Please enable JavaScript.

Coggle requires JavaScript to display documents.

The history of Astronomy, Used as an anchor for the calendar - Coggle…

- - - - It's security depends on the reading of the omens(some are from the stars)
      - developed brilliant technique for arithmetical notation (Sexagesimal/六十进制)
      - Babylonian court officials were very alert of omens of all kind, meaning that they would relate two unrelated things together if they happened one after the other --> watch out for it in the future
      - systematically record astronomical and meteorological phenomena --> for prognostication(精确性)
        
        the cycles of the movement of Moon, Sun, and planets
        
        ex. sun's speed increase and decrease during different time of the year
    - - Far-Flung Country --> administration: CALENDAR
        
        Tell time at night
        
        orient monuments
        
        pyramids
        
        stars are important for the religion of the Egyptians by symbolizing gods (deities)
        
        pyramids are immense labour used to ensure that the reigning pharaoh would join them after death.
        
        alignment by joining two particular stars
        
        the pyramids build in the 3rd millennium had a almost precise North-South alignments
        
        movement of the celestial north pole due to the wobble of the earth's axis (precession)
        will cause systematic errors
        
        There are no exact number of days in lunar month or the solar year
        
        Depends on the annual flooding of the Nile
        (Around the day when Sirius rose helically(rising or near to the sun))
        
        a)12 Lunar months & 11 days
        b) Sirius would always rise in the 12th month
        c) Take action if it came late
        
        Enough for religious festivals
        Not enough for the administration of a complex and highly organized society
    - - Aristotle (384-322 BC)
        
        Attempt to understand nature without supernatural explanations
        
        recognition of "Earth is a sphere"
        
        Earth's shadow is circular when casted on moon during lunar eclipses
      - Eratosthenes (c.276-c.195)
        
        Estimated the size of earth
        
        Eratosthenes's measurement of the circumference of the spherical earth
      - Geocentric model (Geocentrism)
        
        we see half of the sky(celestial sphere), we must be the center of universe