MF Tycho Brahe MF Tycho Brahe M/F "Tycho Brahe" is a Danish train and car ferry that operates at the HH Ferry route between Helsingør, Denmark and Helsingborg, Sweden, a distance of just 5 km. M/F "Tycho Brahe" has been in use since 1991. The ship is bidirectional, therefore it can change direction without turning around, so no time is lost for this. The ship is also able to accelerate and decelerate quite quickly to and from her maximum speed of 14 knots. The ship is named after the Danish astronomer Tycho Brahe. M/F "Tycho Brahe" was built by Langsten Slip & Båtbyggeri
Two-body problem in general relativity The Kepler problem derives its name from Johannes Kepler, who worked as an assistant to the Danish astronomer Tycho Brahe. Brahe took extraordinarily accurate measurements of the motion of the planets of the Solar System. From these measurements, Kepler was able to formulate Kepler's laws, the first modern description of planetary motion: Kepler published the first two laws in 1609 and the third law in 1619. They supplanted earlier models of the Solar System, such as those of Ptolemy and Copernicus. Kepler's laws apply only in the limited case of the two-body problem. Voltaire and Émilie du Châtelet were the