Love to see someone do this for a harmonigraph [1].
[1] https://en.wikipedia.org/wiki/Harmonograph
(I contributed to this Wikipedia article over two decades ago!)
Interactive Double Pendulum Playground
21–26 of 26 posts
Re: Interactive Double Pendulum Playground
#22This is hilariously bad. If you want to see what a real physically sensible double pendulum sim looks like: https://www.myphysicslab.com/pendulum/double-pendulum-en.htm...
I don't see the difference. The motion in the version you linked is slower but I guess it can be fixed changing g. What are the visible errors in the main post? EDIT: I just noticed someone found an error and apparently it's fixed now.
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Re: Interactive Double Pendulum Playground
#23Could someone explain why turning off gravity makes it path so uniform ?
Re: Interactive Double Pendulum Playground
#24Could someone explain why turning off gravity makes it path so uniform ?
Because of the constant-length rigid connections, they start behaving like celestial objects in perfect orbit.
Re: Interactive Double Pendulum Playground
#25Could someone explain why turning off gravity makes it path so uniform ?
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Re: Interactive Double Pendulum Playground
#26Could someone explain why turning off gravity makes it path so uniform ?
The system is periodical; not counting the absolute angle but the velocities, angular velocities, and the angle at the joint are all periodical functions.
When the angle at the joint is 180° the Energy and Angular momentum determines v_1 and v_2, the velocities of the masses. It is known that Energy and Angular momentum both conserve.
Therefore the system will play out the same after states when the inner joint is 180°, and all the parameters will be periodical between 2 such states.
You can observe this in the demonstration in TFA: set gravity to 0, and observe how the graph rotates, especially the furthest points from the origin (where the angle at the joint is 180°).
edit: there are probably 2 different solutions for when the joint angle is 180°? I've found a graph where one furthest place from the origin is really pointy, and then the other is rather round.