Ole Rømer was a Danish astronomer known for making the first quantitative measurements of the speed of light in 1676. Born into a wealthy family where his interest in mathematics and astronomy were encouraged, he went on to study at the University of Copenhagen. He had a high-profile career and was employed by the French government under King Louis XIV.
Peter Naur was a Danish computer science pioneer. Along with John Backus, he contributed to the development of the Backus–Naur Form (BNF) notation used in describing the syntax for most programming languages. He began his career as an astronomer, eventually shifting to computers. He was a professor of computer science at the University of Copenhagen for many years.
John Louis Emil Dreyer was a Danish astronomer. He is best remembered for serving as the president of the Royal Astronomical Society from 1923 to 1925. Prior to his service as the president John Louis Emil Dreyer was honored with the gold medal, the highest award given by the society, in 1916.
Christen Sørensen Longomontanus was a Danish astronomer best remembered for developing Tycho Brahe's geoheliocentric model of the universe. Brahe's geoheliocentric model, which was also known as the Tychonic system, was widely accepted at that time. Christen Sørensen Longomontanus also published major works in astronomy and mathematics such as Systematis Mathematici and Disputatio de Eclipsibus.