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
Pension term assurance effectively stopped any more new PTA business being written. Those with existing policies were allowed to keep them running. Despite what the name might suggest, Pension Term Assurance did not have to form part of a pension - it merely needed to be taken out at the same time as a new pension was set up. Pension term assurance Pension Term Assurance (PTA) was a form of life insurance available within the United Kingdom. Although PTA had been available for several years, it only became mainstream when changes were made to pension legislation on "A Day", 6 April 2006. Following