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105 results for "Metonic cycle" — page 1 of 6
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_1_16 — The Antikythera Mechanism and Greek Astronomical Devices: Precision Gearing in the Ancient World
The Antikythera mechanism — recovered from a Roman-era shipwreck off the Greek island of Antikythera in 1901 — is the most sophisticated scientific instrument known from the ancient world, a hand-cranked astronomical cal
ZH_1_07 — Antikythera Mechanism: World's First Astronomical Computer
The Antikythera mechanism is a corroded mass of bronze gears and inscribed plates recovered in 1901 from an ancient shipwreck off the Greek island of Antikythera, dated to approximately 60–70 BCE (though the mechanism it
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
E_2_09 — Heinrich Events and Bond Cycles: Millennial-Scale Climate Oscillations
Heinrich events are episodes of massive iceberg discharge from the Laurentide Ice Sheet through Hudson Strait into the North Atlantic, depositing distinctive layers of ice-rafted debris (IRD) across the ocean floor. Firs
E_4_07 — Calendar Systems and Ancient Time-Keeping
This document examines Calendar Systems and Ancient Time-Keeping, a topic within the Cataclysms and Chronology research area. Key areas of investigation include Sumerian Lunisolar Calendar, Babylonian Calendar, The MUL.A
J_1_11 — Antikythera Mechanism and Ancient Computing Devices
The Antikythera Mechanism — recovered in 1901 from a Roman-era shipwreck off the Greek island of Antikythera (dated to c. 70–60 BCE by ceramic and coin evidence; the device itself likely constructed c. 150–100 BCE) — is
Catastrophe_Migration_Civilization_Cycle
The archaeological and paleoclimatic record reveals at least five major catastrophe-migration cycles in the last ~75,000 years, each following a recognizable pattern: a sudden environmental shock (volcanic eruption, cosm
A_1_06 — Ugaritic Literature and the Baal Cycle
This document examines Ugaritic Literature and the Baal Cycle, a topic within the Foundations research area. Key areas of investigation include Ras Shamra — Accidental Discovery, The City of Ugarit, The Library and Archi
ZH_3_01 — Maya Astronomical Science: Venus Tables, Eclipse Cycles
The ancient Maya (c. 2000 BCE–1500 CE, with the Classic period c. 250–900 CE) developed one of the most sophisticated astronomical traditions of the pre-modern world — rivaling and in some respects exceeding Babylonian m
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_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
C_5_26 — World Age Doctrine: Cycles of Creation and Destruction
The World Age Doctrine — the belief that cosmic time is divided into successive ages or epochs, each ending in destruction and giving way to the next — is one of the most widespread cosmological frameworks in human thoug
C_5_29 — Moon Mythology: Lunar Deities, Cycles, and Symbolism Across Cultures
The Moon — the most visible and regularly changing celestial object — has been a primary religious and mythological symbol for every known culture. Its predictable cycle of waxing, full, waning, and new (approximately 29
Z_4_11 — The Cell Cycle: Division, Checkpoints, and Cancer
The cell cycle — the ordered series of events by which a cell grows, replicates its DNA, and divides into two daughter cells — is one of the most fundamental processes in biology and one of the most intensively studied i
E_4_21 — Oxygen Isotope Stages: Marine Isotope Record and Climate Cycles
The marine oxygen isotope record — constructed from measurements of the ratio of oxygen-18 to oxygen-16 (δ¹⁸O) in the calcium carbonate (CaCO₃) shells of foraminifera (single-celled marine organisms) preserved in deep-se
E_4_13 — Milankovitch Cycles and Orbital Forcing
Milankovitch cycles are periodic variations in Earth's orbital geometry that modulate the distribution and intensity of solar radiation reaching Earth's surface, driving the glacial-interglacial cycles that have dominate
ZB_5_30 — Phosphorus Cycle: Biogeochemistry, Eutrophication, and the Coming Scarcity Crisis
Phosphorus (P) is the rate-limiting nutrient for life on Earth — essential to DNA, RNA, ATP (the universal energy currency), cell membranes (phospholipids), and bone (hydroxyapatite), yet available in nature only through
O_5_05 — Ice Ages and Milankovitch Cycles: Orbital Forcing of Climate
Ice ages — periods when massive continental ice sheets expand to cover large portions of Earth's surface — are among the most dramatic climate events in the planet's history. The Quaternary glaciation (beginning ~2.6 mil
P_5_22 — Cyclical Time: Eternal Return, Historical Cycles, and Non-Linear Temporality
The concept of cyclical time — that history, cosmic processes, or existence itself follows recurring patterns rather than a single linear progression — is one of the most ancient and widespread ideas in human thought. Vi
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