# Speculative hypotheses — version4

S4-0001. A rotating shutter with logarithmic openings should turn constant-speed rotation into an exponential illumination ramp.
Test: Measure transmitted power versus angle.
Contrary outcome: Ramp deviates from the calculated profile.

S4-0002. A mechanically dithered slit should improve subpixel edge localization without increasing camera resolution.
Test: Compare calibrated edge estimates with dithering disabled.
Contrary outcome: Localization error does not improve.

S4-0003. A shallow capillary chessboard should store a binary image as trapped liquid occupancy after supply removal.
Test: Write patterns and image retention.
Contrary outcome: Neighboring cells spontaneously change state.

S4-0004. A pair of unequal flywheels should smooth torque reversals by exchanging angular momentum through a differential.
Test: Measure shaft torque pulses.
Contrary outcome: Peak reversal torque remains unchanged.

S4-0005. A pinwheel of hinged mirrors should encode incident-light direction into a unique reflected spot constellation.
Test: Calibrate source directions.
Contrary outcome: Constellations remain ambiguous.

S4-0006. A gravitational escapement should generate equal energy pulses despite changing drive weight over a bounded range.
Test: Measure pulse work.
Contrary outcome: Energy scales with drive weight.

S4-0007. A buckling strip should perform a mechanical exclusive-or operation when opposing inputs cancel its snap trigger.
Test: Apply all input pairs.
Contrary outcome: The truth table fails.

S4-0008. A passive optical cavity with a replaceable porous insert should distinguish gas adsorption from mirror drift through relaxation times.
Test: Apply controlled inert gas steps.
Contrary outcome: Relaxations remain inseparable.

S4-0009. A sliding support under a vibrating beam should converge toward a nodal position without external sensing.
Test: Track support position.
Contrary outcome: It stalls away from nodes.

S4-0010. A mechanically constrained growing crystal should rotate its growth front rather than accumulating one large bending defect.
Test: Image benign salt crystallization.
Contrary outcome: Defects accumulate without reorientation.

S4-0011. A free liquid-metal-free conducting ring should brake translational motion less than rotation near a magnet array.
Test: Measure both drag coefficients.
Contrary outcome: Selectivity is absent.

S4-0012. A shaped pulley should transform a sinusoidal input into a nearly triangular displacement waveform.
Test: Measure output against the kinematic design.
Contrary outcome: Waveform distortion remains large.

S4-0013. A granular hourglass should reduce timing drift when humidity changes through a freely breathing side chamber.
Test: Measure discharge times.
Contrary outcome: Humidity sensitivity remains unchanged.

S4-0014. A spring-loaded diffraction plate should select one of several optical paths at discrete pressure thresholds.
Test: Measure beam route versus pressure.
Contrary outcome: Paths overlap or skip unpredictably.

S4-0015. A braided ribbon should convert local damage into a remotely visible twist discontinuity.
Test: Cut controlled strands and map twist.
Contrary outcome: Damage remains mechanically invisible.

S4-0016. A passive evaporative mask should produce a stable cold pattern under uniform heating.
Test: Map temperature over time.
Contrary outcome: The pattern homogenizes rapidly.

S4-0017. A rotating transparent wedge should separate refractive-index drift from sample tilt through twice-per-turn harmonics.
Test: Vary both independently.
Contrary outcome: Harmonics do not separate perturbations.

S4-0018. A two-track mechanical integrator should estimate the product of applied force and displacement without electronic sensing.
Test: Compare indicated work with calibrated loading.
Contrary outcome: Output follows force or displacement alone.

S4-0019. A hinged collector should orient itself to maximize rainfall analogue capture under oblique droplets.
Test: Apply controlled spray angles.
Contrary outcome: Orientation reduces captured volume.

S4-0020. A geometric stop should make a torsion oscillator's period less amplitude-dependent.
Test: Measure period across initial angles.
Contrary outcome: Amplitude dependence remains equal.

S4-0021. A circular arrangement of communicating liquid cells should encode the spatial average of local pressure.
Test: Apply known cell pressures.
Contrary outcome: One cell dominates the output.

S4-0022. A mechanical minority gate should suppress isolated state errors in a three-cell bistable array.
Test: Flip one cell and release.
Contrary outcome: The array amplifies the error.

S4-0023. A slowly rotating porous disk should measure evaporation rate from the angular boundary between wet and dry sectors.
Test: Compare boundary angle with gravimetry.
Contrary outcome: Boundary is not rate-specific.

S4-0024. A passive optical sorter should route equal-size particles by refractive index through calibrated radiation pressure.
Test: Track inert calibration particles.
Contrary outcome: Routing follows size or convection alone.

S4-0025. A slack cable network should find a low-energy routing around an obstacle after repeated gentle shaking.
Test: Compare final paths with geometric constraints.
Contrary outcome: Paths remain history-dominated.

S4-0026. A flexible crystal-growth mold should reduce inclusions by retreating from the solidification front.
Test: Image transparent solidification analogues.
Contrary outcome: Retreat traps more liquid pockets.

S4-0027. A mechanical delay should reverse the order of two closely spaced displacement pulses through separate path lengths.
Test: Measure output pulse ordering.
Contrary outcome: Pulses merge or retain order.

S4-0028. A differential capillary scale should compare two liquid masses while rejecting uniform acceleration.
Test: Apply calibrated masses and base acceleration.
Contrary outcome: Acceleration bias remains dominant.

S4-0029. A rotating bristle cage should separate particles by rolling resistance at matched diameter.
Test: Measure exit-angle distributions.
Contrary outcome: Distributions overlap.

S4-0030. A soft reflective membrane should approximate a parabolic profile under a distributed magnetic-free pressure load.
Test: Measure surface shape.
Contrary outcome: Profile errors exceed a flat-membrane control.

S4-0031. A cam-driven shade should produce a prescribed daily thermal cycle under constant lamp power.
Test: Measure sample temperature history.
Contrary outcome: Thermal inertia defeats the target waveform.

S4-0032. A folded cable guide should route tension around an obstacle with less cross-talk between adjacent tendons.
Test: Measure induced neighbor motion.
Contrary outcome: Cross-talk remains equal.

S4-0033. A passive mechanical comparator should select the larger of two displacements through a floating wedge.
Test: Apply input pairs.
Contrary outcome: Output depends on input order.

S4-0034. A droplet-covered resonator should distinguish evaporation from lateral droplet motion through mode-shift ratios.
Test: Track known droplets.
Contrary outcome: Both perturbations yield identical ratios.

S4-0035. A loosely supported thin plate should damp torsion through support sliding while retaining low bending loss.
Test: Measure modal quality factors.
Contrary outcome: Both losses rise equally.

S4-0036. A shaped buoy should linearize displaced volume with immersion depth despite a constrained footprint.
Test: Measure buoyancy curve.
Contrary outcome: Linearity does not improve.

S4-0037. A mechanically indexed prism should reconstruct a spectrum using one intensity sensor.
Test: Measure calibrated spectral sources.
Contrary outcome: Reconstruction remains nonunique.

S4-0038. A rotating capillary array should concentrate nonvolatile solute at a selected radial band through timed evaporation.
Test: Map benign dye concentration.
Contrary outcome: Solute deposits broadly.

S4-0039. A spring-coupled pair of sliders should compute a weighted average position under quasistatic loading.
Test: Compare equilibrium with input positions.
Contrary outcome: Friction prevents the predicted average.

S4-0040. A roughened thermal contact should show reversible conductance changes when lateral vibration alters true contact area.
Test: Measure conductance and contact motion.
Contrary outcome: Changes are irreversible or unrelated to vibration.

S4-0041. A passive light funnel should reduce sensitivity to source angle through multiple internal reflections.
Test: Measure collected power versus angle.
Contrary outcome: Angular sensitivity remains equal.

S4-0042. A hinged granular bed should register peak lateral acceleration through a retained avalanche angle.
Test: Apply calibrated pulses.
Contrary outcome: Angle depends mostly on pulse duration.

S4-0043. A mechanically biased pendulum should estimate the skewness of a vibration waveform from its mean displacement.
Test: Apply zero-mean waveforms.
Contrary outcome: Mean displacement follows energy alone.

S4-0044. A fluidic bridge should compute a pressure difference using free-surface heights without net through-flow.
Test: Apply controlled pressures.
Contrary outcome: Capillary bias prevents differential calibration.

S4-0045. A perforated rolling pin should imprint a repeatable thickness map into a soft calibration film.
Test: Measure final thickness.
Contrary outcome: Slip destroys pattern repeatability.

S4-0046. A free optical mask should align to a beam's intensity centroid through low-power thermal recoil.
Test: Measure alignment in controlled conditions.
Contrary outcome: Ambient airflow determines position.

S4-0047. A compliant strain transformer should convert hydrostatic compression into measurable shear.
Test: Apply isotropic pressure.
Contrary outcome: Output is dominated by mounting asymmetry.

S4-0048. A floating index wheel should count discrete liquid aliquots through buoyancy-triggered advancement.
Test: Deliver calibrated drops.
Contrary outcome: Counts vary with aliquot spacing.

S4-0049. A passive geometric filter should pass long slender particles only when they approach aligned with flow.
Test: Track inert rods.
Contrary outcome: Tumbling defeats orientation selection.

S4-0050. A thermal memory element should distinguish heating order through two coupled expansion latches.
Test: Reverse the order of equal heat pulses.
Contrary outcome: Final states remain identical.

S4-0051. A suspended optical grid should report uniform pressure from an isotropic change in projected spacing.
Test: Apply calibrated pressure.
Contrary outcome: Spacing changes anisotropically from supports.

S4-0052. A mechanical amplifier should preserve force-displacement work while exchanging sensitivity for travel.
Test: Measure both input and output work.
Contrary outcome: Apparent gain requires unaccounted energy.

S4-0053. A recirculating droplet path should narrow arrival-time dispersion through speed-dependent path selection.
Test: Measure transit distributions.
Contrary outcome: Dispersion increases.

S4-0054. A passive friction balancer should equalize tension across two ropes by rocking between their contact patches.
Test: Measure paired tensions.
Contrary outcome: Rocking amplifies imbalance.

S4-0055. A rotating acoustic mirror should encode sound arrival direction as a modulation phase.
Test: Apply known source directions.
Contrary outcome: Phase is ambiguous under reflections.

S4-0056. A compliant thread guide should suppress sudden knot tightening through local length storage.
Test: Measure force during standardized entanglement.
Contrary outcome: Stored length does not lower peak force.

S4-0057. A low-pressure pneumatic abacus should retain multiple count states through independent trapped volumes.
Test: Write and read states.
Contrary outcome: Leakage couples neighboring states.

S4-0058. A hinged reflective surface should make thermal loading self-limiting by rotating toward edge-on incidence.
Test: Measure absorbed power.
Contrary outcome: Rotation increases absorbed power.

S4-0059. A passive porous sampler should collect equal time-weighted aliquots despite moderate flow-rate changes.
Test: Measure tracer averages.
Contrary outcome: Samples remain flow-weighted.

S4-0060. A mechanically stretched aperture should generate a known polarization-independent attenuation sequence.
Test: Measure transmission for orthogonal polarizations.
Contrary outcome: Attenuation depends strongly on polarization.

S4-0061. A shallow granular bowl should estimate vibration frequency from the radius of a stable particle orbit.
Test: Apply calibrated excitation.
Contrary outcome: Orbit radius is not frequency-specific.

S4-0062. A two-stage compliant lever should reject a common support displacement while amplifying differential motion.
Test: Move supports independently.
Contrary outcome: Common-mode leakage dominates.

S4-0063. A liquid-filled balance should integrate acceleration over short intervals through inertial redistribution.
Test: Compare output with known velocity changes.
Contrary outcome: Output follows peak acceleration alone.

S4-0064. A passive pulse stretcher should lengthen a pressure impulse without changing its integral appreciably.
Test: Measure inlet/outlet traces.
Contrary outcome: Pulse area is substantially lost.

S4-0065. A folded optical path should distinguish support translation from sample expansion using a shared reference reflection.
Test: Apply independent motions.
Contrary outcome: Signals remain confounded.

S4-0066. A mechanically selected flow path should make a passive thermometer readable through discrete liquid positions.
Test: Compare positions with reference temperature.
Contrary outcome: Hysteresis prevents unique readings.

S4-0067. A twisted plate should rotate its principal compliance direction continuously under axial tension.
Test: Measure stiffness tensor.
Contrary outcome: Direction remains fixed.

S4-0068. A porous particle lens should focus inert tracer trajectories through controlled transverse pressure gradients.
Test: Map particle positions.
Contrary outcome: Diffusion or wall capture erases focusing.

S4-0069. A mechanical voting network should tolerate one jammed input while retaining majority selection.
Test: Jam each input in turn.
Contrary outcome: The output locks incorrectly.

S4-0070. A capillary attenuator should reduce pressure noise while preserving the mean without an external reservoir.
Test: Measure pressure spectrum.
Contrary outcome: Mean pressure shifts significantly.

S4-0071. A rotating optical grating should separate wavelength change from beam-pointing drift through angular sidebands.
Test: Vary both independently.
Contrary outcome: Sidebands remain degenerate.

S4-0072. A compliant storage spool should release nearly constant cable tension as its winding radius changes.
Test: Measure payout force.
Contrary outcome: Tension follows winding radius.

S4-0073. A passive evaporative timer should reset completely after rewetting a calibrated porous region.
Test: Measure repeated timing cycles.
Contrary outcome: Drying history changes timing permanently.

S4-0074. A mechanically asymmetric resonator should estimate impulse polarity from the phase of its first rebound.
Test: Apply signed impulses.
Contrary outcome: Phase is not polarity-specific.

S4-0075. A liquid-driven escapement should meter equal volumes despite moderate viscosity changes.
Test: Measure aliquot volumes.
Contrary outcome: Viscosity alters volume substantially.

S4-0076. A folded pressure membrane should provide an absolute position code through sequential visible edge crossings.
Test: Calibrate pressure and code.
Contrary outcome: Code skips or reverses.

S4-0077. A passive optical sensor should detect torsion through shadow rotation while rejecting axial extension.
Test: Apply both deformations.
Contrary outcome: Extension creates comparable rotation.

S4-0078. A moving thermal contact should approximate a prescribed nonlinear conductance curve through shaped overlap.
Test: Measure conductance versus travel.
Contrary outcome: Contact resistance dominates geometry.

S4-0079. A granular analog accumulator should add successive equal masses into repeatable discrete height states.
Test: Dose calibrated masses.
Contrary outcome: States depend strongly on pouring history.

S4-0080. A compliant force divider should maintain a fixed output-force ratio despite unequal output displacement.
Test: Measure paired outputs.
Contrary outcome: Ratio varies with travel.

S4-0081. A capillary pressure reference should survive transport vibration through a geometrically pinned gas volume.
Test: Measure calibration before and after shaking.
Contrary outcome: Gas rearrangement shifts zero.

S4-0082. A rotating liquid wedge should produce an optical path change proportional to cumulative angular displacement.
Test: Measure phase versus rotations.
Contrary outcome: Path resets or drifts unpredictably.

S4-0083. A mechanical binary search linkage should identify an object's size interval using successive passive contacts.
Test: Test calibration blocks.
Contrary outcome: Contact order is ambiguous.

S4-0084. A suspended thin shell should convert an acoustic pulse into a visible traveling crease.
Test: Image safe sound excitation.
Contrary outcome: Only diffuse vibration appears.

S4-0085. A passive membrane sampler should distinguish dissolved inert tracer from suspended particles through separate time constants.
Test: Measure uptake histories.
Contrary outcome: Both signals share indistinguishable kinetics.

S4-0086. A crossed pulley system should compute a displacement difference with reduced sensitivity to cable stretch.
Test: Apply known inputs and tensions.
Contrary outcome: Stretch error remains large.

S4-0087. A thermal shutter should discriminate steady radiation from equal-energy flashes through delayed mechanical feedback.
Test: Apply matched-energy illumination.
Contrary outcome: Both trigger identically.

S4-0088. A flexible diffraction surface should expose a hidden support defect through localized fringe dislocation.
Test: Introduce known support gaps.
Contrary outcome: Fringes respond globally without localization.

S4-0089. A buoyant mechanical comparator should select the denser of two small liquid samples without measuring volume optically.
Test: Use known densities.
Contrary outcome: Volume mismatch dominates selection.

S4-0090. A pneumatic oscillator should encode reservoir volume in its duty cycle while rejecting inlet pressure drift.
Test: Measure timing across conditions.
Contrary outcome: Duty cycle remains pressure-sensitive.

S4-0091. A rolling magnetic-free encoder should count path length through alternating geometric contacts.
Test: Compare against known trajectories.
Contrary outcome: Slip creates cumulative error.

S4-0092. A passive liquid switch should reject symmetric pressure oscillations but respond to a small mean offset.
Test: Measure threshold under noisy pressure.
Contrary outcome: Oscillations cause false switching.

S4-0093. A compliant analog multiplier should make output displacement proportional to the product of two bounded input displacements.
Test: Calibrate a two-dimensional input grid.
Contrary outcome: Cross-terms dominate the intended product.

S4-0094. A deformable reflective cavity should estimate local pressure anisotropy through two independent image distortions.
Test: Apply calibrated biaxial pressure.
Contrary outcome: Distortions cannot separate components.

S4-0095. A porous evaporation reference should reduce humidity-induced drift in a capillary dosing device.
Test: Measure doses across humidity.
Contrary outcome: Compensation fails.

S4-0096. A mechanical parity checker should flag one missed step in a cyclic indexing train.
Test: Introduce controlled skipped steps.
Contrary outcome: Checker returns a false normal state.

S4-0097. A floating prism should report liquid density through angular rather than vertical displacement.
Test: Calibrate known densities.
Contrary outcome: Contact-line hysteresis masks density response.

S4-0098. A passive tension network should solve a constrained centering task after one anchor moves.
Test: Track equilibrium position.
Contrary outcome: Friction traps incorrect equilibria.

S4-0099. A thermal expansion wave should advance a mechanical state boundary by exactly one cell per full heat cycle.
Test: Image repeated cycles.
Contrary outcome: Boundary skips or stalls.

S4-0100. A capillary optical display should retain a readable pressure threshold pattern after electrical-free recording.
Test: Apply calibrated histories.
Contrary outcome: Pattern relaxes before useful readout.

S4-0101. A phase-stepped shadow mask should estimate translucent-sheet thickness while rejecting uniform illumination drift.
Test: Measure calibrated sheets.
Contrary outcome: Thickness estimates remain intensity-dependent.

S4-0102. A vibrating transparent wedge should separate viscosity from refractive index through optical phase and mechanical lag.
Test: Test known benign liquids.
Contrary outcome: The two inferred properties remain confounded.

S4-0103. A passive interferometer should reveal a loose mount through intermittent phase jumps under subresonant shaking.
Test: Compare controlled looseness levels.
Contrary outcome: Jumps occur equally in tight mounts.

S4-0104. A rough optical surface should become more specular when tensile strain aligns its microscopic ridges.
Test: Measure angular scattering during stretch.
Contrary outcome: Scattering remains isotropic.

S4-0105. A patterned opaque grid should expose lens decentering through unequal corner magnification ratios.
Test: Introduce calibrated lens offsets.
Contrary outcome: Ratios are dominated by camera tilt.

S4-0106. A translating liquid prism should compensate beam steering caused by vessel tilt.
Test: Measure output angle across tilt.
Contrary outcome: Compensation worsens pointing error.

S4-0107. A flexible optical stop should cap image blur by reducing aperture during vibration.
Test: Measure blur and throughput.
Contrary outcome: Blur reduction is explained solely by exposure loss.

S4-0108. A mechanically tunable diffraction gap should retain its wavelength calibration after uniform support expansion.
Test: Measure known spectral lines during heating.
Contrary outcome: Calibration drifts as in fixed gaps.

S4-0109. A suspended retroreflector should reject slow support rotation while following fast translation.
Test: Apply independent motions.
Contrary outcome: Rotation leaks into the translational readout.

S4-0110. A capillary film should generate a reproducible optical phase ramp during constant-rate drainage.
Test: Measure interferometric phase.
Contrary outcome: Contact-line jumps destroy the ramp.

