{ "model": { "rank": 6185, "code": "thing-q104225", "model_id": "vr.tr.precession", "name": "precession", "purpose": "Enable an AI agent to recognise precession, assess how a rotational or orbital orientation evolves, and judge which predictions or interventions are justified.", "family": "Thing Registry", "category": "Activities and processes", "status": "research-draft", "kind": "thing", "plane": "ACT", "domain": "ACT.ACT", "industry": "", "version": "", "url": "/models/thing/q104225/", "tier": 2, "score": 62, "payload": { "layer": "wikidata", "aliases": [ "Lense–Thirring precession", "nodal precession", "Larmor precession", "Lunar precession", "Pugh–Schiff precession" ], "aliasCount": 5, "merged": 5, "knownIn": 62, "facets": null, "markers": [], "lexicalClass": "", "senseRank": null, "alsoRegisteredAs": "vr.tr.precession", "source": { "dataset": "wikidata", "item": "Q104225", "url": "https://www.wikidata.org/wiki/Q104225", "license": "CC0 1.0" } }, "research": { "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-07T12:01:52Z", "providers": [ "Codex", "Grok" ], "missingProviders": [], "pass": 2, "cost": { "grok": { "usd": 0.00487458, "turns": 1, "seconds": 70.2, "error": null }, "codex": { "seconds": 74, "error": "Reading additional input from stdin...\nOpenAI Codex v0.153.3\n--------\nworkdir: R:\\02_PROJECTS\\02_Meta_Models_Platforms\\Ver.cy\\current\\thing-registry-backlog\nmodel: gpt-6-astra\nprovider: openai\napproval: never\nsandbox: read-only\nreasoning effort: none\nreasoning summaries: none\nsession id: 01a07bbc-54f0-7dc2-83ac-a6774da70a85\n--------\nuser\nYou are drafting a Vercy meta-model for one registered thing. Answer as JSON only, no prose around it.\n\nThing: precession\nRegistry id: vr.tr.precession\nPlane / domain: ACT / ACT.ACT\nRegistry definition: (none recorded)\nNames folded into this entry: (none)\n\nA V" } } }, "metaModel": { "id": "THING-Q104225", "registryId": "vr.tr.precession", "name": "precession", "version": "0.1.0-research.1", "entryKind": "thing", "family": "Thing Registry", "domain": [ "ACT.ACT" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q104225/", "model": { "registry_id": "vr.tr.precession", "name": "precession", "purpose": "Enable an AI agent to recognise precession, assess how a rotational or orbital orientation evolves, and judge which predictions or interventions are justified.", "definition": "Precession is the slow, continuous change in orientation of a rotating body's spin axis, produced by a torque (or an equivalent geometric constraint) that is not aligned with that axis, so that the axis traces a cone rather than remaining fixed in inertial space.", "scope_statement": "This model owns precession as the evolution of a specified axis or orbital direction relative to an explicit reference frame, including its geometry, rate, evidence, proposed mechanism and intervention limits; axial, apsidal and nodal cases remain within one model pending registry clarification.", "in_scope": [ "Identification of the axis or orbital direction that precesses", "Reference frames, reference directions and conventions for measuring orientation", "Precession angle, rate, direction and changes over time", "Separation of precession from spin, nutation and reference-frame motion", "Evidence for the mechanism and conditions governing precession", "Prediction, monitoring and feasible modification of precessional behaviour" ], "out_of_scope": [ "Complete physical descriptions of the rotating body or orbiting system", "Spin dynamics unrelated to a change in the specified orientation", "Full orbital trajectories beyond what establishes precession", "General vibration, translation and structural deformation", "Design and operation of instruments or actuators beyond their role in observing or changing precession" ], "distinguishing_features": [ "Identify a changing axis or orbital direction: rotation of material around an unchanged axis establishes spin but does not by itself establish precession.", "Express the orientation change in a declared frame and determine how much follows from motion of that frame.", "For axial motion, distinguish progression around a reference direction from oscillation of the axis's inclination; record coupled precession and nutation when both occur.", "For orbital motion, distinguish rotation of the apsidal direction within the orbital plane from reorientation of the orbital plane through nodal precession.", "Require a resolved orientation history or a supported dynamical prediction; one tilted configuration alone does not establish precession." ], "characteristics": [ { "name": "Precession case", "kind": "category", "unit_or_values": "axial | apsidal | nodal | other specified | unresolved", "why_it_matters": "Determines which orientation is tracked and which comparisons are meaningful." }, { "name": "Precessing referent", "kind": "relation", "unit_or_values": "identified body axis, angular-momentum direction, orbital apsidal direction or orbital-plane