{ "model": { "rank": 5432, "code": "thing-q146657", "model_id": "vr.tr.great-circle", "name": "great circle", "purpose": "Let an agent explain great circles and their properties, relay uses in navigation, geodesy and astronomy from mathematics and navigation sources, describe the celestial circles the registry aliases name, and distinguish great circles from small circles, rhumb lines and lunar mansions.", "family": "Thing Registry", "category": "Cross-cutting context", "status": "research-draft", "kind": "thing", "plane": "XCT", "domain": "XCT.QLT", "industry": "", "version": "", "url": "/models/thing/q146657/", "tier": 2, "score": 67, "payload": { "layer": "wikidata", "aliases": [ "north-south running great circle", "celestial meridian", "hour circle", "Riemannian circle", "lunar mansion", "vertical circle" ], "aliasCount": 6, "merged": 6, "knownIn": 67, "facets": null, "markers": [], "lexicalClass": "", "senseRank": null, "alsoRegisteredAs": null, "source": { "dataset": "wikidata", "item": "Q146657", "url": "https://www.wikidata.org/wiki/Q146657", "license": "CC0 1.0" } }, "research": { "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-13T18:31:19Z", "providers": [ "Claude" ], "breadth": "written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify", "pass": 2, "wave": 4, "engine": "claude" }, "metaModel": { "id": "THING-Q146657", "registryId": "vr.tr.great-circle", "name": "great circle", "version": "0.2.0-wave.4", "entryKind": "thing", "family": "Thing Registry", "domain": [ "XCT.QLT" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q146657/", "model": { "registry_id": "vr.tr.great-circle", "name": "great circle", "purpose": "Let an agent explain great circles and their properties, relay uses in navigation, geodesy and astronomy from mathematics and navigation sources, describe the celestial circles the registry aliases name, and distinguish great circles from small circles, rhumb lines and lunar mansions.", "definition": "The largest circle that can be drawn on a sphere, formed by the intersection of the sphere with a plane through its centre, giving the shortest path between two points on the surface, used in navigation and aviation routes, and in astronomy as reference circles on the celestial sphere such as the celestial equator, celestial meridians, hour circles and vertical circles; on Earth, meridians are great circles; the registry aliases also list the lunar mansion, a division of the zodiac along the Moon s path, which is not a great circle itself, and the Riemannian circle, a related metric space notion.", "what_it_is_for": "Shortest routes and celestial reference.", "affordances": [ "explain properties", "relay navigation and astronomy uses", "describe celestial circles", "distinguish related curves" ], "distinguishing_features": [ "Through sphere centre", "Shortest path", "Divides sphere equally", "Celestial reference" ], "appearance": "Not a visible object; a circle dividing a sphere into halves.", "visual_identification": [ "Circle on a sphere with the sphere s centre", "Meridian, celestial meridian, hour circle, vertical circle, Riemannian circle; lunar mansion as misfiled", "Small circles do not pass through the centre; rhumb lines keep constant bearing; lunar mansions are zodiac divisions" ], "physical_properties": [ { "quantity": "Earth great circle length", "typical_range": "about 40000", "unit": "km", "note": "" }, { "quantity": "shortest path", "typical_range": "geodesic on a sphere", "unit": "note", "note": "" }, { "quantity": "equator", "typical_range": "the only parallel that is a great circle", "unit": "note", "note": "" } ], "families_and_kinds": [ "terrestrial meridians and the equator", "great-circle routes", "celestial equator and ecliptic", "celestial meridians, hour circles and vertical circles", "Riemannian circles in metric geometry" ], "related_models": [ { "relation": "is a kind of", "target": "closed geodesic", "why": "in registry terms" }, { "relation": "is contrasted with", "target": "rhumb line", "why": "" }, { "relation": "includes", "target": "meridian", "why": "" }, { "relation": "is distinct from", "target": "lunar mansion", "why": "a misfiled alias" } ], "identifiers": [], "standards_and_regulation": [ "Aviation route planning practice" ], "failure_modes_and_hazards": [ "Confusing great-circle and rhumb-line navigation", "Map projection distortion of routes", "Registry alias lunar mansion misfiled" ], "in_scope": [], "out_of_scope": [], "characteristics": [] }, "sources": [], "structure": { "bundles": [ { "id": "understand", "name": "Understand", "description": "What a great circle is.", "rationale": "Science.", "layers": [ { "id": "definition", "name": "Definition", "description": "Definition.", "findings": [ { "id": "definition-finding", "name": "Definition", "description": "Definition.", "questions": [ { "text": "What is a great circle, and how does it differ from a small circle, rhumb line and lunar mansion?", "kind": "definition" }, { "text": "Is the question about geometry, navigation, astronomy or a misfiled alias?", "kind": "boundary" } ] } ] }, { "id": "kinds", "name": "Kinds", "description": "Named circles.", "findings": [ { "id": "kinds-finding", "name": "Kinds", "description": "Kinds.", "questions": [ { "text": "What are meridians, celestial meridians, hour circles, vertical circles and Riemannian circles?", "kind": "definition" }, { "text": "Which entry fits the specific