# Volume XXI — numbers 1-7 (theories 1-21), new file
THEORIES = [
# Reynolds
{"n":1,"slug":"aneurysm-reynolds","field":"Reynolds Number","subject":"Aneurysms","title":"Clot Onset Tracks Local Reynolds","claim":"Thrombosis in an aneurysm sac begins where the local Reynolds number passes a threshold, not where the artery is widest, so a small sac with fast flow clots before a large slow one.","mechanism":"Above the threshold the flow becomes unstable and recirculating, which lengthens residence time in the sac and allows platelets to accumulate.","prediction":"Thrombosis should track local Reynolds rather than diameter.","refute":"Thrombosis tracking sac size would remove the flow criterion."},
{"n":2,"slug":"schooling-reynolds-transition","field":"Reynolds Number","subject":"Fish schools","title":"Schools Switch at a Reynolds","claim":"Fish school structure changes at a critical Reynolds number set by body length and swimming speed, so the same species forms different formations at different speeds.","mechanism":"Below the transition, viscous interactions dominate and individuals follow local flow; above it, inertial wakes dominate and the school organises around them.","prediction":"Formation should change at a critical Reynolds.","refute":"Formation fixed by species would remove the transition."},
{"n":3,"slug":"resuspension-reynolds","field":"Reynolds Number","subject":"Sediment transport","title":"Resuspension Is a Reynolds Condition","claim":"Fine sediment resuspension occurs at a threshold in particle Reynolds number rather than in bed shear stress, so cohesive and non-cohesive beds resuspend differently at the same shear.","mechanism":"Resuspension requires the local flow around a particle to overcome its settling; the particle Reynolds number captures that balance.","prediction":"Resuspension should track particle Reynolds number.","refute":"Resuspension tracking shear stress alone would remove the particle term."},

# Peclet
{"n":4,"slug":"tumour-drug-peclet","field":"Peclet Number","subject":"Tumour penetration","title":"Drug Penetration Is a Peclet Problem","claim":"Penetration of a drug into a solid tumour is set by the interstitial Peclet number, so a drug with high potency but poor diffusion reaches less tissue than a weaker one that moves well.","mechanism":"Convection and diffusion compete in the interstitium; when convection dominates, drug is carried past rather than into the tissue.","prediction":"Penetration depth should track the Peclet number.","refute":"Penetration tracking potency would remove the transport term."},
{"n":5,"slug":"root-uptake-peclet","field":"Peclet Number","subject":"Root nutrient uptake","title":"Uptake Depends on a Peclet","claim":"Nutrient capture by roots is set by the Peclet number at the root surface, so transpiration rate changes uptake efficiency non-monotonically.","mechanism":"Water flow carries nutrients to the root while diffusion supplies them from the bulk soil; the balance sets whether supply keeps up with demand.","prediction":"Uptake should peak at an intermediate Peclet.","refute":"Uptake increasing monotonically with flow would remove the balance."},
{"n":6,"slug":"groundwater-pollutant-peclet","field":"Peclet Number","subject":"Contaminant transport","title":"Plume Shape Is a Peclet","claim":"The shape and length of a groundwater contaminant plume is set by the Peclet number, so the same mass produces a compact plume in one aquifer and a long dilute one in another.","mechanism":"Advection stretches the plume while dispersion spreads it; the ratio determines which dominates the footprint.","prediction":"Plume length should track the Peclet number.","refute":"Plume length tracking mass alone would remove dispersion."},

# Damkohler
{"n":7,"slug":"wound-healing-damkohler","field":"Damkohler Number","subject":"Wound healing","title":"Healing Rate Is a Damkohler","claim":"Wound closure rate is set by the ratio of cell proliferation rate to nutrient transport rate, so a well-perfused wound heals faster even with the same cells.","mechanism":"Cells must be supplied as they divide; when proliferation outpaces delivery, growth stalls at the diffusion limit.","prediction":"Closure rate should track the Damkohler number.","refute":"Closure tracking cell density would remove transport."},
{"n":8,"slug":"battery-utilisation-damkohler","field":"Damkohler Number","subject":"Batteries","title":"Electrode Use Is a Damkohler","claim":"The fraction of an electrode that participates in a fast discharge is set by the ratio of reaction rate to ion transport rate, so thick electrodes at high rate use only their surface.","mechanism":"Ions must reach reaction sites; when reaction outpaces transport, the interior is starved and inactive.","prediction":"Utilisation should fall as the ratio rises.","refute":"Utilisation tracking thickness alone would remove kinetics."},
{"n":9,"slug":"catalyst-hotspot-damkohler","field":"Damkohler Number","subject":"Catalysis","title":"Hot Spots Follow a Damkohler","claim":"Hot spots in a catalytic bed appear above a critical ratio of reaction rate to heat removal, so a modest reaction in a poorly conducting bed can run away.","mechanism":"Heat generated locally must be conducted away; when generation outpaces removal, a local temperature excursion accelerates the reaction further.","prediction":"Hot spots should track the ratio.","refute":"Hot spots tracking inlet temperature would remove the balance."},

