RESEARCH BASE

Search 3,721 documents across 34 fields — every claim tier-rated by evidence

3,721 Documents 34 Sections 43,625 Citations 34,852 Keywords Indexed 4 Evidence Tiers

3,633 are the core, quality-scored corpus (34 lettered sections — see How We Work); the remaining 88 are cross-corpus synthesis documents (68 InterDocs, 12 Connections, 8 Theories) also indexed here.

1,812 results for "Friday the 13th" — page 69 of 91

ZH_5_16 Verified Archaeoastronomy

ZH_5_16 — Eclipse Prediction and the Saros Cycle

The Saros cycle — a period of approximately 6,585.3 days (18 years, 11 days, 8 hours) after which the Sun, Moon, and lunar nodes return to nearly identical relative positions — has been the primary tool for eclipse predi

Saros-cycle eclipse-prediction Babylonian-astronomy Thales-eclipse lunar-nodes eclipse-periodicity
ZH_5_02 Verified Archaeoastronomy

ZH_5_02 — Megalithic Lunar Observatories: Thom's Hypothesis Revisited

The hypothesis that Neolithic and Bronze Age megalithic monuments in Britain, Ireland, and Brittany functioned as sophisticated lunar observatories — capable of tracking the Moon's complex motions to high precision — is

Alexander Thom megalithic lunar observatory standstill Callanish Carnac
ZH_5_04 Verified Archaeoastronomy

ZH_5_04 — Precession of the Equinoxes: Hipparchus, Axial Wobble, and the Great Year

The precession of the equinoxes — the slow, continuous westward shift of the equinoctial points (where the ecliptic crosses the celestial equator) along the ecliptic — is one of the most consequential astronomical phenom

precession equinoxes Hipparchus axial wobble Platonic year Great Year
ZH_5_22 Verified Archaeoastronomy

ZH_5_22 — Indian Astronomical Traditions: From Vedanga Jyotisha to the Kerala School

Indian astronomical traditions represent one of the longest continuous programs of celestial observation and mathematical modeling in human history, spanning from Vedic-period naked-eye observations (c. 1500–500 BCE) thr

Indian astronomy Vedanga Jyotisha Aryabhata Surya Siddhanta nakshatras Kerala school
ZH_2_17 Credible Archaeoastronomy

ZH_2_17 — Islamic Golden Age Astronomy: Observation, Innovation, and the Preservation of Knowledge

Islamic astronomy — the astronomical tradition developed in the Islamic world from the 8th through the 15th centuries CE — represents one of the most productive and consequential scientific enterprises in human history,

Islamic astronomy Golden Age al-Battani al-Tusi Maragha observatory
ZH_2_06 Verified Archaeoastronomy

ZH_2_06 — Astronomy in the Rig Veda and Early Indian Texts

The Rig Veda — the oldest of the four Vedas and among the oldest religious texts still in continuous use (~1500–1200 BCE, though dating is debated) — contains hymns, references, and cosmological imagery that reflect the

Rig Veda Vedic astronomy Jyotish nakshatra lunar mansions Surya Siddhanta
ZH_2_15 Verified Archaeoastronomy

ZH_2_15 — Astronomical Time: Defining Days, Years, Hours, and the Second

The measurement and definition of time is humanity's oldest astronomical enterprise — and one that has undergone a radical transformation from celestial observation to atomic precision. The fundamental units derive from

time measurement solar day sidereal day tropical year sidereal year Julian year
ZH_1_15 Verified Archaeoastronomy

ZH_1_15 — Star Catalogs: From Hipparchus to Hipparcos and the Tycho Catalog

A star catalog — a systematic list of stars with their positions, magnitudes, and sometimes colors, proper motions, and spectral types — is the foundational document of observational astronomy. The compilation of ever mo

star catalog Hipparchus Ptolemy Almagest Ulugh Beg Tycho Brahe
ZH_1_20 Credible Archaeoastronomy

ZH_1_20 — Egyptian Decans & Star Clocks: Timekeeping by the Night Sky

The Egyptian decan system — a method of dividing the night sky into 36 stellar groups (decans) whose sequential heliacal risings (first visible appearance on the eastern horizon just before sunrise) marked ten-day period

decan egyptian-astronomy star-clock diagonal-star-table coffin-texts-astronomy heliacal-rising
ZH_1_19 Credible Archaeoastronomy

