Uploaded January 2026 | Updated September 2026, 2 weeks ago

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

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

134217728 balls falling on a right-angled wedge

Balls dropped on a cone, f(x, y) = sqrt(x^2 + y^2)

Just another Fourier expanded step function

$Photographing a trillion-star galaxy (quick-and-dirty how-to) Shown is an image I took earlier this year of one of the most majestic galaxies as seen from us; the M101 (so-called Pinwheel galaxy). Its located about 20 million lightyears from us and houses approx 1 trillion stars. Its face-on characteristic is a truly spectacular sight. Image acquisition was done with ZWOs AM5 mount and ASI2600MC PRO camera through a Skywatcher 100ED DS-PRO refractor with a .85 reducer, i.e., at 765 mm focal length and f/7.65. Taken from a Bortle 4 zone. In total 80 5-minute exposures (6 hours and 20 minutes). Stacking, edge cropping and background extraction was made in Siril, and the remaining postprocessing in PixInsight. Particularly, the magic wands Blur- and Noise exterminator were used therein. I spend typically 30 minutes on post and have much to learn as some may notice. No affiliation involved. Astrophoto channels I like: @NebulaPhotos Nico is brilliant on what he does and is the main reason that I eventually went into astrophoto two years ago (with a DSLR and a tripod). @lukomatico Superb in-depth comparisons among gears, and always provide interesting tutorials and reviews. @CuivTheLazyGeek Enthusiastic and entertaining reviews/comparisons/tutorials. Always a pleasure to watch. Visuals made with my astro camera and telescope; images stitched and blended in ffmpeg, as well as some Python tweaks. The beautiful music was made by @gpcbass; the song title is Starless (a King Crimson cover from 2022). A vocal version can be found here: https://www.youtube.com/watch?v=TbJvKYycOAY&ab_channel=gpcbass$

Spiral of 999 balls with varying bounciness dropped on parabola

Gaussian wavepacket bouncing in a 2D box

Alexander Gustafsson |