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
Tycho Brahe an astronomer at the Imperial court in Prague, whom Tycho accused of having plagiarized his cosmological model. Craig refused to accept Brahe's conclusion that the comet of 1577 had to be located within the aetherial sphere rather than within the atmosphere of Earth. Craig tried to contradict Brahe by using his own observations of the comet, and by questioning his methodology. Brahe published an "apologia" (a defense) of his conclusions, in which he provided additional arguments, as well as condemning Craig's ideas in strong language for being incompetent. Another dispute concerned the mathematician Paul Wittich, who, after staying on Hven