RESEARCH BASE
Search 3,721 documents across 34 fields — every claim tier-rated by evidence
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 68 of 91
W_5_35 — I Ching: The Book of Changes, Divination, and Binary Philosophy
The I Ching (Yìjīng, 易經, "Classic of Changes") is among the oldest continuously used texts in human history, with roots extending to the Western Zhou dynasty (c. 1000–750 BCE) and legendary attribution to Fu Xi (trigrams
W_5_26 — Chachapoya: Warriors of the Clouds
The Chachapoya ("People of the Clouds") were a pre-Inca civilization inhabiting the cloud forests of northeastern Peru's Amazonas region (~800–1470 CE). Known for their monumental fortress of Kuelap — a massive stone cit
W_5_32 — Taíno People of the Caribbean
The Taíno were the dominant indigenous people of the Greater Antilles (Hispaniola, Cuba, Jamaica, Puerto Rico) and the Bahamas at the time of Christopher Columbus's arrival on October 12, 1492 — making them the first ind
W_5_34 — Late Bronze Age Collapse: Systems Failure in the Ancient Mediterranean
Between approximately 1200 and 1150 BCE, every major civilization in the Eastern Mediterranean collapsed or suffered catastrophic decline within a single generation. The Mycenaean palatial system, the Hittite Empire, the
W_5_37 — The House of Wisdom: Baghdad and the Islamic Golden Age of Knowledge
The House of Wisdom (Bayt al-Ḥikma) was a major intellectual institution in Baghdad during the Abbasid Caliphate (est. c. 762 CE), reaching its zenith under Caliph al-Maʾmūn (r. 813–833 CE). While its exact nature — libr
W_5_16 — The Venetian Republic: Maritime Empire, Statecraft, and Cultural Innovation
The Most Serene Republic of Venice (Serenissima Repubblica di Venezia) endured for 1,100 years (697–1797 CE), making it one of the longest-lived republics in history. Founded as a refuge community on marshy lagoon island
W_5_27 — Valdivia Culture: Oldest Pottery in the Americas
The Valdivia culture (~3500–1800 BCE) of coastal Ecuador produced the oldest known pottery in the Americas, making it one of the earliest complex societies in the Western Hemisphere. Discovered by Emilio Estrada in 1956
W_5_36 — Shang Dynasty: Bronze Age China and the Foundations of Chinese Civilization
The Shang dynasty (c. 1600–1046 BCE) is the earliest Chinese dynasty confirmed by both archaeological evidence and written records, representing the foundational period of Chinese civilization. Centered at Anyang (Yinxu,
W_5_21 — Iron Age Transition in the Mediterranean (1200–500 BCE)
The Iron Age transition (c. 1200–500 BCE) in the Mediterranean represents one of history's most transformative periods: the collapse of the interconnected Late Bronze Age palatial economies (Mycenaean Greece, Hittite Emp
W_5_13 — Mississippian Decline: Cahokia Collapse and Abandonment Theories
Cahokia — the largest pre-Columbian city north of Mexico, located in the American Bottom floodplain of the Mississippi River near modern-day St. Louis, Missouri/East St. Louis, Illinois — rose rapidly around 1050 CE to b
W_5_30 — Lambayeque and Sicán Culture: Lords of the Northern Coast
The Lambayeque (or Sicán) culture (~750–1375 CE) was a wealthy, metallurgically advanced civilization of Peru's north coast that succeeded the Moche and preceded the Chimú in the Lambayeque Valley. Discovered through sys
W_5_06 — Siberian Shamanism and the Origin of the Word 'Shaman'
Siberian shamanism is the mother tradition from which the very word "shaman" enters Western scholarship — derived from the Tungusic (Evenki) term šaman. This vast, diverse tradition spans the taiga and tundra from the Ur
ZH_4_08 — Lunar Calendars: Tracking the Moon Across Cultures
Lunar calendars — systems of timekeeping governed by the synodic month (the ~29.53-day cycle from new moon to new moon) — represent humanity's oldest systematic method of measuring time. Evidence from the Lascaux cave pa
ZH_3_16 — Polynesian Star Compass: Celestial Navigation of the Pacific
The Polynesian star compass represents one of humanity's most sophisticated non-instrument navigation systems — enabling deliberate, repeatable voyages across thousands of miles of open Pacific Ocean centuries before Eur
ZH_3_05 — Nazca Lines: Astronomical and Ecological Hypotheses
The Nazca Lines are a vast complex of geoglyphs — ground drawings created by removing the dark, iron-oxide-coated desert pavement to reveal the lighter ground beneath — spread across the arid Pampa de Nazca and surroundi
ZH_3_20 — The Inca Ceque System: Astronomical Lines, Sacred Geography & Cusco's Cosmic Order
The ceque system (zeq'e, "line" or "boundary" in Quechua) — a network of 41 conceptual lines radiating outward from the Coricancha (Temple of the Sun) in Cusco, Peru, connecting approximately 328 sacred sites (huacas: sp
ZH_3_12 — South American Archaeoastronomy Beyond the Inca
While the Inca astronomical tradition (the ceque system, the Intihuatana, and the dark-cloud constellations of the Milky Way) is the most thoroughly studied in South America, numerous pre-Inca and non-Inca civilizations
ZH_3_07 — Celestial Navigation in the Pacific: Micronesian Stick Charts
The peoples of Micronesia — particularly the Marshall Islands and the Caroline Islands — developed some of the most sophisticated non-instrument navigation systems in human history. While Polynesian navigation (covered i
ZH_5_21 — Precession of the Equinoxes: The Great Year and Ancient Awareness
The precession of the equinoxes — the slow westward drift of the vernal equinox point along the ecliptic, completing a full cycle in approximately 25,772 years (the "Great Year" or "Platonic Year") — is the longest astro
ZH_5_23 — Ancestral Puebloan Archaeoastronomy: Celestial Alignments in the American Southwest
The Ancestral Puebloan civilization (c. 100–1300 CE) of the American Southwest developed one of the most sophisticated archaeoastronomical traditions outside the Old World. Chaco Canyon (New Mexico), the cultural center
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