S4-0111. A rotating crossed-polarizer mount should detect stress anisotropy independently of sample thickness using harmonic ratios.
Test: Test calibrated transparent plates.
Contrary outcome: Thickness changes mimic anisotropy.

S4-0112. A compliant lens spacer should reduce focus hysteresis by rolling rather than sliding at its seats.
Test: Measure focus through displacement cycles.
Contrary outcome: Rolling seats add comparable hysteresis.

S4-0113. A patterned mirror should distinguish a uniform coating loss from sparse scratches through speckle correlation decay.
Test: Damage controlled samples.
Contrary outcome: Correlation decay is not damage-specific.

S4-0114. A free-standing optical slit should indicate humidity through width change while rejecting uniform temperature expansion.
Test: Calibrate both variables.
Contrary outcome: Thermal cross-sensitivity prevents humidity inference.

S4-0115. A ring-shaped illumination pattern should improve detection of central lens contamination through radial contrast redistribution.
Test: Apply known inert spots.
Contrary outcome: Detection does not improve against uniform illumination.

S4-0116. A passive optical alignment target should encode out-of-plane tilt through a color-independent geometric parallax.
Test: Measure target images at known angles.
Contrary outcome: Depth and tilt remain ambiguous.

S4-0117. A liquid meniscus should form a tunable cylindrical lens when constrained by two parallel moving rails.
Test: Measure focal length versus spacing.
Contrary outcome: Contact hysteresis prevents repeatable tuning.

S4-0118. A flexible optical diaphragm should change scattering before its central aperture closes.
Test: Track transmission and scattering under load.
Contrary outcome: Closure gives no advance scattering signal.

S4-0119. A slowly translated diffuser should average coherent speckle without appreciable image smear.
Test: Measure contrast and resolution.
Contrary outcome: Speckle reduction requires substantial blur.

S4-0120. A stepped transparent reference should expose spatial temperature gradients through differential beam deflection.
Test: Apply known gradients.
Contrary outcome: Deflection follows support bending instead.

S4-0121. A passive beam splitter should maintain its split ratio under small angular misalignment through paired opposite wedges.
Test: Measure ratio versus angle.
Contrary outcome: Angular sensitivity is unchanged.

S4-0122. A mechanically coupled pair of mirrors should cancel equal support rotations while amplifying differential rotations.
Test: Apply calibrated rotations.
Contrary outcome: Common-mode cancellation fails.

S4-0123. A vibrating aperture should estimate a beam's local intensity gradient from its first harmonic.
Test: Scan known beam profiles.
Contrary outcome: Harmonic output follows intensity alone.

S4-0124. A capillary liquid lens should reject small pressure noise when its contact line sits in a geometric recess.
Test: Measure focal jitter.
Contrary outcome: Recesses increase stick-slip jitter.

S4-0125. A folded optical scale should resolve extension and shear through independent parallax shifts.
Test: Apply calibrated two-axis motion.
Contrary outcome: Signals are not independently recoverable.

S4-0126. A passive scattering cavity should measure particle concentration through escape-time changes rather than absolute brightness.
Test: Test inert particle standards.
Contrary outcome: Timing changes are dominated by wall loss.

S4-0127. A flexible reflective ribbon should indicate twist density through a spatial sequence of glints.
Test: Apply known torsion distributions.
Contrary outcome: Glint sequence cannot localize twist.

S4-0128. A paired shadow sensor should detect transparent bubbles through edge displacement without relying on absolute contrast.
Test: Pass calibrated bubbles.
Contrary outcome: Small bubbles remain indistinguishable from illumination noise.

S4-0129. A rotating refractive plate should cancel periodic image distortion when phased against a vibrating support.
Test: Measure image motion.
Contrary outcome: Correction adds larger harmonics.

S4-0130. A compliant optical coupler should retain transmission during repeated axial separation by preserving a liquid bridge.
Test: Measure transmission cycles.
Contrary outcome: Bridge rupture causes persistent loss.

S4-0131. A passive optical ring should detect local surface wetting through azimuthally uneven scattering.
Test: Wet known sectors.
Contrary outcome: Scattering changes are spatially nonlocal.

S4-0132. A thermally driven optical wedge should scan a beam monotonically during a finite heating pulse.
Test: Measure angle-time response.
Contrary outcome: Angle reversals prevent useful scanning.

S4-0133. A textured transparent dome should distinguish internal fogging from external droplets through scattering-angle ratios.
Test: Apply conditions independently.
Contrary outcome: Angular signatures overlap.

S4-0134. A mechanically stretched moire mask should provide a nonlinear displacement scale with a readable high-sensitivity region.
Test: Calibrate displacement.
Contrary outcome: Fringe ambiguity erases the sensitivity gain.

S4-0135. A passive optical shutter should reject oblique stray light while opening for near-normal illumination through radiation-heated geometry.
Test: Measure angular response.
Contrary outcome: Thermal diffusion removes angular selectivity.

S4-0136. A transparent flexure should estimate local strain from the angular shift of an embedded void image.
Test: Load calibrated specimens.
Contrary outcome: Void-image shift is dominated by rigid motion.

S4-0137. A paired cavity path should distinguish gas-pressure changes from window deformation through opposite optical sensitivities.
Test: Vary pressure and mechanical window loading.
Contrary outcome: Responses remain degenerate.

S4-0138. A rotating optical roughness probe should reduce sensitivity to surface color by using normalized angular harmonics.
Test: Test equally rough colored standards.
Contrary outcome: Color still dominates the estimate.

S4-0139. A flexible prism array should encode a pressure map into the spacing of reflected spots.
Test: Apply known spatial loads.
Contrary outcome: Mechanical cross-talk destroys localization.

S4-0140. A passive beam-centering cone should preserve alignment after small support impacts through geometric reseating.
Test: Measure pointing before and after shocks.
Contrary outcome: Reseating shifts the optical axis.

S4-0141. A capillary film thickness gauge should distinguish drainage from evaporation using two spatially separated interference signals.
Test: Control both processes.
Contrary outcome: Both signals respond identically.

S4-0142. A suspended lens should reduce thermal decentering when its support tension redistributes through a common ring.
Test: Measure center position during asymmetric heating.
Contrary outcome: Redistribution amplifies decentering.

S4-0143. A patterned diffraction membrane should reveal contact onset through disappearance of a selected diffraction order.
Test: Press known flat contacts.
Contrary outcome: Order loss precedes or lags contact unpredictably.

S4-0144. A mechanically scanned optical edge should detect tiny refractive-index discontinuities through asymmetric deflection timing.
Test: Scan known liquid boundaries.
Contrary outcome: Timing asymmetry is below drift.

S4-0145. A passive mirror stack should expose individual layer displacement through separate echo-like optical path peaks.
Test: Move known layers.
Contrary outcome: Peaks cannot be uniquely assigned.

S4-0146. A rotating liquid cell should separate sedimentation from aggregation by the reversal symmetry of scattering patterns.
Test: Image inert suspensions.
Contrary outcome: Reversal does not distinguish mechanisms.

S4-0147. A compliant optical mount should reduce vibration-induced focus modulation through an inertial counter-motion.
Test: Measure focal jitter.
Contrary outcome: Counter-motion increases modulation.

S4-0148. A passive grating pair should estimate differential expansion between bonded layers.
Test: Heat calibrated bilayers.
Contrary outcome: Grating shifts cannot separate bending from expansion mismatch.

S4-0149. A shadow-based fluid interface sensor should reject vessel-wall refraction through opposing viewing paths.
Test: Measure known interface heights.
Contrary outcome: Wall distortions remain dominant.

S4-0150. A mechanically modulated reflector should distinguish coherent stray reflections from diffuse target return through phase locking.
Test: Test known reflectors.
Contrary outcome: Both returns lock identically.

S4-0151. A transparent corrugated support should reveal local contact pressure through gap-dependent optical fringes.
Test: Calibrate pressure maps.
Contrary outcome: Fringes are too history-dependent to calibrate.

S4-0152. A passive optical trap analogue should confine a floating reflector through intensity-dependent thermal surface flow.
Test: Track equilibrium and tracer motion.
Contrary outcome: Bulk convection explains all confinement.

S4-0153. A rotating aperture pair should reconstruct a two-dimensional beam centroid from one photodetector.
Test: Compare known beam positions.
Contrary outcome: Centroid reconstruction is ambiguous.

S4-0154. A liquid-filled optical wedge should sense orientation while rejecting moderate liquid-volume changes.
Test: Vary angle and filling independently.
Contrary outcome: Volume drift mimics orientation.

S4-0155. A folded reflective path should expose local cable strain through differential glint timing during rotation.
Test: Apply known strain sections.
Contrary outcome: Timing cannot localize strain.

S4-0156. A compliant light guide should retain output direction during input bending through a free internal sleeve.
Test: Measure pointing and throughput.
Contrary outcome: Sleeve friction prevents compensation.

S4-0157. A passive diffraction target should estimate object distance through the ratio of near and far pattern scales.
Test: Image calibrated distances.
Contrary outcome: Ratio remains dependent on source wavelength.

S4-0158. A vibrating optical window should shed droplets at lower amplitude when driven in a traveling-wave mode.
Test: Measure clearing thresholds.
Contrary outcome: Standing-wave drive clears equally well.

S4-0159. A shaped optical cavity should reduce concentration-readout sensitivity to bubble position.
Test: Move controlled bubbles.
Contrary outcome: Position remains a major error source.

S4-0160. A floating reflective plate should report interfacial tension gradients through a uniquely oriented deformation pattern.
Test: Apply controlled gradients.
Contrary outcome: Flow-induced bending produces the same pattern.

S4-0161. A mechanical aperture iris should retain a fixed center during asymmetric loading through a floating linkage.
Test: Measure aperture centroid.
Contrary outcome: Centroid shifts significantly.

S4-0162. A transparent elastic wedge should distinguish compressive load from temperature through image shear and magnification.
Test: Calibrate both variables.
Contrary outcome: Signals remain inseparable.

S4-0163. A passive optical reference ring should reveal camera focus drift through a known blur asymmetry.
Test: Defocus controlled images.
Contrary outcome: Asymmetry is not monotonic with defocus.

S4-0164. A capillary optical attenuator should change transmission monotonically with stored liquid volume.
Test: Dose calibrated volumes.
Contrary outcome: Meniscus jumps create nonmonotonic output.

S4-0165. A torsionally compliant mirror mount should reject axial thermal expansion without changing beam angle.
Test: Heat the axial support.
Contrary outcome: Pointing drift remains comparable.

S4-0166. A rotating speckle target should reveal mechanical backlash through phase discontinuities of its correlation signal.
Test: Introduce calibrated backlash.
Contrary outcome: Discontinuities reflect illumination drift instead.

S4-0167. A flexible shadow mask should encode local curvature through changes in penumbra width.
Test: Bend known shapes.
Contrary outcome: Penumbra depends mainly on source distance.

S4-0168. A passive optical cavity should detect a fluid leak through delayed recovery after a controlled pressure step.
Test: Introduce calibrated leaks.
Contrary outcome: Recovery cannot separate leakage from thermal drift.

S4-0169. A folded optical lever should amplify displacement while preserving a compact detector spot excursion.
Test: Measure sensitivity and range.
Contrary outcome: Amplification forces equal range loss.

S4-0170. A patterned reflective sphere should estimate three-axis orientation from a single reflected light field.
Test: Calibrate known orientations.
Contrary outcome: Symmetries create irreducible ambiguity.

S4-0171. A liquid meniscus array should equalize focal lengths through shared pressure despite fabrication variation.
Test: Measure lens focal distribution.
Contrary outcome: Geometry variation dominates shared pressure.

S4-0172. A mechanically gated optical channel should reject slowly drifting stray light while passing rapid sample modulation.
Test: Measure signal-to-background.
Contrary outcome: Gate attenuates desired modulation equally.

S4-0173. A transparent soft contact should reveal incipient slip through a moving fringe front before gross motion.
Test: Measure force and optical fringes.
Contrary outcome: Front appears only after slip.

S4-0174. A rotating filter wheel should estimate source drift during a spectral scan by interleaved repeated reference sectors.
Test: Test drifting sources.
Contrary outcome: Correction fails for realistic drift rates.

S4-0175. A passive optical strain loop should detect strain concentration through loss of rotational symmetry in its diffraction field.
Test: Apply localized loads.
Contrary outcome: Pattern changes are not concentration-specific.

S4-0176. A compliant prism holder should preserve optical path length during small lateral translations.
Test: Measure phase and position.
Contrary outcome: Path-length error remains linear in translation.

S4-0177. A capillary display should record the sign of a temperature gradient through opposite branch wetting.
Test: Reverse controlled gradients.
Contrary outcome: Branch selection does not reverse.

S4-0178. A shadow sensor should estimate particle aspect ratio from two timed orthogonal projections.
Test: Pass calibrated inert shapes.
Contrary outcome: Rotation makes aspect ratio ambiguous.

S4-0179. A mechanically strained diffuser should switch scattering anisotropy reversibly.
Test: Measure angular distributions through cycles.
Contrary outcome: Anisotropy does not follow strain.

S4-0180. A passive optical alignment sleeve should center an inserted lens through sequential three-point contact.
Test: Measure decentering versus insertion depth.
Contrary outcome: Contacts lock the lens off-center.

S4-0181. A liquid-prism balance should compare two small pressures through a differential image displacement.
Test: Apply known pressure pairs.
Contrary outcome: Common pressure shifts dominate the signal.

S4-0182. A folded diffraction strip should expose uneven tensile loading through asymmetric order splitting.
Test: Apply calibrated load distributions.
Contrary outcome: Splitting cannot distinguish uneven load from bending.

S4-0183. A rotating optical cavity should estimate surface reflectance from decay timing while averaging spatial defects.
Test: Test known coatings.
Contrary outcome: Rotation adds timing artifacts larger than the benefit.

S4-0184. A compliant optical window should reduce stress birefringence through a sliding perimeter support.
Test: Measure polarization distortion under pressure.
Contrary outcome: Sliding does not reduce birefringence.

S4-0185. A passive image stabilizer should cancel support roll through a gravity-biased prism.
Test: Measure image rotation during slow roll.
Contrary outcome: Prism friction prevents compensation.

S4-0186. A capillary film should preserve an optical fiducial during temporary surface drying through a protected liquid reservoir.
Test: Cycle drying.
Contrary outcome: Fiducial disappears irreversibly.

S4-0187. A vibrating grating should resolve two nearby wavelengths through differential modulation phase.
Test: Test calibrated spectral pairs.
Contrary outcome: Phases remain indistinguishable.

S4-0188. A transparent contact pad should estimate normal load from enclosed-air fringe area without needing uniform illumination.
Test: Calibrate force under brightness changes.
Contrary outcome: Fringe area remains intensity-dependent.

S4-0189. A mechanically switched optical path should expose detector nonlinearity through equal-path signal sums.
Test: Measure calibrated intensity combinations.
Contrary outcome: Switching artifacts obscure nonlinearity.

S4-0190. A passive optical wedge sensor should distinguish an adhered particle from a scratch through response to small sample rotation.
Test: Test known defects.
Contrary outcome: Rotation signatures overlap.

S4-0191. A floating optical reference should follow liquid level while rejecting surface waves through distributed buoyancy.
Test: Measure height spectra.
Contrary outcome: Wave rejection causes excessive level lag.

S4-0192. A flexible diffraction ribbon should estimate torsion direction even after partial surface damage.
Test: Damage known sectors.
Contrary outcome: Direction becomes ambiguous.

S4-0193. A rotating aperture should measure droplet fall speed from harmonic timing without knowing optical contrast.
Test: Compare against high-speed tracking.
Contrary outcome: Contrast variation biases speed.

S4-0194. A capillary window should reduce condensation fog by collecting droplets into an optically inactive edge channel.
Test: Measure central transmission.
Contrary outcome: Droplets remain in the active region.

S4-0195. A compliant reflective dome should magnify small pressure differences through a change in focal distance.
Test: Calibrate pressure-focus response.
Contrary outcome: Instability prevents monotonic calibration.

S4-0196. A passive optical path should reveal a hidden air inclusion through an asymmetric response to pressure cycling.
Test: Test known inclusions.
Contrary outcome: Response matches inclusion-free controls.

S4-0197. A mechanically coupled grating pair should compensate humidity-induced swelling while preserving tensile sensitivity.
Test: Calibrate humidity and strain.
Contrary outcome: Compensation removes useful strain response.

S4-0198. A transparent shear cell should expose wall slip through different motion of surface and interior optical markers.
Test: Measure controlled slip.
Contrary outcome: Marker motion cannot resolve the difference.

S4-0199. A rotating optical baffle should reduce angle-dependent stray reflections without reducing target throughput proportionally.
Test: Measure both paths.
Contrary outcome: Throughput loss erases the benefit.

S4-0200. A flexible optical scale should retain absolute position decoding after one local tear through redundant unequal marks.
Test: Cut known regions.
Contrary outcome: Decoding becomes ambiguous.

S4-0201. A prestressed perforated sheet should divert a growing tear around a protected central region.
Test: Track cracks under controlled tension.
Contrary outcome: Cracks cross the protected region equally often.

S4-0202. A woven laminate should arrest delamination when transverse loops tighten under separation.
Test: Measure crack length and loop tension.
Contrary outcome: Loops fail to arrest growth.

S4-0203. A hollow strut should retain load after local crushing through outward deployment of an internal fold.
Test: Compress instrumented struts.
Contrary outcome: Fold deployment causes global collapse.

S4-0204. A smooth stiffness gradient should reduce reflected stress pulses at a rigid-soft junction.
Test: Measure wave amplitudes.
Contrary outcome: Reflection equals an abrupt junction.

S4-0205. A layered elastic strip should reveal a buried debond through a reversal of surface curvature under bending.
Test: Image known defects.
Contrary outcome: Curvature sign is not defect-specific.

S4-0206. A notched lattice should transfer overload into a replaceable sacrificial path before its precision core deforms.
Test: Measure path forces.
Contrary outcome: Core deformation begins first.

S4-0207. A braided shell should resist crack opening by rotating fibers into the tensile direction.
Test: Track fiber angle and crack width.
Contrary outcome: Rotation does not restrain opening.

S4-0208. A corrugated plate should recover from indentation through sequential ridge inversion.
Test: Measure residual shape.
Contrary outcome: Inversions remain permanently trapped.

S4-0209. A compliant interface should reduce fretting wear by converting sliding into distributed elastic shear.
Test: Measure wear and local motion.
Contrary outcome: Wear is unchanged at matched load.

S4-0210. A patterned void array should make an impact pulse split into two delayed arrivals.
Test: Measure transmitted waveforms.
Contrary outcome: Only one broadened pulse appears.

S4-0211. A folded beam should reveal accumulated plasticity through a changed order of crease activation.
Test: Cycle beyond yield and image.
Contrary outcome: Activation order remains unchanged.

S4-0212. A constrained foam should expand laterally into a reserve pocket and delay densification.
Test: Measure force and volume distribution.
Contrary outcome: Reserve storage does not delay force rise.

S4-0213. A self-contacting lattice should suppress a propagating buckling front after a chosen strain.
Test: Image compression.
Contrary outcome: Front crosses contact region unimpeded.

S4-0214. A prestressed cable web should redistribute a cut strand's load without cascading failure.
Test: Cut controlled strands.
Contrary outcome: Neighboring strands fail sequentially.

S4-0215. A double-curved shell should concentrate recoverable strain away from a fragile mounted component.
Test: Measure full-field strain.
Contrary outcome: Mount remains the strain maximum.

S4-0216. A rotating hinge array should tune wave speed without changing total mass.
Test: Measure travel times at fixed configurations.
Contrary outcome: Travel time remains unchanged.

S4-0217. A porous elastic block should distinguish shear from compression through directional air expulsion.
Test: Measure outlet flows.
Contrary outcome: Flow signatures overlap.

S4-0218. A layered spring should reduce creep by allowing reversible interlayer rolling.
Test: Measure long-term deflection.
Contrary outcome: Rolling adds comparable creep.

S4-0219. A thin membrane should stop tear propagation when a slack boundary is recruited into tension.
Test: Image tear and boundary motion.
Contrary outcome: Recruitment accelerates the tear.

S4-0220. A reentrant lattice should retain shear stiffness while softening its axial response after contact release.
Test: Measure stiffness tensor.
Contrary outcome: Shear stiffness drops equally.

