{ "model": { "rank": 5939, "code": "thing-q179856", "model_id": "vr.tr.alpha-decay", "name": "alpha decay", "purpose": "Let an agent explain alpha decay, relay mechanism, examples, detection, hazards and uses from nuclear physics and radiation protection sources, route exposure concerns to authorities, and distinguish alpha decay from beta decay, gamma emission, spontaneous fission and cluster decay.", "family": "Thing Registry", "category": "Activities and processes", "status": "research-draft", "kind": "thing", "plane": "ACT", "domain": "ACT.PRC", "industry": "", "version": "", "url": "/models/thing/q179856/", "tier": 2, "score": 63, "payload": { "layer": "wikidata", "aliases": [], "aliasCount": 0, "merged": 0, "knownIn": 63, "facets": null, "markers": [], "lexicalClass": "", "senseRank": null, "alsoRegisteredAs": null, "source": { "dataset": "wikidata", "item": "Q179856", "url": "https://www.wikidata.org/wiki/Q179856", "license": "CC0 1.0" } }, "research": { "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-14T00:25:09Z", "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-Q179856", "registryId": "vr.tr.alpha-decay", "name": "alpha decay", "version": "0.2.0-wave.4", "entryKind": "thing", "family": "Thing Registry", "domain": [ "ACT.PRC" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q179856/", "model": { "registry_id": "vr.tr.alpha-decay", "name": "alpha decay", "purpose": "Let an agent explain alpha decay, relay mechanism, examples, detection, hazards and uses from nuclear physics and radiation protection sources, route exposure concerns to authorities, and distinguish alpha decay from beta decay, gamma emission, spontaneous fission and cluster decay.", "definition": "A type of radioactive decay in which an atomic nucleus emits an alpha particle, a helium-4 nucleus of two protons and two neutrons, reducing the atomic number by two and the mass number by four, as in uranium-238, radium-226, radon-222 and polonium-210, explained by quantum tunnelling through the Coulomb barrier in the theory of George Gamow, Ronald Gurney and Edward Condon in 1928; alpha particles are stopped by paper or the outer skin but are hazardous if alpha emitters are inhaled or ingested, as with radon, a leading cause of lung cancer after smoking, and uses include smoke detectors with americium-241 and radioisotope power sources. Suspected radiation exposure needs contact with authorities and medical advice.", "what_it_is_for": "Understanding a mode of radioactive decay.", "affordances": [ "explain mechanism and examples", "relay detection and hazards", "describe uses", "distinguish other decay modes" ], "distinguishing_features": [ "Heavy charged particle", "Short range", "Internal hazard", "Quantum tunnelling" ], "appearance": "Not visible directly; tracks seen in cloud chambers.", "visual_identification": [ "Emission of helium-4 nuclei from nuclei", "Alpha decay, alpha emission", "Beta decay emits electrons or positrons; gamma emission releases photons; spontaneous fission splits nuclei; cluster decay emits heavier fragments" ], "physical_properties": [ { "quantity": "alpha particle", "typical_range": "2 protons and 2 neutrons", "unit": "note", "note": "" }, { "quantity": "typical alpha energy", "typical_range": "about 4-9", "unit": "MeV", "note": "" }, { "quantity": "Gamow tunnelling theory", "typical_range": "1928", "unit": "year", "note": "also Gurney and Condon" } ], "families_and_kinds": [ "uranium and thorium series alpha decays", "radon and progeny decays", "transuranic alpha emitters", "alpha emitters in medicine" ], "related_models": [ { "relation": "is a kind of", "target": "radioactive decay", "why": "in registry terms" }, { "relation": "emits", "target": "alpha particle", "why": "" }, { "relation": "is explained by", "target": "quantum tunnelling", "why": "" }, { "relation": "is contrasted with", "target": "beta decay", "why": "" } ], "identifiers": [], "standards_and_regulation": [ "IAEA radiation safety standards", "Radon action levels in homes and workplaces", "Rules for smoke detector disposal" ], "failure_modes_and_hazards": [ "Underestimating internal alpha hazards", "Radon exposure in homes", "Mishandling sources" ], "in_scope": [], "out_of_scope": [], "characteristics": [] }, "sources": [], "structure": { "bundles": [ { "id": "understand", "name": "Understand", "description": "What alpha decay is.", "rationale": "Science.", "layers": [ { "id": "definition", "name": "Definition", "description": "Definition.", "findings": [ { "id": "definition-finding", "name": "Definition", "description": "Definition.", "questions": [ { "text": "Has someone found a damaged radioactive source or had possible internal contamination, in which case keep away and contact authorities or emergency services?", "kind": "boundary" }, { "text": "What is alpha decay, and how does it differ from beta decay, gamma emission, spontaneous