normal", "why_it_matters": "Prevents treating distinct directions in the same system as interchangeable." }, { "name": "Reference frame and direction", "kind": "relation", "unit_or_values": "named frame, reference direction or plane, epoch and transformation where applicable", "why_it_matters": "Makes an orientation change interpretable and separates it from frame motion." }, { "name": "Precession phase", "kind": "measurement", "unit_or_values": "radians or degrees, with zero direction and wrapping convention", "why_it_matters": "Locates the tracked orientation along its measured progression." }, { "name": "Precession rate", "kind": "measurement", "unit_or_values": "radians per second, degrees per unit time or angle per orbit, with averaging interval", "why_it_matters": "Supports comparison and prediction without conflating instantaneous and mean rates." }, { "name": "Sense of progression", "kind": "category", "unit_or_values": "positive | negative | reversing | unresolved, under a stated convention", "why_it_matters": "Prevents ambiguous use of clockwise, prograde and retrograde." }, { "name": "Inclination to reference", "kind": "measurement", "unit_or_values": "radians or degrees; not applicable where no corresponding inclination is defined", "why_it_matters": "Describes the precession geometry and helps distinguish it from nutation." }, { "name": "Observed progression pattern", "kind": "state", "unit_or_values": "approximately uniform | varying | reversing | unresolved, over a stated interval", "why_it_matters": "Determines whether a constant-rate description is adequate." }, { "name": "Mechanism hypothesis", "kind": "relation", "unit_or_values": "linked dynamical explanation, assumptions and supporting evidence", "why_it_matters": "Connects observed progression to predictions and possible interventions." }, { "name": "Resolution and uncertainty", "kind": "measurement", "unit_or_values": "angular and rate uncertainty with method, time coverage and confidence convention", "why_it_matters": "Determines whether apparent precession or a change in rate is distinguishable from measurement error." } ], "affordances": [ "Classify an observed orientation change as a specified precession case or leave it unresolved.", "Estimate phase and rate with explicit reference conventions and uncertainty.", "Separate precessional progression from spin, nutation and frame motion where the evidence permits.", "Compare candidate dynamical explanations against the orientation history.", "Predict future orientation within the supported interval and assumptions.", "Evaluate and, where authorised and physically feasible, apply a change to governing conditions while monitoring the resulting precession." ] }, "sources": [ { "id": "goldstein-classical-mechanics", "title": "Classical Mechanics", "url": "", "what_it_supports": "Rigid-body Euler equations, torque-free motion, and torque-induced gyroscopic precession of a symmetric top." }, { "id": "landau-mechanics", "title": "Mechanics (Course of Theoretical Physics, Vol. 1)", "url": "", "what_it_supports": "Poinsot construction and free precession of a rigid body; forced precession of a heavy symmetric top." }, { "id": "explanatory-supplement-aa", "title": "Explanatory Supplement to the Astronomical Almanac", "url": "", "what_it_supports": "IAU treatment of lunisolar (axial) precession, nutation, and the distinction from polar motion." }, { "id": "iau-2006-precession", "title": "IAU 2006 precession model (P03) and related IAU resolutions on precession-nutation", "url": "", "what_it_supports": "Official astronomical precession of the equator and ecliptic used in celestial reference-frame transformations." }, { "id": "vallado-fundamentals", "title": "Fundamentals of Astrodynamics and Applications", "url": "", "what_it_supports": "Orbital nodal and apsidal precession from Earth oblateness (J2) and third-body perturbations." }, { "id": "mtw-gravitation", "title": "Gravitation", "url": "", "what_it_supports": "Geodetic (de Sitter) precession and Lense-Thirring frame-dragging as general-relativistic spin-orbit effects." }, { "id": "jackson-classical-ed", "title": "Classical Electrodynamics", "url": "", "what_it_supports": "Larmor precession of a magnetic moment in an external B-field and the Thomas precession contribution to spin-orbit coupling." } ], "structure": { "bundles": [ { "id": "precessing-direction", "name": "Precessing direction", "description": "Establish exactly what changes orientation and relative to what.", "rationale": "A body axis, angular momentum and orbital direction can describe different motions even within the same system.", "layers": [ { "id": "orientation-referent", "name": "Orientation referent", "description": "Identify the physical or derived direction whose evolution is called precession.", "findings": [ { "id": "tracked-axis-or-orbit", "name": "Tracked axis or orbital direction", "description": "Record the precessing referent and the case it supports.", "questions": [ { "text": "Is the tracked