{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.momentum","code":"thing-q41273","url":"https://ver.cy/models/thing/q41273/","name":"momentum","alternateNames":["four-momentum","Fermi momentum","Crystal momentum","Sandcastle","momentum operator"],"kind":"thing","status":"published","version":"0.2.0-wave.3","language":"en","classifiers":{"family":"Thing Registry","category":"Cross-cutting context","entryKind":"thing","plane":"XCT","domain":["XCT.QLT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A vector physical quantity equal to the product of the mass and velocity of a body in classical mechanics, with a system's total momentum conserved when the net external force is zero and changing according to Newton's second law otherwise; related concepts include four-momentum in relativity, the momentum operator in quantum mechanics, crystal momentum in solids and the Fermi momentum of electrons in metals, while angular momentum is a distinct rotational quantity; momentum conservation underlies collisions, rocket propulsion and particle physics, and the word is also used figuratively.","purpose":"Let an agent explain momentum and its conservation, relay the classical, relativistic and quantum forms from physics references, describe applications and specialised forms, and distinguish physical momentum from figurative and financial uses.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["Vector quantity","Conservation law","Relativistic and quantum generalisations","Noether symmetry link"],"structure":{"bundles":[{"id":"understand","name":"Understand","description":"What momentum is.","layers":[{"id":"definition","name":"Definition","description":"Definition and conservation.","findings":[{"id":"definition-finding","name":"Definition","description":"Definition.","questions":[{"text":"What is momentum, and why is it conserved?","kind":"definition"},{"text":"Is the question about physical momentum or a figurative or financial sense?","kind":"boundary"}]}]},{"id":"laws","name":"Laws","description":"Newton laws and impulse.","findings":[{"id":"laws-finding","name":"Laws","description":"Laws.","questions":[{"text":"How do force, impulse and momentum relate in Newton second law?","kind":"definition"},{"text":"Which entry fits impulse?","kind":"action"}]}]}]},{"id":"advanced","name":"Advanced","description":"Relativity and quantum.","layers":[{"id":"relativity","name":"Relativity","description":"Relativistic momentum.","findings":[{"id":"relativity-finding","name":"Relativity","description":"Relativity.","questions":[{"text":"How do relativistic momentum and four-momentum generalise the classical definition?","kind":"provenance"},{"text":"Which entry fits four-momentum?","kind":"action"}]}]},{"id":"quantum","name":"Quantum","description":"Quantum and solid state.","findings":[{"id":"quantum-finding","name":"Quantum","description":"Quantum.","questions":[{"text":"What are the momentum operator, crystal momentum and Fermi momentum?","kind":"provenance"},{"text":"Which references are standard?","kind":"provenance"}]}]}]},{"id":"apply","name":"Apply","description":"Applications.","layers":[{"id":"collisions","name":"Collisions","description":"Collisions and rockets.","findings":[{"id":"collisions-finding","name":"Collisions","description":"Collisions.","questions":[{"text":"How does momentum conservation explain collisions, recoil and rocket propulsion?","kind":"action"},{"text":"Which entry fits collision?","kind":"action"}]}]},{"id":"particles","name":"Particles","description":"Particle physics.","findings":[{"id":"particles-finding","name":"Particles","description":"Particles.","questions":[{"text":"How is momentum used in particle detectors and scattering experiments?","kind":"provenance"},{"text":"Which sources are cited?","kind":"provenance"}]}]}]},{"id":"context","name":"Context","description":"History and symmetry.","layers":[{"id":"history","name":"History","description":"History.","findings":[{"id":"history-finding","name":"History","description":"History.","questions":[{"text":"How did the momentum concept develop from Descartes and Newton to Noether?","kind":"provenance"},{"text":"Which entry fits the history of mechanics?","kind":"action"}]}]},{"id":"symmetry","name":"Symmetry","description":"Symmetry.","findings":[{"id":"symmetry-finding","name":"Symmetry","description":"Symmetry.","questions":[{"text":"How does Noether theorem link momentum conservation to translation symmetry?","kind":"provenance"},{"text":"Which entry fits Noether theorem?","kind":"action"}]}]}]}]},"agentConduct":{"may":["Calculate and explain momentum in classical and relativistic mechanics.","Use momentum to estimate impacts in simulations for vehicle and safety design."],"mustNot":["Present the colloquial meaning, such as political momentum, as the physical quantity.","Give impact estimates for safety decisions without stating the assumptions and errors.","Report a momentum calculation as checked when it was not.","Hide momentum results that show a design fails a safety test."],"requiresHuman":["Accepting momentum-based safety calculations for a vehicle or barrier design."]},"ethics":{"considerations":["Collision and barrier design relies on momentum, so errors can cost lives.","Clear teaching of basic physics supports fair access to science."],"affectedParties":["Students","Road users protected by safety design","Engineers"]},"owners":{"steward":"Nobody owns a physical quantity; it belongs to shared scientific knowledge.","roles":[],"masterSystems":[]},"relations":[{"target":"Q107715","type":"parent","note":"registry parent class"},{"target":"Q135524371","type":"parent","note":"registry parent class"},{"target":"Q2672914","type":"parent","note":"registry parent class"},{"target":"Q643669","type":"parent","note":"registry parent class"},{"target":"vector quantity","type":"related","note":"in registry terms"},{"target":"physical quantity","type":"related","note":"in registry terms"},{"target":"conservation of momentum","type":"related","note":"in closed systems"},{"target":"force","type":"related","note":"as its rate of change"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.momentum","Wikidata: Q41273 (https://www.wikidata.org/wiki/Q41273)","SI unit: kilogram metre per second","ISO 80000-4: momentum mechanics quantities"]},"properties":{"applicability":"not-applicable","items":["SI unit: kg m/s unit","definition: p = m v formula - classical"]},"recognition":{"applicability":"optional","items":["Classical linear momentum is mass times velocity, and total momentum is conserved when the net external force on the system is zero.","Related concepts include four-momentum, crystal momentum, Fermi momentum and the momentum operator, while angular momentum is a distinct rotational quantity.","Kinetic energy is scalar, impulse is change in momentum, and market momentum is a financial term.","Not a visible object; a vector quantity in equations."]},"capabilities":{"applicability":"required","items":["explain the concept and conservation","relay classical, relativistic and quantum forms","describe applications","distinguish other senses"]},"hazards":{"applicability":"required","items":["Confusing momentum with energy or force","Confusing with figurative uses","Sign and frame errors in problems"]},"interfaces":{"applicability":"required","items":["ISO 80000-4 quantities and units in mechanics","No regulation"]},"context":{"applicability":"required","items":["Not applicable; a physical quantity.","linear momentum","angular momentum","relativistic momentum and four-momentum","momentum operator and de Broglie relation","crystal momentum in periodic solids","Fermi momentum in metals","momentum of fields and radiation"]}},"sources":[{"title":"Wikidata item Q41273: momentum","url":"https://www.wikidata.org/wiki/Q41273","note":"identity and sense of the item"},{"title":"Wikipedia: Momentum","url":"https://en.wikipedia.org/wiki/Momentum","note":"general description of the item"}],"openQuestions":["Should angular momentum and four-momentum be separate entries?","How should physics references be linked?","The registry entry has merged aliases naming specialised forms and an unclear term; should they be split off?"],"resources":{"spec":"/models/things/publications/thing-q41273/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q41273/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-13T01:23:35Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"not-applicable","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:30+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.properties":"Plane XCT: no invented physical properties."},"score":1.0}}