Reimarus Ursus
Encyclopedia
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
and imperial mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
to Emperor Rudolf II. Due to his family's background, he was also known as Bär, Latinized to Ursus ("bear
Bear
Bears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives. Although there are only eight living species of bear, they are widespread, appearing in a wide variety of habitats throughout the Northern...
").
Reimers was born at Hennstedt and received hardly any education in his youth, herding pigs until the age of 18. Yet, Heinrich Rantzau
Heinrich Rantzau
Heinrich Rantzau or Ranzow was a German humanist writer and statesman, a prolific astrologer and an associate of Tycho Brahe. He was son of Johan Rantzau....
discovered his talents and employed him from 1574 to 1584 as geometer. Accordingly, Reimers in 1583 published his Geodaesia Ranzoviana. Rantzau also arranged a meeting with Tycho Brahe
Tycho Brahe
Tycho Brahe , born Tyge Ottesen Brahe, was a Danish nobleman known for his accurate and comprehensive astronomical and planetary observations...
.
From 1586 to 1587, Reimers stayed at the court of William IV, Landgrave of Hesse-Kassel
William IV, Landgrave of Hesse-Kassel
William IV of Hesse-Kassel , also called William the Wise, was the first Landgrave of Hesse-Kassel . He was the founder of the oldest line, which survives to this day.-Life:...
in Kassel
Kassel
Kassel is a town located on the Fulda River in northern Hesse, Germany. It is the administrative seat of the Kassel Regierungsbezirk and the Kreis of the same name and has approximately 195,000 inhabitants.- History :...
, where he met Swiss instrument maker Jost Bürgi
(1552-1632). Both were autodidacts and thus had a similar background. As Bürgi did not understand Latin, Reimers translated Copernicus' De Revolutionibus Orbium Coelestium
De revolutionibus orbium coelestium
De revolutionibus orbium coelestium is the seminal work on the heliocentric theory of the Renaissance astronomer Nicolaus Copernicus...
into German for Bürgi. A copy of the translation survived in Graz
Graz
The more recent population figures do not give the whole picture as only people with principal residence status are counted and people with secondary residence status are not. Most of the people with secondary residence status in Graz are students...
, it is thus called "Grazer Handschrift".
Reimers was a bitter rival of Tycho Brahe
Tycho Brahe
Tycho Brahe , born Tyge Ottesen Brahe, was a Danish nobleman known for his accurate and comprehensive astronomical and planetary observations...
(his successor as imperial mathematician) after he tried to claim the Tychonic system
Tychonic system
The Tychonic system was a model of the solar system published by Tycho Brahe in the late 16th century which combined what he saw as the mathematical benefits of the Copernican system with the philosophical and "physical" benefits of the Ptolemaic system...
, which is also attributed to Paul Wittich
Paul Wittich
Paul Wittich was a German mathematician and astronomer whose Capellan geoheliocentric model, in which the inner planets Mercury and Venus orbit the sun but the outer planets Mars, Jupiter and Saturn orbit the Earth, may have directly inspired Tycho Brahe's more radically heliocentric...
, as his own.
Johannes Kepler
Johannes Kepler
Johannes Kepler was a German mathematician, astronomer and astrologer. A key figure in the 17th century scientific revolution, he is best known for his eponymous laws of planetary motion, codified by later astronomers, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican...
committed a faux pas
Faux pas
A faux pas is a violation of accepted social norms . Faux pas vary widely from culture to culture, and what is considered good manners in one culture can be considered a faux pas in another...
early in his career by sending a laudatory letter to Reimers while seeking the patronage of Tycho; Ursus published the letter in the preface to his work claiming priority for Tycho's cosmological ideas.
But unlike Tycho's geoheliocentric system in which the Earth does not rotate and the Martian and Solar orbits intersect, in that of Ursus and his follower Roslin the Earth had a daily rotation and also the Martian and Solar orbits do not intersect, thus avoiding the Tychonic conclusion in respect of the Martian orbit that there are no solid celestial spheres on the ground that they cannot possibly interpenetrate. But on the other hand the orbits of Mercury and Venus would obviously intersect the Martian orbit in Reimers' illustration of his model, and indeed also intersect Jupiter's orbit.
However Kepler discovered Tycho had posited intersecting Martian and Solar orbits because he had mistakenly concluded from his data that at opposition Mars was closer to the Earth than the Sun was. The source of the error was a research assistants' mistaken calculation of Mars's daily parallax from observations during its 1582-3 opposition as greater than that of the Sun's presumed 3' parallax. Kepler discovered Tycho’s observations revealed little or no Martian parallax, implying it was further than the Sun at opposition. This would have refuted Tycho's system in favour of Ursus's and Roslin's. It seems it has yet to be determined whether the dominant astronomical system of the 17th century was the geoheliocentric system of Tycho or that of Ursus and Roslin at least in respect of non-intersecting Solar and Martian orbits, and also in that of the Earth's rotation or not.
Reimers died in Prague
Prague
Prague is the capital and largest city of the Czech Republic. Situated in the north-west of the country on the Vltava river, the city is home to about 1.3 million people, while its metropolitan area is estimated to have a population of over 2.3 million...
.
Work
- Geodaesia Ranzoviana, Leipzig 1583.
- Nicolai Raymari Ursi Dithmari Fundamentum astronomicum, Straßburg 1588.
- Metamorphosis Logicae, Straßburg 1589.
- Nicolai Raimari Ursi Dithmarsi de Astronomicis hypothesibus, Prag 1597.
- Chronotheatron, Prag 1597.
- Nicolai Raimari Ursi dithmarsi Arithmetica analytica vulgo Cosa oder Algebra, 1601.