Environmental model evolution

Recovered development history; current conclusions live in 600.

The habitat stopped behaving like a roofed cylinder.

Development increasingly treated the inner rim as a planetary-scale rotating environment rather than a landscape beneath a transparent shell. The approximately 60 km atmospheric figure emerged as a scale-study envelope: gas thins continuously with altitude instead of terminating at a roof. This allowed terrain, towers and exposed high regions to share one environmental gradient.

The useful conclusion was architectural, not a solved atmospheric calculation. Surface pressure, composition and scale-height behaviour remain open.

Atmosphere supplied a natural limit where geometry alone did not.

Once no hard ceiling was required, very tall mountains and polarward structures became possible in principle. Discussion then shifted their practical limit toward pressure, wind and exposure. Rough 10–20 km terrain figures were explored as landscape-scale extremes but were never adopted as universal maxima.

A permanently inward-facing landscape cannot obtain night from ordinary rotation.

The rotating inner surface continually faces the central star, so a terrestrial day/night terminator cannot arise merely from the Station's roughly day-length rotation. Recognising that contradiction produced the static or largely static equatorial occluder concept: the inhabited rim rotates beneath a shadow-making structure, converting relative motion into an engineered illumination cycle.

The roughly eighteen-hour night discussed later is retained as a working consequence, not a locked specification. No recovered drawing yet fixes occluder width, height, edge treatment, twilight or latitude behaviour.

Red daylight became a physical lighting problem rather than a colour grade.

Lighting experiments initially explored ordinary emitters and false-colour approximations. Subsequent scale and stellar work moved toward a cool central source around 2,075 K with a broad apparent disc, infrared-heavy output and soft-edged shadows. The surviving values belong to the current 600 model; the abandoned shortcut was treating terrestrial-looking illumination tinted red as sufficient.

Removing the roof changed what environmental failure means.

A roofed-habitat model makes puncture an obvious catastrophe. The open-atmosphere model instead shifts serious failures toward rotation loss, circulation changes, atmospheric migration into unintended volumes, altered heating, occluder malfunction and terrain/support collapse. Local structural damage can therefore coexist with continued regional habitability.

Hard enclosure and ordinary planetary night are superseded assumptions.

Superseded imagery includes a necessary transparent atmospheric roof and any assumption that rim rotation alone naturally alternates day and night. Still open are the quantitative atmospheric model, weather cells, precipitation, long-term gas losses, occluder engineering and ecological feedbacks. Those questions should remain unresolved until recovered evidence or explicit modelling addresses them.

Design history is not external validation.

This record preserves internal concept evolution. Real rotating-atmosphere, climate and illumination evidence belongs in 700; fictional habitat comparisons in 750; and Tribunal environmental specifications or occluder documents represented as in-universe objects in 100.