Chaotic Waterwheel

[@FiveTrackTape]

This model of my brain function is perfect.

[@mrhaftbar]

Janitor on campus: no messy shit Students:

[@NatSciDemos]

:)

[@shaunh1725]

Found this video after reading Chaos by James Gleick. This is a great physical demonstration of non-linearity!

[@IsaiahStJohn]

It's too bad this video doesn't show how changing the rate of water changes the waterwheel's behavior. At a very low rate, the waterwheel will turn steadily. At a higher rate, the waterwheel will periodically and regularly reverse directions. If the rate is increased further, only then does the waterwheel show chaotic motion. It's quite neat to see these transitions, and they can be demonstrated with an even cruder setup than this.

[@peterhojnos6705]

I also missed the deterministic behaviour.

[@the_runofff]

that's neat. period doubling bifurcations!

[@cjw6659]

Charming and instructive.

[@anushaoberoi]

Thanks! Needed it a lot

[@parispersiancat]

The chance of any 2 wheels turning in exactly the same same way is still WAY smaller than a storm blowing through a junkyard and causing the trash to pile up in a way to form a fully functioning Boeing 747.

[@-kat]

turning the exact same way in what time period?

[@zack_120]

​@@-katpresumably for even once for a fraction of a sec at the identical direction and velocity

[@John-yf8qh]

There’s relativity confounderations throughout this idea, which is nothing like like me being disparaging. Far more of a compliment in my eyes, what? Jolly good!

[@SciFiFactory]

This is super cool and the middle part was hilarious :D Thank you!

[@NatSciDemos]

Glad you liked it!

[@yazajag]

Imagine if you went to an amusement park and this was one of the rides. Good times lol. 😳

[@John-yf8qh]

It could do with being hooked up to a Rolex-style, either-direction winder type system used on their automatic watches. Obviously a more regulated flow would be the answer but you brought me this crazy contraption, I’m just figuring out a power-delivery system for what you gave me :) :) x

[@Humongous_Pig_Benis]

Could this thing be used to generate true random numbers to be used in some very secure IT need?

[@NatSciDemos]

While it's true that the motion of the waterwheel is unpredictable, that doesn't necessarily mean that it's also random. Let's think for a minute about a situation we know is random: flipping a coin over and over. Each time we flip the coin, the chance of getting heads or tails is always the same, no matter the outcome of the previous flip. With our mechanical waterwheel, the situation is a little different. Since the wheel can't suddenly go from turning, say, in the clockwise direction to turning clockwise without first slowing down (or stopping, or oscillating...), the chance of the wheel changing its state of motion at some instant is determined by the state of its motion in the preceding instant. The weather is the same way: it can be unpredictable in how it evolves over time, but when it's raining and cold it's not as likely for it to suddenly change to sunny and warm as it is to change to cool and cloudy. A better physical example of randomness can be found in radioactive decay processes, and in Brownian motion (sciencedemonstrations.fas.harvard.edu/presentations/brownian-motion-latex-spheres).

[@Humongous_Pig_Benis]

@@NatSciDemos Thanks for the reply. Cheers and keep up with the great work.

[@aron8999]

Also, the dynamics of the Lorenz system have patterns if you look hard enough: If you plot the maximum z values attained before each lobe transition, there's an astonishingly regular relation between one z-max and the next. I'm not sure what that translates to for the waterwheel.

[@stebot1]

@@NatSciDemos I dont think I agree that it isn’t random. The velocity and displacement are serially correlated but keep differentiating the and you will eventually find a random stationary series. I think acceleration would already be enough but you might need to go to jerk. Either way sampling a state variable at a fixed frequency and differentiating would lead to a fairly good random number generator Alternatively if the wheel is divided into sectors with alternating colors and the colors were to be directly sampled as binary bits this should also allow a random bitstream to be created as the serial correlation will again be broken. In point of fact this is the same underlying idea below flow instability generally but more specifically convection that Lorenz was studying. Convection instability has in fact been used as random number generators by a number of companies. Silicon graphics first proposed the idea in a 1996 patent. Seeing as this waterwheel was first proposed as a system to demonstrate this same underlying behavior that leads to this chaotic behavior in fluid flow it should also make a good random number generator.

excelente video saludos :)

[@KhangNguyen-jo3zm]

Thank you for giving my dynamic prof idea for problem set. 😂😭😢

[@MS-sv1tr]

Think you need a bigger bucket

[@JeremyVaught]

The book Determined by Robert M Sapolsky brought me here, indirectly. Apply your free will and read this book, it’s amazing.

[@alexliu1996]

It is like a Ferris wheel 🎡

[@niemandwirklich]

Thanks for this interesting phenomenon. The description though: (...) 1 meter diameter (...) ¼” holes (...)

[@NatSciDemos]

Yeah well, the 1/4" drill bits are easier to find in our shop than the metric stuff ;)

[@Кровушки]

Cool. Thanks!

[@ToyotaKTM]

And then the pump ran out of water and a chaotic fire ensued.

[@meox4tralaitamtritoiday]

more about this in chaos by james gleick 😉

[@kleinjahr]

It’s Kaos! Get Smart!

[@MikeTrieu]

CHAO-tician!

[@alexrobainaincognitasporde7358]

Top notch!!

[@massivec0k653]

Can you do this with mercury and the audience bets who's going to die of poisoning first?

[@robertpitt8418]

Flying in a rusty old plain in the pitch of darkness just ABOVE the Amazon, battling true Gail FORCE winds and the shattering sounds of lightning . : )

[@ImTheReal]

First aleatory algorithm 🤣😂🤣😂🤣😂🤣

[@АндрейСтепанов-ь3о]

Амфидримические циклы, учитывались ?

[@Kerrosene]

Saw trap..

[@Muonium1]

K

[@foureyedchick]

5 minutes, 20 seconds waste of time!

[@johanliebert2601]

If you know what it's then it's not waste lmao.

[@rolandstepanoff3674]

Would someone mind putting some intelligence in this machine? Is this an allegory of egality? Maybe of the french moto? The question is who has invented this machine, and what for, or how did it occur? Wich nationality is the guy who did that? Is intelligence an english word or first a french one?

[@weird_cookies]

It's called the Lorenz wheel and it was designed to demonstate the inability to curb chaos. The basic notion is this : nothing can be predicted with 100% certainty

[@kojimo1313]

Why is this considered chaotic? There is a clear pattern that happens. You can clearly see that the creator had no idea what this thing does so came up to the conclusion that it's chaotic. Even the theory of chaos proves that there is no such thing as chaos... This is just a video of a very incompetently made wheel which redirects more than half the energy put into it backward. This should be changed for section entertainment, not education.

[@leonardocp21]

From Strogatz Non Linear Dynamics and Chaos: "Chaos is aperiodic long-term behavior in a deterministic system that exhibits sensitive dependence on initial conditions." . This waterwheel has a chaotic behaviour under certain conditions of gravity, water inflow, cup leakage and wheel damping. When this condition is satisfied, the wheel presents and aperiodic motion and there is no clear pattern that you can predict. You can see that from the half of the video, there are 4 systems with near initial conditions and they present very different behaviour after some time, so this is clearly a chaotic system.

[@aliasmassistance5807]

@@leonardocp21 I'm here cause of Sapolsky!🦋

[@massivec0k653]

Open a fucking book on non linear dynamics and read the lorenz equations section

[@ArjunJagadeeshV]

​@@aliasmassistance5807me too