Physical Geography (World of Earth Science)
Physical geography is a scientific discipline that addresses the distribution of natural features and processes within a spatial, or geographical, reference frame. This subdiscipline of geography is an interdisciplinary amalgam of such diverse subjects as geology, ecology, environmental science, computer science, and aerospace engineering. When examined, the narrow definition of physical geography as the study and creation of physical maps expands into a broad array of topics from satellite remote sensing to computer-aided mapping known as geographic information systems (GIS), to the study of surficial geological processes. The basic work of physical geology lies in determining how natural phenomena are spatially ordered, and in illuminating these geographic patterns using maps and images; the fundamental question behind physical geographic studies is why these patterns exist in nature.
The history of physical geography spans nearly four thousand years. Archeologists have discovered maps created by ancient Chinese, Phoenician, and Egyptian explorers, including a Babylonian map carved in a clay tablet dated at about 2300 B.C.Aristotle (38422 B.C.) suggested that the earth is a sphere based on his observations of lunar cycles. Eratosthenes (circa 27694 B.C.) accurately calculated the circumference of the earth using a geometric proof. Ptolemy (circaA.D.10070) developed a number of map projection schemes, as well as the coordinate system using latitude and longitude. Most of these early Greek and Roman geographical insights were forgotten during the Middle Ages (600400), especially in Europe. In fact, the idea of a spherical Earth did not resurface until the Renaissance when European navigators, including Christopher Columbus, Ferdinand Magellan, and Sir Francis Drake, explored the oceans and the Americas. Increasingly detailed physical and cultural geographic studies accompanied the rapid population growth, European colonization, and exploration of the American frontier that took place from the late 1700s the early 1900s.
Physical geography underwent a quantitative revolution beginning in the 1950s, when geographic investigations became more scientifically rigorous. This revolution continues today with ever-improving geographical methods and tools like satellite-aided navigation using the Global Positioning System (GPS), and images of the earth collected from space. Another change in the science of physical geography since the 1950s has been an increasing focus on the ways that humans affect their natural environment. Precise geographical information that documents or explains anthropogenic changes in the natural world is valuable to decision-makers across the ideological spectrum, from environmentalists, to government resource managers, to insurance actuaries.
See also History of exploration I (Ancient and classical); History of exploration II (Age of exploration); Mapping techniques; Projections