{ "model": { "rank": 10178, "code": "thing-q126818", "model_id": "vr.tr.dimensionless-quantity", "name": "dimensionless quantity", "purpose": "Let an agent handle dimensionless quantities with their definition and reference quantities, because the number alone says nothing about what was compared.", "family": "Thing Registry", "category": "Cross-cutting context", "status": "research-draft", "kind": "thing", "plane": "XCT", "domain": "XCT.QLT", "industry": "", "version": "", "url": "/models/thing/q126818/", "tier": 2, "score": 45, "payload": { "layer": "wikidata", "aliases": [ "air changes per hour", "characteristic number", "return on investment", "Bagnold number", "thrust coefficient", "Lagrange number", "elasticity number", "Görtler number", "Stokes number for vibrating particles", "Stokes rotameter number", "Stokes number for gravity", "Stokes drag number", "Froude number for heat transfer", "heat transfer number", "Pomerantsev number", "Stark number", "Fourier number for mass transfer", "Péclet number for mass transfer", "Grashof number for mass transfer", "Nusselt number for mass transfer", "Stanton number for mass transfer", "Graetz number for mass transfer", "mass transfer factor", "Biot number for mass transfer", "expansion number", "capillary number", "Hooke number", "Lorentz number", "Batchelor number", "Nusselt electric number", "first Cowling number", "Stuart electrical number", "magnetic pressure number", "Roberts number", "magnetic number", "electric field parameter", "Hall number", "Joule electrothermal number", "Grashof magnetic number", "Naze number" ], "aliasCount": 353, "merged": 360, "knownIn": 45, "facets": null, "markers": [], "lexicalClass": "", "senseRank": null, "alsoRegisteredAs": null, "source": { "dataset": "wikidata", "item": "Q126818", "url": "https://www.wikidata.org/wiki/Q126818", "license": "CC0 1.0" } }, "research": { "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-11T05:15:23Z", "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": 1, "engine": "claude" }, "metaModel": { "id": "THING-Q126818", "registryId": "vr.tr.dimensionless-quantity", "name": "dimensionless quantity", "version": "0.2.0-wave.1", "entryKind": "thing", "family": "Thing Registry", "domain": [ "XCT.QLT" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q126818/", "model": { "registry_id": "vr.tr.dimensionless-quantity", "name": "dimensionless quantity", "purpose": "Let an agent handle dimensionless quantities with their definition and reference quantities, because the number alone says nothing about what was compared.", "definition": "A quantity with no physical dimension, obtained as a ratio of quantities of the same dimension or as a combination in which units cancel, such as a Reynolds number, a ratio or a coefficient.", "what_it_is_for": "Comparing systems independent of scale, characterising flows and processes, and expressing ratios.", "affordances": [ "compute it, from its definition", "compare systems by it, as in similarity analysis", "express it, as a number, percentage or in units of one", "use it, in engineering correlations" ], "distinguishing_features": [ "Units cancel; the value is in units of one", "Needs its definition to be meaningful", "Supports scaling and similarity", "Percentages and ratios are dimensionless" ], "appearance": "A plain number, sometimes with a named symbol such as Re or Ma.", "visual_identification": [ "A number without units, often with a named symbol", "Named numbers such as Reynolds, Mach, Bagnold", "Coefficients such as thrust coefficient" ], "physical_properties": [], "families_and_kinds": [ "characteristic numbers in fluid mechanics and heat transfer", "ratios and fractions", "coefficients", "economic ratios such as return on investment", "rates per hour expressed as counts" ], "related_models": [ { "relation": "is a kind of", "target": "physical quantity", "why": "of dimension one" }, { "relation": "has kind", "target": "ratio and efficiency", "why": "dimensionless measures" }, { "relation": "is used in", "target": "engineering", "why": "similarity" }, { "relation": "is confused with", "target": "unitless number", "why": "numbers without meaning" } ], "identifiers": [], "standards_and_regulation": [ "ISO 80000-1 and ISO 80000-11 characteristic numbers", "SI Brochure on quantities of dimension one" ], "failure_modes_and_hazards": [ "Using the wrong reference length or velocity", "Applying correlations outside their valid range", "Treating hidden dimensions such as per hour as dimensionless" ], "in_scope": [], "out_of_scope": [], "characteristics": [] }, "sources": [], "structure": { "bundles": [ { "id": "definition", "name": "Definition", "description": "What is compared.", "rationale": "The definition makes the number meaningful.", "layers": [ { "id": "formula", "name": "Formula", "description": "Defining ratio.", "findings": [ { "id": "formula-finding", "name": "Definition", "description": "The defining formula.", "questions": [ { "text": "What is the defining formula?", "kind": "definition" }, { "text": "Which reference quantities are used?", "kind": "definition" } ] } ] }, { "id": "name", "name": "Name", "description": "Named number.", "findings": [ { "id": "name-finding", "name": "Name", "description": "Name and symbol.", "questions": [ { "text": "Which named number is this, and what symbol does it use?", "kind": "definition" }, { "text": "Is the definition standard?", "kind": "provenance" } ] } ] } ] }, { "id": "computation", "name": "Computation", "description": "Getting the value.", "rationale": "Inputs must be consistent.", "layers": [ { "id": "inputs", "name": "Inputs", "description": "Measured quantities.", "findings": [ { "id": "inputs-finding", "name": "Inputs", "description": "Input values and units.", "questions": [ { "text": "What input values were used, in consistent units?", "kind": "measurement" }, { "text": "How uncertain are they?", "kind": "measurement" } ] } ] }, { "id": "value", "name": "Value", "description": "Result.", "findings": [ { "id": "value-finding", "name": "Value", "description": "The computed value.", "questions": [ { "text": "What is the value?", "kind": "measurement" }, { "text": "Is it within the expected range?", "kind": "boundary" } ] } ] } ] }, { "id": "use", "name": "Use", "description": "What the number tells.", "rationale": "Dimensionless numbers classify regimes.", "layers": [ { "id": "regime", "name": "Regime", "description": "Flow or process regime.", "findings": [ { "id": "regime-finding", "name": "Regime", "description": "The regime indicated.", "questions": [ { "text": "Which regime does this value indicate?", "kind": "definition" }, { "text": "Where are the transitions?", "kind": "boundary" } ] } ] }, { "id": "scaling", "name": "Scaling", "description": "Similarity.", "findings": [ { "id": "scaling-finding", "name": "Similarity", "description": "Similarity conditions.", "questions": [ { "text": "Does the model match the prototype in this number?", "kind": "measurement" }, { "text": "Which other numbers must also match?", "kind": "boundary" } ] } ] } ] }, { "id": "pitfalls", "name": "Pitfalls", "description": "Common errors.", "rationale": "Errors come from definitions and ranges.", "layers": [ { "id": "validity", "name": "Validity", "description": "Range of correlations.", "findings": [ { "id": "validity-finding", "name": "Validity", "description": "Valid ranges.", "questions": [ { "text": "Is the correlation valid at this value?", "kind": "boundary" }, { "text": "What happens outside the range?", "kind": "boundary" } ] } ] }, { "id": "hidden", "name": "Hidden dimensions", "description": "Per time and similar.", "findings": [ { "id": "hidden-finding", "name": "Dimension check", "description": "Whether it is truly dimensionless.", "questions": [ { "text": "Is this quantity truly dimensionless?", "kind": "boundary" }, { "text": "Which unit is implied?", "kind": "definition" } ] } ] } ] } ] }, "openQuestions": [ "Should named characteristic numbers be separate entries?", "How should reference quantities be recorded?", "The registry entry includes air changes per hour, which has dimension; should it 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 dimensionless quantity, record what state it is in, and decide what may be done with it.", "whatItIs": "Let an agent handle dimensionless quantities with their definition and reference quantities, because the number alone says nothing about what was compared.", "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: air changes per hour, characteristic number, return on investment, Bagnold number, thrust coefficient, Lagrange number, elasticity number, Görtler number, Stokes number for vibrating particles, Stokes rotameter number, Stokes number for gravity, Stokes drag number.", "360 finer distinctions are held as aliases rather than separate entries, because telling them apart needs a task that asks for it.", "Described in 45 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 dimensionless quantity, 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": [ "air changes per hour", "characteristic number", "return on investment", "Bagnold number", "thrust coefficient", "Lagrange number", "elasticity number", "Görtler number", "Stokes number for vibrating particles", "Stokes rotameter number", "Stokes number for gravity", "Stokes drag number" ] } ], "standing": "Described in 45 Wikipedia languages, which measures how widely it is written about rather than how important or how common it is. 360 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 dimensionless quantity from another, and a dimensionless quantity 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 dimensionless quantity, 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 dimensionless quantity, 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 dimensionless quantity 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 dimensionless quantity, 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 dimensionless quantity, 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 dimensionless quantity 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 dimensionless quantity 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 dimensionless quantity, 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 dimensionless quantity, 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 dimensionless quantity 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 dimensionless quantity from the things most often confused with it.", "questions": [ { "id": "distinguishing-features-q01", "text": "What identifies and describes what distinguishes a dimensionless quantity, 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 dimensionless quantity, 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 dimensionless quantity 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 dimensionless quantity 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 dimensionless quantity between them.", "questions": [ { "id": "stages-and-transitions-q01", "text": "What identifies and describes the lifecycle of a dimensionless quantity, 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 dimensionless quantity, 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 dimensionless quantity 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 dimensionless quantity, how often and by whom.", "findings": [ { "id": "observation-record", "name": "Observation record", "description": "How an observation of a dimensionless quantity 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 dimensionless quantity, 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 dimensionless quantity, 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 dimensionless quantity 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 dimensionless quantity 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 dimensionless quantity 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 dimensionless quantity 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 dimensionless quantity 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 dimensionless quantity?", "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 dimensionless quantity?", "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 dimensionless quantity 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 dimensionless quantity and how confident it is.", "questions": [ { "id": "claim-provenance-q01", "text": "What identifies and describes a claim about a dimensionless quantity, 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 dimensionless quantity, 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 dimensionless quantity 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 dimensionless quantity is retired without being erased.", "questions": [ { "id": "validity-and-supersession-q01", "text": "What identifies and describes the validity of a claim about a dimensionless quantity, 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 dimensionless quantity, 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 dimensionless quantity 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 } } } }