direction a body axis, angular-momentum direction, apsidal direction, orbital-plane normal or another explicitly defined direction?", "kind": "definition", "id": "tracked-axis-or-orbit-q01" }, { "text": "Which observation or calculation establishes that this direction, rather than another direction in the system, is being tracked?", "kind": "provenance", "id": "tracked-axis-or-orbit-q02" } ] } ] }, { "id": "reference-conventions", "name": "Reference conventions", "description": "Fix the frame and angular conventions required to interpret progression.", "findings": [ { "id": "frame-and-sense", "name": "Frame and sense", "description": "Record the reference frame, zero direction, epoch and sign convention.", "questions": [ { "text": "Relative to which frame, direction or plane is the precession angle defined?", "kind": "definition", "id": "frame-and-sense-q01" }, { "text": "How does motion of the reference frame contribute to the reported progression?", "kind": "boundary", "id": "frame-and-sense-q02" }, { "text": "Which viewing direction and sign convention determine the stated sense of precession?", "kind": "definition", "id": "frame-and-sense-q03" } ] } ] } ] }, { "id": "precession-geometry", "name": "Precession geometry", "description": "Describe the orientation path and distinguish accompanying motions.", "rationale": "A single precession angle can hide changing inclination, orbital-plane motion or an ill-defined reference direction.", "layers": [ { "id": "orientation-path", "name": "Orientation path", "description": "Capture the geometric path without presuming a fixed cone or closed cycle.", "findings": [ { "id": "path-and-inclination", "name": "Path and inclination", "description": "Record how the direction moves and whether the chosen angular representation remains defined.", "questions": [ { "text": "What path does the tracked direction follow, and does its inclination to the chosen reference remain approximately constant?", "kind": "measurement", "id": "path-and-inclination-q01" }, { "text": "At which configurations does the chosen phase, node or apsidal direction become undefined or poorly determined?", "kind": "boundary", "id": "path-and-inclination-q02" } ] } ] }, { "id": "motion-separation", "name": "Motion separation", "description": "Distinguish precession from spin, nutation and other orientation changes.", "findings": [ { "id": "coupled-angular-motions", "name": "Coupled angular motions", "description": "Record the decomposition used and any ambiguity in assigning motion to precession.", "questions": [ { "text": "Which measured components represent spin, progression around a reference direction and oscillation of inclination?", "kind": "measurement", "id": "coupled-angular-motions-q01" }, { "text": "For an orbital case, can apsidal progression and nodal progression be distinguished with the available observations?", "kind": "boundary", "id": "coupled-angular-motions-q02" }, { "text": "Which decomposition convention or filtering method produced this separation?", "kind": "provenance", "id": "coupled-angular-motions-q03" } ] } ] } ] }, { "id": "precession-timing", "name": "Precession timing", "description": "Establish phase, rate and the time interval over which they are supported.", "rationale": "Precession may be reported per unit time or per orbit, and a mean rate can conceal substantial variation.", "layers": [ { "id": "phase-and-rate", "name": "Phase and rate", "description": "Measure angular progression using explicit temporal and angular conventions.", "findings": [ { "id": "resolved-progression", "name": "Resolved progression", "description": "Record accumulated angle, elapsed time and rate estimation.", "questions": [ { "text": "How much unwrapped precession angle accumulates over the stated observation interval?", "kind": "measurement", "id": "resolved-progression-q01" }, { "text": "Is the reported rate instantaneous, averaged over time or measured per orbit, and what interval supports it?", "kind": "measurement", "id": "resolved-progression-q02" } ] } ] }, { "id": "rate-variation", "name": "Rate variation", "description": "Assess departures from uniform progression and the meaning of any reported period.", "findings": [ { "id": "uniformity-and-recurrence", "name": "Uniformity and recurrence", "description": "Distinguish a supported recurring cycle from an extrapolation of a local rate.", "questions": [ { "text": "Does the rate vary or reverse beyond its estimated uncertainty during the observed interval?", "kind": "measurement", "id": "uniformity-and-recurrence-q01" }, { "text": "Is a stated precession period observed, dynamically predicted or inferred by extending a mean rate?", "kind": "provenance", "id": "uniformity-and-recurrence-q02" }, { "text": "Over what interval is a constant-rate approximation adequate for the intended decision?", "kind": "boundary", "id": "uniformity-and-recurrence-q03" } ] } ] } ] }, { "id": "mechanism-and-evidence", "name": "Mechanism and evidence", "description": "Connect