Sleep's surface, watched: the bout is the circuit's, the rhythm is the animal's

[YesterdaysLemon]

Closes #197.

What

A new instrument, tools/sleep_surface.py, does the thing nobody had done since the homeostat landed: watch the animal simply live with it — ten undisturbed minutes per seed, two plates (the default plate is the ecology; the pharynx fixture's dense lawn is the incubator where bout statistics accumulate).

The record (600 s × seeds 0/1/2 per plate)

dense   seed 0: onset 121 s, 6 bouts, 46.5 ± 0.5 s, interval 32.8 ± 0.4 s
        seed 1: onset  98 s, 3 bouts, 46.0 ± 0.0 s, interval 43.5 ± 10.5 s
        seed 2: onset  85 s, 4 bouts, 39.8 ± 11.4 s, interval 114 ± 114 s
default seed 0: onset 483 s, one 46 s bout    seed 2: onset 448 s, one 46 s bout
        seed 1: left the dish at 118 s (→ #211)

The reading

• Bout duration belongs to the circuit: 46 s ≈ tau_sleep · ln(0.69/0.25) almost exactly — the discharge is the bout.
• Bout timing belongs to the ecology: intervals run from metronomic (a seed parked on food) to 114 ± 114 s (a seed wandering off the lawn edge, stalling its own pressure build). On the default plate sleep is a rare late event (7–8 min to onset) because dopamine only builds while the roamer happens to feed. That variance is foraging, not an injected noise term — the lifelike way to come by it.
• Both quiescence effectors show on every bout (pump 1.3–2.6 Hz awake vs ~0.4 asleep; speed to a third), and the depth curve (Sleep depth: arousal threshold should ride the standing FLP-11 #204) rides each one (peak FLP-11 0.86–0.89).
• The gap against You 2008 is variance in bout durations — and the record says where it should come from if it ever matters: satiety reaching tau_sleep, not a noise dial.

Bycatch

A default-plate roamer pushed through the dish rim's 0.05 mm repulsion zone and diverged at 118 s — filed as #211 with the geometry. The instrument now reports a dish-leaver as a finding instead of dying on it.

No model change; one new instrument, its record, and the NEXT.md sleep item flipped from "unmeasured" to measured.

🤖 Generated with Claude Code

https://claude.ai/code/session_01CBroMXcYdfkyb5buJPcKvL

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Generated by Claude Code