zodiac
Enable an AI agent to recognise a zodiac system, assess whether its divisions and assignment rules are sufficiently specified, and determine which classifications or interpretations it can support.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to recognise a zodiac system, assess whether its divisions and assignment rules are sufficiently specified, and determine which classifications or interpretations it can support.
The zodiac is the band of the celestial sphere, typically taken as about eight to nine degrees of latitude on either side of the ecliptic, that contains the apparent annual path of the Sun and is partitioned into twelve equal 30-degree signs whose names derive from the classical ecliptic constellations.
It can be Identify the zodiac tradition and variant from its divisions and reference rules.; Check whether the division sequence and boundary rules form a coherent system.; Assign a supplied celestial or calendrical position when the necessary conventions and inputs are available.; Explain why two zodiac variants assign different signs to the same supplied event or position.; Retrieve symbolic correspondences with their tradition and source attribution.; Withhold an assignment or qualify an interpretation when required rules, inputs or evidence are missing..
Distinguishing features
Determine whether the referent defines an ordered system of divisions; a single named sign is a component rather than the whole zodiac.
Determine whether a celestial position or calendrical input can be assigned to a division by an identifiable rule; a collection of animal symbols alone is insufficient.
Check whether similarly named signs and constellations have the same boundaries before treating them as equivalent.
Determine whether the referent specifies reusable classification rules or is an individual chart or interpretation generated from those rules.
Check the tradition, reference frame and cycle boundary before equating systems that share the name zodiac.
Scope
+ The zodiac's identity, tradition, version and intended astronomical, calendrical or interpretive use
+ Its signs or divisions, their ordering and their boundaries
+ The celestial reference frame or calendrical cycle that determines membership
+ Rules, required inputs and uncertainty for assigning a position or time to a division
+ Tradition-specific symbolic correspondences and the evidence status of associated claims
- Individual natal charts, horoscopes and readings produced using a zodiac
- Astronomical objects and constellations as independently described entities
- Complete calendar systems beyond the rules needed for zodiac assignment
- People, their biographies and their psychological or medical assessments
- Astrology as a complete practice, including techniques that do not define the zodiac itself
Characteristics
- Zodiac family and tradition
- Source-attested family, tradition and variant; unresolved Determines which divisions, reference conventions and interpretive rules belong together.
- Classification basis
- Celestial position; calendrical position; combined; other documented basis; unresolved Establishes what an agent must observe or receive before assigning a sign.
- Division count
- Number of divisions in the specified system Allows an agent to check completeness without assuming every zodiac has the same membership.
- Reference convention
- Connection to a documented celestial origin, constellation boundary convention or calendar Sign names alone do not establish how membership is determined.
- Cycle position
- Angular position in degrees or calendrical position in the system's documented units Provides the quantity used by the applicable assignment rule.
- Boundary convention
- Documented interval endpoints, transition rule and treatment of exact boundaries; unresolved Prevents inconsistent assignments near sign or cycle transitions.
- Assignment readiness
- Rules and inputs complete; missing inputs; ambiguous convention; conflicting rules Determines whether an agent can assign a division or must request clarification.
- Interpretive claim status
- Traditional attribution; empirically assessed claim with recorded outcome; disputed attribution; unassessed Keeps a tradition's symbolic meanings distinct from evidence supporting predictions about people or events.
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.zodiac
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Zodiac identity Establishes which meaning and tradition of zodiac the agent is handling.
The registry has no definition, and the shared name does not establish a single classification mechanism.
Referent and family
Separates the zodiac system from its components, representations and outputs.
Intended zodiac referent
Record whether the referent is a celestial division system, calendrical sign cycle, celestial band or another explicitly documented usage.
- What does zodiac denote in this entry's originating context? definition
- Does the referent define a whole system, a celestial region, one sign or an individual chart? boundary
Tradition and variant
Identifies the lineage and particular convention being represented.