measured precession to supported explanations and discriminating observations.", "rationale": "Similar orientation histories can arise from different dynamics or from the measurement frame, with different implications for action.", "layers": [ { "id": "dynamical-explanation", "name": "Dynamical explanation", "description": "Record candidate mechanisms and their applicability conditions.", "findings": [ { "id": "governing-mechanism", "name": "Governing mechanism", "description": "Identify the proposed dynamics without assuming that all precession requires the same cause.", "questions": [ { "text": "Which mechanism is proposed, such as applied torque, torque-free rigid-body dynamics, orbital perturbation or relativistic effects?", "kind": "definition", "id": "governing-mechanism-q01" }, { "text": "Which source or derivation supports that mechanism for this particular system?", "kind": "provenance", "id": "governing-mechanism-q02" }, { "text": "Which assumptions about the body, orbit, forces or fields must hold for the proposed explanation?", "kind": "boundary", "id": "governing-mechanism-q03" } ] } ] }, { "id": "observational-discrimination", "name": "Observational discrimination", "description": "Assess whether observations resolve precession and distinguish proposed explanations.", "findings": [ { "id": "signal-and-alternatives", "name": "Signal and alternatives", "description": "Record uncertainty, sampling limits and competing interpretations.", "questions": [ { "text": "Do angular precision, sampling cadence and observation duration resolve the claimed progression?", "kind": "measurement", "id": "signal-and-alternatives-q01" }, { "text": "Which alternative explanations remain compatible with the data, including frame motion, nutation or sampling ambiguity?", "kind": "boundary", "id": "signal-and-alternatives-q02" }, { "text": "What additional observation would best distinguish the remaining explanations?", "kind": "action", "id": "signal-and-alternatives-q03" } ] } ] } ] }, { "id": "prediction-and-influence", "name": "Prediction and influence", "description": "Translate the assessed precession into bounded forecasts and feasible changes.", "rationale": "An agent needs to know when orientation predictions are usable and whether governing conditions can actually be changed.", "layers": [ { "id": "orientation-forecast", "name": "Orientation forecast", "description": "Predict the tracked direction while carrying forward uncertainty and model limits.", "findings": [ { "id": "forecast-validity", "name": "Forecast validity", "description": "Record the forecast horizon and conditions requiring revision.", "questions": [ { "text": "What orientation and uncertainty are predicted at the decision time using the supported precession model?", "kind": "measurement", "id": "forecast-validity-q01" }, { "text": "Which changes in rate, inclination or governing conditions would invalidate that prediction?", "kind": "boundary", "id": "forecast-validity-q02" } ] } ] }, { "id": "precession-intervention", "name": "Precession intervention", "description": "Determine whether and how the progression can be changed.", "findings": [ { "id": "controllable-conditions", "name": "Controllable conditions", "description": "Connect available interventions to predicted changes and observable outcomes.", "questions": [ { "text": "Which governing conditions can actually be changed in this system, and which available intervention is predicted to alter its precession?", "kind": "action", "id": "controllable-conditions-q01" }, { "text": "What accompanying changes to spin, inclination or orbit must be evaluated before applying that intervention?", "kind": "boundary", "id": "controllable-conditions-q02" }, { "text": "Which measured change in phase, rate or orientation would establish whether the intervention achieved its intended effect?", "kind": "measurement", "id": "controllable-conditions-q03" } ] } ] } ] }, { "id": "evidence-and-external-alignment", "name": "Evidence and external alignment", "description": "What the world already says about this thing, gathered so the model can be checked against it.", "rationale": "A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.", "layers": [ { "id": "reported-evidence", "name": "Reported evidence", "description": "Findings from the breadth pass, kept separate from the structural claims.", "findings": [ { "id": "evidence-kinds", "name": "Kinds and varieties", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "axial (lunisolar) precession of a planet or satellite", "apsidal precession of an orbit (periapsis advance)", "nodal precession of an orbital plane", "torque-induced gyroscopic precession of a spinning rigid body", "torque-free (body-cone / space-cone) precession of an asymmetric rigid rotor", "Thomas precession of a relativistic spinning particle", "Larmor / magnetic-moment precession in an external field", "general-relativistic geodetic and frame-dragging precession" ], "questions": [ { "id": "evidence-kinds-q01", "text": "Which of these kinds and varieties hold for the sense of precession this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-identifiers", "name": "Identifiers and schemes", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "scheme": "Wikidata", "value_or_pattern": "Q180704 (precession)", "note": "Parent item; more specific items exist for axial precession (Q1283911), apsidal precession, and Thomas precession." }, { "scheme": "IAU / SOFA frame transformation", "value_or_pattern": "IAU 2006 precession (P03); CIP/CIO based IAU 2000A/2006 nutation-precession", "note": "Names the adopted model, not a single numeric code for the phenomenon." }, { "scheme": "InChI / CAS / ISO product code", "value_or_pattern": "", "note": "Not applicable; precession is a kinematic/dynamical phenomenon, not a chemical or commercial article." } ], "questions": [ { "id": "evidence-identifiers-q01", "text": "Which of these identifiers and schemes hold for the sense of precession this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-standards-and-regulation", "name": "Standards and regulation", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "IAU 2000/2006 precession-nutation models and related IAU resolutions (International Astronomical Union) for celestial-to-terrestrial frame transformations", "IERS Conventions (International Earth Rotation and Reference Systems Service) for practical implementation of precession, nutation, and Earth orientation parameters", "ISO 80000-3 (ISO) quantities and units for plane and solid angles used when reporting precession rates", "NATO STANAG / military inertial-navigation practice (national defence standards bodies) for gyrocompass and IMU error models that treat gyroscopic precession as a systematic effect" ], "questions": [ { "id": "evidence-standards-and-regulation-q01", "text": "Which of these standards and regulation hold for the sense of precession this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-real-world-use", "name": "Real-world use", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Transforming star catalogues and satellite ephemerides between the International Celestial Reference System and a date equator/equinox (IAU precession-nutation).", "Designing sun-synchronous and frozen orbits by matching nodal or apsidal precession rates produced by Earth J2 to a required secular drift.", "Explaining and compensating gyrocompass, control-moment gyro, and spinning-projectile behaviour, where applied torque produces a precession of the spin axis at right angles to the torque.", "NMR, MRI, and atomic clocks, where nuclear or electron magnetic moments precess at the Larmor frequency in a controlled field.", "Relativistic corrections to spacecraft clocks and to the perihelion of Mercury (apsidal precession) and Gravity Probe B (geodetic and frame-dragging precession)." ], "questions": [ { "id": "evidence-real-world-use-q01", "text": "Which of these real-world use hold for the sense of precession this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-measurements", "name": "Typical measurements", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "quantity": "Lunisolar axial precession rate of Earth (general precession in longitude)", "typical_range": "about 50.3 arcseconds per year; period ~25,700-25,800 years", "unit": "arcsecond/year (or rad/s)" }, { "quantity": "Gyroscopic precession rate of a symmetric rotor, Ω = τ / (Iω)", "typical_range": "from ~10^-3 rad/s (slow tops, CMGs) to tens of rad/s (fast small gyros under large torque)", "unit": "radian/second" }, { "quantity": "Earth J2 nodal precession rate for LEO satellites", "typical_range": "order 0.5-8 deg/day depending on inclination and altitude (sun-synchronous ~0.986 deg/day)", "unit": "degree/day" }, { "quantity": "Larmor (NMR) precession frequency γB/2π", "typical_range": "protons ~42.6 MHz/T; clinical MRI 64 MHz at 1.5 T, 128 MHz at 3 T", "unit": "hertz (or MHz)" }, { "quantity": "Mercury perihelion (apsidal) precession", "typical_range": "43 arcseconds/century (GR excess over Newtonian perturbations)", "unit": "arcsecond/century" }, { "quantity": "Gravity Probe B geodetic precession", "typical_range": "measured ~6,600 mas/year about the predicted 6,606 mas/year", "unit": "milliarcsecond/year" } ], "questions": [ { "id": "evidence-measurements-q01", "text": "Which of these typical measurements hold for the sense of precession this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-failure-modes-and-hazards", "name": "Failure modes and hazards", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Using a mean-equinox of date without applying IAU precession-nutation, which misplaces celestial coordinates by tens of arcseconds after a few years and by degrees over centuries.", "Treating a spinning vehicle, projectile, or satellite as if torque changed spin-rate along the torque axis; the actual response is precession (and possibly nutation), producing attitude or impact-point error.", "Unmodelled J2 