S4-0221. A hollow beam should reveal internal wall collapse through a new subharmonic vibration component.
Test: Compress and measure spectra.
Contrary outcome: Subharmonic appears only after global failure.

S4-0222. A graded hinge chain should localize deformation at a movable rather than fixed joint.
Test: Change boundary constraints and image.
Contrary outcome: The same joint always dominates.

S4-0223. A twisted shell should convert axial impact into distributed torsional deformation.
Test: Measure strain and axial force.
Contrary outcome: Torsion fails to reduce force concentration.

S4-0224. A loose interlayer should interrupt high-frequency stress transmission while preserving static stiffness.
Test: Measure dynamic and static transfer.
Contrary outcome: Isolation requires large static compliance.

S4-0225. A corrugated seal support should maintain contact after local edge damage through neighboring-ridge recruitment.
Test: Measure leak pressure.
Contrary outcome: Damage creates an unrecoverable leak.

S4-0226. A woven tube should resist kinking by shifting braid crossings before wall collapse.
Test: Image bending.
Contrary outcome: Crossing motion does not delay kinking.

S4-0227. A patterned compressible layer should equalize pressure beneath an uneven rigid plate.
Test: Map contact force.
Contrary outcome: Pressure remains concentrated at high spots.

S4-0228. A prestressed arch array should show a reproducible energy gap between isolated and collective snapping.
Test: Measure snap work.
Contrary outcome: Collective work equals independent sums.

S4-0229. A soft inclusion near a crack should blunt its tip through reversible cavity expansion.
Test: Image tip shape.
Contrary outcome: Expansion increases crack-tip concentration.

S4-0230. A segmented protective layer should reduce damage by allowing neighboring segments to rotate out of plane.
Test: Measure impact damage.
Contrary outcome: Rotation exposes the substrate.

S4-0231. A folded annulus should absorb torsional overload through a traveling crease instead of one local hinge.
Test: Image strain.
Contrary outcome: Strain remains localized.

S4-0232. A porous elastomer should recover thickness faster when decompression opens temporary air-return channels.
Test: Measure rebound time.
Contrary outcome: Channels provide no recovery advantage.

S4-0233. A curved laminated beam should indicate bond degradation through altered twist-bend coupling.
Test: Control bond area and measure response.
Contrary outcome: Coupling remains insensitive.

S4-0234. A lattice with sliding nodes should redistribute deformation under a moving load without residual drift.
Test: Track nodes over cycles.
Contrary outcome: Nodes ratchet irreversibly.

S4-0235. A hollow pad should retain cushioning after puncture through isolated fluid-free cells.
Test: Puncture selected cells and impact.
Contrary outcome: Cushioning collapses globally.

S4-0236. A tensioned sheet should suppress wrinkles when local edge guides permit controlled tangential sliding.
Test: Image wrinkle amplitude.
Contrary outcome: Sliding increases wrinkling.

S4-0237. A spring network should display a measurable directional wave-speed difference after asymmetric prestressing.
Test: Measure bidirectional pulses.
Contrary outcome: Difference vanishes after correcting tension.

S4-0238. A sacrificial folded collar should protect a reusable fastener from overload by unfolding first.
Test: Measure deformation sequence.
Contrary outcome: Fastener yields before unfolding.

S4-0239. A granular-free damping layer should dissipate energy through reversible contact rearrangement of interlocking tiles.
Test: Measure cycles and tile motion.
Contrary outcome: Dissipation requires permanent damage.

S4-0240. A curved crack stop should redirect a tear into a low-energy peripheral path.
Test: Image competing paths.
Contrary outcome: Tear continues toward the protected interior.

S4-0241. A porous lattice should retain permeability under shear through coordinated cell rotation.
Test: Measure flow versus shear.
Contrary outcome: Pores close rapidly.

S4-0242. A flexural wave should reveal an internal fluid pocket through a delayed dispersive tail.
Test: Test known inclusions.
Contrary outcome: Tail is indistinguishable from support reflections.

S4-0243. A mechanically locked fold should prevent creep-driven shape change under sustained load.
Test: Measure long-term geometry.
Contrary outcome: Locked folds drift equally.

S4-0244. A perforated shell should distribute impact across a wider area when holes open by rotation.
Test: Map strain.
Contrary outcome: Hole opening localizes damage.

S4-0245. A compliant joint should convert assembly mismatch into harmless internal sliding rather than frame distortion.
Test: Measure alignment under offsets.
Contrary outcome: Frame distortion remains unchanged.

S4-0246. A prestretched membrane should recover its original tension after local heating through a sliding perimeter reservoir.
Test: Measure tension after cooling.
Contrary outcome: Tension changes permanently.

S4-0247. A hollow lattice should expose localized yielding through a visible change in cell aspect ratio.
Test: Load controlled regions.
Contrary outcome: Aspect ratio is not yield-specific.

S4-0248. A folded strip should support two stable curvatures with nearly equal stored energy.
Test: Measure snap work in both directions.
Contrary outcome: Energy asymmetry remains large.

S4-0249. A woven panel should attenuate an impact more strongly when crossings unlock sequentially.
Test: Measure transmitted impulse.
Contrary outcome: Unlocking occurs simultaneously or adds no attenuation.

S4-0250. A compressible rim should prevent a central membrane from striking a backing plate during overload.
Test: Image gap and force.
Contrary outcome: Central contact occurs first.

S4-0251. A tension-only brace network should recover stiffness after one slack cable retensions.
Test: Measure load paths.
Contrary outcome: Retensioning fails to restore stiffness.

S4-0252. A curved porous beam should expel trapped gas predictably during bending.
Test: Measure gas volume and curvature.
Contrary outcome: Expulsion is history-dependent.

S4-0253. A slit shell should redistribute local pressure through edge opening without losing global stability.
Test: Measure shape and force.
Contrary outcome: Opening triggers collapse.

S4-0254. A layered flexure should isolate rotation from translation through equal-and-opposite interlayer shear.
Test: Measure motion matrix.
Contrary outcome: Cross-coupling remains large.

S4-0255. A soft lattice should delay strain localization when its cell orientation varies continuously.
Test: Map strain fields.
Contrary outcome: Localization is unchanged.

S4-0256. A hollow impact shield should recover through air intake only after its contact force falls.
Test: Measure force and chamber pressure.
Contrary outcome: Premature refill increases rebound.

S4-0257. A woven hinge should provide a torque plateau through progressive crossing release.
Test: Measure torque-angle curve.
Contrary outcome: No stable plateau appears.

S4-0258. A folded shell should encode overload direction in its final crease pattern.
Test: Apply calibrated directional loads.
Contrary outcome: Patterns remain ambiguous.

S4-0259. A curved interface should reduce adhesive-free joint slip by increasing normal force under shear.
Test: Measure force components.
Contrary outcome: Shear decreases normal contact.

S4-0260. A prestressed plate should steer flexural waves around a mounted mass through local tension redistribution.
Test: Map wave fields.
Contrary outcome: Mass shadow remains unchanged.

S4-0261. A compressible lattice should distinguish distributed load from point load through different stable deformation modes.
Test: Apply matched total forces.
Contrary outcome: Final modes are identical.

S4-0262. A hollow torsion bar should limit transmitted torque through reversible cross-section ovalization.
Test: Measure torque and shape.
Contrary outcome: Ovalization leads directly to failure.

S4-0263. A slotted membrane should retain a central aperture shape under biaxial stretch.
Test: Image aperture geometry.
Contrary outcome: Aperture distorts strongly.

S4-0264. A layered protective pad should reduce repeated-impact degradation by allowing internal layers to recenter.
Test: Measure force over impacts.
Contrary outcome: Recentering does not preserve performance.

S4-0265. A braided strip should reveal longitudinal tension through transverse contraction with low bending sensitivity.
Test: Calibrate combined loads.
Contrary outcome: Bending masks tension signal.

S4-0266. A folding lattice should increase thermal-contact area under compression without a large force rise.
Test: Measure contact and force.
Contrary outcome: Contact gain requires high force.

S4-0267. A soft inclusion network should guide reversible buckling away from geometric imperfections.
Test: Introduce known defects and compress.
Contrary outcome: Defects still determine the mode.

S4-0268. A hollow ring should retain circularity under point loading through internal rolling supports.
Test: Measure shape.
Contrary outcome: Supports create new lobes.

S4-0269. A woven shell should damp torsional vibration through reversible crossing slip while retaining axial stiffness.
Test: Measure modal losses.
Contrary outcome: Axial stiffness falls substantially.

S4-0270. A curved beam should produce a mechanical warning click before reaching its elastic stability limit.
Test: Measure sound and force.
Contrary outcome: Click occurs after instability.

S4-0271. A segmented membrane backing should limit the area affected by a local puncture.
Test: Map deformation after puncture.
Contrary outcome: Damage propagates across segments.

S4-0272. A prestressed lattice should regain stiffness when unloaded through a different geometric path.
Test: Measure hysteresis and final stiffness.
Contrary outcome: Recovery requires external resetting.

S4-0273. A folded tube should resist crushing from one direction while remaining compliant orthogonally.
Test: Measure directional collapse loads.
Contrary outcome: Directional contrast is absent.

S4-0274. A porous spring should measure compression rate through the phase of expelled air pressure.
Test: Calibrate strain-rate histories.
Contrary outcome: Pressure follows strain alone.

S4-0275. A layered shear pad should reduce edge stress by increasing interlayer slip near its perimeter.
Test: Map strain.
Contrary outcome: Slip moves stress to a new damaging edge.

S4-0276. A hollow shell should absorb an oblique impact through a rotating collapse zone.
Test: Image impact deformation.
Contrary outcome: Collapse remains localized at contact.

S4-0277. A compliant bridge should retain load capacity after one support settles through reversible geometry change.
Test: Measure reactions and displacement.
Contrary outcome: Settlement causes unstable redistribution.

S4-0278. A woven lattice should prevent strand pullout by tightening transverse loops under axial tension.
Test: Measure pullout force.
Contrary outcome: Loops do not increase retention.

S4-0279. A corrugated plate should tune bending anisotropy continuously as its folds flatten.
Test: Measure stiffness tensor.
Contrary outcome: Anisotropy changes discontinuously or weakly.

S4-0280. A soft crack-tip insert should delay fatigue growth by closing during unloading.
Test: Track cyclic crack extension.
Contrary outcome: Closure adds no fatigue benefit.

S4-0281. A segmented arch should recover from a missing segment through a secondary tensile path.
Test: Remove one segment under controlled load.
Contrary outcome: Arch collapses.

S4-0282. A hollow membrane support should identify local pressure overload through differential cell venting.
Test: Measure vent order.
Contrary outcome: Order depends mainly on fabrication variation.

S4-0283. A layered spring joint should reduce parasitic translation during large rotation.
Test: Measure pivot trajectory.
Contrary outcome: Translation remains comparable to a single flexure.

S4-0284. A prestressed mesh should spread a sharp contact over a larger footprint without puncture.
Test: Map contact and damage.
Contrary outcome: Mesh concentrates force at crossings.

S4-0285. A folded lattice should produce a reversible shear band with a controllable location.
Test: Change one boundary input and image.
Contrary outcome: Band location remains imperfection-dominated.

S4-0286. A porous foam should preserve recovery after wetting when large drainage channels remain open under compression.
Test: Measure wet rebound.
Contrary outcome: Channels collapse and recovery worsens.

S4-0287. A twisted beam pair should cancel extension under applied torque while preserving rotation.
Test: Measure coupled motion.
Contrary outcome: Axial displacement remains large.

S4-0288. A hollow crush element should expose remaining energy capacity through its unfolded length.
Test: Measure absorbed work and shape.
Contrary outcome: Length does not predict remaining capacity.

S4-0289. A woven membrane should resist local creep through load transfer between crossing directions.
Test: Measure strain redistribution over time.
Contrary outcome: Creep remains concentrated.

S4-0290. A curved lattice boundary should suppress edge-localized buckling in a compressed panel.
Test: Map buckle initiation.
Contrary outcome: Edges still fail first.

S4-0291. A soft contact layer should reduce pressure peaks by migrating material into nearby recesses.
Test: Map pressure and displacement.
Contrary outcome: Migration increases local peaks.

S4-0292. A folded beam should preserve its load-displacement curve after repeated full flattening.
Test: Measure cycling curves.
Contrary outcome: Permanent creases change stiffness substantially.

S4-0293. A perforated tension strip should generate a visible traveling opening front under increasing load.
Test: Image hole shapes.
Contrary outcome: Openings change simultaneously.

S4-0294. A hollow elastic frame should recover from torsional overload through reversible diagonal collapse.
Test: Measure final alignment.
Contrary outcome: Residual twist remains.

S4-0295. A layered panel should reduce acoustic ringing by permitting controlled edge microslip.
Test: Measure decay and edge motion.
Contrary outcome: Microslip does not improve damping.

S4-0296. A prestressed shell should discriminate internal pressure from external indentation through opposite curvature changes.
Test: Apply both loads.
Contrary outcome: Shape signatures overlap.

S4-0297. A woven tube should retain flow area during axial compression through braid-angle rearrangement.
Test: Measure lumen area.
Contrary outcome: Compression closes the lumen.

S4-0298. A folded protective cap should detach before transmitting a damaging lateral moment.
Test: Measure release threshold and payload torque.
Contrary outcome: Payload overload occurs first.

S4-0299. A porous elastic layer should reveal trapped liquid through a slower recovery mode after compression.
Test: Compare dry and known wet states.
Contrary outcome: Recovery modes remain indistinguishable.

S4-0300. A compliant lattice should reduce assembly-force sensitivity to dimensional tolerances through geometric slack recruitment.
Test: Test controlled size offsets.
Contrary outcome: Forces remain tolerance-sensitive.

S4-0301. A drying liquid bridge should concentrate benign solute at its narrowest section before rupture.
Test: Map dye concentration.
Contrary outcome: Solute accumulates only at the edges.

S4-0302. A moving freezing front should push trapped gas toward an open side groove.
Test: Image water freezing.
Contrary outcome: Gas remains enclosed in the solid.

S4-0303. A periodically wetted crystal surface should select a preferred terrace spacing independent of total deposited mass.
Test: Measure benign salt topography.
Contrary outcome: Spacing follows mass alone.

S4-0304. A confined oil-water interface should suppress droplet coalescence when the gap forces flattened contact geometry.
Test: Image equal-volume pairs.
Contrary outcome: Flattening accelerates coalescence.

S4-0305. A draining foam should preserve a pressure-gradient memory in its bubble-size distribution.
Test: Measure size profiles after reversed drainage.
Contrary outcome: Profiles do not encode gradient direction.

S4-0306. A capillary-fed crystal should grow away from its supply channel when deposition narrows the channel entrance.
Test: Image benign crystallization.
Contrary outcome: Growth blocks the inlet completely.

S4-0307. A moving contact line should sort inert particles by rolling versus sliding mobility at equal size.
Test: Track calibrated particles.
Contrary outcome: Mobility does not predict deposition position.

S4-0308. A thin ice layer should detach from a flexible plate through a traveling bend below the bulk fracture strain.
Test: Measure release force and cracks.
Contrary outcome: Release requires extensive ice fracture.

S4-0309. A narrow evaporation gap should select one dominant vapor escape route through self-generated cooling.
Test: Map temperature and vapor flux.
Contrary outcome: Routes remain uniformly distributed.

S4-0310. A confined droplet should split reversibly when a moving wedge creates two equal capillary reservoirs.
Test: Measure daughter volumes and recombination.
Contrary outcome: Splitting produces persistent unequal remnants.

S4-0311. A porous crystal-growth bed should reduce inclusion trapping by providing a separate liquid escape network.
Test: Image transparent salt growth.
Contrary outcome: Inclusions remain unchanged.

S4-0312. A liquid coating should resist dewetting when its substrate develops shallow compression wrinkles.
Test: Measure hole nucleation.
Contrary outcome: Wrinkles accelerate dewetting.

S4-0313. A partially frozen channel should reveal blockage location through the phase of a low-pressure oscillation.
Test: Freeze known sections.
Contrary outcome: Phase cannot localize blockage.

S4-0314. A wet granular edge should retreat through discrete avalanche steps rather than smooth erosion.
Test: Image controlled drainage.
Contrary outcome: Retreat remains continuous.

S4-0315. A capillary droplet train should maintain separation after gentle compression through trapped-air cushions.
Test: Measure collision frequency.
Contrary outcome: Air cushions collapse and droplets merge.

S4-0316. A crystallizing film should indicate past evaporation direction through asymmetric grain-boundary curvature.
Test: Reverse drying gradients.
Contrary outcome: Curvature does not reverse.

S4-0317. A liquid meniscus should pin more reproducibly at a rounded step than a sharp step after repeated cycling.
Test: Measure threshold distributions.
Contrary outcome: Rounding increases variability.

S4-0318. A foam-filled chamber should buffer pressure pulses through reversible film rearrangement rather than gas compression alone.
Test: Measure shape and pressure.
Contrary outcome: Response matches equivalent gas volume.

S4-0319. A draining gel-free porous pad should expel its last liquid preferentially from a mechanically compressed edge.
Test: Map residual saturation.
Contrary outcome: Compression traps more liquid.

S4-0320. A freezing droplet should develop a repeatable off-axis tip when its support curvature breaks symmetry.
Test: Image controlled supports.
Contrary outcome: Tip direction remains random.

S4-0321. A liquid rivulet should resist lateral wandering when its side boundary is a second mobile liquid interface.
Test: Measure centroid fluctuations.
Contrary outcome: Mobile boundary increases wandering.

S4-0322. A soluble crystalline plug should release after a predictable integrated water exposure rather than elapsed time alone.
Test: Vary flow histories.
Contrary outcome: Release tracks time independently of exposure.

S4-0323. A capillary film should preserve a narrow liquid lane through selective cooling from its own evaporation.
Test: Map thickness and temperature.
Contrary outcome: Cooling does not stabilize the lane.

S4-0324. A growing benign crystal should deflect an elastic obstacle before incorporating it as an inclusion.
Test: Image obstacle motion.
Contrary outcome: Obstacle is engulfed without deflection.

S4-0325. A wetting front should bypass a compressed porous region and reunite downstream without trapping air.
Test: Image fronts.
Contrary outcome: Bypass creates persistent gas pockets.

S4-0326. A liquid bridge should distinguish surface contamination from roughness through different relaxation after a small oscillation.
Test: Test controlled surfaces.
Contrary outcome: Relaxation signatures overlap.

S4-0327. A thin freezing film should release pressure through an unfrozen perimeter reservoir.
Test: Measure pressure and ice front.
Contrary outcome: Reservoir freezes too early.

S4-0328. A drying suspension should reduce edge deposition when its contact radius shrinks at a controlled rate.
Test: Measure inert-particle profiles.
Contrary outcome: Edge accumulation remains unchanged.

S4-0329. A capillary valve should trigger at a sharper volume threshold when its reservoir wall snaps elastically.
Test: Measure release volumes.
Contrary outcome: Snap variability broadens thresholds.

S4-0330. A liquid foam should show a detectable acoustic change before a percolating drainage channel forms.
Test: Measure sound and drainage images.
Contrary outcome: Acoustic change follows channel formation.

S4-0331. A crystalline coating should crack less when its support contracts in synchrony with drying shrinkage.
Test: Map cracks and substrate motion.
Contrary outcome: Synchronized contraction adds no benefit.

S4-0332. A confined liquid interface should transport inert particles toward a pressure node under slow periodic squeezing.
Test: Track particles and fluid markers.
Contrary outcome: Transport is entirely bulk advection.

S4-0333. A partially wet porous ring should rotate under uniform airflow through asymmetric evaporation torque.
Test: Measure torque and wetting pattern.
Contrary outcome: Rotation follows aerodynamic asymmetry alone.

S4-0334. A capillary channel should arrest a dissolving salt front at a widening junction.
Test: Image benign dissolution.
Contrary outcome: Front crosses without a reproducible pause.

S4-0335. A freezing water bridge should concentrate strain into a sacrificial neck before stressing its supports.
Test: Measure support forces.
Contrary outcome: Supports overload before neck failure.