ZH_1_19 — Origins of the Zodiac

The zodiac — the band of ~8° on either side of the ecliptic (the Sun's apparent annual path across the sky) divided into 12 equal 30° segments, each named after a constellation — originated in Mesopotamian astronomy duri

zodiac babylonian-astronomy ecliptic twelve-signs mul-apin hellenistic-astrology
ZH_1_11 Verified Archaeoastronomy

ZH_1_11 — Copernicus, Kepler, and the Astronomical Revolution

The astronomical revolution of the 16th and 17th centuries — transforming humanity's understanding of its place in the cosmos from an Earth-centered (geocentric) to a Sun-centered (heliocentric) model — is one of the mos

Copernicus Kepler heliocentrism Ptolemy geocentrism De revolutionibus
C_1_04 Global Traditions

C_1_04 — Orpheus and the Descent to the Underworld Archetype

This document examines Orpheus and the Descent to the Underworld Archetype, a topic within the Global Traditions research area. Key areas of investigation include Definition and Etymology, The Common Structure, Joseph Ca

katabasis descent to underworld Orpheus Eurydice Inanna Ereshkigal
C_1_18 Credible Global Traditions

C_1_18 — The Wise Old Man / Mentor Archetype: Cross-Cultural Analysis

The Wise Old Man / Mentor archetype — identified by Carl Jung as the Senex or Mana personality — represents one of the most consistent character patterns in world mythology and narrative tradition. This figure appears as

wise-old-man mentor-archetype senex jung-archetype gandalf merlin
C_1_20 Credible Global Traditions

C_1_20 — The Shadow Archetype in World Mythology

The Shadow archetype, articulated by Carl Gustav Jung as a fundamental component of the psyche, manifests across world mythologies as the dark double, the rejected brother, or the monstrous other that heroes must confron

shadow-archetype jungian-psychology dark-double mythological-antagonist set-osiris caliban
C_1_08 Global Traditions

C_1_08 — Twin Mythology — Duality, Doubling, and the Divine Pair

Twin mythology represents one of the most widely distributed narrative patterns in world religion — divine or semi-divine twins appear across every major cultural tradition: the Vedic Ashvins, Greek Dioscuri (Castor and

twins divine twins Ashvins Dioscuri Castor Pollux
C_1_01 Global Traditions

C_1_01 — Cross-Cultural Patterns & Synthesis

This synthesis document maps the universal serpent/reptilian being across 13 major civilizations, finding that all 13 originally depicted serpent figures positively — as teachers, civilizers, and wisdom-keepers. The nega

cross-cultural patterns serpent knowledge-giver teacher flood
C_1_13 Global Traditions

C_1_13 — Sacred Mountains and the Cosmic Mountain

The sacred mountain is one of humanity's most enduring religious symbols — a vertical axis connecting earth and heaven that appears in virtually every major civilization. From Mount Meru at the center of Hindu-Buddhist-J

sacred mountain cosmic mountain axis mundi Mount Meru Mount Olympus Mount Sinai
C_4_19 Credible Global Traditions

C_4_19 — The Labyrinth as Ritual Pathway: From Knossos to Chartres

The labyrinth — a single-path (unicursal) design leading to a center and back — is one of humanity's most persistent geometric-symbolic forms, appearing across at least 4,000 years and five continents. Distinct from the

labyrinth ritual-pathway knossos chartres minotaur maze
C_5_22 Verified Global Traditions

C_5_22 — Calendar Cosmology: How Ancient Civilizations Encoded the Universe in Time

Calendar cosmology — the encoding of cosmological beliefs, mythological narratives, and astronomical observations into calendrical systems — is a universal feature of complex civilizations. Every major culture developed

calendar cosmology Maya Long Count Egyptian calendar Metonic cycle Hindu Yuga
C_5_25 Verified Global Traditions

C_5_25 — Underworld Journey / Katabasis: Descent to the Land of the Dead

The katabasis (Greek: κατάβασις, "going down") — the hero's or god's descent to the underworld and return — is one of the oldest and most universal narrative structures in world mythology. The Descent of Inanna (Sumerian

katabasis underworld descent Inanna Orpheus Odysseus