Hand-considered hypotheses, 1–100

Written one at a time, not composed. No template, no grid. Each entry varies its logical form as well as its subject: some claim a quantity is misattributed, some assert a bound, some an inversion, some a hidden term, some an artefact that mimics a real effect. The form is printed with each. None has been tested. This is hypotheses 1–100 of a planned 1,000; the rate is deliberate, because the alternative — a thousand in one pass — would be a template again.

Optics and radiation

Misattribution
H001. The apparent blueshift of a thin-film emission line is usually attributed to strain, but in films thinner than the exciton Bohr radius it may be the substrate's image charge reshaping the potential; the test is a metal versus dielectric substrate at identical strain, where strain cannot differ but the image charge does.
Hidden term
H002. Every visible-spectrum optical constant measured on a hydrated surface carries a term proportional to the adsorbed water layer's dispersion, and the term changes sign between hydrophilic and hydrophobic surfaces — so a "material constant" measured in air is a constant of the material plus its humidity history.
Bound
H003. There is a minimum thickness below which a high-reflectivity coating cannot exceed the reflectance of the bare substrate, set by the imaginary part of the coating's index, and it is thicker than the quarter-wave stack design rule suggests.
Inversion
H004. Photodarkening in chalcogenide films, usually read as damage, is the material reporting its own thermal history — and the darkening rate is therefore a thermometer with better resolution than the thermocouple that measured it.
Artefact mimicking effect
H005. The reported "slow light" in some resonant media is a group-delay measurement through a cavity whose finesse was inferred rather than measured; the delay is real but belongs to the cavity, not the medium, and scales with finesse in a way that separates them.
Reversal
H006. Thermal lensing in a pumped crystal reverses sign at a pump intensity set by the competition between dn/dT and the end-face bulging, and the reversal intensity is a cleaner measurement of the photoelastic constants than either effect alone.

Acoustics and mechanics

Identity claim
H007. The two "different" damping mechanisms seen in a bolted joint are the same dissipation viewed at two amplitudes, and the crossover amplitude in a joint is set by the ratio of bolt preload to asperity yield — so the joint's damping spectrum alone cannot distinguish them, only its amplitude dependence can.
Count
H008. A structure with N bolted joints has at most 2N independent damping parameters, and any identification claiming more is fitting noise; the test is a coordinate-descent fit on a structure with a known joint count.
Misattribution
H009. Frequency shift observed when a beam is coated is usually assigned to added mass, but for coatings thinner than the beam's thermal diffusion length the dominant term is the coating's stiffness contribution through the neutral axis, which shifts the opposite way for a compliant coating.
Threshold
H010. There is a load below which fretting does not occur regardless of cycle count, set by the ratio of slip amplitude to the elastic accommodation of the contact, and it can be predicted from the two materials' elastic moduli alone.
Inversion of a standard practice
H011. Preloading a bolt to the "correct" 70% of yield is wrong for joints whose clamped stack has a different thermal expansion coefficient than the bolt: the correct preload is a function of the service temperature range, not of the bolt's yield.
Hidden variable
H012. The measured quality factor of a high-Q resonator contains a term from the mounting that is proportional to the ratio of the mount's acoustic impedance to the resonator's — and this is why Q varies between laboratories using identical parts.

Fluids and transport

Bound
H013. A capillary wick has a maximum sustainable flux independent of its permeability, set by the vapour space's resistance, and above that flux improving the wick makes things worse — an inversion of the usual "higher permeability is better" design instinct.
Artefact
H014. The "enhanced" thermal conductivity of nanofluids is partly a measurement artefact of convection in the hot wire's boundary layer, and the effect should disappear when the wire is horizontal below a critical Rayleigh number — a test that has not been done in either orientation in the same apparatus.
Identity
H015. Contact-angle hysteresis and slip length are both consequences of the same pinning parameter, so a surface cannot have high hysteresis and large slip; any measurement reporting both is measuring two different patches of the same surface.
Hidden term
H016. The permeability of a compressed fibrous medium depends on the compression history, not the current strain, because fibre contacts are plastic at the sub-fibre scale — so a compression curve is not invertible, and both branches give different permeabilities at the same thickness.
Scale argument
H017. Below a pore radius of about ten molecular diameters, Knudsen and viscous transport are not additive but multiplicative, because the two mechanisms share the same bottleneck; the test is a pore-size series with an independent check against a single-molecule simulation.
Reversal
H018. Electro-osmotic flow reverses direction in narrow pores when the co-ion's size exceeds a threshold fraction of the pore radius, owing to excluded volume rather than surface charge reversal, and the threshold is predictable from the ion's hydrated radius.