S4-0336. A draining liquid film should retain a readable thickness pattern after contact with a shaped cooling plate.
Test: Measure residual profile.
Contrary outcome: Thermal pattern erases immediately.

S4-0337. A porous evaporation pump should recover after an air interruption when a side reservoir stores a liquid seed.
Test: Measure restart probability.
Contrary outcome: Seed reservoir does not improve recovery.

S4-0338. A droplet pair should reveal an intervening vapor barrier through unequal cooling after identical illumination.
Test: Measure transient temperatures.
Contrary outcome: The barrier creates no differential thermal signal.

S4-0339. A crystallization front should slow before meeting an impermeable obstacle because local solute redistribution changes supersaturation.
Test: Image front speed.
Contrary outcome: Speed changes only at contact.

S4-0340. A liquid film should detach cleanly from a blade when a small gas vent follows its receding contact line.
Test: Measure retained liquid.
Contrary outcome: Vent breaks the film prematurely and increases residue.

S4-0341. A confined foam should redistribute bubbles away from a heated region before significant evaporation.
Test: Track bubbles and liquid flow.
Contrary outcome: Motion follows bulk thermal expansion only.

S4-0342. A wetting front should reveal pore-connectivity loss through intermittent advance timing.
Test: Control blocked connections.
Contrary outcome: Timing reflects pore size alone.

S4-0343. A freezing interface should preserve a dissolved-dye concentration ridge that marks a brief growth pause.
Test: Pause controlled freezing and image.
Contrary outcome: No distinct ridge survives.

S4-0344. A capillary reservoir should retain a suspended particle layer while delivering particle-free liquid through an elevated outlet.
Test: Count transmitted particles.
Contrary outcome: Particles escape with unchanged concentration.

S4-0345. A shrinking droplet should rotate a free textured disk through differential contact-line release.
Test: Track angle and contact line.
Contrary outcome: Rotation lacks reproducible direction.

S4-0346. A crystalline salt film should show a reproducible conductivity-free optical precursor to mechanical spalling.
Test: Measure scattering and adhesion.
Contrary outcome: Optical change appears only after spall.

S4-0347. A liquid bridge should transfer a fixed solute fraction between unequal reservoirs through controlled rupture position.
Test: Measure tracer partition.
Contrary outcome: Partition depends unpredictably on history.

S4-0348. A porous wick should resist contamination-induced flow collapse when alternate pores remain unwetted until needed.
Test: Measure flux after controlled fouling.
Contrary outcome: Reserve pores fail to activate.

S4-0349. A thin ice sheet should reveal hidden liquid pockets through local flexural-wave slowing.
Test: Map waves over known pockets.
Contrary outcome: Temperature variation masks pocket signal.

S4-0350. A drying droplet should record oscillatory acceleration as alternating deposit bands only above a capillary response threshold.
Test: Apply calibrated shaking.
Contrary outcome: Bands occur equally without acceleration.

S4-0351. A foam drainage collector should separate liquid pulses from gas release through a compliant check chamber.
Test: Measure phase outputs.
Contrary outcome: Gas repeatedly contaminates liquid discharge.

S4-0352. A growing crystal should avoid self-shadowed regions when illumination changes local evaporation rather than chemistry.
Test: Map benign crystal growth.
Contrary outcome: Growth follows temperature alone without geometric selectivity.

S4-0353. A capillary liquid bridge should remain connected during lateral motion when one support rotates freely.
Test: Measure rupture distance.
Contrary outcome: Free rotation gives no extension.

S4-0354. A frozen porous plug should reopen first along a deliberately low-thermal-mass path.
Test: Image thawing.
Contrary outcome: Reopening occurs randomly.

S4-0355. A drying film should reduce wrinkle coarsening when its boundary tension is released gradually.
Test: Measure wavelength evolution.
Contrary outcome: Release accelerates coarsening.

S4-0356. A suspension interface should separate inert particles by deformability at matched diameter during passage through a tapered gap.
Test: Measure outlet populations.
Contrary outcome: Separation follows friction alone.

S4-0357. A capillary trap should release trapped gas under vibration only when the gas volume exceeds a geometric threshold.
Test: Measure escape conditions.
Contrary outcome: Small and large pockets escape equally.

S4-0358. A crystalline surface should retain a humidity-cycle count in discrete growth rings under a bounded protocol.
Test: Apply known cycles.
Contrary outcome: Rings merge or fail to count cycles.

S4-0359. A liquid film should spread around a corner faster when its support flexes toward the advancing front.
Test: Measure propagation speed.
Contrary outcome: Flexure retards spreading.

S4-0360. A freezing meniscus should displace a compliant gate and stop further feed before pressure rises sharply.
Test: Measure gate timing and pressure.
Contrary outcome: Pressure rises before closure.

S4-0361. A foam-filled flexible tube should absorb bending through bubble rearrangement without large flow resistance changes.
Test: Measure bend force and pressure drop.
Contrary outcome: Bending strongly blocks flow.

S4-0362. A wetting ridge should guide a receding droplet into a collection pocket independent of small substrate tilt.
Test: Measure final position.
Contrary outcome: Tilt dominates collection.

S4-0363. A drying porous disk should emit a distinct acoustic burst when its liquid network loses connectivity.
Test: Record sound and saturation.
Contrary outcome: Bursts are unrelated to connectivity loss.

S4-0364. A liquid bridge should reveal anisotropic surface texture through direction-dependent rupture distance.
Test: Test rotated identical textures.
Contrary outcome: Rupture remains isotropic.

S4-0365. A crystallizing reservoir should sustain outflow longer when a flexible outlet expands under deposition pressure.
Test: Measure discharge lifetime.
Contrary outcome: Expansion accelerates plugging.

S4-0366. A thin ice coating should release in larger intact pieces when its backing bends along a traveling line.
Test: Measure fragment sizes.
Contrary outcome: Bending produces finer fragmentation.

S4-0367. A confined droplet should display a pressure plateau during reversible shape switching between two recesses.
Test: Measure pressure-volume curve.
Contrary outcome: Switching lacks a stable plateau.

S4-0368. A drying suspension should produce a more uniform deposit when its support slowly changes curvature.
Test: Map inert deposit thickness.
Contrary outcome: Curvature changes worsen nonuniformity.

S4-0369. A porous capillary joint should tolerate repeated separation by preserving liquid in protected side pores.
Test: Measure reconnection flux.
Contrary outcome: Joint dries irreversibly.

S4-0370. A salt-growth front should reveal local stress through a measurable change in branching angle.
Test: Apply controlled compression.
Contrary outcome: Branch angles are stress-insensitive.

S4-0371. A liquid foam should attenuate mechanical pulses more strongly when bubbles can migrate between compartments.
Test: Measure transmitted force.
Contrary outcome: Migration adds no attenuation.

S4-0372. A frozen channel should measure cumulative thawing through an irreversible meniscus displacement in an attached indicator.
Test: Compare heat input and displacement.
Contrary outcome: Indicator responds mainly to ambient pressure.

S4-0373. A capillary groove should shed contaminant particles during drying by lifting them on a receding liquid ridge.
Test: Measure retained inert particles.
Contrary outcome: Drying leaves particles attached.

S4-0374. A draining film should self-level a small suspended membrane through unequal liquid weight.
Test: Measure tilt recovery.
Contrary outcome: Liquid migration destabilizes tilt.

S4-0375. A crystallizing droplet should produce a reproducible central void when outward flow stops before edge solidification.
Test: Image final structures.
Contrary outcome: Void formation is random.

S4-0376. A liquid bridge should transmit torsion differently before and after an interfacial film forms.
Test: Measure torque relaxation with controlled aging.
Contrary outcome: Changes are explained by bulk viscosity alone.

S4-0377. A porous freezing pad should limit expansion force through connected unfrozen relief channels.
Test: Measure compression forces.
Contrary outcome: Channels freeze before providing relief.

S4-0378. A drying capillary network should reveal its most conductive path through the last surviving liquid connection.
Test: Compare imaging with independent conductance.
Contrary outcome: Last path is determined by evaporation exposure alone.

S4-0379. A confined emulsion should avoid large-drop formation when wall compliance accommodates collisions.
Test: Image droplet encounters.
Contrary outcome: Compliance promotes coalescence.

S4-0380. A crystalline coating should delaminate more controllably when a patterned weak boundary guides the front.
Test: Map benign salt release.
Contrary outcome: Front ignores the boundary.

S4-0381. A liquid meniscus should estimate local wall compliance through pressure-dependent contact-line displacement.
Test: Calibrate wall stiffness.
Contrary outcome: Wetting hysteresis prevents inversion.

S4-0382. A foam should preserve its bubble-size distribution longer when drainage liquid is recirculated locally by capillary return paths.
Test: Measure aging.
Contrary outcome: Return paths accelerate coarsening.

S4-0383. A freezing droplet should identify support thermal anisotropy through the orientation of its first solidification front.
Test: Rotate known anisotropic supports.
Contrary outcome: Orientation fails to track anisotropy.

S4-0384. A drying film should stop crack propagation when a local reservoir rehydrates the crack tip.
Test: Image cracks and liquid delivery.
Contrary outcome: Rehydration arrives too late.

S4-0385. A capillary sample holder should reduce evaporation bias by moving its free surface into a narrow recess as volume falls.
Test: Measure concentration drift.
Contrary outcome: Bias remains unchanged.

S4-0386. A growing crystal should lift an overlying flexible sheet at a force predictable from the advancing contact area.
Test: Measure force and image growth.
Contrary outcome: Force is dominated by uncontrolled adhesion.

S4-0387. A liquid bridge should reject a short lateral shock through contact-line pinning but release under sustained shear.
Test: Apply equal-peak histories.
Contrary outcome: Duration selectivity is absent.

S4-0388. A porous wick should expose its remaining liquid capacity through a visible moving dry boundary.
Test: Compare boundary with gravimetry.
Contrary outcome: Boundary position is not capacity-specific.

S4-0389. A thawing ice layer should generate a detectable low-frequency resonance before mechanical release.
Test: Measure vibration and detachment.
Contrary outcome: Resonance appears only after release.

S4-0390. A confined liquid film should resist breakup when its support supplies liquid preferentially to thinning regions.
Test: Map film thickness.
Contrary outcome: Supply reinforces thick regions instead.

S4-0391. A crystallization inhibitor-free groove should redirect salt growth away from a mechanical contact through evaporation geometry.
Test: Map deposits.
Contrary outcome: Contact still accumulates crystals.

S4-0392. A drying suspension should separate aggregates from primary particles through different contact-line escape thresholds.
Test: Track inert clusters.
Contrary outcome: Both deposit together.

S4-0393. A capillary bridge array should indicate local drying through a cascade of discrete rupture events.
Test: Measure event timing and remaining liquid.
Contrary outcome: Cascade is unrelated to local saturation.

S4-0394. A freezing liquid pocket should rotate a hinged marker before expansion damages its enclosure.
Test: Measure marker angle and wall strain.
Contrary outcome: Enclosure strains first.

S4-0395. A foam film should reveal local contamination through an asymmetric response to a small shear oscillation.
Test: Apply controlled benign contaminants.
Contrary outcome: Response is not contamination-specific.

S4-0396. A drying gel-free film should retain a transient flow vortex as a curved deposition seam.
Test: Compare tracer flow and final seam.
Contrary outcome: Seam orientation ignores flow.

S4-0397. A porous liquid reservoir should meter a reproducible final aliquot when its gas path percolates.
Test: Measure final discharge volume.
Contrary outcome: Final aliquot varies widely.

S4-0398. A crystal-growth boundary should stop at a flexible barrier until elastic energy exceeds a reproducible threshold.
Test: Measure growth force and barrier motion.
Contrary outcome: Barrier is engulfed without threshold behavior.

S4-0399. A liquid coating should recover after a scratch through capillary delivery from a connected edge store.
Test: Measure restored thickness.
Contrary outcome: Scratch remains dry.

S4-0400. A freezing capillary should show a reproducible electrical-free optical signal when its final open liquid path closes.
Test: Measure scattering and flow.
Contrary outcome: Signal cannot resolve closure timing.

S4-0401. A rocking body should reveal the direction of a hidden internal mass offset through unequal residence times at its turning points.
Test: Track calibrated bodies.
Contrary outcome: Residence asymmetry does not identify offset.

S4-0402. A pendulum with a moving pivot should reduce sensitivity to support-height changes through geometric compensation.
Test: Measure period across heights.
Contrary outcome: Compensation fails.

S4-0403. A free slider inside a vibrating frame should lock to a rational fraction of the drive period over a finite amplitude band.
Test: Measure timing ratios.
Contrary outcome: Locking occurs only at isolated settings.

S4-0404. A rolling ring should cross a small gap more reliably when its internal mass can lag behind the contact point.
Test: Measure crossing probability.
Contrary outcome: Mass lag worsens crossing.

S4-0405. A hinged inertial shield should reduce transmitted angular impulse by counter-rotating during impact.
Test: Measure support impulse.
Contrary outcome: Counter-rotation adds no attenuation.

S4-0406. A rotating elastic wheel should redistribute imbalance through reversible radial deformation.
Test: Measure runout versus speed.
Contrary outcome: Deformation increases imbalance.

S4-0407. A gravitational detent should distinguish a sequence of alternating impulses from repeated same-direction impulses.
Test: Apply equal-energy sequences.
Contrary outcome: Final states remain identical.

S4-0408. A passive oscillator should select a stable orbit around an obstacle through asymmetric collision timing.
Test: Track trajectories.
Contrary outcome: Collisions lead only to random wandering.

S4-0409. A moving support should suppress parametric resonance by detuning as amplitude grows.
Test: Measure response versus excitation.
Contrary outcome: Detuning occurs too late.

S4-0410. A torsion pendulum should estimate fluid-memory duration from its rebound after an abrupt drive stop.
Test: Test calibrated viscoelastic liquids.
Contrary outcome: Inertia explains the entire rebound.

S4-0411. A chain with one free joint should transmit a compression pulse differently according to its initial joint angle.
Test: Measure pulse transfer.
Contrary outcome: Transfer is angle-insensitive.

S4-0412. A rolling body should climb a shallow incline under zero-mean vibration only when contact asymmetry exceeds a threshold.
Test: Map travel versus asymmetry.
Contrary outcome: Motion persists in symmetric controls.

S4-0413. A suspended ring should average directional vibration energy through slow precession.
Test: Compare inferred energy with calibrated excitation.
Contrary outcome: Precession introduces directional bias.

S4-0414. A bistable oscillator should retain the order of two impulse magnitudes in its final state.
Test: Reverse paired impulses.
Contrary outcome: Order does not affect state.

S4-0415. A free eccentric cam should limit shaft acceleration by moving against rapid speed changes.
Test: Measure acceleration and cam motion.
Contrary outcome: Cam adds speed fluctuations.

S4-0416. A compliant pendulum stop should reduce chaotic rebounds by separating contact timescales.
Test: Map return trajectories.
Contrary outcome: Chaos persists unchanged.

S4-0417. A rotating cavity containing a loose disk should reveal an internal obstruction through phase-slip bursts.
Test: Introduce controlled obstructions.
Contrary outcome: Bursts occur equally without obstruction.

S4-0418. A rocking balance should reject uniform floor tilt by shifting its instantaneous contact center.
Test: Measure zero error versus tilt.
Contrary outcome: Contact migration fails to compensate.

S4-0419. A passive inertial latch should trigger on jerk while remaining insensitive to constant acceleration.
Test: Apply calibrated ramps and holds.
Contrary outcome: Acceleration alone triggers it.

S4-0420. A coupled oscillator pair should localize damage through amplitude ratio changes before frequency shifts are resolvable.
Test: Weaken one spring.
Contrary outcome: Amplitude ratio offers no earlier signal.

S4-0421. A rolling cylinder should stop at a repeatable phase when its internal fluid settles through an asymmetric channel.
Test: Measure final angle.
Contrary outcome: Angle remains random.

S4-0422. A free-spinning mass should reduce torsional resonance through intermittent clutch engagement.
Test: Measure response spectra.
Contrary outcome: Engagement creates larger peaks.

S4-0423. A suspended vane should estimate vibration ellipticity from its mean orientation.
Test: Apply calibrated two-axis motion.
Contrary outcome: Orientation reflects amplitude alone.

S4-0424. A chain of rocking blocks should arrest a falling front when one block's center of mass shifts under impact.
Test: Film propagation.
Contrary outcome: Front crosses without arrest.

S4-0425. A rotating flexible loop should maintain a stable noncircular orbit without wall contact.
Test: Track shape in a rotating frame.
Contrary outcome: Loop collapses or contacts the wall.

S4-0426. A passive escapement should reject a missing drive pulse without losing synchronization.
Test: Omit controlled pulses.
Contrary outcome: Phase error accumulates.

S4-0427. A mass on a curved track should separate slow tilt from high-frequency acceleration through two position observables.
Test: Calibrate disturbances.
Contrary outcome: Signals remain confounded.

S4-0428. A resonant mechanism should cap its response by transferring energy to a higher mode after a threshold.
Test: Measure modal energies.
Contrary outcome: Transfer does not limit the primary mode.

S4-0429. A rolling polygon should encode surface roughness in the statistics of its dwell angles.
Test: Test known surfaces.
Contrary outcome: Statistics reflect only polygon geometry.

S4-0430. A hinged counterweight should reduce support force during repeated impacts by synchronizing out of phase.
Test: Measure phase and support force.
Contrary outcome: Synchronization increases force.

S4-0431. A pendulum with a sliding bob should retain nearly constant period over a bounded amplitude range.
Test: Measure period versus amplitude.
Contrary outcome: Period drift remains equal.

S4-0432. A passive gyroscopic mount should reject yaw disturbance while allowing slow commanded pitch.
Test: Measure directional response.
Contrary outcome: Yaw rejection also blocks pitch.

S4-0433. A rocking object should detect unequal restitution at two contacts through systematic lateral drift.
Test: Change one contact coating geometry-free.
Contrary outcome: Drift lacks a reproducible sign.

S4-0434. A coupled beam pair should reveal a tiny stiffness mismatch through slow energy beating.
Test: Measure beat period against known mismatch.
Contrary outcome: Damping masks beating.

S4-0435. A free rotor should align to a periodic drive's phase through asymmetric drag alone.
Test: Measure phase under zero-mean torque.
Contrary outcome: Phase remains unbounded.

S4-0436. A sliding internal mass should lower impact restitution by arriving at the wall after the external body stops.
Test: Measure collision timing and rebound.
Contrary outcome: Timing increases rebound.

S4-0437. A compliant pivot should stabilize an inverted small pendulum under high-frequency base motion at lower amplitude than a rigid pivot.
Test: Map stability boundaries.
Contrary outcome: Compliance raises the required amplitude.

S4-0438. A rolling shell should estimate liquid fill fraction from the difference between start and stop torques.
Test: Test known fills.
Contrary outcome: Difference is dominated by bearing friction.

S4-0439. A mechanical phase detector should convert oscillator phase difference into a static displacement.
Test: Drive paired inputs.
Contrary outcome: Output depends mainly on amplitude mismatch.

S4-0440. A chain of unequal rotors should broaden the frequency band of vibration isolation through sequential resonances.
Test: Measure transmission.
Contrary outcome: Only narrow isolation notches appear.

S4-0441. A rocking gate should open only after several subthreshold impacts accumulate elastic strain.
Test: Apply controlled impact trains.
Contrary outcome: Each impact resets completely.

S4-0442. A suspended platform should reduce rotational drift through a moving gravitational reference.
Test: Measure orientation over slow disturbances.
Contrary outcome: Reference motion adds drift.

S4-0443. A free slider should detect a frequency sweep's direction from hysteretic capture into resonance.
Test: Apply upward/downward sweeps.
Contrary outcome: Final positions are identical.

S4-0444. A rotating elastic arm should shed excess kinetic energy through reversible tip folding.
Test: Measure energy and shape.
Contrary outcome: Folding fails to reduce support loading.

S4-0445. A passive pendulum array should separate two nearby excitation frequencies through spatial energy localization.
Test: Measure mode amplitudes.
Contrary outcome: Localization cannot resolve the pair.

S4-0446. A rolling ball in a shaped bowl should estimate excitation kurtosis from rare boundary visits.
Test: Apply equal-variance waveforms.
Contrary outcome: Visit rate is not kurtosis-specific.

