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
Otte Brahe noble houses in several Danish cities including Copenhagen. They built a brick castle at Knudstrup completed in 1550. Their first child was a daughter, Lizbeth. This was followed by twin boys on 14 December 1546. However, one of the twins died before being baptized and named. The other was named Tyge (after Brahe's father). It is for their son Tyge that Brahe is best known as he became a famous astronomer and took on the name Tycho Brahe as a teenager. Strangely, their son Tyge was kidnapped by Brahe's older brother, Jørgen, in 1548. Tycho later wrote: "without the knowledge