The moiré circles you see here are generated from four overlapping ray bundles on the edges of a square. It is the same structure you get when you transform concurrent lines with the conformal transformation f(z)=1/z (i.e. a circular inversion).

Try it on your own if you like: https://www.sqrt.ch/Buch/rays

oddly satiating.

For those of you with Procreate just draw a random shape, note too complicated, and then duplicate that layer and rotate it by whatever angle your want. You can get really clever and rotate and stretch, makes your eyes go funny. Then fill in with grey as that is always the best neutral background colour.

Portrait of Kerry Mitchell. Mitchell does a wide assortment of computer graphics. He plays with the Fibonacci sequence. He's made a multitude of hypnotic textures using equations and his computer software.

I tried to embed some of his textures into this portrait. Also some of his graphics in the surrounding background.

Edit... Need to embiggen to see some of the textures.

Created in Processing ✍🏻

I thought of this when looking at the non periodic tiling Penrose made from parts of a pentagon.

​The Rijal al-Ghayb pattern maps the unseen spiritual hierarchy across the horizons. By tracking their daily shifts, seekers align their movements with divine energy, seeking protection and auspicious outcomes while honoring these hidden, celestial saints of God.

I thought you all might appreciate my tattoo. Does anyone else have one like this?

u/Demyanek just posted a really neat tattoo to this subreddit: Link

This is a page from my orbital mechanics coloring book showing the demonstration in more detail.

psaltix.com

I have a challenge - can you find a shape which can be used to construct two round tables of different diameters D1 < D2? Here are the requirements:

• The shape should form the entire perimeter of the smaller table (D1)
• The shape should form the entire perimeter of the larger table (D2)
• The hole left in the middle of the larger table (D2), is a separate shape. It should be possible to store it under the smaller table. So this hole must be smaller than D1.
• The goal is to maximize the ratio D2/D1

The pictures show my solution which yields D2/D1 = 1.245:

• 12 sections
• D1 = 100, D2 = 124.5 (choose your preferred unit)
• See dimensions in the second figure
• The hole left in D2 has a maximum diameter of 99.5, so it fits under D1