{ "model": { "rank": 9023, "code": "thing-q208395", "model_id": "vr.tr.spheroid", "name": "spheroid", "purpose": "Let an agent explain spheroids, relay geometry, formulas and geodetic uses from mathematics and geodesy sources, describe the named forms, and distinguish spheroids from spheres, triaxial ellipsoids, geoids and ovoid or egg shapes.", "family": "Thing Registry", "category": "Cross-cutting context", "status": "research-draft", "kind": "thing", "plane": "XCT", "domain": "XCT.QLT", "industry": "", "version": "", "url": "/models/thing/q208395/", "tier": 2, "score": 49, "payload": { "layer": "wikidata", "aliases": [ "Earth ellipsoid", "oblate spheroid", "prolate spheroid" ], "aliasCount": 3, "merged": 3, "knownIn": 49, "facets": null, "markers": [], "lexicalClass": "", "senseRank": null, "alsoRegisteredAs": "vr.tr.spheroid", "source": { "dataset": "wikidata", "item": "Q208395", "url": "https://www.wikidata.org/wiki/Q208395", "license": "CC0 1.0" } }, "research": { "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-13T23:45:34Z", "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-Q208395", "registryId": "vr.tr.spheroid", "name": "spheroid", "version": "0.2.0-wave.4", "entryKind": "thing", "family": "Thing Registry", "domain": [ "XCT.QLT" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q208395/", "model": { "registry_id": "vr.tr.spheroid", "name": "spheroid", "purpose": "Let an agent explain spheroids, relay geometry, formulas and geodetic uses from mathematics and geodesy sources, describe the named forms, and distinguish spheroids from spheres, triaxial ellipsoids, geoids and ovoid or egg shapes.", "definition": "A surface formed by rotating an ellipse about one of its principal axes, called an oblate spheroid when rotated about the minor axis, flattened at the poles like the Earth, and a prolate spheroid when rotated about the major axis, elongated like a rugby ball; reference ellipsoids such as the Earth ellipsoid of WGS 84, with an equatorial radius of 6,378,137 metres and a flattening of about 1/298.257, underpin GPS, mapping and geodesy. Spheroids are special cases of ellipsoids with two equal axes.", "what_it_is_for": "Describing flattened or elongated round shapes.", "affordances": [ "explain geometry", "relay formulas", "describe Earth reference ellipsoids", "distinguish related shapes" ], "distinguishing_features": [ "Two equal axes", "Rotational symmetry", "Oblate or prolate", "Geodetic importance" ], "appearance": "A ball flattened at the poles or stretched along an axis.", "visual_identification": [ "Ellipsoid of revolution", "Earth ellipsoid, oblate spheroid, prolate spheroid", "Spheres have all axes equal; triaxial ellipsoids have three different axes; geoids model gravity equipotential; ovoids are asymmetric eggs" ], "physical_properties": [ { "quantity": "WGS 84 equatorial radius", "typical_range": "6,378,137", "unit": "m", "note": "" }, { "quantity": "WGS 84 inverse flattening", "typical_range": "298.257223563", "unit": "number", "note": "" }, { "quantity": "Newton predicted Earth oblateness", "typical_range": "1687", "unit": "year", "note": "Principia" } ], "families_and_kinds": [ "oblate spheroids", "prolate spheroids", "reference ellipsoids", "spheroidal coordinates" ], "related_models": [ { "relation": "is a kind of", "target": "ellipsoid", "why": "in registry terms" }, { "relation": "includes", "target": "oblate spheroid", "why": "" }, { "relation": "is used in", "target": "World Geodetic System", "why": "" }, { "relation": "is contrasted with", "target": "geoid", "why": "" } ], "identifiers": [], "standards_and_regulation": [ "WGS 84 and GRS 80 geodetic standards", "ISO 19111 coordinate reference systems" ], "failure_modes_and_hazards": [ "Mixing datums in mapping", "Confusing ellipsoid and geoid heights", "Assuming Earth is a sphere for precise work" ], "in_scope": [], "out_of_scope": [], "characteristics": [] }, "sources": [], "structure": { "bundles": [ { "id": "understand", "name": "Understand", "description": "What a spheroid is.", "rationale": "Definition.", "layers": [ { "id": "definition", "name": "Definition", "description": "Definition.", "findings": [ { "id": "definition-finding", "name": "Definition", "description": "Definition.", "questions": [ { "text": "What is a spheroid, and how does it differ from spheres, triaxial ellipsoids, geoids and ovoids?", "kind": "definition" }, { "text": "Is the question about geometry, mapping, GPS or physics?", "kind": "boundary" } ] } ] }, { "id": "forms", "name": "Forms", "description": "Named forms.", "findings": [ { "id": "forms-finding", "name": "Forms", "description": "Forms.", "questions": [ { "text": "What are oblate and prolate spheroids and Earth ellipsoids?", "kind": "definition" }, { "text": "Which entry fits the specific form?", "kind": "action" } ] } ] } ] }, { "id": "geometry", "name": "Geometry", "description": "Geometry.", "rationale": "Science.", "layers": [ { "id": "formulas", "name": "Formulas", "description": "Volume and surface.", "findings": [ { "id": "formulas-finding", "name": "Formulas", "description": "Formulas.", "questions": [ { "text": "How are volume and surface area of spheroids computed?", "kind": "measurement" }, { "text": "Which references are standard?", "kind": "provenance" } ] } ] }, { "id": "flattening", "name": "Flattening", "description": "Flattening and eccentricity.", "findings": [ { "id": "flattening-finding", "name": "Flattening", "description": "Flattening.", "questions": [ { "text": "What are flattening and eccentricity of a spheroid?", "kind": "measurement" }, { "text": "Which sources are cited?", "kind": "provenance" } ] } ] } ] }, { "id": "geodesy", "name": "Geodesy", "description": "Geodesy.", "rationale": "Regulation.", "layers": [ { "id": "wgs84", "name": "WGS 84", "description": "WGS 84.", "findings": [ { "id": "wgs84-finding", "name": "WGS 84", "description": "WGS 84.", "questions": [ { "text": "How does WGS 84 define the Earth ellipsoid used by GPS?", "kind": "provenance" }, { "text": "Which entry fits World Geodetic System?", "kind": "action" } ] } ] }, { "id": "geoid", "name": "Geoid", "description": "Ellipsoid and geoid.", "findings": [ { "id": "geoid-finding", "name": "Geoid", "description": "Geoid.", "questions": [ { "text": "Why do ellipsoidal heights differ from heights above the geoid?", "kind": "provenance" }, { "text": "Which entry fits geoid?", "kind": "action" } ] } ] } ] }, { "id": "context", "name": "Context", "description": "History and nature.", "rationale": "Context.", "layers": [ { "id": "history", "name": "History", "description": "Figure of the Earth.", "findings": [ { "id": "history-finding", "name": "History", "description": "History.", "questions": [ { "text": "How did 18th-century expeditions confirm the Earth is oblate?", "kind": "provenance" }, { "text": "Which entry fits French Geodesic Mission?", "kind": "action" } ] } ] }, { "id": "planets", "name": "Planets", "description": "Rotating bodies.", "findings": [ { "id": "planets-finding", "name": "Planets", "description": "Planets.", "questions": [ { "text": "Why are fast-rotating planets such as Saturn strongly oblate?", "kind": "provenance" }, { "text": "Which entry fits flattening?", "kind": "action" } ] } ] } ] } ] }, "openQuestions": [ "Should reference ellipsoids be a separate entry?", "How should geodesy standards be linked?", "Should prolate spheroid be split off?" ], "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 spheroid, record what state it is in, and decide what may be done with it.", "whatItIs": "Let an agent explain spheroids, relay geometry, formulas and geodetic uses from mathematics and geodesy sources, describe the named forms, and distinguish spheroids from spheres, triaxial ellipsoids, geoids and ovoid or egg shapes.", "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: Earth ellipsoid, oblate spheroid, prolate spheroid.", "3 finer distinctions are held as aliases rather than separate entries, because telling them apart needs a task that asks for it.", "Described in 49 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 spheroid, 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": [ "Earth ellipsoid", "oblate spheroid", "prolate spheroid" ] } ], "standing": "Described in 49 Wikipedia languages, which measures how widely it is written about rather than how important or how common it is. 3 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 spheroid from another, and a spheroid 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 spheroid, 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 spheroid, 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 spheroid 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 spheroid, 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 spheroid, 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 spheroid 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 spheroid 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 spheroid, 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 spheroid, 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 spheroid 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 spheroid from the things most often confused with it.", "questions": [ { "id": "distinguishing-features-q01", "text": "What identifies and describes what distinguishes a spheroid, 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 spheroid, 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 spheroid 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 spheroid 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 spheroid between them.", "questions": [ { "id": "stages-and-transitions-q01", "text": "What identifies and describes the lifecycle of a spheroid, 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 spheroid, 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 spheroid 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 spheroid, how often and by whom.", "findings": [ { "id": "observation-record", "name": "Observation record", "description": "How an observation of a spheroid 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 spheroid, 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 spheroid, 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 spheroid 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 spheroid 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 spheroid 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 spheroid 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 spheroid 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 spheroid?", "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 spheroid?", "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 spheroid 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 spheroid and how confident it is.", "questions": [ { "id": "claim-provenance-q01", "text": "What identifies and describes a claim about a spheroid, 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 spheroid, 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 spheroid 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 spheroid is retired without being erased.", "questions": [ { "id": "validity-and-supersession-q01", "text": "What identifies and describes the validity of a claim about a spheroid, 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 spheroid, 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 spheroid 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 } } } }