Geocentric model explanation in terms of the Earth's revolution about the sun. In 1838, astronomer Friedrich Wilhelm Bessel measured the parallax of the star 61 Cygni successfully, and disproved Ptolemy's claim that parallax motion did not exist. This finally confirmed the assumptions made by Copernicus, providing accurate, dependable scientific observations, and conclusively displaying how distant stars are from Earth. A geocentric frame is useful for many everyday activities and most laboratory experiments, but is a less appropriate choice for solar system mechanics and space travel. While a heliocentric frame is most useful in those cases, galactic and extragalactic astronomy is easier if
Procedure (term) Procedure (term) A procedure is a document written to support a "policy directive". A procedure is designed to describe who, what, where, when, and why by means of establishing corporate accountability in support of the implementation of a "policy". The "how" is further documented by each organizational unit in the form of "work instructions" which aims to further support a procedure by providing greater detail. As an example, suppose a manufacturing facility established a policy that all overtime shall be approved. A procedure can be created to establish “Who” can approve overtime (ranks, roles & responsibilities), "What" forms or systems