Triple Pendulum Chaotic Acrobatics

The pendulum oscillates harmonically when displacements from equilibrium are small. Motion turns dramatically chaotic and unpredictable when displacements are large.

Timestamps:
00:04 Harmonic Motion Stage 1
00:18 Harmonic Motion Stage 2
00:33 Harmonic Motion Stage 3
00:55 Chaotic Motion Stage 1
01:39 Chaotic Motion Stage 2
02:40 Chaotic Motion Stage 3

"The extreme sensitivity of future behavior to small differences at early times is a characteristic of chaotic systems. This extreme sensitivity also affects predictions. Even if the theoretical model is perfect in every detail, the future behavior of a chaotic system is unpredictable because the starting conditions for the model can never be 100% accurate.

For example, the chaotic nature of weather makes accurate long-term forecast impossible. To predict the future weather, the current conditions are used as input. Any small difference between the true current conditions and those used as input will grow to huge errors in the forecast later on." University of Florida, Department of Physics, demo of Chaotic Pendulum.

Watch other chaotic and coupled pendulums in action at:

Reference: Make magazine Volume 22, June 2010.

[derpsterproductionstcg]

What if this was an amusement park ride and you rode in a cart on the bottom...

This would be one heck of a ride

[tai-t-]

What bearings were used on these?!! Wow

[MrInitialMan]

What would happen if the pendulum fixed to the wall was attached to a motor, so it had a constant kinetic energy supply?

[lightningfirst]

When Shaggy thinks he's seen a ghost: 0:55

[Riley-Thurm]

Somebody make this an amusement park ride

[funkybear]

Holy cow ! more chaos now.. I guess just having studied the double pendulum one gains the insight.. about the n-pendulum.. haha. Nice video. Thanks Ami Varsano.

[sumobear]

I could see that as the next carnival ride. The silver parts are where the people would sit.

[josephjackson]

Imagine seeing this tuned mass damper in your skyscraper.

[tartredarrow]

If you knew the velocities, vectors, mass and dimensions of this pendulum at any given moment, couldn't you technically figure out the next second or two, even ignoring friction?

[Nikhil-blkl]

double pendulum:- chaos
triple pendulum :- chaos × ∞

[paulpaese]

Ami, I love this video. Thank you for making it. A couple of questions. How much weight is added (relative to the entire weight of the bar) to the tops of the two upper pendulums? And how much weight is added to the bottom of the bottom pendulum? I ask because I might want to make a version of this pendulum using discs rather than bars and if I do it would be helpful to know the upper half versus lower half weight proportions of each of the three pendulums. Thank you! –Paul

[MabInstruments]

Has someone tried adding escapement so that you don't have to keep adding energy by hand and the system acts as a chaotic clock, not measuring time but producing interesting ticking rhythms?

[leila]

Is there a formula that explains or tries to explain or predict the randomness? I heard, F=ma Newton's Law of motion?

[josephastier]

It needs to be MUCH larger. And on the weighted ends mount giant fireworks pinwheels.

[MarkWaddington-vr]

Hi Ami - Many thanks for your creativity - I would like to use part of your video within a presentation around working with complexity - hoping you're OK with this BW Mark

[unknownhours]

And this is why robotic control is hard

[derpderp]

yeah, why stop at 2 pendulum? make it 3, heck, 5, make it 50 pendulum slowly spiraling out of control! go

[mohamedbensellam]

Dommage qu'il n'y a pas de descriptions afin de reproduire.

[miertjestoer]

Were I can buy this or another triple pendulum? ( I know an store in UK but I lost it)

[josephjackson]

Imagine seeing a tuned mass damper like this.