The chair stopped. Why can the turning feeling linger?: sources & model
Brake a virtual chair, open a real inner-ear reconstruction, and solve a motion-clue puzzle. Discover why actual movement, sensory responses and what you feel are different.
The source and model records are available for inspection. No external scientific reviewer has signed off yet.
canal-history-1 · content 1 · setup format 1
What supports the explanation?
Vestibular anatomy and complementary sensory information.
Agency-owned descriptions of canals, cupula, hair cells, otolith organs and multiple causes of dizziness. No outdated prevalence statistic or clinical maneuver is imported.
Smaller membranous anatomy and geometry-dependent mechanical modeling.
Scientific Reports 6, 32772. Full Figures 1 and 2, captions, methods and Table 2 support the anatomy distinction and declared four-second example. Figures CC BY 4.0; human panels/specimen differences remain labeled.
Indirect peripheral and central mode fitting must be distinguished.
Fitted mean 4.2 ± 0.6 s in ten humans from slow-phase eye-velocity responses. Verified abstract only; no unverified methods or human symptom predictions.
Mechanical displacement and neural response can have different dynamics.
Original simultaneous optical and afferent study in toadfish. Fish parameters are not human constants. The paper is linked; noncommercial-licensed figures are not redistributed.
Canal information can contribute to interpreting tilt and translation.
Five rhesus monkeys and eye-movement outcomes under controlled motions; intervention in two animals. Supports the interpretation problem, not a direct report of a human feeling.
Gravity and linear acceleration pose an interpretation problem.
Human eye responses tested against internal-model predictions. Our vector construction illustrates the mechanics ambiguity without reproducing provocative laboratory motions.
Co-registered clinical CT/micro-CT and segmented surfaces from 23 human specimens. F01’s bony space is separate from David’s soft-tissue specimens and this mechanical model.
Version 1.0, CC BY 4.0. F01 descriptor confirms LEFT. Exact topology retained; centered, converted from millimeters to meters and recolored. Source and derivative hashes are in the downloadable provenance record.
Material disagreement in human time-scale estimates.
Used specifically to disclose the approximately 16–20 s estimate and its assumptions. It does not override the original studies or settle a universal constant.
The dimensionless response index is not perceived speed, percentage dizziness, a measured cupula displacement, a nerve firing rate or a balance score.
Four seconds is an explicitly chosen example time constant, not a universal human physiological constant or the duration of a dizzy spell. Published estimates depend on assumptions and remain disputed.
The one-mode reduction omits the fast mechanical mode, hair-cell/afferent processing, bilateral canal coupling, central velocity storage and complete postural or perceptual integration. It is not applied to impacts, sound or high-frequency vibration.
F01 is one static ex-vivo left bony-space reconstruction. It is neither a live fluid movie nor an average person. Its source coordinate frame is cochlear, not a measured head-yaw sensitivity frame.
The animated cupula is an enlarged, original signed illustration. It spans the ampulla; no fluid is shown completing laps through a hole. Its dimensions and deflection are not measured from F01.
The cabin puzzle matches a declared instantaneous two-axis mechanical vector. It does not match all sensory histories or calculate the brain’s interpretation. No fixed sensory-weight percentages are assigned.
The camera and room do not rotate with the rider. The paper activity uses supplied records while seated; it is not an induced-spinning experiment or vestibular-function test.
A sensor with a history: The selected single-mode reduction is dy/dt + y/τ = α, with angular acceleration α, example time constant τ = 4 s and scaled state y. The plotted index is y divided by π/3 rad/s. Finite ramps avoid treating a speed discontinuity as an ordinary time step. Natural canal, afferent and central responses are more complex than this mechanical reduction.
Why the response changes during a constant speed: During a constant-speed interval, angular acceleration is zero and the model state relaxes exponentially. During braking, the acceleration drives it the opposite way. A response can therefore cross zero before physical rotation stops. With no further input, one time constant reduces its magnitude to 1/e, about 0.368, rather than erasing it.
The worked example: A 2 s start reaches 60°/s; an 8 s cruise precedes a 2 s stop. The normalized response is approximately +0.787 at the end of the start, +0.107 before braking, −0.722 when motion stops, and −0.266 four seconds later. Keeping the same cruise and braking over 8 s instead gives approximately −0.418 at the stop. These are calculated model states, not measured feelings.
A material uncertainty: The 2016 geometry-based study reports a human lateral-duct model time constant around 4.0 ± 0.8 s. An earlier indirect eye-response fit reports 4.2 ± 0.6 s in ten humans. Other biomechanical estimates report about 16–20 s under different assumptions. We do not resolve this disagreement or claim four seconds is a universal human constant. The 2016 uncertainty is not a between-person standard deviation.
The same two-axis vector: In our head-fixed right/down convention, f = g − a. A stationary 15° tilted cabin has f = [2.538148, 9.472497] m/s². An upright cabin can match it with acceleration [−2.538148, 0.334153] m/s²: leftward and slightly downward. Horizontal acceleration alone matches only one component. These momentary constructed vectors do not make the entire sensory histories identical.
What the real geometry establishes: The Wimmer dataset contains co-registered imaging and bony-labyrinth reconstructions from 23 specimens. Our rotatable F01 is a left-side micro-CT surface with 87,155 vertices and 174,318 triangles. Its original sampling is 0.06 mm; the largest source bounding-box extent is about 16.264 mm. No membrane, cupula mechanics or head-aligned yaw frame is inferred from that bony surface.
Anatomy is not physiology: David et al.’s stained micro-CT shows smaller membranous structures inside bony space. Direct toadfish measurements in a separate study distinguish cupula motion from diverse afferent responses; those fish times are not human constants. Human and primate motion studies test additional neural and sensory-integration processes. Our anatomy, mechanical model and cue cards keep these evidence roles distinct.
What has been checked
Analytical reference cases, conservation or transition invariants, finite drawing commands, bounded setup parsing, discovery and route integrity are checked automatically. These checks do not establish anatomical fidelity, learner outcomes or browser/device compatibility. Independent subject review, learner trials, comprehensive accessibility review and browser video encoding checks remain pending.
Each source supports the associated claim. Sources do not certify this implementation or its visuals.
About the cover illustration
Actual F01 left bony-labyrinth micro-CT reconstruction. Wimmer et al. (2019), Zenodo 10.5281/zenodo.3355272, CC BY 4.0. Exact source topology; centered, converted and recolored by Brytalearn. Static bony space, not recorded fluid motion.