Tycho Brahe produce much of his astronomical data, Tycho relied heavily on the then new technique of "prosthaphaeresis", an algorithm for approximating products based on trigonometric identities that predated logarithms. Although Tycho admired Copernicus and was the first to teach his theory in Denmark, he was unable to reconcile Copernican theory with the basic laws of Aristotelian physics, that he considered to be foundational. He was also critical of the observational data that Copernicus built his theory on, which he correctly considered to have a high margin of error. Instead, Tycho proposed a "geo-heliocentric" system in which the Sun and Moon orbited
Ven (Sweden) The latter is located at the south-western coast just beneath the old church "Sankt Ibb". This coast is known as "Backafall." The island was historically under Danish rule. Danish astronomer Tycho Brahe (1546–1601) built two observatories there, Uraniborg and Stjerneborg, during 1576–1596. The observatories were built by the inhabitants of the island with Tycho Brahe as their Lord. The Swedish took over control in 1658, as the rest of Scania was ceded to Sweden by the Treaty of Roskilde. The island was not specifically mentioned in the treaty, and according to the Danes it was not part of Scania, but