5. Astronomical Cycles Time Unit Approx Length Origin Day 24 hours Earth’s rotation Month 30 days Moon’s revolution (phases) Year 365 days Earth’s revolution “ Great Year” 26,000 years Earth’s precession
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8. Sidereal and Solar Day [ Animation ] http://www-astronomy.mps.ohio-state.edu/~pogge/Ast161/Unit2/Images/sidereal.gif “ Fixed stars”
13. Time Units Time Unit Length Origin Day 24 hours (solar) 23.93 (sidereal) Earth’s rotation Month 29.5 days (synodic) 27.33 days (sidereal) Moon’s revolution (phases) Year 365.242 days (tropical) 365.256 (sidereal) Earth’s revolution
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19. Quarter Days : Solstices and Equinoxes http://www-astronomy.mps.ohio-state.edu/~pogge/Ast161/Unit2/Images/QuarterDays.gif
20. Quarter Day Table Event Date Season Sun Transit (latitude) Tradition March Equinox 21-Mar Spring Equator, 0° Easter June Solstice 21-Jun Summer Cancer, +23.5° July 4th September Equinox 23-Sep Autumn Equator, 0° First Day of School December Solstice 21-Dec Winter Capricorn, -23.5 ° Christmas
24. Cross-Quarter Days Name Date Other Names (season) Groundhog Day Feb 2 Candlemas (spring) May Day May 1 Beltane (summer) Lammas Aug 2 Lughnasadh (autumn) Halloween Oct 31, Nov 1 All Saints, Samhain (winter)
53. Castaway Stranded on a deserted island in the South Pacific following the crash of his Fed Ex airplane, Chuck Noland (Tom Hanks) constructs an analemma on a cave wall to track the daily displacement in the shaft of sunlight through a small natural portal. He explains the science and the repetitive annual figure-8 cycle to his sanity companion, Wilson, the volleyball.
73. Western Calendars *legendary founders of Rome Calendar Used Founder Features Roman (355 days) < 45 BC Romulus & Remus* 10 months initially Julian (365.25 days) 45 BC Julius Caesar Leap day Gregorian (365.2425 days) 1582 AD to present Pope Gregory XIII Leap day (refined)
82. Jewish Calendar *Mar Equinox, **Sep Equinox Month Name Length Gregorian Holidays (dates) 1 Nissan 30 days Mar-Apr* Passover (15 Nissan) 2 Iyar 29 days Apr-May 3 Sivan 30 days May-June 4 Tammuz 29 days June-July 5 Av 30 days July-Aug 6 Elul 29 days Aug-Sep 7 Tishri 30 days Sep-Oct** Rosh Hashanah (1-2) 8 Cheshvan 29 or 30 days Nov-Dec 9 Kislev 29 or 30 days Nov-Dec Chanukkah (25) 10 Tevet 29 days Dec-Jan 11 Shevat 30 days Jan-Feb 12 Adar I 30 days Feb-Mar 13 Adar II (leap) 29 days Feb-Mar
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84. 2008 Islamic Calendar Month Name Gregorian Holidays (dates) 1 Muharram 1429 Jan 10 New Year 2 Safar Feb 8 3 Rabi-I Mar 9 4 Rabi-II Apr 7 5 Jumada-I May 6 6 Jumada-II June 5 7 Rajab July 4 8 Sha’ban Aug 2 9 Ramadan Sept 1 Ramadan 10 Shawwal Oct 1 11 Dhul-Qi’dah Oct 30 12 Dhul-Hiija Nov 29 Pilgrimage to Mecca 1 Muharram 1430 Dec 29 New Year
85. Lunar Calendar Holidays March Equinox September Equinox Gregorian Easter Jewish New Year Muslim New Year 2001 Apr 15 Sept 18 Mar 26 2002 Mar 31 Sept 7 Mar 15 2003 Apr 20 Sept 27 Mar 5 2004 Apr 11 Sept 16 Feb 22 2005 Mar 27 Oct 4 Feb 10 2006 Apr 16 Sept 23 Jan 31 2007 Apr 8 Sept 13 Jan 20 2008 Mar 23 Sept 30 Jan 10 2009 Apr 12 Sept 19 Dec 29 2010 Apr 4 Sept 9 Dec 18
86. Competing Years (2009) Western Calendar 2009 AD Birth of Jesus Jewish Calendar 5760 Age of universe in Torah (Genesis) Islamic Calendar 1430 Mohammed flees to Medina (Hegira) Calendar Current Year Start
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99. Maya Venus “Observatory” at Chichen Itza http://centros.edu.aytolacoruna.es/sfxabier/world_links/mexico_observatory.jpg
