[{"n": "Ancient Greek astronomy", "u": "/e/ancient-greek-astronomy/ancient-greek-astronomy/", "s": "Ancient Greek astronomy: from flat Earth to heliocentrism, the foundations of Western stargazing."}, {"n": "Astronomical rings", "u": "/e/ancient-greek-astronomy/astronomical-rings/", "s": "Portable ring instrument for time and latitude determination, designed by Gemma Frisius."}, {"n": "Celestial Matters", "u": "/e/ancient-greek-astronomy/celestial-matters/", "s": "Alternate history novel blending Greek and Chinese physics."}, {"n": "Celestial spheres", "u": "/e/ancient-greek-astronomy/celestial-spheres/", "s": "Ancient Greek and medieval cosmological model of nested, rotating spheres carrying the planets and stars."}, {"n": "Concentric spheres", "u": "/e/ancient-greek-astronomy/concentric-spheres/", "s": "Ancient geocentric model using spheres centered on Earth."}, {"n": "Counter-Earth", "u": "/e/ancient-greek-astronomy/counter-earth/", "s": "Hypothetical planet opposite Earth, proposed by Philolaus."}, {"n": "Deferent and epicycle", "u": "/e/ancient-greek-astronomy/deferent-and-epicycle/", "s": "Ancient geometric model explaining planetary retrograde motion via circles on circles."}, {"n": "Dynamics of the celestial spheres", "u": "/e/ancient-greek-astronomy/dynamics-of-the-celestial-spheres/", "s": "Theories of celestial motion from Plato to medieval scholastics."}, {"n": "Equant", "u": "/e/ancient-greek-astronomy/equant/", "s": "Mathematical point used to explain planetary speed variations."}, {"n": "Exeligmos", "u": "/e/ancient-greek-astronomy/exeligmos/", "s": "A 54-year, 33-day cycle for predicting similar eclipses."}, {"n": "Geocentrism", "u": "/e/ancient-greek-astronomy/geocentrism/", "s": "Earth-centered model of the cosmos, dominant for over 1,500 years."}, {"n": "Globe of Matelica", "u": "/e/ancient-greek-astronomy/globe-of-matelica/", "s": "Ancient Greek marble sundial with inscribed lines and holes."}, {"n": "Great Year", "u": "/e/ancient-greek-astronomy/great-year/", "s": "Ambiguous term for precession cycle or eternal return."}, {"n": "Heliocentrism", "u": "/e/ancient-greek-astronomy/heliocentrism/", "s": "Superseded model placing Sun at universe's center."}, {"n": "Metonic cycle", "u": "/e/ancient-greek-astronomy/metonic-cycle/", "s": "19-year cycle aligning lunar phases with the solar year."}, {"n": "Mural instrument", "u": "/e/ancient-greek-astronomy/mural-instrument/", "s": "Wall-mounted angle measurer for meridian astronomy."}, {"n": "Pythagorean astronomical system", "u": "/e/ancient-greek-astronomy/pythagorean-astronomical-system/", "s": "Early non-geocentric model with Earth orbiting a Central Fire."}, {"n": "The Sand Reckoner", "u": "/e/ancient-greek-astronomy/the-sand-reckoner/", "s": "Archimedes devised a system to name and calculate extremely large numbers."}, {"n": "Scaphe", "u": "/e/ancient-greek-astronomy/scaphe/", "s": "Ancient Greek hemispherical sundial, commonly attributed to later astronomers such as Berossus."}, {"n": "Spherical Earth", "u": "/e/ancient-greek-astronomy/spherical-earth/", "s": "Earth is approximately spherical, confirmed by ancient and modern science."}, {"n": "Sublunary sphere", "u": "/e/ancient-greek-astronomy/sublunary-sphere/", "s": "The changing realm below the Moon in classical cosmology."}, {"n": "Urania", "u": "/e/ancient-greek-astronomy/urania/", "s": "Muse of astronomy and astrology in Greek mythology."}]