Attested system variant
Record the named tradition, variant and sources that establish its rules without combining incompatible conventions.
- Which source establishes this variant's name, divisions and reference convention? provenance
- Which differences distinguish this variant from other systems carrying the same zodiac name? boundary
Signs and divisions Describes the zodiac's membership, sequence and partition rules.
Recognising a zodiac requires more than recognising familiar sign names or symbols.
Division inventory
Captures the divisions recognised by the selected tradition.
Ordered sign membership
Record division names, identifying symbols, aliases and sequence, preserving distinctions between signs and similarly named constellations.
- Which divisions belong to this zodiac, and in what order do they recur? definition
- Which names denote equivalent signs, and which denote distinct constellations or tradition-specific divisions? boundary
Division extents
Establishes how the classified domain is partitioned.
Sign boundaries and coverage
Record each division's angular or temporal extent and whether the rules produce gaps, overlaps or unambiguous coverage.
- What angular or calendrical interval defines each division, and are the intervals equal or variable? measurement
- How are exact endpoints, overlaps and any positions outside the divisions handled? boundary
Celestial and calendar anchors Captures the reference conventions that give sign boundaries operational meaning.
A sign sequence cannot support assignment until its origin, cycle and applicable reference system are known.
Celestial reference
Specifies the coordinate and origin conventions for position-based variants.
Angular origin and frame
For celestial variants, record the coordinate frame, zero point and any epoch-dependent correction or adopted boundary authority.
- Which coordinate system and origin determine sign position, and does the convention require an epoch or offset such as an ayanamsa? measurement
- Which source specifies the adopted celestial reference or constellation boundaries? provenance
Calendar reference
Specifies the temporal anchor for calendar-based variants.
Cycle start and rollover
For calendrical variants, record the underlying calendar, cycle anchor, assignment period and transition convention.
- Which calendar and anchor identify the current cycle position, and what event starts the next sign period? definition
- How do time zone, intercalation and competing year-start conventions affect assignments near a transition? boundary
Sign assignment Determines when and how an agent can classify supplied inputs using the zodiac.
Operational use depends on sufficient inputs and explicit rules, particularly near transitions.
Assignment inputs
Identifies the subject of classification and required observations.
Required position or time
Record whether assignment concerns a celestial body's position, a calendrical period or another tradition-defined input.
- What is being assigned a sign, and which position, date, time or location inputs does that assignment require? definition
- What input precision is needed to distinguish adjacent signs under the selected rules? measurement
Assignment decision
Makes the resulting classification reproducible and uncertainty visible.
Reproducible sign result
Record the applied convention and whether the inputs yield one sign, multiple possible signs or no supported assignment.
- Which documented procedure converts the supplied input into a sign, and what reference examples can check it? action
- When uncertainty crosses a sign boundary, should the agent return alternatives or request a more precise input? action
Symbolism and interpretation Separates sign-associated meanings from classification rules and assessed predictive claims.
Agents must preserve cultural meaning without treating a sign assignment as evidence for an attributed personal trait or outcome.
Traditional correspondences
Captures meanings and relationships attributed within a specified tradition.
Sign symbolic associations
Record attested associations such as animals, elements, modalities or rulerships only where the selected variant uses them.
- Which symbolic associations belong to each sign in this particular tradition? definition
- Which sources support those associations, and where do sources or schools disagree? provenance
Interpretive use limits
Establishes what may follow from an assignment and what requires separate justification.
Attribution versus supported inference
Record whether an interpretation is a traditional attribution, a claim evaluated against evidence or a use beyond what the model establishes.
