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.
3,697 results for "vitamin D" — page 98 of 185
ZH_4_10 — Sirius in World Cultures: Rising Star and Calendar Anchor
Sirius (α Canis Majoris) is the brightest star in the night sky (apparent magnitude −1.46) — and has been one of the most culturally significant stars in human history. Its pre-dawn heliacal rising (the first day it beco
ZH_3_04 — Chaco Canyon: Solar Markers and Pueblo Astronomy
Chaco Canyon (northwestern New Mexico) was the center of Ancestral Puebloan (formerly called Anasazi) civilization from approximately 850–1150 CE, featuring monumental Great Houses containing hundreds of rooms, extensive
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_10 — North American Mound Builders and Celestial Alignments
The mound-building cultures of eastern North America — spanning from Poverty Point (~1700 BCE) through the Adena (~800–100 BCE), Hopewell (~100 BCE–500 CE), Fort Ancient (~1000–1650 CE), and Mississippian (~800–1500 CE)
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_18 — Polynesian Star Navigation and Wayfinding
Polynesian star navigation is the non-instrument celestial wayfinding system that enabled the colonization of the Polynesian Triangle — the vast oceanic region bounded by Hawaiʻi, Rapa Nui (Easter Island), and Aotearoa (
ZH_3_09 — Solar Geometry in Pueblo Architecture: Mesa Verde, Hovenweep
The Ancestral Puebloan peoples (formerly termed "Anasazi") of the American Southwest incorporated sophisticated solar geometry into their architecture, settlement planning, and ceremonial life across a vast region center
ZH_3_14 — Nighttime Navigation Without Instruments: Stars, Moon, and Memory
For most of human history, navigators crossing deserts, oceans, and arctic wastes found their way using the stars, the Moon, the Sun's position, and memory — without magnetic compasses, chronometers, or sextants. Non-ins
ZH_5_15 — Astronomical Symbolism: Stars, Crescents, and Suns in Heraldry and Currency
Astronomical symbols — stars, crescents, and suns — are among the most universal and enduring elements in human visual culture, appearing on the flags of over 70 nations, on coinage from the earliest electrum staters of
ZH_5_09 — Ancient Observatories: Kokino, Goseck, and Pre-Stonehenge Horizon Sites
Stonehenge is the world's most famous archaeoastronomical site — but it is neither the earliest nor the only ancient structure demonstrating systematic astronomical observation. Across Europe, the Near East, and Africa,
ZH_5_05 — Cross-Cultural Constellation Patterns: Connecting Star Groupings Worldwide
Every documented human culture groups stars into constellations or asterisms — named patterns that organize the sky into a readable, memorizable, and culturally meaningful map. Yet surprisingly few star groupings are uni
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_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
ZH_5_11 — Solar Eclipse as Political Event: Thales, Omens, and Dynastic Legitimacy
Throughout history, solar eclipses — sudden, dramatic, and seemingly unnatural — have been interpreted not merely as astronomical events but as political signs, divine warnings, and instruments of power. The most famous
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
ZH_5_14 — Dark Sky Preservation: Light Pollution and Heritage Night Skies
Light pollution — the excessive, misdirected, or obtrusive artificial light that brightens the night sky — has transformed humanity's relationship with the stars more profoundly than any development since the invention o
ZH_2_05 — Japanese and Korean Astronomical Traditions
The astronomical traditions of Japan and Korea developed in close dialogue with Chinese astronomy — but were far from mere copies. Both civilizations adapted Chinese astronomical models, instruments, and calendrical meth
ZH_2_04 — Cosmic Cycle Doctrines: Great Year, Yuga, Precession Ages
Many civilizations have conceived of cosmic time as cyclical rather than linear — repeating through grand cycles of creation, decline, and renewal that span thousands or millions of years. The most influential of these d
ZH_2_03 — Islamic Golden Age Astronomy: Observatories and Star Catalogs
Islamic astronomy (c. 750–1500 CE) represents one of the most productive and sophisticated periods in the history of astronomical science — a sustained tradition of observation, mathematical innovation, and critical enga
ZH_2_09 — Celestial Cartography: Star Maps and Globes Through History
Celestial cartography — the art and science of mapping the sky — is one of humanity's oldest intellectual undertakings, spanning from Mesopotamian star lists (~1200 BCE), through Hipparchus's star catalog (~129 BCE), the
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