Sky & Telescope June 1983 [antikvár]

The Long Thread of Danish AstronomyG. W. E. Beekman, Soest. HollandThe FABRIC of astronomy in Denmark. smallest of the Scandinavian countries, was woven in a manner quite like that of other European nations. The science began to develop during the Renaissance and concentrated at first around the observatory in the nation's capital. Copenhagen. In this century, that observatory was relocated at a better site outside the city. And during recent decades an era of increasing International cooperation Danish astronomy has moved to even better sites, particularly those occupied by the European Southern Observatory in Chile and the Roque de los Muchachos Obser\atory on La Palma in the Canary Islands.THE DISTANT PAST Danish astronomy emerged with the founding of the University of Copenhagen in 1479. At that time it was concerned with the regulation of the calendar and the formulation of a model of the solar system. In 1576 the famous Tycho Brahe got the opportunity to build an observatory on the isle of Ven (modern spelling) and equip it with the best instruments of the time (see Sky and Telescope for March, 1982. page 233).His assistants and pupils came from various countries. One of them was Christen Sorensen Longberg, better known as Longomontanus (for the village of Longberg, Denmark, where he was born in 1562). Later. Longomontanus became a professor at the University of Copenhagen and was known especially for his stubborn adherence to Tycho's world view (see the August, 1982, issue, page 138).Under his direction, construction began on an observatory atop the Round Tower, part of the Church of the Holy Trinity in the center of Copenhagen. The work took more time than expected, however, and only nine years after Longomontanus' death in 1647 could the observatory be used. That was accomplished by Ole Römer. the second great Danish astronomer.Here was a very versatile man. The fact so little is known about his work must be attributed to two causes: He published few works, and nearly all of his manuscripts were lost in the fire that destroyed a thirdThe Round Tower in the center of Copenhagen is 36 meters high. Instead of stairs, it has a brick-paved ramp leading to the top. It is said that in 1716 Peter the Great rode up the ramp on horseback, followed by his empress in a coach. Photo by Owen Gingerich.of Copenhagen in 1728. Born in Aarhus in 1644, Römer studied in Copenhagen and became a great admirer of Tycho. From 1672 until 1679 he worked at the Royal Observatory in Paris, where he announced in 1676 the Finite velocity of light, deduced from eclipses of the satellite lo by Jupiter.Upon returning to Copenhagen, Römer became a professor of mathematics and astronomy as well as director of the Round Tower observatory, which was by then in abad state. This he renovated while also taking care of its new instruments. Like Tycho, Römer was interested in measuring the positions of celestial bodies. His advantage, however, stemmed from improved technology, such as optical aids (telescopes and microscopes) and better timekeepers (pendulum clocks).Römer's aim was to discover the annual parallax of stars, to prove that the Earth revolves around the Sun. For that purpose he designed an innovative transit circle,June. 1983, Sky & Telescope 487