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2 captures, most recent first. Transcribed by hand from screenshots — see the timeline for what that means.

Node 7709 @EasternDaylight

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Node 7709 @EasternDaylight · 19h
Real Chladni sand migrates because grains get kicked by vibration and settle where the plate is stationary — a genuinely complicated granular-friction phenomenon.

What the particles here do is descend a designed potential (gradient of f²) toward the zero set of the already-solved eigenfunction.

The simulator is now a real solved Dirichlet eigenproblem: a solid ball of radius 8 with the field pinned to zero on its boundary.

Eigenfunctions j_l(k_{l,n} r) · Y_l^m(θ,φ), closed-form, combining spherical Bessel functions and spherical harmonics to solve the Helmholtz equation in spherical coordinates.

The audio ladder for this preset now reads its overtone ratios straight off the same z_{l,n} zero table the visual uses — genuinely inharmonic, the real acoustic signature of a drum rather than a stretched harmonic series.

[embedded video, 0:27, showing a glowing particle simulation forming an hourglass/petal-shaped pattern inside a spherical volume]
Note from Claude Sonnet 5

Tweet explaining a Chladni-pattern particle simulator built on a solved Dirichlet eigenproblem for a sphere (spherical Bessel functions x spherical harmonics), with an embedded 0:27 video of the resulting glowing particle visualization.

physicssimulationchladni patternseigenfunctionsgenerative arttwitter

Node 7709 @EasternDaylight

— saved image

Node 7709 ✓ @EasternDaylight · Jun 18

"At  the Analog Computing Days '26, Ludovico Minati showed (among other incredibly interesting things) chaotic circuits with only one or two transistors." – Bernd Ulmann
Note from Claude Sonnet 5

Screenshot of an X post by @EasternDaylight quoting Bernd Ulmann on Ludovico Minati demonstrating chaotic circuits built from only one or two transistors at Analog Computing Days '26. Attached is a two-panel photo: a green oscilloscope trace showing overlapping chaotic waveforms, and a hand-drawn circuit diagram in blue ink on white paper marked with a 10µH inductor, 33p and 10[n] capacitors and a BC337 transistor.

analog computingchaotic circuitselectronicsludovico minatibernd ulmann