Second build · second-island

The tools came before the island.

The second build started clean on 18 August 2026. It wrote its checking tools first, then broke copies of itself to watch each tool catch the break.

Copernicus Sentinel-2, 13 July 2026 · sources

Stage 0

Every checker was watched failing first.

A digital twin is a computer model of a real place that shows where every number came from. Minjerribah's second twin is called second-island.

A checker is a small program that reads the build and reports faults. A fault is a break switched on by name. One makes a part read the real clock.

The self-test runs each checker twice per fault: a good copy, then a broken one. A catch counts only if the checker passed clean, failed broken and named the break.

33
named ways to break the build
docs/JURISDICTION.md, generated 20 August 2026
21
checkers every fault is run against
docs/JURISDICTION.md
33 of 33
caught on 20 August 2026, each one named by its checker
docs/STATE-OF-PLAY.md

One file lists which checker owns which claim, and which breaks nothing catches. One blind spot: a mobile number in the sealed inbox, where the personal-data rule does not scan. From the Stage 0 file: "'Exists, untested' is an acceptable row. 'Works' without a receipt is not."

Checker

Headless

Runs the whole island in a terminal. Fails loud on any error or blown budget.

Checker

Determinism

Runs the world twice from one seed. Names the first tick that differed.

Checker

Shot

Checks the test picture pixel by pixel. It misses a renamed label: a picture cannot read words.

Checker

Bench

Times each frame against a budget. Reports the slow end and the worst frame, never the average.

Checker

Interface probe

Every panel needs a name. Every number must point at a record on disk.

Checker

Gate

Runs fourteen rule checks over the files. A broken rule blocks the build.

Checker

Board

One note per file. A finding that lives only in a chat counts as never made.

Checker

Selftest

The checker that checks the checkers. It writes down what each one caught.

The kernel

One tick is one island minute.

The kernel is the core everything runs on: the clock, the store of facts, the random numbers.

The same seed gives the same island on anyone's machine.

The README records a simulated year running in a terminal in 0.144 seconds, about one blink.

The record

Every fact has eight fields.

A record is one fact: a departure time, a jetty, a bus call, a tide reading. The kernel refuses one missing any of the eight.

FieldWhat it means
sourceAn id from the build's source list, nothing else.
locatorPage, column or web address. Enough to check the claim.
valid fromWhen it became true on the island.
valid toWhen it stopped being true. Empty means still true.
recorded atWhen the twin learned it.
recorded untilWhen a newer belief replaced it. Empty means current.
confidenceHigh, medium, low, contested or unknown.
registerKnown, modelled, proposed or contributed.

"Valid" is island time, when the thing was so. "Recorded" is twin time, when the twin believed it. A store that overwrites cannot show what Tuesday saw after Thursday corrects it.

Known

The 5:30pm vehicle sailing

One record in the crossings pack. The SeaLink vehicle barge leaves Junner Street, Dunwich, at 17:30 on the vessel marked SB.

  • source: sealink-timetables
  • locator: "SeaLink vehicle ferry base timetable, Departs Dunwich column, row 5:30pm"
  • valid from: 19 August 2026, the day it was supplied. The timetable prints no start date
  • valid to: empty, still true
  • recorded at: 19 August 2026
  • recorded until: empty, current belief
  • confidence: high
  • register: known
A correction

If SeaLink publishes a new time

The old record stays and gets a "recorded until" date. A new record goes in with the new time. A break named correction-overwrites tries to overwrite instead, and the store caught it.

The 19 August times also have a seal: a second copy of every time, vessel code and day rule. Change a time and the build stops until the pack, the typed copy and the seal agree.

The source ladder

Four rungs, best source first.

A panel does not take the first figure it finds. Each field has its own ladder.

  1. Island sensor. A sensor on this island.
  2. Official observation. A reading from a body that publishes it.
  3. Model. A published model or forecast for this place.
  4. Simulation. What this twin computed. The bottom rung.

An old reading drops a rung, so a stale official reading ranks where a model would. Each field sets its own use-by: a tide reading ages faster than a bus timetable. From the ladder file: "The bottom rung never wins in live mode."

The ladder gives back a value with its rung, source and date, or "not known" with the date and reason. No panel prints "not known" as a number.

Harmonic constituents are the numbers behind a port's rising and falling tide. Nobody has found a published table for Dunwich, so the tide pack ships none. The tide panel reads "contested or unknown" with the date. Anything below the confidence bar prints no number.

The gate

Fourteen rules that block the build.

The gate reads every file and flags broken rules. A blocking flag stops the build. An advisory flag prints. From the contract: "A rule that is not in the gate does not exist."

  1. imports. The simulation never imports the renderer or the interface.
  2. no-wallclock. No wall clock. No unseeded randomness.
  3. lore. No Aboriginal language word off the allowlist. Cultural material stays out.
  4. provenance. Every record has its source, locator and two times.
  5. style. No em dash, no en dash, Australian spelling.
  6. personal. No personal contact details anywhere.
  7. sealed. Raw downloads cannot be committed. Git proves it.
  8. derived. No download is committed while its licence is open.
  9. crossings. Passenger and vehicle crossings never get added together.
  10. ground-truth. Every departure time and vessel code matches the supplied timetable.
  11. ports. The first build's two server ports are never used here.
  12. board. Every noticeboard note has the right header.
  13. instruments. No hidden fault switch, no unproven checker, no unexplained blind spot.
  14. failure-modes. Advisory only. A claim that something cannot work needs a measurement.

The gate ran on 20 August 2026. It reported "PASS: 0 blocking, 15 advisory", all fifteen already known.

The lab

The bench has its own page.

The lab page. An acknowledgement of Country panel, four solid squares in red, green, blue and yellow, and a pale plate with a dark swatch.
The lab page, 2 September 2026. The swatch changes colour with the tick.

The lab is the test bench: the test picture, the island clock, the sun and tide panels. A test picture has known colours at known points, so a program can check what was drawn. From the lab page: "Flat rectangles on purpose." Draw island data there and the test starts testing the data.

Two frames from different ticks must differ at the swatch. That is how the shot check spots a frozen picture.

A picture cannot read labels, so two witnesses check the screen. The page reports every panel and value. A screen reader's list of named parts is checked against it. On 20 August 2026 the shot check passed 6 of 6 points, the probe 10 rules over 8 panels and 28 values.

Until 20 August 2026 the bench was the front page. It moved to lab.html so a visitor meets the ferry question first. Every checker was repointed.

Today

What is on screen today.

0
parts of the second build running
from the parts list
0
of them checkers
from the parts list
0
part not finished: the connectors, still in the sealed inbox
from the parts list
On screen

Running now

  • The test picture and the island clock.
  • The sun's position, checked eighteen different ways.
  • A tide that says it does not know its own height.
  • Three ferry services, two operators, two island jetties, 76 sailings.
  • The TransLink bus feed: two routes, 44 stops, enough to say if a bus meets a boat.
Not there

Not built yet

  • No ground. No terrain, no buildings, no map. From the README: "There is no island yet." Terrain waits on the elevation lane, which has not run.
  • No residents. None generated yet. When they are, every card must say so.
  • No live feed. The ferry page reads the printed timetable against the island clock. No boat is tracked.
  • Downloads waiting. Five connectors have pulled real data with receipts: OpenStreetMap, TransLink, past weather, the 2021 census and the Atlas of Living Australia. Only the bus pack is committed. The rest waits in the sealed inbox until the licences are settled.

Open it: the live page and the repository. Open them yourself has the one command for your machine.