fission and cluster decay?", "kind": "definition" } ] } ] }, { "id": "examples", "name": "Examples", "description": "Examples.", "findings": [ { "id": "examples-finding", "name": "Examples", "description": "Examples.", "questions": [ { "text": "Which nuclides such as uranium-238 and polonium-210 decay by alpha emission?", "kind": "definition" }, { "text": "Which entry fits the specific nuclide?", "kind": "action" } ] } ] } ] }, { "id": "physics", "name": "Physics", "description": "Mechanism.", "rationale": "Science.", "layers": [ { "id": "tunnelling", "name": "Tunnelling", "description": "Quantum tunnelling.", "findings": [ { "id": "tunnelling-finding", "name": "Tunnelling", "description": "Tunnelling.", "questions": [ { "text": "How did Gamow explain alpha decay by tunnelling, and what is the Geiger-Nuttall law?", "kind": "provenance" }, { "text": "Which references are standard?", "kind": "provenance" } ] } ] }, { "id": "rutherford", "name": "Rutherford", "description": "Discovery.", "findings": [ { "id": "rutherford-finding", "name": "Rutherford", "description": "Rutherford.", "questions": [ { "text": "How did Rutherford identify alpha particles as helium nuclei?", "kind": "provenance" }, { "text": "Which sources are cited?", "kind": "provenance" } ] } ] } ] }, { "id": "safety", "name": "Safety", "description": "Hazards.", "rationale": "Regulation.", "layers": [ { "id": "radon", "name": "Radon", "description": "Radon.", "findings": [ { "id": "radon-finding", "name": "Radon", "description": "Radon.", "questions": [ { "text": "Why is radon a lung cancer risk, and how can homes be tested?", "kind": "provenance" }, { "text": "Which entry fits radon?", "kind": "action" } ] } ] }, { "id": "internal", "name": "Internal hazard", "description": "Internal exposure.", "findings": [ { "id": "internal-finding", "name": "Internal hazard", "description": "Internal hazard.", "questions": [ { "text": "Why are alpha emitters dangerous inside the body, as in the Litvinenko polonium case?", "kind": "provenance" }, { "text": "Is the information accurate?", "kind": "boundary" } ] } ] } ] }, { "id": "context", "name": "Context", "description": "Uses.", "rationale": "Context.", "layers": [ { "id": "detectors", "name": "Smoke detectors", "description": "Smoke detectors.", "findings": [ { "id": "detectors-finding", "name": "Smoke detectors", "description": "Smoke detectors.", "questions": [ { "text": "How do americium-241 smoke detectors work?", "kind": "provenance" }, { "text": "Which entry fits smoke detector?", "kind": "action" } ] } ] }, { "id": "therapy", "name": "Therapy", "description": "Targeted alpha therapy.", "findings": [ { "id": "therapy-finding", "name": "Therapy", "description": "Therapy.", "questions": [ { "text": "How are alpha emitters such as radium-223 used in cancer treatment, in general terms?", "kind": "provenance" }, { "text": "Which entry fits targeted alpha-particle therapy?", "kind": "action" } ] } ] } ] } ] }, "openQuestions": [ "Should radon be linked as a separate hazard entry?", "How should radiation protection guidance be linked?", "Should targeted alpha therapy be a separate entry?" ], "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 alpha decay, record what state it is in, and decide what may be done with it.", "whatItIs": "Let an agent explain alpha decay, relay mechanism, examples, detection, hazards and uses from nuclear physics and radiation protection sources, route exposure concerns to authorities, and distinguish alpha decay from beta decay, gamma emission, spontaneous fission and cluster decay.", "characteristics": { "substance": "activity", "origin": "conceptual", "agency": "inert" }, "whatYouCanDoWithIt": [ "observed and measured" ], "distinguishingFeatures": [ "Described in 63 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 alpha decay, and on what evidence are they told apart?" ], "whatItIsMadeOf": "something that happens over time", "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": [], "standing": "Described in 63 Wikipedia languages, which measures how widely it is written about rather than how important or how common it is.", "structure": { "bundles": [ { "id": "identity-and-classification", "name": "Identity, naming and classification", "description": "How an agent tells one alpha decay from another, and a alpha decay 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 alpha decay, 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 alpha decay, 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 alpha decay 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 alpha decay, 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 alpha decay, 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 alpha decay 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 alpha decay 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 alpha decay, 