{"query": "The wave equation for sound", "count": 20, "results": [{"id": "card_works_acoustics", "title": "The wave equation for sound", "shelf": "the-works", "surface": "secular", "snippet": "For any wave, speed = frequency × wavelength. A 343 Hz tone with a one-metre wavelength travels at 343 m/s — the speed of sound in air.  Worked & sealed by the engine — c = f·λ = 343·1 = 343 m/s.  [HO", "authority_tier": "verified", "source": "The Works — worked & sealed", "generated": false}, {"id": "card_theory_differential_equations", "title": "Differential equations (the language every physical law is written in)", "shelf": "theories", "surface": "secular", "snippet": "Differential equations (the language every physical law is written in) — an engine domain that can touch it: mathematics. Calibration: seals — solutions verify by substitution; specific integrations c", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_maxwell_s_equations_classical_electromagnetism", "title": "Maxwell's equations / classical electromagnetism", "shelf": "theories", "surface": "secular", "snippet": "Maxwell's equations / classical electromagnetism — an engine domain that can touch it: electrical. Calibration: partial — circuit and field relations verify; the full field theory is map-only. Four eq", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_law_of_conservation_of_mass", "title": "Law of conservation of mass (Lavoisier)", "shelf": "theories", "surface": "secular", "snippet": "Law of conservation of mass (Lavoisier) — an engine domain that can touch it: chemistry. Calibration: seals — balanced equations verify exactly. Mass is neither created nor destroyed in a chemical rea", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_quantum_mechanics", "title": "Quantum mechanics (Schrödinger equation)", "shelf": "theories", "surface": "secular", "snippet": "Quantum mechanics (Schrödinger equation) — an engine domain that can touch it: physics. Calibration: partial — energy levels and specific relations verify; interpretation is map-only. A system is desc", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_fundamental_theorem_of_algebra", "title": "Fundamental theorem of algebra", "shelf": "theories", "surface": "secular", "snippet": "Fundamental theorem of algebra — an engine domain that can touch it: mathematics. Calibration: partial — root counts verify; the existence proof is map-only. Every non-constant polynomial with complex", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_algebraic_geometry", "title": "Algebraic geometry (solution sets as shapes)", "shelf": "theories", "surface": "secular", "snippet": "Algebraic geometry (solution sets as shapes) — an engine domain that can touch it: mathematics. Calibration: map-only — specific curve computations verify; the theory is abstract. The study of the sha", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_general_relativity", "title": "General relativity", "shelf": "theories", "surface": "secular", "snippet": "General relativity — an engine domain that can touch it: physics. Calibration: partial — specific relations verify; the field equations as a whole are map-only. Gravity is not a force but the CURVATUR", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_dimensional_analysis", "title": "Dimensional analysis & similarity (Buckingham Π)", "shelf": "theories", "surface": "secular", "snippet": "Dimensional analysis & similarity (Buckingham Π) — an engine domain that can touch it: physics. Calibration: seals — dimensional consistency and Π-group counts check exactly. Any true physical equatio", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_population_ecology", "title": "Population ecology (Lotka–Volterra, carrying capacity)", "shelf": "theories", "surface": "secular", "snippet": "Population ecology (Lotka–Volterra, carrying capacity) — an engine domain that can touch it: ecology. Calibration: seals — logistic and predator-prey models compute. Unlimited resources give exponenti", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_epidemiology_models", "title": "Compartmental epidemiology (SIR models and R₀)", "shelf": "theories", "surface": "secular", "snippet": "Compartmental epidemiology (SIR models and R₀) — an engine domain that can touch it: medicine. Calibration: seals — R0, herd-immunity thresholds and epidemic curves compute. Divide a population into S", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_electromagnetic_spectrum", "title": "The electromagnetic spectrum & modulation (radio to gamma, one axis)", "shelf": "theories", "surface": "secular", "snippet": "The electromagnetic spectrum & modulation (radio to gamma, one axis) — an engine domain that can touch it: physics. Calibration: seals — c = fλ, photon energy E = hf, and bandwidth relations all recom", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_plasma_physics", "title": "Plasma physics (the fourth state, and most of the universe)", "shelf": "theories", "surface": "secular", "snippet": "Plasma physics (the fourth state, and most of the universe) — an engine domain that can touch it: physics. Calibration: map-only — specific relations compute; the regime as a whole is not a sealable c", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_shannon_information_theory", "title": "Shannon information theory (entropy, channel capacity)", "shelf": "theories", "surface": "secular", "snippet": "Shannon information theory (entropy, channel capacity) — an engine domain that can touch it: information_theory. Calibration: seals. H = -Σ p log p. Information is measured by how much UNCERTAINTY a m", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_newton_s_three_laws_of_motion", "title": "Newton's three laws of motion", "shelf": "theories", "surface": "secular", "snippet": "Newton's three laws of motion — an engine domain that can touch it: physics. Calibration: seals. (1) A body keeps its velocity unless a force acts — which contradicts everyday experience only because ", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_bioenergetics_energy_balance", "title": "Bioenergetics / energy balance (calorimetry, 4-9-4)", "shelf": "theories", "surface": "secular", "snippet": "Bioenergetics / energy balance (calorimetry, 4-9-4) — an engine domain that can touch it: nutrition. Calibration: seals — energy budgets compute directly. Food energy is measured by combustion: carboh", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_hydrologic_cycle_open_channel_flow", "title": "Hydrologic cycle & open-channel flow (Manning, Darcy)", "shelf": "theories", "surface": "secular", "snippet": "Hydrologic cycle & open-channel flow (Manning, Darcy) — an engine domain that can touch it: hydrology. Calibration: seals — Manning velocity, Darcy flow and catchment volumes compute. Water circulates", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_statistical_mechanics", "title": "Statistical mechanics (Boltzmann — why the second law is a counting argument)", "shelf": "theories", "surface": "secular", "snippet": "Statistical mechanics (Boltzmann — why the second law is a counting argument) — an engine domain that can touch it: thermodynamics. Calibration: seals — Boltzmann distributions, partition functions an", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_second_law_of_thermodynamics", "title": "Second law of thermodynamics (entropy)", "shelf": "theories", "surface": "secular", "snippet": "Second law of thermodynamics (entropy) — an engine domain that can touch it: thermodynamics. Calibration: partial — efficiency and entropy changes compute; the arrow of time is map-only. The entropy o", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}, {"id": "card_theory_fluid_mechanics", "title": "Fluid mechanics (Bernoulli, Reynolds, Navier–Stokes)", "shelf": "theories", "surface": "secular", "snippet": "Fluid mechanics (Bernoulli, Reynolds, Navier–Stokes) — an engine domain that can touch it: hydrology. Calibration: seals — continuity, Bernoulli and Reynolds number compute directly. CONTINUITY first:", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "generated": false}]}