110 likes | 425 Views
TIME. Solar time and Sidereal (Star) Time. Lines of Longitude. Separated by 15 degrees (time zones) 24 x 15 degrees = 360 degrees. Latitude. Latitude of equator = 0 Latitude of poles = + 90 and -90. Latitude and Longitude. Prime meridian Greenwich England Two number define a point.
E N D
TIME Solar time and Sidereal (Star) Time
Lines of Longitude • Separated by 15 degrees (time zones) • 24 x 15 degrees = 360 degrees
Latitude • Latitude of equator = 0 • Latitude of poles = + 90 and -90
Latitude and Longitude • Prime meridian Greenwich England • Two number define a point
Time Zones • A time zone is 15 degrees wide • There are 24 in all, 24 x 15 = 360 degrees
Real Time Zones • Time Zones are irregular for political and practical reasons (4 in USA)
International Date Line • Time zone at 180 degrees from Greenwich
Crude History of Calender • Leap Year and Major Corrections • Modern Gegorian Calendar
Solar vs. Sidereal Time • Solar Time has 24 hours (arbitrary) • Sidereal Time is 4 minutes less (23h56m)
Lunar Calendar Solar Months • Synodic or Solar Month (~ 29.5 days) • Sidereal Month (27.3 days)
Phases of the Moon • Angle between Earth, Moon and Sun