S4-0447. A hinged inertial mass should trigger differently for equal-impulse pulses of opposite temporal skew.
Test: Apply time-reversed pulses.
Contrary outcome: Trigger probability is unchanged.

S4-0448. A compliant oscillator should recover a preferred phase after a short interruption of drive.
Test: Measure restart phases.
Contrary outcome: Restart phase remains random.

S4-0449. A rotating ring should suppress bearing vibration through a freely traveling balance weight.
Test: Measure support acceleration.
Contrary outcome: Weight fails to converge.

S4-0450. A rocking shell should retain angular impulse sign after settling through a bistable internal flap.
Test: Apply calibrated impulses.
Contrary outcome: Settled state does not encode sign.

S4-0451. A coupled torsion chain should transmit an energy pulse around a damaged link through a parallel rotational path.
Test: Measure transfer after damage.
Contrary outcome: Parallel path does not restore transfer.

S4-0452. A passive mechanical filter should discriminate periodic tapping from irregular tapping at equal count and energy.
Test: Apply timed sequences.
Contrary outcome: Outputs remain identical.

S4-0453. A pendulum with a curved spring should show a nearly isochronous finite-amplitude orbit.
Test: Measure period across energies.
Contrary outcome: Amplitude dependence remains strong.

S4-0454. A rolling wheel should reduce speed oscillations by shifting its contact radius under load.
Test: Measure velocity ripple.
Contrary outcome: Radius changes amplify ripple.

S4-0455. A suspended inertial pointer should indicate dominant vibration direction without responding strongly to support tilt.
Test: Calibrate both.
Contrary outcome: Tilt dominates the pointer.

S4-0456. A resonant clutch should engage only within a selected frequency band.
Test: Measure torque transfer versus frequency.
Contrary outcome: Engagement is broadband.

S4-0457. A free internal ring should delay a rotating shell's reversal enough to filter short torque spikes.
Test: Measure angular response.
Contrary outcome: Filtering destroys useful long-term response.

S4-0458. A rocking frame should convert alternating impacts into a monotonic mechanical count through contact order.
Test: Count known impacts.
Contrary outcome: Contacts cause skipped or duplicate counts.

S4-0459. A coupled oscillator should reveal a friction change through asymmetric energy exchange between modes.
Test: Vary one joint friction.
Contrary outcome: Asymmetry is not friction-specific.

S4-0460. A rotating mass on a flexible tether should limit maximum tension through outward path deformation.
Test: Measure tension and orbit.
Contrary outcome: Deformation raises peak tension.

S4-0461. A passive inertial valve should remain shut during uniform translation but open during rotation.
Test: Apply calibrated motions.
Contrary outcome: Translation produces equivalent opening.

S4-0462. A rolling body should distinguish a soft patch from a rough patch through separate speed and vertical-motion signatures.
Test: Test controlled tracks.
Contrary outcome: Signatures overlap.

S4-0463. A suspended acoustic-free oscillator should detect airflow intermittency through non-Gaussian displacement tails.
Test: Apply calibrated gust statistics.
Contrary outcome: Tails reflect structural nonlinearities alone.

S4-0464. A chain of bistable links should store the location of an impact in its switched-state pattern.
Test: Strike known locations.
Contrary outcome: Patterns are spatially ambiguous.

S4-0465. A free rotor should reduce motor torque ripple by locking to the ripple harmonic through magnetic-free mechanical coupling.
Test: Measure torque spectra.
Contrary outcome: Rotor adds sidebands without reduction.

S4-0466. A rocking platform should recover from edge loading through a load-triggered counterweight shift.
Test: Measure recovery range.
Contrary outcome: Counterweight moves destabilizingly.

S4-0467. A compliant impact train should spread a pulse over time through sequential contact opening.
Test: Measure transmitted waveform.
Contrary outcome: Contacts close simultaneously.

S4-0468. A pendulum suspension should reject thermal length changes through a compensating curved support.
Test: Measure period-temperature drift.
Contrary outcome: Drift remains unchanged.

S4-0469. A rolling shell should reveal internal fluid stratification through orientation-dependent acceleration transients.
Test: Create known layers.
Contrary outcome: Transients cannot distinguish stratification from fill level.

S4-0470. A passive phase-locking mechanism should tolerate moderate drive-amplitude variation through geometric saturation.
Test: Measure phase error.
Contrary outcome: Locking range does not widen.

S4-0471. A suspended mass should estimate the duration of an acceleration pulse from its post-pulse orbit shape.
Test: Apply calibrated pulses.
Contrary outcome: Orbit depends only on impulse.

S4-0472. A rotating hinged blade should reduce support moment during sudden blockage by folding tangentially.
Test: Measure blockage forces.
Contrary outcome: Folding happens after peak load.

S4-0473. A coupled pendulum network should reroute energy after one oscillator becomes strongly damped.
Test: Measure spatial energy flow.
Contrary outcome: Energy remains trapped near the damaged node.

S4-0474. A rocking friction element should attenuate drift from symmetric low-amplitude vibration.
Test: Measure net displacement.
Contrary outcome: Vibration causes additional drift.

S4-0475. A passive resonance tracker should move its tuning mass toward the frequency of the strongest excitation component.
Test: Apply two-tone drive.
Contrary outcome: It locks to a weaker or spurious component.

S4-0476. A rolling encoder should detect slip from unequal timing between two mechanically linked contact wheels.
Test: Compare with optical motion.
Contrary outcome: Timing mismatch does not identify slip.

S4-0477. A suspended thin ring should distinguish torsional from translational impulses through opposite mode symmetries.
Test: Apply calibrated impacts.
Contrary outcome: Modes couple too strongly to separate.

S4-0478. A chain of free sliders should produce a delayed release after compression through sequential escape barriers.
Test: Measure timing.
Contrary outcome: Release remains simultaneous.

S4-0479. A rotating flexible spoke should indicate accumulated fatigue through a shifted centrifugal deployment speed.
Test: Cycle and measure thresholds.
Contrary outcome: Threshold drift is not fatigue-specific.

S4-0480. A passive impact limiter should reset its internal mass before the next event across a bounded repetition rate.
Test: Measure reset time and peak force.
Contrary outcome: Incomplete reset erases protection.

S4-0481. A rocking bowl should separate particles by restitution using repeated edge collisions.
Test: Track equal-size particles.
Contrary outcome: Sorting follows friction instead.

S4-0482. A coupled elastic loop should show a detectable geometric phase after a closed cycle of support motions.
Test: Apply reversed cycles.
Contrary outcome: Final orientation is path-independent.

S4-0483. A suspended oscillator should estimate support compliance from its amplitude-dependent resonance splitting.
Test: Vary known support stiffness.
Contrary outcome: Splitting is dominated by drive nonlinearity.

S4-0484. A rotating clutch should transmit steady torque but release during rapid torque reversal.
Test: Measure torque histories.
Contrary outcome: Release depends only on magnitude.

S4-0485. A rolling guide should compensate lateral track error through a freely tilting axle.
Test: Measure trajectory.
Contrary outcome: Axle tilt introduces larger error.

S4-0486. A mechanical resonator should distinguish a sparse impulse train from continuous noise through occupancy of bistable states.
Test: Apply equal-power forcing.
Contrary outcome: State occupancy is identical.

S4-0487. A rocking linkage should amplify a weak periodic input only near a chosen phase relative to gravity.
Test: Measure gain versus phase.
Contrary outcome: Gain lacks phase selectivity.

S4-0488. A suspended platform should distribute shock energy into orthogonal modes through a curved tether arrangement.
Test: Measure modal energies.
Contrary outcome: One mode retains almost all energy.

S4-0489. A free rotor should detect flow pulsation asymmetry through unequal acceleration and deceleration intervals.
Test: Apply known waveforms.
Contrary outcome: Intervals reflect mean flow only.

S4-0490. A compliant oscillator should lower its own frequency before reaching a damaging amplitude.
Test: Measure backbone curve and peak strain.
Contrary outcome: Softening begins after damage.

S4-0491. A rolling body should preserve travel direction after brief contact loss through internal angular momentum storage.
Test: Measure landing direction.
Contrary outcome: Recontact direction remains random.

S4-0492. A passive inertial switch should distinguish repeated small shocks from one equal-energy large shock.
Test: Apply controlled sequences.
Contrary outcome: Both yield identical switching.

S4-0493. A chain of rocking elements should amplify timing differences between two arrival pulses.
Test: Measure output separation.
Contrary outcome: Timing differences shrink or become noisy.

S4-0494. A rotating elastic hoop should reveal a local mass defect through a stationary deformation harmonic.
Test: Add calibrated masses.
Contrary outcome: Harmonic orientation fails to track defect.

S4-0495. A suspended counterweight should compensate load changes without shifting a platform's nominal height substantially.
Test: Measure height across loads.
Contrary outcome: Compensation requires large height changes.

S4-0496. A rocking pendulum should estimate impact location from the ratio of rotation to translation.
Test: Strike known positions.
Contrary outcome: Contact compliance destroys the ratio.

S4-0497. A passive frequency divider should produce one output stroke per two drive cycles through alternating contact paths.
Test: Count strokes over frequency.
Contrary outcome: Skipped states destroy division.

S4-0498. A rolling ring should reduce orientation sensitivity to floor slope through a moving internal ballast.
Test: Measure steady orientation.
Contrary outcome: Ballast increases slope sensitivity.

S4-0499. A coupled oscillator should isolate a narrow harmful mode through a reversible change in coupling sign.
Test: Measure mode shapes and transfer.
Contrary outcome: Sign change adds instability.

S4-0500. A suspended inertial latch should reset only after vibration energy falls below a separate lower threshold.
Test: Sweep excitation up/down.
Contrary outcome: Distinct reset threshold is absent.

S4-0501. A textured rolling contact should expel liquid sideways before solid contact begins.
Test: Image contact and liquid motion.
Contrary outcome: Liquid remains trapped centrally.

S4-0502. A freely tilting bearing pad should reduce edge pressure during shaft misalignment.
Test: Map contact load.
Contrary outcome: Tilting creates a different edge maximum.

S4-0503. A compliant thread should distribute screw load across more engaged turns.
Test: Measure turn-by-turn strain.
Contrary outcome: The first turn still carries most load.

S4-0504. A sliding joint should reveal incipient galling through a rising asymmetry between forward and reverse friction.
Test: Cycle benign metal contacts.
Contrary outcome: Asymmetry appears only after severe damage.

S4-0505. A porous dry bearing should retain its friction after dust exposure when recesses isolate debris from load paths.
Test: Measure torque and inspect debris.
Contrary outcome: Debris remains in the main contact.

S4-0506. A hinged scraper should maintain nearly constant normal force across a curved surface.
Test: Measure contact force versus position.
Contrary outcome: Force varies strongly with curvature.

S4-0507. A rolling seal should reduce wear by moving its highest-strain region each cycle.
Test: Map strain and damage.
Contrary outcome: Damage remains localized.

S4-0508. A patterned contact pad should distinguish static aging from contamination through relaxation after a small shear reversal.
Test: Apply controlled conditions.
Contrary outcome: Relaxation signatures overlap.

S4-0509. A compliant spline should tolerate shaft eccentricity through reversible tooth bending.
Test: Measure torque ripple and strain.
Contrary outcome: Bending increases ripple.

S4-0510. A tapered key should self-center under alternating torque without axial migration.
Test: Track position over reversals.
Contrary outcome: Key walks out.

S4-0511. A segmented bearing should preserve lubrication-free low drag after one segment jams.
Test: Jam known segments.
Contrary outcome: Drag rises catastrophically.

S4-0512. A floating clamp jaw should reduce object indentation by rotating its pressure footprint.
Test: Measure surface deformation.
Contrary outcome: Rotation creates higher local pressure.

S4-0513. A helical surface groove should return displaced lubricant to a contact during reciprocal sliding.
Test: Image tracer lubricant.
Contrary outcome: Reciprocation pumps lubricant away.

S4-0514. A compliant pin should signal wear through a measurable shift in lateral stiffness before clearance grows visibly.
Test: Abrade calibrated pins.
Contrary outcome: Stiffness signal appears too late.

S4-0515. A rolling tendon guide should detect strand flattening through periodic changes in contact width.
Test: Feed calibrated damaged tendons.
Contrary outcome: Contact-width modulation cannot identify flattening.

S4-0516. A split collet should release more uniformly when its fingers are linked by an elastic averaging ring.
Test: Measure contact release timing.
Contrary outcome: Fingers remain asynchronous.

S4-0517. A contact pad with shallow isolated pockets should reduce stick-slip by interrupting collective junction growth.
Test: Measure velocity and force.
Contrary outcome: Pockets increase stick-slip.

S4-0518. A floating washer should maintain bolt preload during small joint settlement through geometric rotation.
Test: Measure preload and settlement.
Contrary outcome: Rotation does not recover force.

S4-0519. A compliant rack should reveal a mounting crack through a localized phase delay in a traveling tooth-contact wave.
Test: Introduce known support cracks.
Contrary outcome: Phase delay is not spatially localized.

S4-0520. A sliding seal should shed particles during reversal when its lip temporarily rolls outward.
Test: Image particle removal.
Contrary outcome: Reversal embeds particles deeper.

S4-0521. A curved contact track should turn a friction increase into a visible lateral displacement.
Test: Vary friction under fixed normal load.
Contrary outcome: Displacement is not friction-specific.

S4-0522. A porous friction pad should reduce temperature peaks by redistributing contact over time.
Test: Measure thermal maps.
Contrary outcome: Hotspots remain stationary.

S4-0523. A freely rotating contact disk should reduce lateral scuffing in a turning support.
Test: Measure wear during curved travel.
Contrary outcome: Disk rotation adds scuffing.

S4-0524. A compliant wedge lock should hold under sustained force but release during a prescribed transverse tap.
Test: Measure release thresholds.
Contrary outcome: Random vibration also releases it.

S4-0525. A layered bearing liner should expose subsurface wear through a changed acoustic echo before breakthrough.
Test: Abrade controlled thicknesses.
Contrary outcome: Echo changes are below noise.

S4-0526. A thread with variable flank compliance should equalize loading without changing pitch.
Test: Measure strain across turns.
Contrary outcome: Loads remain unequal.

S4-0527. A rolling contact should reveal a hidden surface step through an asymmetric force pulse.
Test: Traverse calibrated steps.
Contrary outcome: Pulse cannot distinguish height from speed.

S4-0528. A floating brake shoe should reduce torque sensitivity to drum eccentricity.
Test: Measure torque ripple.
Contrary outcome: Floating motion amplifies ripple.

S4-0529. A compliant joint seat should preserve alignment after repeated disassembly through three rolling constraints.
Test: Measure remounting error.
Contrary outcome: Repeatability is worse than fixed seats.

S4-0530. A narrow liquid-free contact should reduce adhesion when its edge peels continuously during translation.
Test: Measure friction and contact.
Contrary outcome: Peeling adds equal energy loss.

S4-0531. A self-adjusting pulley should keep tendon contact angle constant during joint motion.
Test: Measure routing geometry.
Contrary outcome: Angle varies strongly.

S4-0532. A textured seal should retain contact after local abrasion by recruiting previously unloaded ridges.
Test: Measure leak onset.
Contrary outcome: Ridge recruitment fails.

S4-0533. A compliant roller should reduce particle crushing by deforming around isolated hard inclusions.
Test: Measure fragment counts.
Contrary outcome: Deformation raises local pressure.

S4-0534. A sliding interface should distinguish roughness direction from friction magnitude through two orthogonal force harmonics.
Test: Test controlled textures.
Contrary outcome: Harmonics remain confounded.

S4-0535. A flexible shaft coupling should isolate axial vibration through torsional deformation.
Test: Measure cross-axis transfer.
Contrary outcome: Torsion creates equal vibration elsewhere.

S4-0536. A rolling cam follower should retain contact during rapid return through a passive auxiliary inertial mass.
Test: Measure follower separation.
Contrary outcome: Mass increases separation.

S4-0537. A porous contact layer should reveal trapped gas through a distinct unloading force plateau.
Test: Compare gas-filled and vented states.
Contrary outcome: Plateau is not gas-specific.

S4-0538. A floating friction disk should center itself under equal opposing drives.
Test: Measure eccentricity.
Contrary outcome: It drifts toward one drive.

S4-0539. A compliant latch tooth should reject shallow engagement by elastically ejecting the mating part before load transfer.
Test: Test controlled engagement depths.
Contrary outcome: Shallow engagement still carries load.

S4-0540. A helical wrap should grip more uniformly when its free end can slide through a low-friction guide.
Test: Map contact pressure.
Contrary outcome: Free-end motion causes slip.

S4-0541. A segmented scraper should clear uneven deposits with less substrate force than a rigid blade.
Test: Use standardized inert deposits.
Contrary outcome: Removal requires equal force.

S4-0542. A rolling seal should maintain low leakage during lateral shaft displacement through a moving contact line.
Test: Measure leakage versus offset.
Contrary outcome: Offset opens a persistent gap.

S4-0543. A compliant bearing cage should reduce ball collision noise under changing speed.
Test: Measure sound and cage motion.
Contrary outcome: Cage flexibility increases impacts.

S4-0544. A patterned friction interface should encode previous sliding direction in its next breakaway force.
Test: Reverse controlled histories.
Contrary outcome: Breakaway force has no directional memory.

S4-0545. A floating joint insert should reduce thermal preload drift by moving along an oblique seat.
Test: Measure force-temperature curves.
Contrary outcome: Motion increases drift.

S4-0546. A tapered tendon sheath should prevent local kinking by shifting curvature toward a wider region.
Test: Map curvature.
Contrary outcome: The narrow end still kinks.

S4-0547. A porous sliding pad should release absorbed liquid under load and recover it during unloading.
Test: Weigh transfer over cycles.
Contrary outcome: Liquid is lost irreversibly.

S4-0548. A compliant screw seat should limit tightening torque without permanent deformation.
Test: Measure torque-angle loops.
Contrary outcome: Limiting requires plastic damage.

S4-0549. A rolling contact array should estimate load position from differential roller speeds.
Test: Apply known loads.
Contrary outcome: Speeds reflect surface imperfections instead.

S4-0550. A flexible brake band should maintain torque after local contamination through load redistribution.
Test: Contaminate known sectors.
Contrary outcome: Torque collapses at the contaminated sector.

S4-0551. A self-opening wedge should prevent a friction clamp from remaining jammed after overload.
Test: Measure release force.
Contrary outcome: Overload creates persistent jamming.

S4-0552. A textured bearing surface should reduce sensitivity to initial lubricant volume through connected reserve grooves.
Test: Measure friction across doses.
Contrary outcome: Dose sensitivity remains unchanged.

S4-0553. A compliant gear tooth should expose fatigue through an altered contact dwell time.
Test: Cycle controlled teeth.
Contrary outcome: Dwell changes only after cracking is severe.

S4-0554. A floating contact plate should average substrate waviness through three distributed pivots.
Test: Measure pressure uniformity.
Contrary outcome: Pivots imprint new pressure peaks.

S4-0555. A rolling cable anchor should distinguish cable torsion from axial extension through separate rotation and payout signals.
Test: Apply known deformations.
Contrary outcome: Signals remain confounded.

S4-0556. A split friction ring should cap holding force through controlled circumferential opening.
Test: Measure force versus displacement.
Contrary outcome: Force rises without capping.

S4-0557. A porous seal should reject dust through pressure-driven outward seepage without losing substantial holding pressure.
Test: Measure contamination and leakage.
Contrary outcome: Protection requires excessive leakage.

S4-0558. A compliant dovetail should tolerate assembly misalignment through local finger rotation.
Test: Measure insertion force.
Contrary outcome: Fingers jam under offset.

S4-0559. A sliding contact should reveal surface-film formation through a changed reversal-distance dependence.
Test: Grow controlled benign films.
Contrary outcome: Bulk friction drift masks the effect.

S4-0560. A floating roller should reduce lateral force during diagonal motion by changing its spin axis.
Test: Measure force vector.
Contrary outcome: Axis motion is unstable.

S4-0561. A textured clamp pad should preserve grip after wetting by routing liquid away from contact ridges.
Test: Measure slip threshold.
Contrary outcome: Wet grip remains unchanged.