nodal precession that walks a satellite ground-track off the intended repeat cycle or sun-synchronous lighting.", "In MRI, B0 inhomogeneity and chemical shift make local Larmor frequencies differ, causing spatial distortion, signal loss, and heating if RF is mistuned.", "Gyroscopic precession of a motorcycle or aircraft propeller that couples pitch and yaw; unanticipated coupling is a handling and training hazard, not a material failure of 'precession' itself." ], "questions": [ { "id": "evidence-failure-modes-and-hazards-q01", "text": "Which of these failure modes and hazards hold for the sense of precession this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-regional-variation", "name": "Regional variation", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Astronomy: older catalogues and some national almanacs still quote equinox B1950.0 or J2000.0 with the IAU 1976 precession; operations now use the IAU 2000/2006 CIP/CIO formulation. The phenomenon is the same; the numerical model and axis names differ.", "Language: English 'precession of the equinoxes' / French 'précession des équinoxes' / German 'Präzession' are standard; some engineering texts in Russian use 'прецессия' for both forced gyroscopic motion and free Euler motion, which English often splits as precession vs. nutation or wobble.", "Orbital practice: US/NASA two-line element users quote RAAN drift in degrees/day; some GNSS and geodesy groups work in the CIO-based Earth orientation series instead of an equinox-based precession matrix." ], "questions": [ { "id": "evidence-regional-variation-q01", "text": "Which of these regional variation hold for the sense of precession this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-neighbours", "name": "Neighbouring kinds and how to tell them apart", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "name": "nutation", "difference": "Nutation is the periodic (short-period) oscillation of the rotation axis superimposed on the secular precession cone; IAU models give a precession polynomial plus a nutation series. If the motion repeats on a ~18.6-year or shorter tidal period rather than accumulating, it is nutation." }, { "name": "polar motion (Chandler wobble, etc.)", "difference": "Polar motion is the motion of the CIP relative to the terrestrial crust (body-fixed); precession-nutation is the motion of the CIP relative to inertial space. Same physical Earth, opposite frame." }, { "name": "spin (angular velocity about the figure axis)", "difference": "Spin rate ω is the rotation about the instantaneous axis; precession rate Ω is the motion of that axis through space. They are coupled by Euler's equations but are not the same angle or the same frequency except in special cases." }, { "name": "orbital regression of nodes vs. apsidal advance", "difference": "Nodal precession rotates the line of nodes (orbital plane); apsidal precession rotates the line of apsides inside that plane. Measure RAAN (Ω) versus argument of periapsis (ω)." }, { "name": "Euler angles / attitude kinematics without torque", "difference": "A changing 3-1-3 Euler angle set always 'looks like' precession kinematically. Dynamical precession additionally requires a conserved or slowly varying angular-momentum vector and a specified torque or inertia asymmetry; if L is not tracing a cone in inertial space, do not call it precession." }, { "name": "Thomas rotation / Wigner rotation", "difference": "Thomas precession is a special-relativistic kinematic rotation of spin under successive Lorentz boosts, present even with no torque in the instantaneous rest frame; gyroscopic precession requires a torque (or equivalent magnetic moment coupling) in that frame." } ], "questions": [ { "id": "evidence-neighbours-q01", "text": "Which of these neighbouring kinds and how to tell them apart hold for the sense of precession this model covers, and on what evidence?", "kind": "provenance" } ] } ] } ] } ] }, "openQuestions": [ "Does this registry entry intend all physical uses of precession, including magnetic-moment and relativistic spin precession, or a narrower mechanical and orbital scope?", "Does an existing Vercy world model already own this concept or part of its intended scope?", "Which authoritative conventions should govern the separation of precession and nutation across the included cases?", "How should cases with changing reference directions, undefined orbital angles or nonperiodic progression be represented consistently?", "Which case-specific evidence and uncertainty thresholds are required before an agent may rely on a forecast or execute an intervention?" ], "statistics": { "bundles": 6, "layers": 11, "findings": 18, "questions": 34 } }, "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 precession, record what state it is in, and decide what may be done with it.", "whatItIs": "Enable an AI agent to recognise precession, assess how a rotational or orbital orientation evolves, and judge which predictions or interventions are