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 alpha decay, 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 alpha decay 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 alpha decay from the things most often confused with it.", "questions": [ { "id": "distinguishing-features-q01", "text": "What identifies and describes what distinguishes a alpha decay, 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 alpha decay, 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 alpha decay 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 alpha decay 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 alpha decay between them.", "questions": [ { "id": "stages-and-transitions-q01", "text": "What identifies and describes the lifecycle of a alpha decay, 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 alpha decay, 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 alpha decay 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 alpha decay, how often and by whom.", "findings": [ { "id": "observation-record", "name": "Observation record", "description": "How an observation of a alpha decay 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 alpha decay, 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 alpha decay, 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 alpha decay is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] }, { "id": "process-and-outcome", "name": "Process, inputs and outcome", "description": "How a alpha decay proceeds, what it needs and what it leaves behind.", "rationale": "An activity is known by its steps and its results, and both have to be recordable while it is still running.", "layers": [ { "id": "steps-and-sequence", "name": "Steps and sequence", "description": "The steps of a alpha decay, their order and what may run in parallel.", "findings": [ { "id": "steps-and-preconditions", "name": "Steps, preconditions and completion", "description": "What has to be true before each step of a alpha decay and what marks it done.", "questions": [ { "id": "steps-and-preconditions-q01", "text": "What identifies and describes a step of a alpha decay, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "steps-and-preconditions-q02", "text": "Who or what asserted this about a step of a alpha decay, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "steps-and-preconditions-q03", "text": "What may an agent decide or do once a step of a alpha decay is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] }, { "id": "inputs-and-results", "name": "Inputs, resources and results", "description": "What a alpha decay consumes and what it produces.", "findings": [ { "id": "inputs-and-outputs", "name": "Inputs, outputs and side effects", "description": "The resources a alpha decay takes and the results it leaves, wanted or not.", "questions": [ { "id": "inputs-and-outputs-q01", "text": "What identifies and describes the inputs and results of a alpha decay, and in what units or vocabulary?", "kind": "definition", "answer_data": [ "identifiers", "types and classes", "values with units", "explicit unknowns" ] }, { "id": "inputs-and-outputs-q02", "text": "Who or what asserted this about the inputs and results of a alpha decay, by which method, and when was it true?", "kind": "provenance", "answer_data": [ "authority", "method", "evidence", "event time", "knowledge time" ] }, { "id": "inputs-and-outputs-q03", "text": "What may an agent decide or do once the inputs and results of a alpha decay 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 alpha decay 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 alpha decay 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 alpha decay 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 alpha decay 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 alpha decay?", "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 alpha decay?", "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 alpha decay 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 alpha decay and how confident it is.", "questions": [ { "id": "claim-provenance-q01", "text": "What identifies and describes a claim about a alpha decay, 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 alpha decay, 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 alpha decay 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 alpha decay is retired without being erased.", "questions": [ { "id": "validity-and-supersession-q01", "text": "What identifies and describes the validity of a claim about a alpha decay, 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 alpha decay, 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 alpha decay is known, and what must it refuse?", "kind": "action", "answer_data": [ "permitted actions", "preconditions", "refusals", "escalation" ] } ] } ] } ] } ] }, "statistics": { "bundles": 6, "layers": 12, "findings": 14, "questions": 38 } } } }