Double pendulum art | 8k60fps @animations

Uploaded November 2021 | Updated September 2026, 2 weeks ago

This is my first 8k resolution video. Each of the chaotic frames in the second part uses 15 MB of disk space. The 8420 frames took in total 84 GB of disk space.

What is shown is 10 000 double pendulums mutually separated by 1e-7 radians. Initial angle for both rods is 3.14 radians, i.e. almost completely upright. The longer rod is 100 times heavier than the shorter.

Music by @gpcbass. The song is called Top Quark Blues.

Visuals done in Python and FFmpeg.

$Light ray hitting an elliptic water drop Shown is a white light ray hitting an elliptic water drop at a relatively large incident angle, where refraction generates one or more rainbows. When the light is transmitted such that it passes between a focal point and the boundary the light may be subject to total internal reflection before leaving the water drop. Such a total reflection cannot occur when the light ray enters the drop such that it passes between the focal points. Except for the final part, the Fresnel equations are used to determine the reflection coefficient at the water-air boundary. In the final part all rays have the same intensity, being certainly unrealistic, although visually quite spectacular, and further emphasising some familiar ellipse billiard properties. The music is made by @gpcbass specifically for this video, and a bit too cool for the visuals. Its a reproduction of the song No No No originally made by Tribal Tech from the album Nomad, 1988. The visual part is made using Python and FFmpeg.$

Rigid body moose dropped in a moose contour

Millions of particles forming cardioid caustics in a circle billiard

$Mandelbrot set: simple equation - complex boundary Some standard basics regarding the famous Mandelbrot set fractal are presented. Needed prior knowledge is familiarity with complex numbers. Dope music by @gpcbass. Song is called Polar_mist and made today specifically for this video. Visuals in Python & FFmpeg.$

How cats actually land (slo-mo softbody)

Painting a butterfly with the butterfly effect

100 million ball mushroom billiard is (not) chaotic

$Raytraced 2D diamonds Ordinary and heart-shaped two-dimensional diamonds (refractive index ~2.4) are exposed to a thin beam of white light consisting of 250 000 wavelengths. GPU throughout. Approx 1.5 hours rendering time per minute of video. Song by @gpcbass, called Twelve Grapes. Visuals in Python & FFmpeg$