2026 · Fourier series · Canvas · Maps
Tube Fourier
The whole London Underground drawn in one unbroken line by 1,500 spinning circles.
How it works
The same trick as Fourier Earth, applied to the tube map: any closed path can be rebuilt by adding up circles spinning at whole-number speeds, each riding on the tip of the last.
A rail network branches, so it isn’t one loop. The path here is a walk that goes out along every stretch of track and back again, starting and ending in central London, so the pen never lifts. Each stretch keeps its line’s colour, so the drawing comes out as the familiar map: thousands of circles, eleven colours, one line.
The layout is the generated tube-map schematic (see Tube Warp). With 15 terms it’s a wobbly blob, with 150 the lines appear, and with all 1,500 it’s within a few hundredths of a percent of the source.