circle?", "kind": "action" } ] } ] } ] }, { "id": "math", "name": "Mathematics", "description": "Mathematics.", "rationale": "Science.", "layers": [ { "id": "geodesic", "name": "Geodesic", "description": "Geodesics.", "findings": [ { "id": "geodesic-finding", "name": "Geodesic", "description": "Geodesic.", "questions": [ { "text": "Why are great circles the shortest paths on a sphere, and how is distance computed?", "kind": "provenance" }, { "text": "Which references are standard?", "kind": "provenance" } ] } ] }, { "id": "trig", "name": "Trigonometry", "description": "Spherical trigonometry.", "findings": [ { "id": "trig-finding", "name": "Trigonometry", "description": "Trigonometry.", "questions": [ { "text": "How does spherical trigonometry use great circles?", "kind": "provenance" }, { "text": "Which sources are cited?", "kind": "provenance" } ] } ] } ] }, { "id": "applications", "name": "Applications", "description": "Applications.", "rationale": "Application.", "layers": [ { "id": "navigation", "name": "Navigation", "description": "Navigation.", "findings": [ { "id": "navigation-finding", "name": "Navigation", "description": "Navigation.", "questions": [ { "text": "How are great-circle routes used in aviation and shipping?", "kind": "provenance" }, { "text": "Which entry fits great-circle navigation?", "kind": "action" } ] } ] }, { "id": "astronomy", "name": "Astronomy", "description": "Astronomy.", "findings": [ { "id": "astronomy-finding", "name": "Astronomy", "description": "Astronomy.", "questions": [ { "text": "How are great circles used as coordinates on the celestial sphere?", "kind": "provenance" }, { "text": "Which entry fits celestial coordinate system?", "kind": "action" } ] } ] } ] }, { "id": "context", "name": "Context", "description": "History and registry note.", "rationale": "Context.", "layers": [ { "id": "history", "name": "History", "description": "History.", "findings": [ { "id": "history-finding", "name": "History", "description": "History.", "questions": [ { "text": "How did ancient astronomers and navigators use great circles?", "kind": "provenance" }, { "text": "Which entry fits the history of navigation?", "kind": "action" } ] } ] }, { "id": "mansion", "name": "Mansion", "description": "Lunar mansions.", "findings": [ { "id": "mansion-finding", "name": "Mansion", "description": "Mansion.", "questions": [ { "text": "What are lunar mansions, and why are they not great circles?", "kind": "provenance" }, { "text": "Which entry fits lunar mansion?", "kind": "action" } ] } ] } ] } ] }, "openQuestions": [ "Should hour circle and vertical circle be separate primary entries?", "How should navigation sources be linked?", "The registry alias lunar mansion is not a great circle and should be detached" ], "statistics": { "bundles": 4, "layers": 8, "findings": 8, "questions": 16 } }, "draft": { "generator": "vr.draft.v3", "status": "draft-generated", "researched": false, "archetype": "abstract concept", "method": "Written from the archetype playbook - what this kind of thing needs beyond identity and provenance - and from the structure that recurred across 6,333 models already researched by two engines. Applied to this entry by rule. No source was read for this thing and no claim here is researched. This entry carries no facets of its own, so they were inferred from its domain - a guess about a whole domain applied to one thing.", "facetsInferred": true, "nextPass": "A researcher replaces this draft with a sourced specification. Treat every sentence below as a proposal to argue with.", "purpose": "Give an agent a durable, checkable way to recognise a great circle, record what state it is in, and decide what may be done with it.", "whatItIs": "Let an agent explain great circles and their properties, relay uses in navigation, geodesy and astronomy from mathematics and navigation sources, describe the celestial circles the registry aliases name, and distinguish great circles from small circles, rhumb lines and lunar mansions.", "characteristics": { "substance": "abstract", "origin": "conceptual", "agency": "inert" }, "whatYouCanDoWithIt": [ "observed and measured" ], "distinguishingFeatures": [ "Names folded into this entry, which a task may need to split apart again: north-south running great circle, celestial meridian, hour circle, Riemannian circle, lunar mansion, vertical circle.", "6 finer distinctions are held as aliases rather than separate entries, because telling them apart needs a task that asks for it.", "Described in 67 Wikipedia languages, which is a measure of how widely the thing is known, not of how important it is." ], "openQuestionsForResearch": [ "Which of the bundles below does a real task actually need, and which are ceremony?", "What does this thing have that the facets do not capture at all?", "Which neighbouring kind is most often confused with a great circle, and on what evidence are they told apart?" ], "whatItIsMadeOf": "an abstraction with no physical instance", "physicalCharacter": [ "Does nothing on its own; everything it does, something else did to it.", "These come from the domain this entry sits in rather than from the entry itself, so treat them as a first guess about the whole domain applied to one thing." ], "whatCanBeDoneWithIt": [ "observe it, measure it, record its state" ], "howItIsRecognised": [ "Nothing to see. What is recognised is an instance of it, and which instances count is exactly what is argued