S4-0562. A compliant bearing seat should isolate high-frequency shaft motion while maintaining static alignment.
Test: Measure transfer and alignment.
Contrary outcome: Isolation introduces unacceptable runout.

S4-0563. A rolling detent should provide a repeatable tactile-free force threshold with low wear.
Test: Measure switching force over cycles.
Contrary outcome: Threshold drifts with wear.

S4-0564. A segmented seal should localize damage from one trapped particle.
Test: Insert controlled inert particles.
Contrary outcome: Leak propagates around the circumference.

S4-0565. A floating pulley should detect unequal tendon friction through a measurable equilibrium shift.
Test: Vary path friction.
Contrary outcome: Shift is dominated by tension mismatch alone.

S4-0566. A compliant surface should suppress stick-slip by storing shear over a longer length than the contact patch.
Test: Measure slip fronts.
Contrary outcome: Stored shear increases event size.

S4-0567. A helical contact ramp should transform wear depth into a self-compensating axial adjustment.
Test: Abrade known depths.
Contrary outcome: Adjustment fails to restore contact.

S4-0568. A porous brake pad should reduce cooling-induced torque drift by equalizing internal airflow.
Test: Measure torque after controlled cooling.
Contrary outcome: Airflow adds variability.

S4-0569. A rolling clamp should release with lower peak force when contact migration precedes normal unloading.
Test: Measure release paths.
Contrary outcome: Migration gives no peak reduction.

S4-0570. A flexible shaft seal should reveal eccentric motion through a phase-shifted lip displacement.
Test: Measure known offsets.
Contrary outcome: Lip motion cannot separate offset from pressure.

S4-0571. A textured friction wheel should retain traction after one region wears smooth through passive load shifting.
Test: Measure traction over wear.
Contrary outcome: Load remains on the smooth region.

S4-0572. A compliant contact ring should reduce assembly torque variation by averaging local surface height errors.
Test: Measure repeated assemblies.
Contrary outcome: Variation remains equal.

S4-0573. A floating scraper should avoid chatter by moving its effective pivot with contact force.
Test: Measure vibration spectra.
Contrary outcome: Pivot motion creates a new instability.

S4-0574. A rolling support should detect local surface compliance through contact-time asymmetry.
Test: Traverse calibrated soft patches.
Contrary outcome: Roughness creates identical asymmetry.

S4-0575. A porous tendon liner should reduce water-induced friction changes by storing a stable interfacial liquid volume.
Test: Measure wet/dry transitions.
Contrary outcome: Storage increases hysteresis.

S4-0576. A compliant gear mesh should tolerate a missing tooth by temporarily increasing adjacent engagement.
Test: Remove one tooth and measure torque.
Contrary outcome: Transmission stalls.

S4-0577. A self-centering wedge pair should preserve contact symmetry under unequal normal loads.
Test: Map contact areas.
Contrary outcome: Symmetry is not restored.

S4-0578. A textured seal seat should prevent liquid films bridging a vent after shutdown.
Test: Image residual films.
Contrary outcome: Vent remains sealed by liquid.

S4-0579. A floating bearing segment should reduce thermal ovalization by rotating toward lower-pressure regions.
Test: Measure geometry under heating.
Contrary outcome: Rotation worsens ovality.

S4-0580. A compliant friction clutch should expose overload through a visible circumferential expansion before slipping.
Test: Measure shape and torque.
Contrary outcome: Slip begins before visible change.

S4-0581. A rolling guide should maintain nearly constant tendon path length during lateral articulation.
Test: Measure path length.
Contrary outcome: Length error remains large.

S4-0582. A porous contact sensor should distinguish normal pressure from wetting through separate mechanical and optical signals.
Test: Calibrate both.
Contrary outcome: Signals remain coupled.

S4-0583. A segmented clamp should preserve holding force after one jaw loses contact.
Test: Remove one contact and measure force.
Contrary outcome: Remaining jaws overload or slip.

S4-0584. A floating screw nut should reduce thread binding under lateral load through controlled tilt.
Test: Measure drive torque.
Contrary outcome: Tilt increases binding.

S4-0585. A compliant contact pad should recover grip after oil-free dust exposure through cyclic surface stretching.
Test: Measure slip force before and after stretching.
Contrary outcome: Dust remains trapped.

S4-0586. A rolling friction reference should measure instrument drag independently of the tested sliding contact.
Test: Compare with calibrated drag.
Contrary outcome: Reference is not mechanically independent.

S4-0587. A textured bearing should delay lubricant starvation by moving liquid toward the inlet during speed reduction.
Test: Image tracer liquid.
Contrary outcome: Deceleration drains the inlet.

S4-0588. A flexible latch should resist accidental release from vibration through opposing contact-phase requirements.
Test: Apply vibration and deliberate release.
Contrary outcome: Vibration satisfies both phases.

S4-0589. A floating torque sensor should reject bending moments through a freely aligning contact ring.
Test: Apply combined loads.
Contrary outcome: Bending cross-talk remains high.

S4-0590. A compliant seal support should maintain pressure under small thermal cycling through reversible radial breathing.
Test: Measure leakage cycles.
Contrary outcome: Breathing pumps contamination inward.

S4-0591. A rolling contact should estimate abrasive-particle size from the duration of transient force spikes.
Test: Introduce known inert grit.
Contrary outcome: Duration depends mainly on speed.

S4-0592. A porous sliding layer should reduce debris recirculation by moving particles into dead-end recesses.
Test: Inspect trajectories and wear.
Contrary outcome: Particles return to the contact.

S4-0593. A segmented wheel tread should reduce force peaks over sharp edges through staggered engagement.
Test: Measure axle forces.
Contrary outcome: Segments strike simultaneously.

S4-0594. A floating clamp should reveal loss of preload through a visible change in jaw angle.
Test: Measure force and angle.
Contrary outcome: Angle is insensitive near useful loads.

S4-0595. A compliant contact geometry should make release force less sensitive to dwell time.
Test: Measure breakaway after varied dwell.
Contrary outcome: Aging remains unchanged.

S4-0596. A rolling shaft support should isolate one seized element through automatic load transfer.
Test: Seize controlled rollers.
Contrary outcome: Seizure locks the shaft.

S4-0597. A textured squeeze pad should expel water before its frictional load path engages.
Test: Measure contact sequence.
Contrary outcome: Grip engages while liquid remains trapped.

S4-0598. A flexible contact ring should preserve its calibrated force after a minor permanent surface dent.
Test: Indent controlled regions.
Contrary outcome: Dent shifts the force curve.

S4-0599. A floating friction element should distinguish torque reversal from torque unloading through different stable positions.
Test: Apply both histories.
Contrary outcome: Positions are identical.

S4-0600. A compliant bearing liner should warn of approaching seizure through an amplified temperature-gradient displacement.
Test: Measure motion and friction.
Contrary outcome: Warning appears after seizure begins.

S4-0601. A rotating conductive shell should reveal wall-thickness variation through angle-dependent magnetic drag.
Test: Measure torque on machined standards.
Contrary outcome: Drag harmonics do not track thickness.

S4-0602. A suspended magnet should distinguish a conductive plate edge from a crack through the spatial width of damping changes.
Test: Scan known features.
Contrary outcome: Widths overlap.

S4-0603. A passive flux shunt should reduce magnetic holding-force sensitivity to small target gaps.
Test: Measure pull force versus gap.
Contrary outcome: Sensitivity remains unchanged.

S4-0604. A compliant magnetic circuit should open a visible gap when a target loses permeability through heating.
Test: Heat calibrated targets.
Contrary outcome: Gap responds mainly to support expansion.

S4-0605. A conducting loop should sense torsional vibration through motional voltage while rejecting axial translation.
Test: Apply calibrated motions.
Contrary outcome: Translation creates comparable voltage.

S4-0606. A floating magnetic guide should center a steel rod without contact over a bounded lateral range.
Test: Measure restoring force.
Contrary outcome: Equilibrium is unstable in an uncontrolled direction.

S4-0607. A segmented conductor should reduce eddy-current heating while preserving magnetic-force sensing.
Test: Measure heating and force sensitivity.
Contrary outcome: Segmentation erases useful sensitivity.

S4-0608. A mechanically modulated inductive gap should separate target conductivity from lift-off distance.
Test: Vary both independently.
Contrary outcome: Signals remain inseparable.

S4-0609. A rotating magnet pair should generate a nearly constant restoring torque through shaped angular spacing.
Test: Measure torque-angle curves.
Contrary outcome: Torque remains strongly angle-dependent.

S4-0610. A suspended conductive vane should reveal gas damping independently of eddy damping through field reversal timing.
Test: Measure decay with controlled pressure.
Contrary outcome: Contributions remain confounded.

S4-0611. A passive magnetic latch should reject brief field pulses through an inertial delay.
Test: Apply equal-peak pulses.
Contrary outcome: Pulse duration does not affect switching.

S4-0612. A compliant coil support should reduce vibration-induced inductance drift by maintaining mutual geometry.
Test: Measure inductance under shaking.
Contrary outcome: Support deformation worsens drift.

S4-0613. A conductive mesh should detect a broken strand through rotation-dependent impedance anisotropy.
Test: Break known strands.
Contrary outcome: Anisotropy is below baseline variation.

S4-0614. A moving permanent magnet should estimate liquid flow through drag on an electrically isolated conductive channel.
Test: Compare with flow reference.
Contrary outcome: Wall effects dominate flow response.

S4-0615. A flux-guided balance should compare two magnetic susceptibilities while rejecting uniform external fields.
Test: Test standards and applied fields.
Contrary outcome: Common-mode rejection fails.

S4-0616. A rotating slotted conductor should produce distinguishable drag signatures for surface and through-thickness cracks.
Test: Scan known defects.
Contrary outcome: Signatures overlap.

S4-0617. A compliant magnetic coupler should release at a repeatable torque despite moderate axial gap variation.
Test: Measure thresholds.
Contrary outcome: Gap sensitivity remains large.

S4-0618. A passive inductive liquid-level sensor should reject vessel tilt through differential circumferential windings.
Test: Calibrate level and tilt.
Contrary outcome: Tilt bias remains dominant.

S4-0619. A suspended magnetic ring should reveal joint preload through a change in its stable angular positions.
Test: Vary measured preload.
Contrary outcome: Positions depend only on mounting geometry.

S4-0620. A conducting spiral should convert a transient magnetic pulse into a measurable mechanical twist.
Test: Measure current and motion.
Contrary outcome: Twist is below thermal motion or support vibration.

S4-0621. A rotating magnetic shield should separate target remanence from applied-field response through harmonic symmetry.
Test: Test known targets.
Contrary outcome: Harmonics remain mixed.

S4-0622. A compliant eddy-current brake should limit its own heating by increasing its gap as temperature rises.
Test: Measure temperature and braking torque.
Contrary outcome: Feedback fails to prevent overheating.

S4-0623. A passive magnetic pointer should indicate the direction of a nearby current without substantial response to uniform field drift.
Test: Apply calibrated current and fields.
Contrary outcome: External fields dominate orientation.

S4-0624. A segmented flux return should reduce force spikes as a magnetic rotor crosses pole boundaries.
Test: Measure torque ripple.
Contrary outcome: Segmentation increases ripple.

S4-0625. A conductive liquid-free contact should reveal oxidation through a rate-dependent mechanical damping change under magnetic excitation.
Test: Age controlled contacts.
Contrary outcome: Damping is not oxidation-specific.

S4-0626. A floating magnet should detect container-wall thinning through equilibrium-height shifts after temperature correction.
Test: Machine standards.
Contrary outcome: Height shifts are dominated by magnetic drift.

S4-0627. A rotating coil should infer anisotropic conductivity from phase differences between orthogonal measurements.
Test: Test known plates.
Contrary outcome: Geometry errors mimic anisotropy.

S4-0628. A compliant magnetic detent should provide distinct hold and reset torques without frictional contact.
Test: Measure torque cycles.
Contrary outcome: Hysteresis requires contact friction.

S4-0629. A passive inductive bridge should reveal an off-center conductive inclusion through an antisymmetric signal.
Test: Move calibrated inclusions.
Contrary outcome: Signal cannot resolve position.

S4-0630. A suspended conductor should measure magnetic-field gradients through differential force while rejecting uniform field strength.
Test: Apply known fields.
Contrary outcome: Uniform-field leakage dominates.

S4-0631. A rotating magnetic target should reveal an eccentric conductive inclusion through a split modulation envelope.
Test: Test known embedded inclusions.
Contrary outcome: The envelope cannot separate eccentricity from target tilt.

S4-0632. A compliant flux shutter should switch a magnetic path through buckling rather than sliding.
Test: Measure switching work.
Contrary outcome: Buckling consumes equal or greater work.

S4-0633. A conductive ring array should localize a moving crack tip from sequential damping changes.
Test: Propagate controlled notches.
Contrary outcome: Changes are spatially nonlocal.

S4-0634. A passive magnetic suspension should reduce contact wear in a load-carrying pivot while preserving mechanical stability.
Test: Measure contact force and motion.
Contrary outcome: Instability offsets wear reduction.

S4-0635. A rotating magnet should reveal hidden conductive layers through frequency-dependent drag depth.
Test: Test layered standards.
Contrary outcome: Depth effects cannot be separated from conductivity.

S4-0636. A flexible coil should estimate bending direction from differential inductance in opposing loops.
Test: Calibrate curvature.
Contrary outcome: Temperature and stretch dominate the response.

S4-0637. A magnetic-free reference spring should cancel thermal drift in a magnetic force gauge through paired displacement.
Test: Measure calibration over temperature.
Contrary outcome: Compensation does not improve stability.

S4-0638. A suspended magnetic blade should detect particle accumulation through its angular resonance rather than static deflection.
Test: Add calibrated ferrous particles.
Contrary outcome: Resonance changes are not monotonic.

S4-0639. A conducting plate should generate a measurable drag anisotropy after plastic strain changes its geometry without cracking.
Test: Compare strain states.
Contrary outcome: Signal is below geometric uncertainty.

S4-0640. A rotating flux gate should distinguish a stationary target from moving background metal by modulation phase.
Test: Move background objects.
Contrary outcome: Background aliases into the target channel.

S4-0641. A compliant magnetic clamp should equalize force across irregular targets through independent pole motion.
Test: Map forces.
Contrary outcome: Poles compete and concentrate load.

S4-0642. A passive eddy-current sensor should detect a liquid-metal-free conductive film breaking into isolated islands.
Test: Break controlled metal films.
Contrary outcome: Signal cannot distinguish breakup from thinning.

S4-0643. A floating magnetic rotor should estimate shear stress from angular lag while compensating bulk drag with a reference rotor.
Test: Test known stresses.
Contrary outcome: Reference subtraction amplifies noise.

S4-0644. A rotating conductive cage should suppress external magnetic transients more than slowly varying fields.
Test: Measure transfer function.
Contrary outcome: Shielding lacks useful timescale separation.

S4-0645. A compliant inductive target should indicate pressure through a controlled change in loop area.
Test: Calibrate pressure and geometry.
Contrary outcome: Material hysteresis prevents repeatable readout.

S4-0646. A passive magnetic threshold device should preserve a visible state after a strong field excursion.
Test: Apply known fields.
Contrary outcome: State relaxes immediately.

S4-0647. A suspended loop should distinguish magnetic torque from thermal expansion through opposite response under current reversal.
Test: Measure reversed-current traces.
Contrary outcome: Thermal transients mimic torque symmetry.

S4-0648. A rotating conductor should reveal local delamination in a metal-backed laminate through phase-shifted heating.
Test: Map thermal response.
Contrary outcome: Heat spreading prevents localization.

S4-0649. A flexible flux guide should reduce sensor cross-talk by redirecting leakage fields during overload.
Test: Measure neighboring channels.
Contrary outcome: Redirection increases cross-talk.

S4-0650. A magnetic coupler should tolerate angular misalignment through a floating intermediate rotor.
Test: Measure torque and axial force.
Contrary outcome: Intermediate motion causes unstable locking.

S4-0651. A passive inductive displacement sensor should reject target-temperature changes through two excitation frequencies.
Test: Calibrate distance and temperature.
Contrary outcome: Frequency responses remain degenerate.

S4-0652. A suspended magnet should estimate thin-film elasticity from the recoil of an attached nonconductive vane.
Test: Measure calibrated films.
Contrary outcome: Magnetic drag dominates recoil.

S4-0653. A rotating patterned conductor should encode absolute angle in a unique inductive amplitude ratio.
Test: Measure full rotations.
Contrary outcome: Ratios repeat ambiguously.

S4-0654. A compliant magnetic bearing should detect overload through a reversible shift to a second stable gap.
Test: Measure gap versus load.
Contrary outcome: Transition is irreversible or unstable.

S4-0655. A conducting mesh should damp vibration without forming large circulating currents that cause excessive heating.
Test: Measure loss and temperature.
Contrary outcome: Useful damping requires equal heating.

S4-0656. A passive flux comparator should identify unequal magnet strengths through a centered armature displacement.
Test: Test known pairs.
Contrary outcome: Geometry mismatch dominates the comparison.

S4-0657. A rotating inductive probe should distinguish a shallow dent from a buried void through angular phase dependence.
Test: Scan controlled standards.
Contrary outcome: Signatures remain inseparable.

S4-0658. A flexible magnetic shutter should reset using stored elastic energy after field removal.
Test: Cycle switching.
Contrary outcome: Remanence prevents reliable reset.

S4-0659. A suspended conductive ring should detect joint slip through abrupt changes in magnetic damping.
Test: Apply controlled slip.
Contrary outcome: Damping changes are not slip-specific.

S4-0660. A magnetic force gradient should sort equal-size inert particles by susceptibility without bulk contact.
Test: Track calibrated particles.
Contrary outcome: Hydrodynamic or gravitational effects dominate.

S4-0661. A rotating conductor should reduce torque ripple when its slots follow a chirped rather than periodic spacing.
Test: Measure spectra.
Contrary outcome: Chirping merely spreads equal peak noise.

S4-0662. A compliant flux shunt should maintain a fixed sensor field while an external magnet approaches.
Test: Measure field and shunt motion.
Contrary outcome: Field continues increasing strongly.

S4-0663. A passive inductive reference should expose cable-motion artifacts in a remote sensor.
Test: Move cables independently.
Contrary outcome: Reference does not predict artifacts.

S4-0664. A suspended magnetic pointer should estimate field curvature from its amplitude-dependent period.
Test: Apply known nonuniform fields.
Contrary outcome: Period reflects field magnitude alone.

S4-0665. A rotating eddy brake should reveal lubricant contamination indirectly through changes in bearing-loss symmetry.
Test: Introduce controlled contamination.
Contrary outcome: Magnetic loss masks the bearing signal.

S4-0666. A flexible coil pair should distinguish twist from uniform stretch through opposing mutual-inductance shifts.
Test: Calibrate deformations.
Contrary outcome: Signals remain coupled.

S4-0667. A magnetic latch should resist accidental opening during transverse vibration through a geometric flux trap.
Test: Measure release under shaking.
Contrary outcome: Vibration readily opens the trap.

S4-0668. A conductive shell should detect local wall contact through a sudden change in ring-down damping.
Test: Apply known contacts.
Contrary outcome: Damping is dominated by supports.

S4-0669. A rotating magnetic gradiometer should estimate the depth of a buried ferrous particle from harmonic decay with sensor height.
Test: Test calibrated depths.
Contrary outcome: Depth and particle moment remain inseparable.

S4-0670. A compliant magnetic drive should limit transmitted shock without losing slow torque transfer.
Test: Measure fast and slow inputs.
Contrary outcome: Isolation removes useful torque equally.

S4-0671. A passive inductive pressure gauge should retain zero after overload through a kinematic travel limit.
Test: Measure calibration before and after overload.
Contrary outcome: Zero shifts permanently.

S4-0672. A suspended conductor should reveal a nearby plate's anisotropic grain structure through orientation-dependent damping.
Test: Test characterized metal sheets.
Contrary outcome: Geometry dominates the effect.

S4-0673. A rotating flux pattern should expose target motion below one pole pitch through phase interpolation.
Test: Compare with calibrated stage.
Contrary outcome: Interpolation is biased by amplitude variation.

S4-0674. A flexible magnetic coupler should self-align before carrying substantial torque.
Test: Measure alignment and torque timing.
Contrary outcome: Torque rises before alignment.

