Glossary
Words this site uses, as the two builds use them. Where the builds differ, both meanings are here.
Copernicus Sentinel-2, 13 July 2026 · sources
The model
A working model of a real place, built from what the place publishes. It has a clock, so a day can run.
One step of the clock. Ten minutes in the first build, one island minute in the second.
A seed is the number every random choice grows from. Same seed, same island, on any machine.
Running the simulation with no picture, in a terminal. A whole year runs in minutes.
A part that runs every tick and publishes what it knows. The tide, the ferry, the koalas, the council.
One kind of thing drawn on screen: terrain, ocean, sky, trees, buildings, roads, people, vehicles.
A panel over the island showing what a system knows. Boards read. They do not change the simulation.
Data painted over the ground in colour, from land cover to who is home tonight. Twenty-two in the first build.
A grid of height values, one per cell, that the ground is drawn from. The first build's is 908 by 1314 cells, each 32 metres across, wider than a house block.
The summary a system publishes for the boards. Some in the first build describe the instant, not the day.
One thing a council or another body could decide to do, with the cost, the time and who decides. The first build's civic board holds 64: 19 to decide, 18 to fund, 26 to ask for, 1 to watch.
The first build's council process: studies to commission, a lodge-it-anyway path, consultations and petitions.
How a claim is marked
First build says real. Second says known.
The panel says what the working rests on.
It stays marked proposed in every panel.
The second build prints contested or unknown, with the date it last looked. The first prints not known for air and wind when no reading is in hand.
A real thing nobody has checked lately. Thirty-one businesses carried it in the first build at 10 August 2026.
Supplied by a contributor, not yet checked against a second source.
Below the confidence line, so it is not shown. This happens often and nothing is wrong.
The kind of claim a value is. Real, modelled or proposed in the first build; known, modelled, proposed or contributed in the second.
How much weight a record holds. High, medium or low in the first build; high, medium, low, contested or unknown in the second.
Where a fact comes from
Where a record came from. The second build uses an id from a sources file, never free text.
Where in the source: a page and line, a row in a table, a sailing in a timetable.
Source, locator, when it was true, when it was believed, how sure, and how the claim is marked.
The second build keeps two dates on every fact: when it was true, and when the twin believed it. A correction closes the old belief instead of writing over it.
A data file of records, one subject each, kept in the repository. No network needed.
A file synced from a real source, with a date on it. The first build reads one at start-up only if it is marked for reading.
A tool that reads one named real source and writes a feed or a pack. Somebody runs it from the terminal, on a stated schedule.
One deliberate run of a connector. The running twin never syncs by itself.
The second build's record of a fetch: address, time, status, size, how long it took, the licence as read. It also keeps a hash, a short fingerprint of the file.
How old a reading is against the window its source states. The first build uses four words: fresh, ageing, stale, unknown.
Four rungs, best first: instrument, observation, model, simulation. The best fresh rung answers. A stale reading drops a rung, and the bottom rung never wins in live mode.
A reading from a device on the island; an official measurement taken elsewhere; a sum from known inputs; the twin's own made-up weather.
Rounding a location before it is saved. A rescue or a letting lands within a hundred or two hundred metres, never at the door.
Checking
A program that reads every file and stops the build when a rule is broken. The first build's gate checks its packs. The second's has fourteen rules.
In the second build: headless, determinism, bench, shot, the interface probe, the gate, the board, the self-test.
A deliberate break switched on in a copy of the build, so a checking tool can be proven to notice it.
Runs every fault against every checking tool, healthy and broken, and writes the table. 33 faults against 21 columns on 20 August 2026.
Which tool catches which fault, and which faults nothing catches.
Where findings are posted, one note per file, in both builds. A finding that lives only in a chat counts as never made.
A draw call is one instruction to the graphics chip. A frame is one drawn picture. The second build reports the worst frame, not the average.
Digging and water
How wide the tunnel hole is, 1.5 metres by default, about twice a doorway.
Digging a narrow tunnel with a machine nobody rides in, steered from the surface.
A tunnelling machine that holds wet sand open with pressurised mud while it cuts.
The sand a tunnel lifts out, sent here into reefs and new ground rather than a dump.
Dug sand takes up about fifteen per cent more room than packed sand, so volumes get a 1.15 multiplier.
What a cubic metre of sand weighs, put here at 1.6 tonnes, heavier than a small car.
One conveyor belt in the tunnel, carrying 260 kilograms a minute, about a quarter of a ute load.
The one two metre tunnel carrying everything the city moves: belts, pipes, a walkway and a services duct.
The rain water sitting in the island's sand, floating on salt water below. It mounds to about 42 metres near the centre.
A lake where the underground water level reaches the surface, so it cannot sit higher than that water.
How high water stands, given in metres; the higher it stands, the harder it pushes.
The Australian Height Datum, the national zero for heights, set close to average sea level.
The island's own words
The barge carries cars and the people in them. The two passenger ferries carry people on foot. SeaLink runs the barge and one ferry. The Gold Cats Flyer is the other.
Where a boat lands: the Junner Street ferry terminal, or the One Mile jetty, both at Dunwich.
The General Transit Feed Specification, the standard file format TransLink publishes bus timetables in.
A standard port is the place a tide table is published for, and Dunwich is ours. Constituents are the regular swings added together to predict a tide. The first build models seven; the second holds none.
The Open Database Licence, which OpenStreetMap data carries. Its share-alike rule keeps four packs out of the second build's committed data.
Creative Commons Attribution, the licence TransLink and the Queensland Government publish much of their data under. Free to use, with credit.