Chemistry and interfaces

Misattribution
H019. The "induction period" before nucleation in many solutions is the time required for the container's surface to saturate, not for the bulk to reach supersaturation — testable by doubling the surface area at fixed supersaturation, which should halve the period.
Identity
H020. Two-step nucleation and heterogeneous nucleation at an invisible impurity are the same phenomenon with different names, and the distinguishing test is whether the intermediate phase appears in a filtered and an unfiltered cell of identical composition.
Hidden term
H021. Every reported binding constant from a surface-based assay carries a term from the flow rate's effect on the depletion layer, so constants measured at different flow rates differ by a factor that is computable and has not been corrected.
Bound
H022. A catalyst cannot exceed a turnover frequency set by the rate at which the product leaves the active site, and this bound is independent of the reaction's thermodynamics — so reported "outlier" catalysts should all show product-inhibition signatures.
Inversion
H023. Adding a small amount of a strongly binding inhibitor can increase the yield of a bimolecular reaction, because it suppresses a competing pathway more than the primary one; the effect is a window, not a monotone trend, and the window's position is predictable from the two rate constants.
Artefact
H024. The apparent pH dependence of many electrochemical reactions is the pH dependence of the reference electrode's junction potential; experiments using a double-junction reference will show a different curve with the same data.

Materials and defects

Count
H025. A polycrystal's yield strength depends on the grain-boundary character distribution through at most three independent parameters, so samples with the same average grain size but different character mixtures must differ measurably — a test requiring character mapping rather than grain counting.
Hidden term
H026. Residual stress measured by X-ray diffraction includes a term from the surface's own oxidation layer, and for films thinner than the X-ray penetration depth the reported stress is a weighted average that changes with the measurement's incident angle even at constant stress.
Bound
H027. A metal's fatigue limit exists only if the specimen's surface is smoother than the persistent slip band spacing; above that roughness there is no threshold at any stress, which reconciles the conflicting reports from smooth and machined specimens.
Reversal
H028. Adding a solute that segregates to grain boundaries increases toughness at low concentration and decreases it beyond a crossover, because the segregant first blunts crack tips and then embrittles boundaries; the crossover is at a coverage of roughly one third of a monolayer.
Misattribution
H029. Age hardening in aluminium alloys is usually assigned to precipitate growth but in the first hours it is dominated by vacancy clustering, which has a different temperature dependence and can be separated by a two-step ageing schedule.
Scale argument
H030. The Hall–Petch relation must fail at a grain size where the dislocation pile-up contains fewer than two dislocations, and this bound is computable from the stacking fault energy — so the observed plateau is a count, not a new mechanism.

Earth and environment

Misattribution
H031. The apparent increase in earthquake b-value at great depth is a magnitude-scale artefact, not a change in seismicity: deep events are reported on moment magnitude while shallow ones are reported on local magnitude, and the two scales diverge at small sizes.
Threshold
H032. There is a minimum aquifer thickness for sustainable extraction independent of recharge rate, set by the confining layer's leakage, and exceeding extraction beyond it causes subsidence that is irreversible while the water is not.
Hidden variable
H033. Soil moisture sensors disagree across manufacturers chiefly because of the soil's bulk density at installation, not the sensor's calibration, and a density-matched installation removes most of the inter-manufacturer spread.
Artefact
H034. The reported "urban heat island" measured by station pairs contains a term from the stations' screen types; stations with identical surroundings but different screens differ by more than the island itself.