- What evidence, if any, supports each proposed predictive claim beyond its presence in the tradition? provenance
- Which outputs can the agent provide as classification or attributed symbolism, and which proposed decisions require independent evidence? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Tropical zodiac (Western/Hellenistic: twelve 30° signs measured from the vernal equinox)
- Sidereal zodiac (Indian/Jyotisha and some Western sidereal schools: twelve 30° signs measured from a fixed stellar fiducial)
- Constellational/astronomical ecliptic belt (IAU constellation boundaries along the ecliptic, including a thirteenth, Ophiuchus)
- Chinese zodiac (shengxiao: twelve earthly-branch animals on a twelve-year cycle, not an ecliptic-sign belt)
- Egyptian decan tradition (thirty-six 10° star-clock segments later absorbed into Greco-Egyptian astrology)
- Babylonian zodiac (MUL.APIN to late-Babylonian equal and unequal constellation lists that supplied the twelve-sign scheme)
- Modern astronomical 'zodiacal' usage (zodiacal light, zodiacal dust, and the ecliptic coordinate belt, without astrological signs)
- Which of these kinds and varieties hold for the sense of zodiac this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q7980 (zodiac); Q142101 (astrological sign); Q8928 (ecliptic) - Q7980 is the usual item for the twelve-sign belt; do not conflate with Q12004085 (Chinese zodiac) or individual sign items.
- Library of Congress Subject Headings - Zodiac; Zodiacal light; Astrology; Constellations - LCSH splits the astronomical belt, the optical phenomenon, and the astrological system.
- Unicode - U+2648-U+2653 (Aries-Pisces); U+26CE (Ophiuchus) - Twelve classical sign glyphs plus a later Ophiuchus symbol; these encode signs, not the belt as a whole.
- Which of these identifiers and schemes hold for the sense of zodiac this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- International Astronomical Union: official constellation names and Delporte (1930) equatorial boundaries used for the astronomical ecliptic belt, not for astrological signs.
- No ISO, IEC, or statutory standard defines astrological zodiac signs; consumer horoscope products are advertising/editorial content, not a metrological standard.
- In several jurisdictions consumer-protection and advertising rules (for example national unfair-commercial-practice laws) constrain paid fortune-telling claims; they do not standardise the zodiac itself.
- Which of these standards and regulation hold for the sense of zodiac this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Celestial-coordinate teaching: the ecliptic belt is the reference for solar, lunar, and planetary longitude in historical and some modern almanacs.
- Western natal and electional astrology: planets and house cusps are placed in tropical signs for horoscopes, software, and print columns.
- Indian calendrics and muhurta: sidereal rāśi and nakṣatra longitudes govern festival dates and ritual timing in pañcāṅga almanacs.
- Cultural naming: birth-year animals in East Asia (Chinese zodiac) used in personal identity, New Year ritual, and commercial branding.
- Planetarium and education media: explaining why astrological signs no longer match the constellations behind the Sun (precession).
- Astronomy of the solar system: 'zodiacal light' and zodiacal dust as observational phenomena concentrated near the ecliptic.
- Which of these real-world use hold for the sense of zodiac this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Sign width in the equal-sign zodiac - exactly 30 (by definition of the twelve-fold equal division) - degree of ecliptic longitude
- Belt half-width (ecliptic latitude of the classical zodiacal band) - about 8 to 9 either side of the ecliptic (wider if all planetary latitudes are included) - degree of ecliptic latitude
- Ayanāṃśa (tropical-sidereal offset due to precession) - about 20 to 25 in the early 21st century, depending on the chosen fiducial (e.g. Lahiri) - degree of longitude
- Precession of the equinoxes (rate that moves tropical signs relative to the stars) - about 50.3 per year; one full circuit in roughly 25 800 years - arcsecond per year
- Sun's time in IAU constellations (unequal) - about 7 days (Scorpius) to about 45 days (Virgo); also about 18 days in Ophiuchus - day
- Which of these typical measurements hold for the sense of zodiac this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Category error: treating twelve equal signs as if they were the IAU constellations (they are not; signs are equal 30° sectors, constellations have irregular boundaries and include Ophiuchus).
- Epoch error: using a tropical chart as if it named the star field behind the Sun, or a sidereal chart as if it used the equinox as zero, without stating the ayanāṃśa.
