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
Populated places in Ukraine localities can refer to two different types of inhabited places: villages and rural settlements. Rural populated places in Ukraine are very underdeveloped and often lack basic types of infrastructure: transportation, utilities and others. Village as a term became systematic for a conventional rural populated place and most numerous out of all terms used for populated places in a country. It is administrated by silrada (a rural council) and is the lowest level and most common form of territorial administration at that level. A rural council may be composed of a single village or group of villages. According to the 2001