justified.", "characteristics": { "substance": "activity", "origin": "conceptual", "agency": "inert" }, "whatYouCanDoWithIt": [ "observed and measured" ], "distinguishingFeatures": [ "Names folded into this entry, which a task may need to split apart again: Lense–Thirring precession, nodal precession, Larmor precession, Lunar precession, Pugh–Schiff precession.", "5 finer distinctions are held as aliases rather than separate entries, because telling them apart needs a task that asks for it.", "Described in 62 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 precession, 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": [ { "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": [ "Lense–Thirring precession", "nodal precession", "Larmor precession", "Lunar precession", "Pugh–Schiff precession" ] } ], "standing": "Described in 62 Wikipedia languages, which measures how widely it is written about rather than how important or how common it is. 5 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 precession from another, and a precession 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 precession, 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 precession, 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 precession 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 precession, 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 precession, 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 precession 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 precession 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 precession, 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 precession, 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 precession 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 precession from the things most often confused with it.", "questions": [ { "id": "distinguishing-features-q01", "text": "What identifies and describes what distinguishes a precession, 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 precession, 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 precession 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 precession 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 precession between them.", "questions": [ { "id": "stages-and-transitions-q01", "text": "What identifies and describes the lifecycle of a precession, 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 precession, 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 precession 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 precession, how often and by whom.", "findings": [ { "id": "observation-record", "name": "Observation record", "description": "How an observation of a precession 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 precession, 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 precession, 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 precession 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 precession 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 precession, 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 precession and what marks it done.", "questions": [ { "id": "steps-and-preconditions-q01", "text": "What identifies and describes a step of a precession, 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 precession, 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 precession 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 precession consumes and what it produces.", "findings": [ { "id": "inputs-and-outputs", "name": "Inputs, outputs and side effects", "description": "The resources a precession 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 precession, 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 precession, 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 precession 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 precession 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 precession 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 precession 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 precession 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 precession?", "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 precession?", "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 precession 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 precession and how confident it is.", "questions": [ { "id": "claim-provenance-q01", "text": "What identifies and describes a claim about a precession, 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 precession, 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 precession 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 precession is retired without being erased.", "questions": [ { "id": "validity-and-supersession-q01", "text": "What identifies and describes the validity of a claim about a precession, 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 precession, 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 precession 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 } } } }