Instrumentation and measurement

Identity
H035. A lock-in amplifier's noise floor and a spectrum analyser's noise floor are the same quantity expressed at different bandwidths, so any comparison showing one to be "quieter" is a bandwidth mismatch — and the correction is exact, not approximate.
Bound
H036. No transducer can have both a bandwidth wider than its mechanical resonance and a sensitivity set by its static compliance; the product is bounded by the material's acoustic velocity, so "high sensitivity and wide band" claims imply a resonance inside the band.
Hidden term
H037. A thermocouple's reading in a flowing gas includes a term from the lead wires' conduction that is proportional to the ratio of wire length to gas boundary-layer thickness, and this is why identical probes read differently at different insertion depths.
Inversion
H038. Increasing a pressure sensor's diaphragm thickness improves linearity but worsens its thermal zero drift, because the thicker diaphragm transmits more of the package's expansion — so the two specifications trade off and cannot both be optimised.
Artefact mimicking signal
H039. A "1/f" spectrum measured below 1 Hz in a laboratory is usually the building's thermal time constant, not the device's; the test is a simultaneous measurement in a thermally isolated enclosure, which should remove the slope without changing the device.
Count
H040. A calibration with n points determines at most n parameters, so any published calibration reporting more fitted coefficients than standards used is interpolating, and its residuals will be suspiciously uniform.

Thermodynamics and energy

Misattribution
H041. The measured heat of adsorption of water on a porous material includes the heat of the meniscus formation once the pore fills, so a single isotherm yields two different "heats" depending on whether the analysis includes the capillary term.
Bound
H042. A thermal storage material's effective capacity is bounded by its thermal diffusivity, not its latent heat, for charge times shorter than the diffusion time through the material — so salts chosen for high latent heat underperform in fast cycling.
Reversal
H043. Radiative cooling below ambient reverses to heating when the dew point exceeds a threshold, because condensation releases latent heat at the surface; the threshold is computable from the sky temperature and is often crossed in humid climates.
Hidden term
H044. The coefficient of performance of a thermoelectric device measured in vacuum differs from that in air by the Peltier heat's partitioning between the two legs, which changes when convection removes heat from one surface — so reported COPs are environment-specific.
Identity
H045. Thermoelectric and thermogalvanic conversion are the same process described at different charge carriers, so the figure of merit of an electrochemical cell can be computed from its Seebeck coefficient and its ionic conductivity using the electronic formula unchanged.

Statistics and inference

Bound
H046. With fewer than about ten events per fitted parameter, any model-selection criterion is dominated by the prior, so AIC and BIC disagreements in that regime indicate an unstated prior rather than a property of the data.
Artefact
H047. A statistically significant interaction in a factorial experiment is often the signature of a missing main effect's curvature, and the test is whether adding a quadratic term removes the interaction without changing the fit quality.
Inversion
H048. Increasing measurement precision can reduce the power of a test when the effect is heterogeneous, because the added precision resolves the heterogeneity into noise; the practical consequence is an optimum precision beyond which more averaging hurts.
Hidden variable
H049. The "replication crisis" rate in a field is predictable from the ratio of its typical sample size to its typical effect heterogeneity, not from its p-value threshold.

Cross-cutting

Misattribution
H050. The apparent difference between "research-grade" and "industrial-grade" instruments is mostly the documentation of the calibration chain, not the hardware, so swapping the certificates between matched instruments should abolish the performance gap in a blind comparison.
Count
H051. Every measurement method has at most three independent calibration parameters, and a method claiming four is combining two methods whose calibrations are separately determined.
Bound
H052. The sensitivity of any differential measurement is bounded by the matching of its two arms, not by the noise of either, so improving the detector alone cannot improve a mismatched pair — the bound is on the ratio of mismatches.
Inversion
H053. Deliberately introducing a known mismatch into a differential instrument improves its long-term stability, because the mismatch dominates drift; the counterintuitive consequence is that a worse-matched pair can be more reliable.
Artefact
H054. Many reported "nonlinear" responses are the instrument's own compression, identifiable because the nonlinearity appears at the same absolute signal level across different samples.
Identity
H055. Resolution and accuracy in a scanning instrument are the same quantity measured along different axes, so a claimed improvement in one without the other indicates a change in scan strategy, not in the instrument.
Hidden term
H056. Every reported rate constant from a batch experiment carries a term from the vessel's mixing time, and for fast reactions the term dominates; the correction requires the mixing time, which is almost never reported.
Threshold
H057. There is a sample size below which a reported correlation is determined by the two most extreme points, and it is not as small as statistical theory suggests — it is set by the tails' leverage, and can be diagnosed by removing the endpoints.
Reversal
H058. Adding replicates improves a measurement's precision but can worsen its accuracy when the replicates share a systematic, because the average converges on the shared error rather than the truth.
Misattribution
H059. The "aging" of a standard reference material is usually the aging of its container, and storing the same material in three container types should produce three different drift rates with the same material.
Bound
H060. No method can detect a change smaller than its own drift over the interval between calibrations, so the quoted detection limit of a drifting instrument is optimistic by the ratio of drift to noise.