about." ], "relatedModels": [ { "relation": "covers", "note": "Finer kinds folded into this entry because telling them apart needs a task that asks for it. Each is a model waiting to be split out when one does.", "targets": [ "north-south running great circle", "celestial meridian", "hour circle", "Riemannian circle", "lunar mansion", "vertical circle" ] } ], "standing": "Described in 67 Wikipedia languages, which measures how widely it is written about rather than how important or how common it is. 6 finer distinctions are held inside this entry as names rather than as separate models.", "structure": { "bundles": [ { "id": "identity-and-classification", "name": "Identity, naming and classification", "description": "How an agent tells one great circle from another, and a great circle from things that resemble it.", "rationale": "Recognition comes before every other claim. Without stable identity nothing else in the model can be trusted to be about the same thing twice.", "layers": [ { "id": "naming-and-identifiers", "name": "Names and identifiers", "description": "The names this thing goes by and the identifiers that survive translation and time.", "findings": [ { "id": "preferred-name-and-aliases", "name": "Preferred name, aliases and local names", "description": "Which name to use, which names mean the same thing, and which merely sound similar.", "questions": [ { "id": "preferred-name-and-aliases-q01", "text": "What identifies and describes the name of a great circle, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "preferred-name-and-aliases-q02", "text": "Who or what asserted this about the name of a great circle, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "preferred-name-and-aliases-q03", "text": "What may an agent decide or do once the name of a great circle is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] }, { "id": "stable-identifiers", "name": "Stable identifiers and external keys", "description": "Identifiers that keep pointing at this kind of thing across systems and languages.", "questions": [ { "id": "stable-identifiers-q01", "text": "What identifies and describes an identifier for a great circle, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "stable-identifiers-q02", "text": "Who or what asserted this about an identifier for a great circle, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "stable-identifiers-q03", "text": "What may an agent decide or do once an identifier for a great circle is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "classification-and-granularity", "name": "Classification and granularity", "description": "Where a great circle sits among kinds, and how finely a task needs to cut it.", "findings": [ { "id": "kind-and-parents", "name": "Kind, parents and neighbouring kinds", "description": "The classes this thing belongs to and the ones it is next to.", "questions": [ { "id": "kind-and-parents-q01", "text": "What identifies and describes the kind of a great circle, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "kind-and-parents-q02", "text": "Who or what asserted this about the kind of a great circle, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "kind-and-parents-q03", "text": "What may an agent decide or do once the kind of a great circle is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] }, { "id": "distinguishing-features", "name": "Distinguishing features", "description": "What separates a great circle from the things most often confused with it.", "questions": [ { "id": "distinguishing-features-q01", "text": "What identifies and describes what distinguishes a great circle, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "distinguishing-features-q02", "text": "Who or what asserted this about what distinguishes a great circle, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "distinguishing-features-q03", "text": "What may an agent decide or do once what distinguishes a great circle is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "state-and-lifecycle", "name": "State and lifecycle", "description": "The states a great circle passes through and the events that move it between them.", "rationale": "Most decisions about a thing depend on what state it is in now, which is a claim with a time on it, not a property.", "layers": [ { "id": "lifecycle-stages", "name": "Lifecycle stages", "description": "From coming into existence to ceasing to be one of these.", "findings": [ { "id": "stages-and-transitions", "name": "Stages and transitions", "description": "The stages worth naming and what moves a great circle between them.", "questions": [ { "id": "stages-and-transitions-q01", "text": "What identifies and describes the lifecycle of a great circle, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "stages-and-transitions-q02", "text": "Who or what asserted this about the lifecycle of a great circle, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "stages-and-transitions-q03", "text": "What may an agent decide or do once the lifecycle of a great circle is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "observations-and-status", "name": "Observations and current status", "description": "What is observed about a great circle, how often and by whom.", "findings": [ { "id": "observation-record", "name": "Observation record", "description": "How an observation of a great circle is recorded so that it can be superseded rather than overwritten.", "questions": [ { "id": "observation-record-q01", "text": "What identifies and describes an observation of a great circle, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "observation-record-q02", "text": "Who or what asserted this about an observation of a great circle, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "observation-record-q03", "text": "What may an agent decide or do once an observation of a great circle is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "definitions-in-contest", "name": "Definitions and who holds them", "description": "What great circle is taken to mean, and by whom.", "rationale": "When a field disagrees about a concept, the disagreement is the content. A model that picks one definition silently destroys the information.", "layers": [ { "id": "competing-definitions", "name": "Competing definitions", "description": "The main readings and the traditions behind them.", "findings": [ { "id": "definition-map", "name": "Definitions and their holders", "description": "Each definition with the school or body that holds it.", "questions": [ { "id": "definition-map-q01", "text": "Which definitions of great circle are in use, and which tradition or body holds each?", "kind": "definition" }, { "id": "definition-map-q02", "text": "What turns on the difference between them in practice?", "kind": "boundary" } ] } ] }, { "id": "operationalisation", "name": "Operationalisation", "description": "How it is measured or applied when it has to be.", "findings": [ { "id": "operational-record", "name": "Measures and proxies", "description": "Instruments and indicators used to stand in for it.", "questions": [ { "id": "operational-record-q01", "text": "How is great circle operationalised or measured in practice, and by what instrument?", "kind": "measurement" }, { "id": "operational-record-q02", "text": "What does that operationalisation leave out, and when does that matter?", "kind": "boundary" } ] } ] } ] }, { "id": "instances-and-use", "name": "Instances, use and consequence", "description": "What counts as an instance of great circle and what follows from calling something that.", "rationale": "Applying a concept is an act with consequences, so a model must say what the label licenses and what it does not.", "layers": [ { "id": "instances", "name": "What counts as an instance", "description": "Clear cases, borderline cases and non-cases.", "findings": [ { "id": "instance-tests", "name": "Tests for an instance", "description": "What would settle whether something falls under it.", "questions": [ { "id": "instance-tests-q01", "text": "What would settle whether something is an instance of great circle?", "kind": "boundary" }, { "id": "instance-tests-q02", "text": "Which borderline cases are argued about, and on what grounds?", "kind": "definition" } ] } ] }, { "id": "consequence", "name": "Consequence of application", "description": "Rights, duties or decisions that follow from the label.", "findings": [ { "id": "consequence-record", "name": "What the label licenses", "description": "What an agent may do once something is classified this way.", "questions": [ { "id": "consequence-record-q01", "text": "What follows practically once something is treated as great circle?", "kind": "action" }, { "id": "consequence-record-q02", "text": "What must an agent not infer from the label alone?", "kind": "action" } ] } ] } ] }, { "id": "provenance-and-evidence", "name": "Provenance, evidence and time", "description": "Where every claim about a great circle came from and when it held.", "rationale": "A claim without a source and a time cannot be superseded, only overwritten, and an agent that overwrites loses the ability to explain itself.", "layers": [ { "id": "source-and-authority", "name": "Source and authority", "description": "Who said it, on what evidence, and how strongly.", "findings": [ { "id": "claim-provenance", "name": "Claim provenance and confidence", "description": "The authority behind each claim about a great circle and how confident it is.", "questions": [ { "id": "claim-provenance-q01", "text": "What identifies and describes a claim about a great circle, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "claim-provenance-q02", "text": "Who or what asserted this about a claim about a great circle, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "claim-provenance-q03", "text": "What may an agent decide or do once a claim about a great circle is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "time-and-versions", "name": "Time, versions and supersession", "description": "When a claim was true, when it was learnt, and what replaced it.", "findings": [ { "id": "validity-and-supersession", "name": "Validity period and supersession", "description": "How an old claim about a great circle is retired without being erased.", "questions": [ { "id": "validity-and-supersession-q01", "text": "What identifies and describes the validity of a claim about a great circle, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "validity-and-supersession-q02", "text": "Who or what asserted this about the validity of a claim about a great circle, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "validity-and-supersession-q03", "text": "What may an agent decide or do once the validity of a claim about a great circle is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] } ] }, "statistics": { "bundles": 5, "layers": 10, "findings": 12, "questions": 32 } } } }