The system of geographical sciences and the history of geography

The history of geography is usually divided into six stages: antiquity, the Middle Ages, the Great Geographical Discoveries, scientific geographical work, the 19th and first half of the 20th century, and the modern period. In antiquity Eratosthenes tried to calculate the size of the Earth and wrote “Geographica”, and Ptolemy compiled maps using a graticule and projections. In the Middle Ages science developed mainly in the East: al-Khwarizmi wrote “Surat al-ard”, Beruni produced many works on geodesy, cartography and climatology, and Babur described the nature and peoples of Central and South Asia in the “Baburnama”. The Great Geographical Discoveries began with the 1492 expedition of Columbus; Vasco da Gama opened the sea route to India in 1498, and the expedition begun by Magellan sailed round the world in 1519–1522, confirming in practice that the Earth is round. In the 19th century Humboldt studied nature as a unified system, Dokuchaev created the doctrine of natural zonality and Vernadsky the doctrine of the biosphere, and in 1820 the expedition of F. Bellingshausen and M. Lazarev discovered Antarctica. In the modern stage geographic information systems, computer models and space imagery have become the main tools.