---
title: "You work it out by playing"
date: 2026-08-08
tags: [daily-finds, web-tools, learning-and-reference]
description: "Five browser toys that teach by letting you push the buttons — drum-head physics you draw yourself, a trout river you learn to read, and a laptop keyboard tuned like a bass."
blurb: "No tutorial, no manual — the explanation is the thing you're already touching."
items:
  - eigendrum
  - read-the-water
  - qwerty-midi
  - bap-studio
  - sbahn-seat-picker
---

> Draw a closed outline and one of these solves the eigenvalue problem for that exact shape and plays what it would really sound like. Another puts a trout somewhere in a simulated current and tells you why your guess was wrong. Nothing here explains itself in prose first.