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Greek

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First to accurately record the motion of the sun and moon ... Built upon the work of Aristotle. Treatise on ... Armillary Sphere - model of celestial sphere ... – PowerPoint PPT presentation

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Title: Greek


1
Greek Roman Calendars
  • Constructions of Time in the Classical World
  • By Robert Hannah

Ashley DeFlumere 12/11/2007
2
Hipparchus
  • 190 - 120 BC
  • Greek Astronomer
  • First to accurately record the motion of the sun
    and moon

http//en.wikipedia.org/wiki/ImageHipparchos_1.jp
eg
3
Ptolemy
  • 83 - 161 AD
  • Greek Astronomer
  • Built upon the work of Aristotle
  • Treatise on Astronomy Almegast

http//en.wikipedia.org/wiki/ImagePtolemaeus.jpg
4
Astronomical Instruments
  • Gnomon - part of a sundial
  • Astrolabe - predicts positions of heavenly bodies
  • Armillary Sphere - model of celestial sphere

http//en.wikipedia.org/wiki/ImageArmillary_spher
e.png
5
Ancient Solar Observations
  • Summer and Winter Solstices
  • Solstice - Latin sol sun, sistere to stand
  • Zodiac Constellations

6
(No Transcript)
7
Measuring a Year
  • Tropical (Solar) Year - time between spring
    equinoxes, 365.24219 solar days
  • Sidereal Year - measure passage of sun across a
    point among the stars, 365.2464 solar days
  • Lunar Year - 12 lunar cycles of 29.53059, for an
    average year of 354 solar days
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