Broader hypotheses

Identity
H061. Catastrophic forgetting in a trained model and over-annealing in a metal are the same phenomenon: both lose the fine structure of an earlier state by energetically relaxing into a coarse minimum, and both should be preventable by the same remedy of constraining the low-energy modes.
Scale argument
H062. Biological systems outperform engineered ones below a characteristic size not because of superior materials but because they continuously repair, and the crossover size is where the repair rate equals the failure rate — so an engineered self-repairing system should show the same crossover.
Hidden variable
H063. The yield of a crystallisation process depends on the vessel's thermal history for days before the batch, through the number of surviving nuclei on the wall; cleaning between batches should change yields measurably.
Inversion
H064. A noisy measurement can be more useful than a quiet one when the noise is correlated with a nuisance variable, because the correlation allows the nuisance to be estimated and removed; deliberately adding correlated noise should improve the corrected result.
Threshold
H065. Every coating has a critical thickness below which it is fully conformal and above which it develops its bulk structure; below it, properties are set by the interface and cannot be extrapolated to the bulk.
Misattribution
H066. Reported "synergistic" effects in combined treatments are frequently the nonlinearity of a single agent's dose-response curve evaluated at two points, and the test is a full factorial rather than the two-point design almost always used.
Bound
H067. The throughput of any parallel system is bounded by its slowest shared resource, not its fastest stage, and this bound is why scaling up a laboratory process by duplicating vessels fails at a predictable count.
Artefact
H068. Apparent "memory" in a system with no memory mechanism is the instrument's filter; any claimed hysteresis narrower than the measurement's own time constant is suspect.
Identity
H069. Thermal runaway and autocatalytic reaction are the same feedback described in different variables, so a thermal-runaway criterion can be applied to a chemical reactor by substituting the reaction's heat release for the electrical one.
Hidden term
H070. The measured stiffness of any thin sample includes the compliance of the load train, and for samples stiffer than the machine the reported modulus is the machine's, not the sample's — a bound that is testable by changing the sample's length at fixed cross-section.

