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
Central High School (Pueblo, Colorado) and an outlying building used as a gym and school meeting area. It was built in 1906. The foyer features right-facing swastikas set into the tile floor. The original Central High School building on Pitkin Avenue (later used as an elementary school) was built of pink rhyolite; the "Stone Schoolhouse" was added to the National Register of Historic Places in 1979. Central first opened in 1883, and in 1886 graduated its first class of nine students. In 1889 Central introduced vocational education into its curriculum, making the district the first west of the Missouri River to introduce what was then