  16. The Franklin Institute in Philadelphia had (may still have) a display based on this principle. I remember seeing it several decades ago.

  17. This is the first science video I’ve seen in a very long time that made me exclaim out loud! Thanks for bringing us stuff that Veritassium, v-Sauce, smarter every day etc don’t do.

  18. Then people put their beliefs into gods and superstition, to feel a great beauty in their lives.

    if they want beauty that can actually be proven, and you can see with your eyes, where else to go than to experience the intricacies of nature.
    The very way our world works, is just bloody fantastic and amazingly beautiful in so many ways.

    What better explanation for beauty do you need, than what is in front of you.

    No need to put your faith into figures of metaphysicality.

  19. Steve'S Wife: "OMG! What is this?? Its a mess in here!! Why is there Couscous all over the floor?"
    Steve: "I just randomly distributed them"

  20. I don't know if it's just me, but you look and sound a lot like Daniel Radcliffe. It's really cool, and so are you videos. Absolutely love them. Cheers.

  21. Oh no tht was cookery vid (not really)…i thought i was bad playing with lego and meccano (as an engineer honest). In truth excellent and fascinating video tho!

  22. Im sure these mathematical equations are used in algorithms to simulate where metal will stress fracture in large machines, airplanes ect. It would be interesting to do this experiment with metal plates with different parts of the plate riveted together and see how the patterns form around the rivets.

  23. I had a dream that applied this phenomenon to the "3D printing" of 3 dimensional structures in a vacuum plasma deposition chamber. The sputtered particles could be positioned by phase changes produced by sound transducers in X, Y, and Z axes. I don't have the resources to make it real, though. It could make amazing things like gold arterial stents etc.

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