地球科学概论 第4讲 地球形状及自转.pdfVIP

第 4 讲 地球形状及自转 申文斌，邓洪涛 ，徐新禹 ，罗佳 2014.5.4 1 内容提要 l  1 历史 l  2 球形 l  3 椭球形 l  4 大地水准面 l  5 地球自转 l  6 地球自转参数观测 l  7 地球自转应用举例 2 1 History l  Greek(Homer, Thales, Pythagoras, Plato, Eratosthenes et al.) p  Homer (800-1000 BC ? poet): the earth resembling a flat disc p  Thales (624-546BC,Think, Sci, Phi): the earth is spherical (600B.C) p  Pythagoras (572-497 BC, Math, Phi) and Aristotels (384-322BC, Phi, Sci, Educ): sphere 3 1 History l  Greek p  Plato (427-347BC): Earth’s circumference is 400,000 stadia (by speculation) （62,800 km - 74,000km), and Archimedes (287-212BC): 30,000 stadia [ Euclid: 325-265BC] p  Eratosthenes (276-194BC, Math, Georagr, Histo, Peot, Astro): earth’s radius is 6267km[39,377stadia] (by calculation, 240B.C) 4 1 History l  China: orbicular sky and rectangular earth （天圆地方） 5 1 History l  Han:张衡(78-139 A.D, Astro, Math, Inventor, Geogra, Map, Liter)《浑天仪注》“天如鸡卵 ，地如卵黄” 6 1 History l  思考: p  What does the Earth look like for the ancient people? p  If you live in 500B.C, could you find any clues indicating that the earth is spherical? p  Can you prove your viewpoint？ 7 2 Sphere l  思考: p  Assume the earth is spherical, how to calculate it’s radius? 8 2 Sphere l  Euclidean geometry (Euclid, 325-265 BC, Greek Math) p  Draw and only draw one straight line from one point t