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.
5 results for "lodestone"
Q_4_15 — Magnetism: From Lodestones to MRI, Domains to Spin
Magnetism — the force exerted by magnets and electric currents, and the response of materials to magnetic fields — has been known since antiquity (the lodestone, a naturally magnetized iron ore, was used in Chinese compa
J_1_10 — Electromagnetism and Ancient Awareness
Ancient civilizations observed and utilized several electromagnetic phenomena — including magnetism (lodestones), static electricity (amber), lightning, and electric fish — without developing a unified theory of electrom
J_5_10 — Chinese Compass and Magnetic Navigation History
The magnetic compass — the first instrument to exploit an invisible natural force for practical human use — was a Chinese invention that underwent a centuries-long development from a ritual divination tool to the mariner
F_4_03 — Ancient Maritime Technology and Naval Knowledge
The history of maritime technology reveals that ancient civilizations achieved levels of nautical engineering and navigational skill far exceeding common assumptions. Phoenician sailors may have circumnavigated Africa ~6
F_3_21 — Compass Navigation and Its Global Spread
The magnetic compass — one of China's "Four Great Inventions" — transformed navigation from a coastal, celestial, and dead-reckoning art into an all-weather, open-ocean capability. [KEY FINDING] The earliest confirmed re
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