Buoyancy. Buoyancy is the tendency of an object to float in a fluid, such as air or water. The principle of buoyancy was first discovered by Greek mathematician Archimedes (c. 287 â 212 b.c.) and is therefore often called Archimedes' Principle.therwise, it floats. The formal statement of Archimedes' Principle is this: the buoyant force acting on an object placed in a fluid is equal to the weight of the fluid displaced by the object. Suppose that the wood block in the example above has a volume of 1 cubic foot. A cubic foot of water weighs about 62.4 pounds.
Epidemic: The occurrence of more cases of a disease than would be expected in a community or region during a given time period.A sudden severe outbreak of a disease such as SARS. From the Greek epi-, upon + demos, people or population = epidemos = upon the population.. See also: Endemic; Pandemic.pidemic: The occurrence of more cases of a disease than would be expected in a community or region during a given time period.
For other uses, see Epidemic (disambiguation) . An epidemic (from Greek á¼ÏÎ¯ epi upon or above and Î´á¿Î¼Î¿Ï demos people) is the rapid spread of infectious disease to a large number of people in a given population within a short period of time, usually two weeks or less.he conditions which govern the outbreak of epidemics include infected food supplies such as contaminated drinking water and the migration of populations of certain animals, such as rats or mosquitoes, which can act as disease vectors.