Prehistory. 1  Chang, Kwang-chih. 2  Discovery of residue from fermented beverage consumed up to 9,000 years ago in Jiahu, Henan Province, China. 3  Zhu, Rixiang; Zhisheng An; Richard Potts; Kenneth A. Hoffman. 4  The Discovery of Early Pottery in China by Zhang Chi, Department of Archaeology, Peking University, China.
There are a couple of popular ways of specifying the location of a celestial object. The first is what you would probably use to point out a star to your friend: the altitude-azimuth system. The altitude of a star is how many degrees above the horizon it is (anywhere from 0 to 90 degrees). The azimuth of a star is how many degrees along the horizon it is and corresponds to the compass direction. Azimuth starts from exactly North = 0 degrees azimuth and increases clockwise: exactly East = 90 degrees, exactly South = 180 degrees, exactly West = 270 degrees, and exactly North = 360 degrees = 0 degrees.
During nautical twilight the center of the sun is between 6 and 12 degrees below the horizon. Sailors can navigate, using a visible horizon as reference. During astronomical twilight the center of the sun is between 12 and 18 degrees below the horizon. Between the end of astronomical twilight in the evening and the beginning of astronomical twilight in the morning, the sky is dark enough for all astronomical observations.