Tolerance
Right Answers from Wrong Parts.
Six live instruments that get the right answer out of noisy, broken, drifting, or
lying parts, and show how each one fails:
| # | Exhibit | What it shows |
|---|
| 01 | The Vote | Triple modular redundancy, von Neumann's threshold, and common-mode failure (Ariane 5) |
| 02 | Scratch the Code | A real, scannable QR code (version 3-H) you can deface, with the Reed–Solomon decoder repairing it live |
| 03 | Where Am I | GPS pseudoranging: solving for position and clock, dilution of precision, and why altitude is worse |
| 04 | Two Wrong Answers | A GPS + accelerometer Kalman filter that also learns the accelerometer's bias |
| 05 | Light Through a Finger | Pulse oximetry's ratio of ratios, motion artifact, perfusion, and camera heart rate with your own finger |
| 06 | Drop It on Purpose | TCP CUBIC through a bloated router buffer, compared with CoDel and fq_codel |
jkastl.github.io/tolerance
The Lab
Four new concepts, each on its own page and built a piece at a time. Every page carries its own
design and build plan, and CLAUDE.md explains how to advance one.
| # | Page | Idea | Status |
|---|
| 07 | liar/ | Twenty questions against an adversary allowed to lie (Ulam's liar game, Berlekamp's volume bound) | blueprint |
| 08 | traitors/ | Pass-the-phone party game running the Byzantine Generals protocol | building (playable) |
| 09 | fingerprint/ | Your phone's sensor calibration errors as an ID (SensorID, 2019), on-device only | blueprint |
| 10 | tearproof/ | Split a secret across printable tags; any k of n rebuild it (Reed–Solomon / Shamir) | blueprint |
No build step, no dependencies, and no backend: everything runs in the browser, and no
data leaves the device. Each page loads an anonymous GoatCounter visit
counter (no cookies) and works without it. Every exhibit and Lab page lives in its own folder.
Exhibit pages share site.css and core.js, and Lab pages share lab.css.
Everything is served by GitHub Pages from main. The QR encoder/decoder
(GF(256), Berlekamp–Massey, Forney), Gauss–Newton GPS solver, Kalman filter, and TCP/CoDel
simulation are all written from scratch in the page. The QR output matches the Python
qrcode library bit for bit.
The camera demo uses getUserMedia, so it needs HTTPS (GitHub Pages is fine). Video frames
are averaged on the device and never sent anywhere.
A sibling of A Field Guide to Emergence.
License
MIT