- Fiducial disagreement: different sidereal schools (Lahiri, Raman, Fagan-Bradley, etc.) disagree on zero-point by up to a degree or more, moving sign cusps.
- Medical or financial harm when horoscopic claims are used in place of evidence-based advice (a use-hazard of the practice, not a physical failure of the belt).
- Encoding confusion: Unicode Ophiuchus (U+26CE) and '13th sign' media stories are mistaken for a change to the tropical twelve-sign system.
- Which of these failure modes and hazards hold for the sense of zodiac this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Western Europe and the Americas: tropical zodiac from the vernal equinox is the default in popular astrology.
- India and the Hindu diaspora: sidereal rāśi zodiac with nakṣatras is standard in jyotiṣa and many regional calendars.
- East Asia: 'zodiac' in ordinary speech usually means the twelve-animal year cycle (and related hour/month cycles), not ecliptic signs; Vietnam replaces the rabbit with a cat, and other local substitutions occur.
- Islamic astronomical handbooks historically used tropical longitudes for timekeeping while folk astrology mixed Hellenistic signs with lunar mansions (manāzil).
- Tibetan and Mongolian practice combines Indian-style signs with a twelve-animal, five-element cycle.
- Which of these regional variation hold for the sense of zodiac this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- ecliptic - The ecliptic is the great circle of the Sun's apparent path (and Earth's orbital plane); the zodiac is a band of latitude around that circle, usually further divided into signs.
- constellation (IAU) - An IAU constellation is an official sky region with irregular boundaries; a zodiac sign is a 30° sector of ecliptic longitude that only historically shares a name with a constellation.
- astrological sign / rāśi - A sign is one twelfth of the zodiac belt; the zodiac is the whole belt (or the system of twelve). Test: a planet can be 'in Leo' (sign) while the question 'what is the zodiac?' names the twelve-fold band.
- Chinese earthly branches / shengxiao - Named by year (and sometimes hour/month) in a sixty-year stem-branch cycle, not by the Sun's ecliptic longitude on a given date; a Gregorian birth date maps to an animal year, not to a 30° star-longitude sign.
- lunar mansions (nakṣatra, manāzil, xiu) - Lunar mansions divide the ecliptic into 27 or 28 star-linked sectors for the Moon's motion; the zodiac divides it into twelve. Test: mansion systems track daily lunar longitude, not the twelve solar signs.
- zodiacal light - An optical phenomenon caused by sunlight scattered on interplanetary dust near the ecliptic; it is named from the belt's location, not a division of longitude.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of zodiac this model covers, and on what evidence? provenance
Sources
- The History and Practice of Ancient Astronomy - Defines the zodiac as the ecliptic belt of twelve 30° signs inherited from Babylonian and Hellenistic astronomy, and distinguishes tropical from sidereal reckoning.
- A History of Ancient Mathematical Astronomy - Documents the Babylonian origin of the equal twelve-sign zodiac and its transmission into Greek mathematical astronomy.
- The IAU constellation boundaries (Delporte 1930; IAU constellation pages) - Shows that modern astronomy uses official constellation boundaries on the celestial sphere, not the twelve equal astrological signs, and that the Sun also traverses Ophiuchus.
- Jyotiḥśāstra: Astral and Mathematical Literature - Describes the Indian sidereal rāśi zodiac and its relation to, and difference from, the tropical Hellenistic signs.
What the second pass must settle
- Does vr.tr.zodiac intend the celestial band, a particular sign system, a family of zodiac systems or all of these meanings?
- Does an existing world-model publication already own this concept or part of its intended scope?
- Which traditions and variants must this entry represent, and which sources establish their authoritative or competing conventions?
- Should calendar-based zodiac cycles and celestial sign systems be variants within this model, given the registry's intended granularity?
- Which symbolic and predictive uses are required by actual agent tasks, and what evidence is available to assess those uses?