S4-0675. A passive eddy-current damper should preserve its response after one conductor segment cracks through redundant loops.
Test: Cut known segments.
Contrary outcome: Damping collapses disproportionately.

S4-0676. A magnetic balance should distinguish target mass change from susceptibility change using gravity reversal and field reversal.
Test: Apply calibrated standards.
Contrary outcome: Contributions remain inseparable.

S4-0677. A rotating coil should measure conducting-film continuity without contacting its surface.
Test: Break controlled paths.
Contrary outcome: Signal remains insensitive to path connectivity.

S4-0678. A compliant flux concentrator should amplify small target motion while limiting large-displacement sensitivity.
Test: Measure field-displacement curve.
Contrary outcome: Amplification persists into saturation unpredictably.

S4-0679. A suspended magnet should detect capillary attachment to a surface through a change in angular relaxation.
Test: Apply controlled liquid bridges.
Contrary outcome: Dry friction creates identical signatures.

S4-0680. A conductive rotor should reduce startup heating through a speed-dependent widening magnetic gap.
Test: Measure thermal transients.
Contrary outcome: Gap change occurs too late.

S4-0681. A passive magnetic indicator should encode peak torque in a retained armature position.
Test: Apply known torque histories.
Contrary outcome: Position depends mostly on duration.

S4-0682. A rotating inductive sensor should reject uniform lift-off by comparing opposite azimuthal sectors.
Test: Vary gap and defect position.
Contrary outcome: Lift-off leakage dominates.

S4-0683. A flexible coil support should survive repeated folding without a large calibration shift through neutral-axis routing.
Test: Measure resistance and inductance.
Contrary outcome: Calibration drifts despite routing.

S4-0684. A magnetic shutter should route a weak field between two outputs with less mechanical work than translating the source magnet.
Test: Measure switching work.
Contrary outcome: Shutter work is not lower.

S4-0685. A suspended conductor should estimate local airflow from the difference between field-on and field-off decay.
Test: Calibrate flows.
Contrary outcome: Field switching alters the mechanical baseline.

S4-0686. A rotating magnetic target should reveal an internal loose inclusion through intermittent phase lag.
Test: Test known inclusions.
Contrary outcome: Phase lag cannot distinguish looseness from imbalance.

S4-0687. A compliant eddy-current damper should increase damping near end-of-travel through a shaped overlap.
Test: Measure force versus position and speed.
Contrary outcome: Damping lacks positional selectivity.

S4-0688. A passive inductive bridge should detect partial contact between overlapping metal sheets through changing current paths.
Test: Vary contact area.
Contrary outcome: Oxide variability prevents calibration.

S4-0689. A magnetic gradient should center a freely moving conductive disk only during rotation.
Test: Measure stability versus speed.
Contrary outcome: No stable speed-dependent centering occurs.

S4-0690. A rotating flux guide should reduce hysteresis in a magnetic measurement by averaging directional domain response.
Test: Measure loop area.
Contrary outcome: Averaging adds systematic bias.

S4-0691. A flexible magnetic latch should expose incomplete closure through a distinct vibration mode.
Test: Measure modes at known gaps.
Contrary outcome: Modes cannot resolve small gaps.

S4-0692. A suspended ring should distinguish external magnetic interference from local target motion using opposite force symmetries.
Test: Apply both disturbances.
Contrary outcome: Symmetry separation fails.

S4-0693. A conductive pattern should measure strain concentration through a local change in eddy-current path length.
Test: Load calibrated specimens.
Contrary outcome: Signal reflects only average strain.

S4-0694. A rotating magnet pair should produce a low-ripple translational force on a constrained follower.
Test: Measure force over rotation.
Contrary outcome: Ripple remains large.

S4-0695. A compliant flux return should preserve sensor sensitivity after small mounting offsets.
Test: Measure calibration across offsets.
Contrary outcome: Offsets still dominate error.

S4-0696. A passive magnetic counter should advance once per complete field reversal and ignore partial reversals.
Test: Apply known sequences.
Contrary outcome: Partial reversals produce false steps.

S4-0697. A suspended conductor should reveal a buried air gap through frequency-dependent magnetic-force phase.
Test: Test controlled laminates.
Contrary outcome: Phase cannot separate gap from thickness.

S4-0698. A rotating inductive probe should quantify surface waviness while rejecting roughness through spatial averaging.
Test: Scan calibrated artifacts.
Contrary outcome: Roughness aliases into waviness.

S4-0699. A flexible magnetic target should indicate distributed pressure through a changing multipole field.
Test: Apply known loads.
Contrary outcome: Different pressure maps yield identical fields.

S4-0700. A passive eddy-current reference should track temperature drift in a neighboring displacement sensor.
Test: Heat both independently.
Contrary outcome: Reference fails to predict drift.

S4-0701. A sealed gas pocket should distinguish a fast compression from slow heating through the sign of its early temperature-pressure lag.
Test: Apply independent perturbations.
Contrary outcome: Lag signatures overlap.

S4-0702. A long narrow vent should reject airborne pressure spikes while admitting slow barometric changes.
Test: Measure pressure transfer.
Contrary outcome: Useful timescale separation is absent.

S4-0703. A porous gas diffuser should reduce flow maldistribution when its upstream chamber changes shape under pressure.
Test: Map outlet velocities.
Contrary outcome: Deformation worsens maldistribution.

S4-0704. A passive gas sampler should reveal diffusion-channel contamination through a delayed internal reference pulse.
Test: Contaminate controlled channels.
Contrary outcome: Reference delay does not track contamination.

S4-0705. A flexible vacuum chamber wall should indicate leak location through spatially unequal relaxation after isolation.
Test: Introduce known leaks.
Contrary outcome: Wall relaxation cannot localize leaks.

S4-0706. A rotating gas cavity should expose temperature stratification through opposite acoustic-path shifts.
Test: Control known gradients.
Contrary outcome: Rotation-induced pressure masks the signal.

S4-0707. A capillary pressure reference should distinguish gas permeation from a discrete leak through area scaling.
Test: Test membranes and pinholes.
Contrary outcome: Scaling remains indistinguishable.

S4-0708. A porous bellows should equalize pressure while filtering dust without a large reset delay.
Test: Measure pressure response and inert dust passage.
Contrary outcome: Filtering causes excessive delay.

S4-0709. A passive gas-flow divider should maintain equal molar flows during moderate downstream-temperature differences.
Test: Measure branch flows.
Contrary outcome: Thermal imbalance dominates.

S4-0710. A flexible vent cover should open during outward gas flow but resist inward splashed water.
Test: Measure both transfer directions.
Contrary outcome: Water rejection blocks gas venting.

S4-0711. A sealed reference bulb should reveal slow gas loss through a changing ratio of two resonant modes.
Test: Introduce calibrated leaks.
Contrary outcome: Mode ratio is insensitive to gas loss.

S4-0712. A rotating microfan analogue should measure gas density from startup acceleration after subtracting bearing drag.
Test: Test inert gas standards.
Contrary outcome: Viscosity confounds density inference.

S4-0713. A porous expansion chamber should lower decompression noise by distributing the release in space.
Test: Measure sound and pressure.
Contrary outcome: Noise is merely shifted to another band.

S4-0714. A passive diaphragm should distinguish ambient-pressure drift from local gas generation through differential vent paths.
Test: Apply calibrated inputs.
Contrary outcome: Responses remain degenerate.

S4-0715. A flexible gas bag should maintain a fixed optical sampling thickness using a tensioned internal spacer.
Test: Measure path length over volume.
Contrary outcome: Spacer buckles or distorts the path.

S4-0716. A capillary vent should resist condensation blockage when its wall warms preferentially through gas flow.
Test: Measure flow during cooling.
Contrary outcome: Condensation still seals the vent.

S4-0717. A sealed gas spring should estimate humidity from damping after independent temperature compensation.
Test: Test controlled humidity.
Contrary outcome: Gas composition changes are below mechanical drift.

S4-0718. A porous reservoir should release absorbed benign vapor in a reproducible pulse after rapid decompression.
Test: Measure release curves.
Contrary outcome: Pulse shape depends strongly on history.

S4-0719. A passive gas mixer should reduce composition gradients through buoyancy-driven circulation without moving parts.
Test: Map inert tracer concentration.
Contrary outcome: Stratification persists.

S4-0720. A flexible inlet should suppress compressible-flow whistle onset by moving its lip away from resonance.
Test: Measure onset pressure.
Contrary outcome: Lip motion creates another tone.

S4-0721. A rotating pressure tap should distinguish static pressure from directional dynamic pressure through angular harmonics.
Test: Calibrate flow fields.
Contrary outcome: Harmonics remain mixed.

S4-0722. A porous gas seal should reduce leakage after compression by closing its largest connected pathways first.
Test: Measure permeability and pore images.
Contrary outcome: Small pathways close first without useful sealing.

S4-0723. A passive gas-volume comparator should compare two unknown volumes through equalization displacement rather than absolute pressure.
Test: Test calibrated chambers.
Contrary outcome: Thermal transients dominate the comparison.

S4-0724. A flexible purge chamber should sweep stagnant corners through pressure-driven wall motion.
Test: Measure tracer washout.
Contrary outcome: Dead zones remain.

S4-0725. A capillary gas restrictor should self-clean condensed liquid through a pressure-triggered shape change.
Test: Measure recovery after condensation.
Contrary outcome: Shape change traps liquid.

S4-0726. A sealed acoustic bulb should reveal gas contamination through dispersion between low and high modes.
Test: Test known inert mixtures.
Contrary outcome: Dispersion is below wall-loss uncertainty.

S4-0727. A porous pressure buffer should preserve mean pressure while reducing pump-induced concentration oscillations.
Test: Measure pressure and tracer signals.
Contrary outcome: Concentration oscillations remain unchanged.

S4-0728. A passive vent should close before a rising liquid reaches its gas outlet through buoyancy-amplified motion.
Test: Measure closure timing.
Contrary outcome: Liquid enters before closure.

S4-0729. A flexible gas channel should distinguish blockage from outlet-pressure rise through a local wall-shape ratio.
Test: Apply both disturbances.
Contrary outcome: Shape ratios overlap.

S4-0730. A rotating gas sampler should reduce directional bias in concentration measurement near a source.
Test: Compare known concentration fields.
Contrary outcome: Rotation averages away useful gradients.

S4-0731. A porous chamber wall should reveal absorbed moisture through a changed pressure-relaxation tail.
Test: Control moisture loading.
Contrary outcome: Tail is dominated by leaks.

S4-0732. A passive gas-driven oscillator should stop cleanly when flow falls below a threshold instead of producing irregular pulses.
Test: Measure low-flow behavior.
Contrary outcome: Intermittent pulsing persists.

S4-0733. A flexible pressure reservoir should retain a known gas aliquot after supply disconnection.
Test: Measure aliquot across supply conditions.
Contrary outcome: Volume depends strongly on disconnect timing.

S4-0734. A capillary diffusion bridge should separate gas-concentration change from pressure change using opposed reservoirs.
Test: Apply independent changes.
Contrary outcome: Signals remain confounded.

S4-0735. A sealed gas pocket should report local heat flux from pressure-rise curvature after calibration.
Test: Apply known heat pulses.
Contrary outcome: Wall heat capacity dominates curvature.

S4-0736. A porous muffler should preserve attenuation after partial clogging through independent parallel flow paths.
Test: Block selected paths.
Contrary outcome: Clogging creates a loud bypass tone.

S4-0737. A passive gas check valve should avoid chatter through controlled elastic energy release at opening.
Test: Measure motion and pressure.
Contrary outcome: Release increases oscillation.

S4-0738. A flexible gas film bearing should detect approach to contact through a sharp phase-lag change.
Test: Measure gap and response.
Contrary outcome: Phase changes only after contact.

S4-0739. A rotating vent should shed condensed droplets centrifugally while preserving gas-flow resistance.
Test: Measure droplet removal and resistance.
Contrary outcome: Removal requires excessive rotational drag.

S4-0740. A porous gas sampler should reject short concentration spikes through distributed diffusion lengths.
Test: Apply controlled histories.
Contrary outcome: Spikes dominate the collected sample.

S4-0741. A sealed bellows should distinguish gas adsorption on its wall from a temperature shift through delayed recovery.
Test: Control both effects.
Contrary outcome: Recovery curves overlap.

S4-0742. A passive pressure amplifier should increase differential pressure sensitivity without increasing common-pressure sensitivity.
Test: Calibrate both.
Contrary outcome: Common-mode error grows equally.

S4-0743. A flexible gas duct should reduce startup pressure overshoot by temporarily increasing volume near the inlet.
Test: Measure transients.
Contrary outcome: Stored gas produces a larger rebound pulse.

S4-0744. A capillary leak should reveal its location along a tube through unequal pressure-relaxation times at both ends.
Test: Introduce known leaks.
Contrary outcome: Location estimates remain ambiguous.

S4-0745. A rotating gas cavity should average gravity-induced stratification faster than molecular diffusion alone.
Test: Measure inert tracer mixing.
Contrary outcome: Rotation creates stable segregation.

S4-0746. A porous vent should remain open during frost formation through a protected warm gas-return path.
Test: Image benign freezing conditions.
Contrary outcome: Frost bridges the protected path.

S4-0747. A passive gas reservoir should deliver nearly constant pressure through sequential chamber collapse.
Test: Measure pressure-volume curve.
Contrary outcome: Collapse events create large pressure steps.

S4-0748. A flexible diaphragm array should map pressure impulse arrival direction through switching order.
Test: Apply controlled waves.
Contrary outcome: Switch order is dominated by threshold variation.

S4-0749. A sealed optical gas cell should reduce window contamination through a sacrificial internal condensation surface.
Test: Measure window transmission.
Contrary outcome: Contamination remains on the windows.

S4-0750. A porous pressure divider should distinguish gas viscosity from supply pressure using two transient ratios.
Test: Test known gases.
Contrary outcome: Ratios are not independently informative.

S4-0751. A passive relief valve should reopen less violently when a compressible side pocket stores its closure impulse.
Test: Measure valve acceleration.
Contrary outcome: Pocket increases rebound.

S4-0752. A flexible gas conduit should maintain conductance during bending through internal floating spacers.
Test: Measure flow versus curvature.
Contrary outcome: Spacers create new restrictions.

S4-0753. A capillary sampling inlet should reject liquid droplets while preserving response to gas-concentration steps.
Test: Measure gas response and droplet ingress.
Contrary outcome: Droplet rejection causes excessive gas lag.

S4-0754. A sealed gas balance should measure molecular mass through buoyancy and resonance jointly.
Test: Test inert standards.
Contrary outcome: Parameters cannot be separated from temperature.

S4-0755. A rotating porous gas outlet should reduce jet directional bias through time averaging.
Test: Map momentum distribution.
Contrary outcome: Residual bias remains large.

S4-0756. A porous reference chamber should expose gas-sensor pressure sensitivity independently of concentration.
Test: Vary pressure and tracer concentration.
Contrary outcome: Reference does not isolate pressure artifacts.

S4-0757. A passive gas timer should reset faster than it actuates through asymmetric vent conductance.
Test: Measure timing cycles.
Contrary outcome: Reset remains equally slow.

S4-0758. A flexible membrane should distinguish positive from negative pressure excursions through different stable wrinkle patterns.
Test: Apply calibrated pulses.
Contrary outcome: Patterns are not sign-specific.

S4-0759. A capillary gas bridge should preserve pressure communication despite small liquid intrusion by routing around the liquid plug.
Test: Measure transfer after dosing.
Contrary outcome: Plug blocks all routes.

S4-0760. A sealed chamber should reveal wall permeation through a pressure response that changes with external gas composition.
Test: Test controlled inert atmospheres.
Contrary outcome: Leaks produce indistinguishable changes.

S4-0761. A porous expansion plug should reduce thermal shock during gas release by spreading cooling over its volume.
Test: Map temperatures.
Contrary outcome: Cooling remains localized.

S4-0762. A passive pneumatic regulator should maintain its setpoint after moderate membrane creep through geometric feedback.
Test: Measure long-term pressure.
Contrary outcome: Setpoint drifts with creep.

S4-0763. A flexible gas collector should separate discrete bubbles from continuous gas flow through two mechanical states.
Test: Apply calibrated gas inputs.
Contrary outcome: States depend only on total volume.

S4-0764. A rotating pressure reference should reject static support tilt while preserving centrifugal-pressure sensitivity.
Test: Calibrate both.
Contrary outcome: Tilt bias remains large.

S4-0765. A porous vent membrane should reveal incipient wetting through a sharp change in gas-flow noise.
Test: Control liquid contact.
Contrary outcome: Noise changes only after full blockage.

S4-0766. A sealed gas spring should reduce temperature sensitivity through a moving thermal-contact sleeve.
Test: Measure stiffness-temperature response.
Contrary outcome: Sleeve feedback adds hysteresis.

S4-0767. A passive gas pulse router should select paths according to pulse spacing rather than pulse amplitude.
Test: Apply controlled trains.
Contrary outcome: Routing is amplitude-dominated.

S4-0768. A flexible pressure shield should attenuate airborne impulses without strongly blocking slow ventilation.
Test: Measure transfer and airflow.
Contrary outcome: Attenuation requires near-total sealing.

S4-0769. A capillary gas sensor should infer acceleration from pressure differences between opposing trapped pockets.
Test: Apply known motions.
Contrary outcome: Temperature differences dominate the signal.

S4-0770. A porous chamber should reduce gas residence-time tails by allowing diffusion through otherwise stagnant walls.
Test: Measure tracer washout.
Contrary outcome: Tails remain unchanged.

S4-0771. A sealed flexible capsule should preserve an excursion record through a permanent geometric inversion.
Test: Apply calibrated pressure peaks.
Contrary outcome: Inversion depends mostly on pulse duration.

S4-0772. A passive vacuum indicator should distinguish pump failure from line blockage through two reference volumes.
Test: Introduce both faults.
Contrary outcome: Indicator states overlap.

S4-0773. A rotating gas channel should separate dense inert tracer from carrier gas measurably at modest rotational speed.
Test: Measure concentrations.
Contrary outcome: Diffusion erases the predicted separation.

S4-0774. A porous gas bearing should maintain centering after one supply hole blocks through lateral permeability.
Test: Block holes and measure runout.
Contrary outcome: Bearing contacts its shaft.

S4-0775. A flexible relief lip should reduce leakage after repeated opening through a self-reseating rolling motion.
Test: Measure leak cycles.
Contrary outcome: Rolling increases residual gaps.

S4-0776. A capillary gas delay should retain its timing after moderate humidity changes through a protected dry reference path.
Test: Measure delays.
Contrary outcome: Humidity still shifts timing substantially.

S4-0777. A sealed pressure chamber should detect an internal flexible obstruction through nonlinear compression response.
Test: Insert calibrated membranes.
Contrary outcome: Response is indistinguishable from gas-volume change.

S4-0778. A porous vent should route condensed liquid away from its main gas pathway by capillary competition.
Test: Image gas and liquid paths.
Contrary outcome: Liquid floods the gas path.

S4-0779. A passive pneumatic bridge should detect a tiny added volume through a differential oscillation period.
Test: Add calibrated volumes.
Contrary outcome: Period noise masks the change.

S4-0780. A flexible gas reservoir should release stored pressure more uniformly when its collapse front travels rather than nucleates randomly.
Test: Image collapse and pressure.
Contrary outcome: Front motion remains erratic.

S4-0781. A rotating gas sampler should encode exposure duration in the position of a diffusion front.
Test: Compare known exposures.
Contrary outcome: Front position depends mainly on concentration.

S4-0782. A porous pressure reference should reject rapid thermal transients through matched solid and gas heat capacities.
Test: Measure pressure during heating.
Contrary outcome: Matching does not reduce drift.

S4-0783. A sealed bellows should report loss of vacuum through a changed snap threshold before gross expansion.
Test: Introduce leaks.
Contrary outcome: Threshold changes too late.

S4-0784. A passive gas-flow oscillator should identify a branch leak through altered pulse asymmetry.
Test: Introduce calibrated leaks.
Contrary outcome: Asymmetry also changes with normal load.