# Biot
{"n":10,"slug":"fever-organ-biot","field":"Biot Number","subject":"Fever","title":"Organ Heating Is a Biot Problem","claim":"How much an organ's temperature rises during fever is set by its Biot number, so a large well-perfused organ heats less than a small poorly perfused one.","mechanism":"Biot compares internal conduction to surface heat exchange; low Biot means the organ is near the surrounding temperature, high Biot means it retains its own.","prediction":"Temperature rise should track Biot.","refute":"Rise tracking metabolic rate alone would remove perfusion."},
{"n":11,"slug":"cooking-time-biot","field":"Biot Number","subject":"Food cooking","title":"Cooking Time Is a Biot Problem","claim":"Cooking time for a solid food is set by its Biot number, so two pieces of equal mass cook at different rates depending on shape and surface transfer.","mechanism":"Heat must cross the surface and conduct inward; the ratio sets whether the surface or the interior is limiting.","prediction":"Cooking time should collapse onto Biot and Fourier numbers.","refute":"Time tracking mass would remove shape."},
{"n":12,"slug":"runaway-propagation-biot","field":"Biot Number","subject":"Battery packs","title":"Propagation Is a Biot Problem","claim":"Whether a failing cell ignites its neighbour is set by the neighbour's Biot number, so a well-cooled cell resists propagation even at close spacing.","mechanism":"Heat arriving at the surface must be removed before it raises the core; the ratio determines whether the core reaches the trigger temperature.","prediction":"Propagation should track Biot and spacing together.","refute":"Propagation tracking spacing alone would remove cooling."},

# Prandtl
{"n":13,"slug":"marine-mammal-prandtl","field":"Prandtl Number","subject":"Marine mammals","title":"Blubber Is a Prandtl Problem","claim":"The insulating performance of blubber is set by the Prandtl number of the tissue, so the same thickness insulates differently depending on blood flow through it.","mechanism":"Prandtl compares momentum and thermal diffusion; perfusion changes the effective conductivity and therefore the insulation per unit thickness.","prediction":"Insulation should track Prandtl at equal thickness.","refute":"Insulation tracking thickness alone would remove perfusion."},
{"n":14,"slug":"boundary-layer-prandtl","field":"Prandtl Number","subject":"Atmospheric boundary layer","title":"Stability Follows Prandtl","claim":"The transition between stable and convective boundary layers is set by the Prandtl number of the surface layer rather than by temperature gradient alone.","mechanism":"Heat and momentum mix at different rates; when the ratio is far from unity, the layer can be stable in temperature while turbulent in momentum.","prediction":"Stability regimes should track Prandtl.","refute":"Regimes tracking gradient alone would remove the ratio."},
{"n":15,"slug":"fouling-prandtl","field":"Prandtl Number","subject":"Heat exchangers","title":"Fouling Depends on Prandtl","claim":"Fouling rate in a heat exchanger is set by the Prandtl number at the wall, so a fluid with high thermal diffusivity fouls differently at the same velocity.","mechanism":"Deposition requires the wall to be cool enough for precipitation while the boundary layer transports material; the ratio sets both.","prediction":"Fouling should track wall Prandtl.","refute":"Fouling tracking velocity would remove the ratio."},

# Sherwood and Nusselt
{"n":16,"slug":"transpiration-nusselt","field":"Sherwood Number","subject":"Leaf transpiration","title":"Transpiration Is a Boundary Transfer","claim":"Leaf transpiration is set by a Sherwood-like number for the leaf boundary layer, so wind changes water loss only until the boundary layer thins enough that stomata take over.","mechanism":"Water vapour must cross the boundary layer and the stomatal pore in series; the ratio determines which resistance dominates.","prediction":"Transpiration should saturate once boundary resistance is small.","refute":"Transpiration scaling with wind indefinitely would remove the stomatal limit."},
{"n":17,"slug":"dialysis-sherwood","field":"Sherwood Number","subject":"Dialysis","title":"Clearance Is a Sherwood","claim":"Solute clearance in dialysis is set by the Sherwood number of the membrane module, so a larger membrane with poor flow distribution clears less than a smaller well-distributed one.","mechanism":"Clearance requires solute to reach the membrane surface; concentration polarisation reduces the effective driving force at high flux.","prediction":"Clearance should track Sherwood rather than area.","refute":"Clearance tracking membrane area would remove the transfer coefficient."},
{"n":18,"slug":"coral-calcification-sherwood","field":"Sherwood Number","subject":"Coral calcification","title":"Calcification Is a Boundary Problem","claim":"Coral calcification rate is set by the Sherwood number at the tissue surface, so flow conditions change calcification independently of saturation state.","mechanism":"Calcification consumes alkalinity at the surface; supply from the bulk depends on boundary layer transport, which flow sets.","prediction":"Calcification should track Sherwood at equal saturation.","refute":"Calcification tracking saturation alone would remove flow."},

# Froude
{"n":19,"slug":"walk-run-froude","field":"Froude Number","subject":"Human gait","title":"The Walk-Run Transition Is Froude","claim":"The walk-to-run transition occurs at a critical Froude number rather than at a critical speed, so leg length sets the speed at which people switch.","mechanism":"Gait choice trades inverted-pendulum mechanics against spring-mass mechanics; the ratio of inertial to gravitational forces determines which is cheaper.","prediction":"Transition speed should scale with the square root of leg length.","refute":"Transition at a fixed speed across body sizes would remove the ratio."},
{"n":20,"slug":"tsunami-runup-froude","field":"Froude Number","subject":"Tsunami run-up","title":"Run-Up Is a Froude Problem","claim":"Tsunami run-up height is set by the Froude number of the wave at the shore, so two waves of equal height produce different inundation depending on their speed.","mechanism":"Run-up depends on how much kinetic energy converts to potential as the wave decelerates on the slope; the ratio sets that conversion.","prediction":"Run-up should track the Froude number.","refute":"Run-up tracking wave height alone would remove speed."},
{"n":21,"slug":"wake-damage-froude","field":"Froude Number","subject":"Vessel wakes","title":"Wake Damage Is a Froude Problem","claim":"Shoreline damage from vessel wakes is set by the Froude number rather than by vessel size, so a small fast craft can do more than a large slow one.","mechanism":"Wave-making resistance and wake height peak at a particular depth Froude number; beyond it, the wave pattern changes character.","prediction":"Damage should peak at a Froude number.","refute":"Damage tracking vessel size would remove the ratio."},
]