The instances catalogued in the problem page look like a set of unrelated slips — a wrong compass direction here, a number in the wrong slot there. They are not. Four causes generate almost all of them, and only one is about carelessness.

1. Three axes, and no horizon to hang them on#

A person standing on a planet orients with two axes and gets the third free. North–south and east–west are horizontal; up is whatever is left. The horizon does the work of separating them: everything below it is ground, everything above it is sky, and far away and toward the horizon are the same direction.

Inside a cylinder none of that survives.

• Axial (north–south) runs along the length. It is the only direction that behaves at all like a terrestrial compass direction.
• Circumferential (east–west) wraps around. Travel far enough and you return. It is the axis the rotation runs along, so it is the only horizontal direction whose two senses behave differently.
• Radial (up–down) points to and from the axis. “Down” is not a gravitational absolute; it is centrifugal, and it aims outward from the axis, which means two people on opposite sides of the cylinder have opposite “downs.”

There is no horizon, so the axes do not sort themselves. The ground does not stop; it curves up and closes overhead. And crucially, far away and toward the horizon are now different directions — a thing 80 km away up the axis and a thing 20 km away overhead are both “distant,” and Earth’s vocabulary has one word for where they are. This is precisely the trap Landscapes of Coriopolis fell into when it put the city’s lights overhead.

2. Earth’s vocabulary arrives with a frame already installed#

The words are not neutral. Each of these carries a planetary premise that is false here, and none of them look like they are making a claim:

A writer using these is not being sloppy. They are using ordinary English correctly, and ordinary English encodes a planet. The last row is the sharpest case: English has two live conventions for directional prepositions and resolves between them by context, and there is no context here to resolve with. The Le Guin rendering’s “the deflected currents pull at them from the west” is not badly written; it is a sentence English cannot disambiguate outside a terrestrial weather intuition the reader does not have.

3. Design choices got written down as physical givens#

This is the most damaging cause and the least visible, because it corrupts the source of truth rather than any individual scene.

The scene prompt lists under Physical givens (from canon): “Light sweeps along the spin direction rather than rising from ‘below.’” That is filed as physics. It is not physics. It is an engineering decision, and it is one of at least three.

The emitter surface rotates with the habitat. An image painted on it and left alone therefore holds still relative to every observer inside. So:

• No animation. The sun never moves. There is no sunrise direction at all, and day and night are a brightness ramp arriving everywhere along the circumference at the same instant. This is the default — the thing that happens if nobody decides otherwise — and it is genuinely alien in a way the project has not explored.
• Animated spinward. The image scrolls slowly west across the emitter surface, with the rotation, and the sun appears to rise in the east and travel west, as on Earth. This is what the prompt specifies, and — since the 2026-08-24 convention revision — what all four renderings that name a direction describe.
• Animated antispinward. The image scrolls east, against the rotation; light lags the spin and dawn arrives from the west.

Note what is not on the list: an image held fixed in non-rotating space. That would make the sun appear to circle the sky once per rotation, and at 1 g in a 20 km cylinder the rotation period is about 200 seconds. A three-and-a-half-minute day. Nobody builds that.

So all three live options are deliberate, none is forced, and the choice is a worldbuilding decision about what the builders of Coriopolis wanted their sky to feel like — nostalgia for Earth, or honesty about the cylinder. That is an interesting decision and it deserves to be made on purpose. Instead it was made in passing, recorded as a given, and then half the renderings overrode it anyway — because writers reaching for a sunrise reach for the one they know, and the prompt gave them no reason not to.

The general failure: in a built environment, arbitrary choices and physical consequences look identical once written down. A later writer cannot tell which constraints are load-bearing, so they treat all of them as soft, and the ones that actually were load-bearing get broken too.

4. Scenes are composed locally and read globally#

Every instance in the audit is invisible from inside the page that contains it. Each rendering is internally coherent — with the single exception of the Tolkien rendering, which puts the light source in the west in its first sentence and in the east three paragraphs later. The contradictions only appear when two pages are laid side by side, which is exactly the reading a book gets and exactly the reading a draft does not.

This is why the problem needs a procedure rather than more care. Care operates at the scale of the sentence being written. The errors live at the scale of the corpus.

Why it compounds#

On Earth, a spatial error is a small mistake against a robust background: the reader’s lifetime of standing on a planet repairs it silently, and most such errors are never noticed. Here the prose is the reader’s only source. There is no background to repair against, so an error does not get absorbed — it gets recorded, and the reader builds their map around it. The next correct sentence is then the one that reads as wrong.

That inversion is the whole reason this bundle exists. Elsewhere, spatial precision is a polish concern. Here it is load-bearing.