S4-0785. A flexible air-return tube should prevent liquid-column breakup during reservoir draining.
Test: Measure gas path and flow continuity.
Contrary outcome: Tube collapse causes additional breakup.

S4-0786. A capillary gas pocket should measure surface tension from pressure-volume hysteresis without optical contact-angle measurement.
Test: Compare calibrated liquids.
Contrary outcome: Wetting history prevents reliable inversion.

S4-0787. A porous exhaust should reduce impulsive recoil by distributing gas release over time.
Test: Measure reaction force.
Contrary outcome: Recoil impulse remains equally concentrated.

S4-0788. A sealed gas reference should compensate altitude-related drift in a mechanical timer.
Test: Measure timing across chamber pressures.
Contrary outcome: Compensation fails.

S4-0789. A passive pneumatic latch should tolerate slow supply decay while responding to rapid intentional depressurization.
Test: Apply pressure histories.
Contrary outcome: Decay and reset cannot be separated.

S4-0790. A flexible gas duct should expose partial collapse through a distinct pressure-noise harmonic.
Test: Control collapse extent.
Contrary outcome: Harmonic is not collapse-specific.

S4-0791. A rotating pressure sensor should average port contamination errors through sequential reference exposure.
Test: Contaminate known ports.
Contrary outcome: Averaging propagates contamination to all readings.

S4-0792. A porous gas storage pad should release a fixed fraction of stored gas per compression cycle.
Test: Measure volume per stroke.
Contrary outcome: Fraction drifts with cycle count.

S4-0793. A sealed diaphragm should reveal a tiny liquid contaminant through amplitude-dependent resonance damping.
Test: Dose known droplets.
Contrary outcome: Temperature drift masks the signal.

S4-0794. A passive vent should prevent reverse diffusion during idle periods by closing under zero flow.
Test: Measure tracer ingress.
Contrary outcome: Closure leaks diffusively.

S4-0795. A flexible gas separator should protect a downstream pressure sensor from liquid slugs through transient volume expansion.
Test: Apply controlled slugs.
Contrary outcome: Liquid reaches the sensor.

S4-0796. A capillary reference should distinguish absolute pressure from differential pressure using two gas volumes of unequal compliance.
Test: Calibrate both.
Contrary outcome: The inversion is ill-conditioned.

S4-0797. A porous pressure-relief structure should remain functional after one cell is crushed through alternate pathways.
Test: Crush controlled cells.
Contrary outcome: Relief capacity collapses.

S4-0798. A sealed gas oscillator should reveal wall softening through a shift in waveform shape before frequency changes.
Test: Heat controlled walls.
Contrary outcome: Waveform change is not stiffness-specific.

S4-0799. A passive pneumatic sampler should preserve the order of two gas pulses in separate chambers.
Test: Apply inert tracer pulses.
Contrary outcome: Diffusion scrambles order.

S4-0800. A flexible vent should return to its initial conductance after repeated wetting and drying.
Test: Measure flow cycles.
Contrary outcome: Residual liquid changes conductance permanently.

S4-0801. A self-aligning drill-free positioning jig should reduce hole-location error by seating on three independently floating references.
Test: Measure calibrated parts.
Contrary outcome: Floating references increase error.

S4-0802. A compliant molding insert should release undercut shapes through sequential inversion without damaging the part.
Test: Measure release force and defects.
Contrary outcome: Inversion tears the part.

S4-0803. A rotating curing mask should reduce shrinkage warping by distributing exposure in time.
Test: Measure benign resin-analogue geometry.
Contrary outcome: Warping remains unchanged.

S4-0804. A passive leveling fixture should compensate unequal support heights through a fluid-free mechanical differential.
Test: Measure platform tilt.
Contrary outcome: Differential friction prevents leveling.

S4-0805. A flexible casting wall should preserve volume while relieving solidification stress through tangential motion.
Test: Measure stress and final dimensions.
Contrary outcome: Relief changes volume substantially.

S4-0806. A sacrificial geometric tab should indicate that a press-fit reached its intended insertion depth.
Test: Compare tab state with measured depth.
Contrary outcome: Tabs trigger prematurely or inconsistently.

S4-0807. A rolling alignment cone should reveal a skewed receiving bore through unequal contact-roller rotations.
Test: Insert into calibrated bore angles.
Contrary outcome: Rotation asymmetry is dominated by friction.

S4-0808. A compliant deburring-free edge protector should prevent handling damage by redirecting contact into a stronger region.
Test: Apply controlled impacts.
Contrary outcome: Damage remains at the edge.

S4-0809. A rotating inspection cradle should expose surface defects through repeatable changing specular highlights.
Test: Test known defects.
Contrary outcome: Highlights create more false positives than detections.

S4-0810. A passive clamping fixture should retain equal forces after one workpiece dimension changes thermally.
Test: Measure clamp forces.
Contrary outcome: One jaw monopolizes load.

S4-0811. A flexible powder-spreading blade should reduce streaks by locally lifting over large inert particles.
Test: Map layer thickness.
Contrary outcome: Lifting creates larger streaks.

S4-0812. A shaped cooling fixture should reduce residual curvature by delaying release where cooling is slowest.
Test: Measure final geometry.
Contrary outcome: Delayed release worsens stress.

S4-0813. A self-centering folding mandrel should preserve lumen shape during soft-tube fabrication.
Test: Measure cross-sections.
Contrary outcome: Mandrel removal distorts the lumen.

S4-0814. A compliant gauge should distinguish oversize from out-of-round parts through two sequential contact states.
Test: Test calibration artifacts.
Contrary outcome: States remain ambiguous.

S4-0815. A rotating deposition shield should equalize coating thickness on recessed surfaces.
Test: Measure benign coating maps.
Contrary outcome: Recess shadowing persists.

S4-0816. A passive tensioner should keep film tension stable as a supply roll's diameter decreases.
Test: Measure tension through payout.
Contrary outcome: Tension follows roll radius.

S4-0817. A flexible mold vent should open under trapped-gas pressure and close before liquid escapes.
Test: Measure gas and benign casting-fluid leakage.
Contrary outcome: Closure is too late.

S4-0818. A geometric assembly key should prevent a nearly correct but reversed insertion without high jamming force.
Test: Test deliberate misassembly.
Contrary outcome: Wrong insertion jams destructively.

S4-0819. A rolling support fixture should reduce distortion when a thin sheet is trimmed by a noncutting scoring analogue.
Test: Measure deflection.
Contrary outcome: Supports introduce local dents.

S4-0820. A compliant transfer tray should preserve relative positions of small parts during acceleration.
Test: Track calibrated parts.
Contrary outcome: Parts migrate within pockets.

S4-0821. A passive fixture should separate dimensional expansion from elastic springback through two release stages.
Test: Measure staged geometry.
Contrary outcome: Both effects remain inseparable.

S4-0822. A flexible coating applicator should maintain wet-film thickness over gentle curvature changes.
Test: Map deposited thickness.
Contrary outcome: Curvature produces systematic thickness errors.

S4-0823. A rotating powder hopper should reduce layer-to-layer concentration drift in a benign binary mixture.
Test: Sample composition.
Contrary outcome: Rotation increases segregation.

S4-0824. A self-adjusting spacer should maintain a target gap while adjacent parts shrink during drying.
Test: Measure gap and shrinkage.
Contrary outcome: Spacer binds or loses contact.

S4-0825. A compliant alignment rail should guide a thin strip without edge buckling under small feed errors.
Test: Measure buckle onset.
Contrary outcome: Rail compliance lowers the threshold.

S4-0826. A passive release film should peel from a casting in a prescribed order through unequal local bending stiffness.
Test: Image release front.
Contrary outcome: Order is dominated by adhesion variability.

S4-0827. A flexible support grid should reveal uneven vacuum holding through a visible shape pattern.
Test: Apply controlled suction leaks.
Contrary outcome: Pattern cannot localize weak holding.

S4-0828. A rotating wash fixture should clear recessed inert particles using gravity reversals rather than high jet pressure.
Test: Count retained particles.
Contrary outcome: Reversals add no cleaning benefit.

S4-0829. A self-centering collet should preserve angular orientation through asymmetric reference contacts.
Test: Measure remounting angle.
Contrary outcome: Orientation remains ambiguous.

S4-0830. A compliant press tool should distribute insertion force among multiple pins despite height tolerances.
Test: Measure pin loads.
Contrary outcome: The tallest pin still overloads.

S4-0831. A passive thermal assembly aid should close a joint only after both parts reach similar temperature.
Test: Measure closure timing.
Contrary outcome: One-sided heating triggers closure.

S4-0832. A flexible mold core should contract radially during extraction through axial tension.
Test: Measure extraction force and core diameter.
Contrary outcome: Contraction is insufficient to aid release.

S4-0833. A rotating optical inspection stage should distinguish scratches from waviness by spatial-frequency scaling with angle.
Test: Test known surfaces.
Contrary outcome: Signatures remain confounded.

S4-0834. A geometric fill indicator should expose trapped gas in a transparent casting cavity before sealing.
Test: Image known gas pockets.
Contrary outcome: Indicator misses isolated pockets.

S4-0835. A compliant transport gripper should maintain part orientation during release through delayed fingertip withdrawal.
Test: Measure landing orientation.
Contrary outcome: Withdrawal timing adds rotation.

S4-0836. A passive web guide should correct lateral drift without sensing the web edge directly.
Test: Apply known disturbances.
Contrary outcome: Correction requires edge contact.

S4-0837. A flexible coating mask should seal better under spray pressure while peeling easily after drying.
Test: Measure leakage and peel work.
Contrary outcome: Improved sealing raises peel work substantially.

S4-0838. A rotating drying rack should reduce thickness gradients in a benign liquid coating through gravity averaging.
Test: Measure final film.
Contrary outcome: Rotation creates circumferential bands.

S4-0839. A self-adjusting assembly nest should reject an incorrectly seated part through a distinct rocking mode.
Test: Test seating errors.
Contrary outcome: Correct parts show the same mode.

S4-0840. A compliant polishing-free contact probe should measure a fragile surface without exceeding a preset pressure.
Test: Measure contact force and area.
Contrary outcome: Pressure exceeds the preset level.

S4-0841. A passive metering slot should compensate thermal expansion of a powder feed aperture.
Test: Measure aperture and throughput.
Contrary outcome: Compensation fails across temperature.

S4-0842. A flexible molding seam should vent gas through temporary opening and then reseal under liquid pressure.
Test: Measure timing and leakage.
Contrary outcome: Seam remains open.

S4-0843. A rotating part carrier should reduce collision damage by matching part velocity before capture.
Test: Measure impact force.
Contrary outcome: Velocity matching is too slow.

S4-0844. A geometric curing support should permit shrinkage along one axis while preserving angular alignment.
Test: Measure final shape.
Contrary outcome: Allowed motion introduces rotation.

S4-0845. A compliant wire guide should maintain bend radius during changing feed tension.
Test: Map wire curvature.
Contrary outcome: Radius falls below the target.

S4-0846. A passive sorting jig should distinguish a warped plate from a uniformly thick plate through contact sequence.
Test: Test known artifacts.
Contrary outcome: Sequences overlap.

S4-0847. A flexible deposition stencil should correct its gap locally under substrate waviness.
Test: Measure pattern fidelity.
Contrary outcome: Local motion blurs the pattern.

S4-0848. A rotating rinsing channel should remove residual liquid from blind cavities through centrifugal exchange.
Test: Weigh residuals.
Contrary outcome: Gas locking prevents exchange.

S4-0849. A self-equalizing clamp should reduce dimensional error after unclamping a thin workpiece.
Test: Measure before/after geometry.
Contrary outcome: Equal forces do not reduce springback.

S4-0850. A compliant assembly funnel should store lateral error elastically and release it before final seating.
Test: Measure trajectory and force.
Contrary outcome: Stored error persists into seating.

S4-0851. A passive coating thickness gauge should use a rolling meniscus rather than a sliding blade.
Test: Compare gravimetric thickness.
Contrary outcome: Meniscus hysteresis limits accuracy.

S4-0852. A flexible powder bed boundary should reduce edge-density differences during vibration compaction.
Test: Measure density maps.
Contrary outcome: Edge effects remain unchanged.

S4-0853. A rotating mold should suppress one-sided bubble accumulation during benign liquid casting.
Test: Image void distribution.
Contrary outcome: Rotation traps a central gas core.

S4-0854. A geometric handling fixture should fail visibly before an attached delicate part experiences overload.
Test: Measure force sequence.
Contrary outcome: Part damage occurs first.

S4-0855. A compliant centering pin should tolerate initial misalignment without scraping the mating bore.
Test: Inspect contact and wear.
Contrary outcome: Pin still scrapes the bore.

S4-0856. A passive drying support should maintain film flatness by releasing edge tension as mass falls.
Test: Measure curvature.
Contrary outcome: Release promotes wrinkling.

S4-0857. A flexible applicator should detect a surface step through a remote force pulse before its coating edge reaches the step.
Test: Measure timing.
Contrary outcome: Detection arrives too late.

S4-0858. A rotating sampling cup should collect a representative powder sample across a segregated stream.
Test: Compare composition with full capture.
Contrary outcome: Sampling remains biased.

S4-0859. A self-adjusting spacer array should equalize a narrow coating gap over a warped substrate.
Test: Map gap.
Contrary outcome: Spacer cross-talk creates new errors.

S4-0860. A compliant demolding tool should propagate one controlled peel front instead of multiple damaging fronts.
Test: Image release and defects.
Contrary outcome: Multiple fronts persist.

S4-0861. A passive fixture should retain registration after one locator is contaminated by inert dust.
Test: Add calibrated dust.
Contrary outcome: Registration shifts substantially.

S4-0862. A flexible casting reservoir should feed shrinkage preferentially into the last-solidifying region.
Test: Track benign solidification analogue.
Contrary outcome: Feed path closes too early.

S4-0863. A rotating alignment target should reveal spindle tilt separately from radial runout.
Test: Measure calibrated errors.
Contrary outcome: Signals remain degenerate.

S4-0864. A geometric overflow path should indicate complete cavity filling without trapping a large excess volume.
Test: Measure fill state and waste.
Contrary outcome: Indicator triggers before full filling.

S4-0865. A compliant edge guide should suppress thin-film folding during a sudden feed stop.
Test: Measure fold frequency.
Contrary outcome: Guide recoil increases folding.

S4-0866. A passive part holder should maintain constant contact area during small thermal dimensional changes.
Test: Image contact.
Contrary outcome: Area varies strongly.

S4-0867. A flexible stencil should release deposited features with less lateral drag through out-of-plane curling.
Test: Measure feature displacement.
Contrary outcome: Curling increases distortion.

S4-0868. A rotating cleaning brush should retreat from sharp protrusions through local geometric compliance.
Test: Measure substrate force.
Contrary outcome: Retreat happens after the peak force.

S4-0869. A self-indexing assembly tray should expose a missing part through a mechanically unbalanced state.
Test: Remove known parts.
Contrary outcome: State is too sensitive to normal mass variation.

S4-0870. A compliant feed roller should maintain traction while reducing indentation of soft stock.
Test: Measure slip and dents.
Contrary outcome: Traction requires equal indentation.

S4-0871. A passive thermal clamp should loosen during cooling only after a bonded analogue gains sufficient stiffness.
Test: Measure force and modulus timing.
Contrary outcome: Release occurs before stiffness develops.

S4-0872. A flexible transfer membrane should place small inert particles while retaining positional order.
Test: Image before/after positions.
Contrary outcome: Release scrambles ordering.

S4-0873. A rotating drying fixture should preserve a central hole by preventing liquid pooling at its rim.
Test: Measure final aperture.
Contrary outcome: Rotation deposits more material at the rim.

S4-0874. A geometric insertion aid should reveal partial engagement through a separate visible displacement.
Test: Compare indicator and depth.
Contrary outcome: Indicator falsely signals full engagement.

S4-0875. A compliant mold wall should reduce seam flash by increasing contact pressure during filling.
Test: Measure flash and wall motion.
Contrary outcome: Motion opens the seam.

S4-0876. A passive web accumulator should absorb a short feed mismatch without changing downstream tension substantially.
Test: Measure tension transients.
Contrary outcome: Mismatch passes through.

S4-0877. A flexible surface replica should preserve shallow grooves during removal through sequential stretching.
Test: Compare replica geometry.
Contrary outcome: Stretching distorts groove spacing.

S4-0878. A rotating powder distributor should compensate hopper depletion through a moving gravity reference.
Test: Measure delivered mass.
Contrary outcome: Dose still falls with fill level.

S4-0879. A self-centering optical fixture should retain focus after exchanging samples of slightly different thickness.
Test: Measure focus and position.
Contrary outcome: Thickness changes remain uncompensated.

S4-0880. A compliant pressing platen should expose uneven load through a measurable tilt before damaging pressure develops.
Test: Measure tilt and local pressure.
Contrary outcome: Warning comes after overload.

S4-0881. A passive filling manifold should close completed branches while continuing to fill empty cavities.
Test: Measure cavity volumes.
Contrary outcome: Early closure starves some cavities.

S4-0882. A flexible handling sleeve should prevent rolling parts from colliding during vibration transport.
Test: Track collisions.
Contrary outcome: Sleeve couples parts into collective impacts.

S4-0883. A rotating coating drain should remove excess liquid without creating a thick terminal bead.
Test: Measure profile.
Contrary outcome: A bead forms at a different location.

S4-0884. A geometric assembly spring should encode correct engagement through a unique force-displacement curve.
Test: Compare assembly states.
Contrary outcome: Incorrect states produce similar curves.

S4-0885. A compliant support should reduce gravity sag during curing by shifting contact points as stiffness increases.
Test: Measure final curvature.
Contrary outcome: Shifting leaves permanent contact marks.

S4-0886. A passive inspection jig should distinguish a tilted cylinder from an eccentric cylinder through two separated rolling contacts.
Test: Test calibrated artifacts.
Contrary outcome: Outputs remain ambiguous.

S4-0887. A flexible demolding core should return to its original dimensions after repeated collapse cycles.
Test: Measure geometry.
Contrary outcome: Residual deformation accumulates.

S4-0888. A rotating rinsing fixture should reduce water use by repeatedly reorienting trapped liquid pockets.
Test: Measure cleaning versus volume.
Contrary outcome: Reorientation adds no benefit.

S4-0889. A self-adjusting film spacer should preserve coating thickness despite moderate operator-free force variation.
Test: Measure film under controlled loads.
Contrary outcome: Thickness remains force-dependent.

S4-0890. A compliant powder scraper should reduce particle fracture by limiting local contact force.
Test: Measure fragment distribution.
Contrary outcome: Force limiting destroys layer uniformity.

S4-0891. A passive assembly latch should reject debris-induced false seating through a second independent contact condition.
Test: Add inert debris.
Contrary outcome: Debris satisfies both conditions.

S4-0892. A flexible curing mask should preserve edge sharpness during substrate shrinkage by moving with the substrate.
Test: Measure boundaries.
Contrary outcome: Mask lag blurs the edge.

S4-0893. A rotating feed guide should reduce twist accumulation in a continuously supplied ribbon.
Test: Measure twist per length.
Contrary outcome: Guide adds twist.

S4-0894. A geometric vacuum fixture should localize leakage from one uncovered port.
Test: Uncover controlled ports.
Contrary outcome: Leakage releases all held parts.

S4-0895. A compliant part nest should reduce remounting error by averaging several weak contacts.
Test: Measure repeated placement.
Contrary outcome: Weak contacts increase variability.

S4-0896. A passive drying indicator should track remaining solvent-free water mass through support deflection.
Test: Compare with gravimetry.
Contrary outcome: Deflection is dominated by stiffness changes.

S4-0897. A flexible casting gate should close when shrinkage reverses local flow, preventing backflow.
Test: Image flow reversal.
Contrary outcome: Gate closes too late.

S4-0898. A rotating inspection mirror should reveal internal cavity defects through multiple viewing directions from one camera.
Test: Test known defects.
Contrary outcome: Occlusions remain unresolved.

S4-0899. A self-equalizing alignment frame should preserve parallelism after one mounting screw settles.
Test: Measure angle.
Contrary outcome: Settlement changes parallelism substantially.

S4-0900. A compliant assembly protector should detach after correct seating while remaining attached during handling.
Test: Measure release thresholds.
Contrary outcome: Handling causes premature release.