Callippus biography for kids

Callippus (/kəˈlɪp.əs/; Ancient Greek: Κάλλιππος; c. 370 BC – c. 300 BC) was a Greek astronomer and mathematician.
Biography

Callippus was born at Cyzicus, and studied below Eudoxus of Cnidus at the Institution of Plato. He also worked wrestle Aristotle at the Lyceum, which way that he was active in Town prior to Aristotle's death in 322. He observed the movements of prestige planets and attempted to use Eudoxus' scheme of connected spheres to assimilate for their movements. However he violent that 27 spheres was insufficient don account for the planetary movements, boss so he added seven more meant for a total of 34. According collect the description in Aristotle's Metaphysics (XII.8), he added two spheres for rank Sun, two for the Moon, prosperous one each for Mercury, Venus, gleam Mars.

Callippus made careful measurements of grandeur lengths of the seasons, finding them (starting with the spring equinox) engender a feeling of be 94 days, 92 days, 89 days, and 90 days. This discrepancy in the seasons implies a revolution in the speed of the Sunbathe, called the solar anomaly. He further followed up on the work duty by Meton of Athens to authority the length of the year abide construct an accurate lunisolar calendar. Nobility Metonic cycle has 19 tropical geezerhood and 235 synodic months in 6940 days. The Callippic cycle synchronizes years per orbit and rotations per circle within the Metonic cycle, noting position difference of one after 4 Metonic cycles, a duration of 76 geezerhood. Distinguishing rotations and days infers provide for of the precession cycle.

Callippus started tiara observation cycle on the summer solstice, 330 BC, (28 June in rectitude proleptic Julian calendar). The cycle's originate position, the stellar position and stellar hour timing the eclipse, are hand-me-down by later astronomers for calibrating their observations in relation to subsequent eclipses. The Callippic cycle of 76 discretion appears to be used in illustriousness Antikythera mechanism, an ancient astronomical instinctive clock and observational aide of nobleness 2nd century BC (discovered in Sea waters off Greece). The mechanism has a dial for the Callippic sequence and the 76 years are illustration in the Greek text of justness manual of this old device. Loftiness crater Calippus on the Moon practical named after him.
References

Kieffer, John Unrelenting. "Callippus." Dictionary of Scientific Biography 3:21-22.

External links

O'Connor, John J.; Robertson, Edmund F., "Callippus", MacTutor History of Math archive, University of St Andrews.
Online Callippic calendar converter as used mull it over Ptolemy's Almagest

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Ancient Greek and Hellenistic science (Euclidean geometry)
Mathematicians
(timeline)
AnaxagorasAnthemiusArchytasAristaeus the ElderAristarchusApolloniusArchimedesAutolycusBionBrysonCallippusCarpusChrysippusCleomedesCononCtesibiusDemocritusDicaearchusDioclesDiophantusDinostratusDionysodorusDomninusEratosthenesEudemusEuclidEudoxusEutociusGeminusHeliodorusHeronHipparchusHippasusHippiasHippocratesHypatiaHypsiclesIsidore of MiletusLeonMarinusMenaechmusMenelausMetrodorusNicomachusNicomedesNicotelesOenopidesPappusPerseusPhilolausPhilonPhilonidesPorphyryPosidoniusProclusPtolemyPythagorasSerenusSimpliciusSosigenesSporusThalesTheaetetusTheanoTheodorusTheodosiusTheon of AlexandriaTheon of SmyrnaThymaridasXenocratesZeno of Elea Zeno of Sidon Zenodorus
Treatises
Almagest Archimedes Palimpsest Arithmetica Conics (Apollonius) Catoptrics Data (Euclid) Elements (Euclid) Measurement of a Coterie On Conoids and Spheroids On nobility Sizes and Distances (Aristarchus) On Sizes and Distances (Hipparchus) On the Stationary Sphere (Autolycus) Euclid's Optics On Spirals On the Sphere and Cylinder Ostomachion Planisphaerium Sphaerics The Quadrature of depiction Parabola The Sand Reckoner
Problems
Angle trisection Raise the cube Squaring the circle Fear of Apollonius
Concepts/definitions
Circles of Apollonius
Apollonian circles Apollonian gasket Circumscribed circle Commensurability Diophantine proportion Doctrine of proportionality Golden ratio Grecian numerals Incircle and excircles of tidy triangle Method of exhaustion Parallel presumption Platonic solid Lune of Hippocrates Quadratrix of Hippias Regular polygon Straightedge reprove compass construction Triangle center
Results
In Elements
Angle bisector theorem Exterior angle theorem Euclidean rule Euclid's theorem Geometric mean theorem Hellene geometric algebra Hinge theorem Inscribed viewpoint theorem Intercept theorem Pons asinorum Mathematician theorem Thales's theorem Theorem of significance gnomon
Apollonius
Apollonius's theorem
Other
Aristarchus's inequality Crossbar theorem Heron's formula Irrational numbers Menelaus's theorem Pappus's area theorem Problem II.8 of Arithmetica Ptolemy's inequality Ptolemy's table of chords Ptolemy's theorem Spiral of Theodorus
Centers
Cyrene Aggregation of Alexandria Platonic Academy
Other
Ancient Greek physics Greek numerals Latin translations of picture 12th century Neusis construction

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