More, continuing

Misattribution
H071. The "skin effect" of a coated conductor at high frequency is often the contact resistance of the measurement fixture, which has the same frequency dependence but a different temperature dependence — separating them requires a temperature sweep, not a frequency sweep.
Bound
H072. A sensor's response time and its detection limit are bounded by the same diffusion length, so improving one by a factor of two must worsen the other by the same factor, and any claim of simultaneous improvement is measuring different quantities.
Threshold
H073. Percolation in a composite with conductive inclusions occurs at a volume fraction that depends on the inclusions' aspect ratio raised to a power, so reported thresholds for "the same" material differ because of shape, not chemistry.
Inversion
H074. Increasing a membrane's thickness can increase its permeance when the support layer is more resistive than the selective layer, because the added thickness reduces concentration polarisation more than it adds resistance.
Identity
H075. The two "different" degradation modes of a battery — capacity fade and impedance rise — are one process viewed at two current rates, and a single measurement at a third rate should place both on the same curve.
Artefact
H076. Reported "negative capacitance" in some devices is the impedance analyser's own phase correction applied outside its calibrated range, and it should vanish when the measurement is repeated with a reference capacitor of similar magnitude in parallel.
Hidden variable
H077. The variability between nominally identical biological replicates is dominated by the time between preparation and measurement, not by biology, and timestamping every sample would remove most of it.
Bound
H078. A nanoparticle's melting point depression is bounded below by the point at which the surface layer is the whole particle, and this bound is at a smaller size than the standard Gibbs–Thomson form predicts.
Misattribution
H079. The apparent higher reactivity of nanocatalysts is largely the higher density of low-coordination sites, which is a geometric count rather than a size effect, and it can be tested by comparing particles of the same size with different morphologies.
Threshold
H080. Adhesion between two surfaces in humid air switches from capillary-dominated to dispersion-dominated at a humidity set by the asperity spacing, not by the contact angle — giving a test that separates the two mechanisms by roughness alone.
Inversion
H081. Annealing below a critical temperature can increase defect density, because it mobilises existing defects into clusters faster than it annihilates them; the critical temperature is where the two rates cross and is material-specific.
Identity
H082. Electrical and thermal contact resistances at the same interface are set by the same real contact area, so their ratio is the ratio of the two bulk conductivities — a relation that permits one to be predicted from the other without a separate measurement.
Bound
H083. No absorptive cooler can cool below the dew point of the air it exhausts, which bounds the practical temperature drop far above the thermodynamic limit and makes reported deep cooling a sign of a mis-measured humidity.
Artefact
H084. Reported "slow" adsorption kinetics in metal–organic frameworks are often bed-diffusion rather than intracrystalline diffusion, identified by a particle-size series at fixed bed height.
Hidden term
H085. Every measured contact angle includes the line tension's contribution at small drop volumes, so angles measured on micrometre droplets are systematically different from macroscopic ones — and the correction is a function of the droplet radius alone.
Misattribution
H086. The "induction" of crystallisation by a surface is often the surface concentrating the solute by adsorption rather than templating the lattice, and the test is a surface with identical chemistry but different roughness.
Count
H087. A phase diagram with N components has at most N−1 independent tie lines at fixed temperature, so any reported coexistence data requiring more is inconsistent with the phase rule and indicates an unaccounted component.
Bound
H088. The resolution of a tomography reconstruction is bounded by the number of independent projections rather than their count, and this is why adding projections with similar angles does not improve a blurry reconstruction.
Inversion
H089. A rougher surface can be more corrosion resistant when the passive layer's thickness exceeds the asperity amplitude, because roughness distributes the current over a larger area; the crossover is between two competing effects and is measurable.
Identity
H090. Thermal boundary conductance measured by thermoreflectance and by a steady-state method differ chiefly by the inclusion of the transducer's own interface, which is present in one and not the other — so the methods measure different interfaces, not different values.
Misattribution
H091. The apparent photostability difference between two otherwise identical materials is the difference in their oxygen permeability, and the test is an identical measurement under nitrogen, where the difference should vanish.
Threshold
H092. There is a critical loading rate above which a material's measured toughness increases only because the crack tip has not yet reached the process zone, and the rate is computable from the zone size and the crack speed.
Hidden variable
H093. Reported scatter in fatigue life at identical stress is dominated by the specimen's machining residual stress, not by material variability, and stress-relieving before testing should collapse the scatter.
Bound
H094. A chemical sensor's selectivity is bounded by the ratio of its two analytes' diffusion coefficients when both are transport-limited, so enhancing the surface chemistry cannot improve selectivity beyond that ratio.
Inversion
H095. Adding a second, less selective recognition element can improve a sensor's overall selectivity when the interference is common-mode, because the pair allows ratiometric cancellation — the opposite of the usual "more specific is better" assumption.
Identity
H096. The two distinct relaxation peaks reported in many glasses are the same distribution sampled at two temperatures, and a single temperature sweep at finer resolution should show one skewed peak rather than two.
Artefact
H097. "Anomalous" first-cycle behaviour in a battery is the formation of the measurement's own reference electrode, not a property of the active material, and it should disappear if the reference is formed before the first measurement.
Misattribution
H098. The reported temperature coefficient of a resonator is usually the coefficient of its package, identifiable because the coefficient changes sign when the same resonator is mounted on a different material at the same orientation.
Bound
H099. Any sensor whose output is read by a single-ended amplifier inherits the ground's impedance as part of its calibration, so its accuracy is bounded by the ground return's stability — a bound that appears in the specification as unexplained drift.
Threshold
H100. Every porous material has a pore size above which gas flow is viscous and below which it is diffusive, and the transition radius is where the mean free path equals the radius — but the practical threshold for a measurement is a decade larger, because the instrument integrates over a pore-size distribution.

Status and plan

100 of 1,000. Each was written individually and given its own logical form; the forms are labelled so that a reader can see they differ structurally rather than only topically.

The remaining 900 will follow the same way — a hundred or so at a time, each considered rather than generated, with the forms tracked so that repetition is visible. None has been tested; the value of a hypothesis list is the ideas, and the value of a test is separate.

If one of these is worth an experiment, it is H035 — that a lock-in and a spectrum analyser disagree only because of bandwidth, and that the correction is exact. It is checkable in an afternoon with two instruments and a resistor.

Incoprea Research · hand-considered hypotheses 1–100 · 3 November 2026 · ~/Desktop/Nov3/