HOME

TheInfoList



OR:

Christen Sørensen Longomontanus (also as Longberg or Severin) (4 October 1562 – 8 October 1647) was a Danish
astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...
. The name Longomontanus was a
Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
ized form of the name of the village of Lomborg,
Jutland Jutland (; , ''Jyske Halvø'' or ''Cimbriske Halvø''; , ''Kimbrische Halbinsel'' or ''Jütische Halbinsel'') is a peninsula of Northern Europe that forms the continental portion of Denmark and part of northern Germany (Schleswig-Holstein). It ...
,
Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...
, where he was born. His father, a laborer called Søren, or Severin, died when Christen was eight years old. An uncle took charge of the child, and had him educated at Lemvig; but after three years sent him back to his mother, who needed his help to work the fields. She agreed that he could study during the winter months with the clergyman of the parish; this arrangement continued until 1577, when the ill-will of some of his relatives and his own desire for knowledge caused him to run away to Viborg. There he attended the
grammar school A grammar school is one of several different types of school in the history of education in the United Kingdom and other English-speaking countries, originally a Latin school, school teaching Latin, but more recently an academically oriented Se ...
, working as a labourer to pay his expenses, and in 1588 went to
Copenhagen Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...
with a high reputation for learning and ability. Engaged by
Tycho Brahe Tycho Brahe ( ; ; born Tyge Ottesen Brahe, ; 14 December 154624 October 1601), generally called Tycho for short, was a Danish astronomer of the Renaissance, known for his comprehensive and unprecedentedly accurate astronomical observations. He ...
in 1589 as his assistant in his great astronomical observatory of
Uraniborg Uraniborg was an astronomical observatory and alchemy laboratory established and operated by the Danish astronomer Tycho Brahe. It was the first custom-built observatory in modern Europe, and the last to be built without a telescope as its pr ...
, he rendered invaluable service for eight years. He held Tycho Brahe in the highest regard and always supported his system and tried to improve upon it throughout his life.Kragh, Helge. (2015). Georgius Frommius (1605–1651) and Danish Astronomy in the Post-Tychonian Era. Acta Baltica Historiae et Philosophiae Scientiarum. 3. 45-68. 10.11590/abhps.2015.1.03. However, he did disagree with the Tycho Brahe's system in some regards, he believed that the earth rotated unlike his master's theory that it was immobile. During this time,
Kepler Johannes Kepler (27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws of p ...
joined the two in trying to come up with a theory on how to predict longitude at oppositions with complete accuracy. Longomontanus used Mars as a model for this. Having left the island of
Hven Ven (, older Swedish spelling ''Hven''), is a Swedish island in the Öresund strait laying between Scania, Sweden and Zealand, Denmark. A part of Landskrona Municipality, Skåne County, the island has an area of and 371 inhabitants as of 2020. ...
with his master, he obtained his discharge at Copenhagen on 1 June 1597, in order to study at some German universities. He rejoined Tycho at
Prague Prague ( ; ) is the capital and List of cities and towns in the Czech Republic, largest city of the Czech Republic and the historical capital of Bohemia. Prague, located on the Vltava River, has a population of about 1.4 million, while its P ...
in January 1600, and having completed the Tychonic lunar theory, turned homeward again in August. Soon after this, Tycho Brahe's untimely demise happened. After Tycho managed to become a mathematician that served the Emperor Rudolph II, he died in October 1601. The Emperor had to appoint a new Mathematician. When doing so, the expected choice would have been Longomontanus since he was Tycho's preferred choice. However, Longomontanus was gone during this time in Denmark and Johannes Kepler was there, so he was anointed.   He visited Frauenburg, where
Copernicus Nicolaus Copernicus (19 February 1473 – 24 May 1543) was a Renaissance polymath who formulated a mathematical model, model of Celestial spheres#Renaissance, the universe that placed heliocentrism, the Sun rather than Earth at its cen ...
had made his observations, took a master's degree at
Rostock Rostock (; Polabian language, Polabian: ''Roztoc''), officially the Hanseatic and University City of Rostock (), is the largest city in the German States of Germany, state of Mecklenburg-Vorpommern and lies in the Mecklenburgian part of the sta ...
, and at Copenhagen found a patron in Christian Friis, chancellor of Denmark, who employed him in his household. Appointed in 1603 rector of the school of Viborg, he was elected two years later to a professorship in the
University of Copenhagen The University of Copenhagen (, KU) is a public university, public research university in Copenhagen, Copenhagen, Denmark. Founded in 1479, the University of Copenhagen is the second-oldest university in Scandinavia, after Uppsala University. ...
, and his promotion to the chair of
mathematics Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...
ensued in 1607. This post was held by Longomontanus till his death in 1647. Longomontanus was not an advanced thinker. He adhered to Tycho's erroneous views about
refraction In physics, refraction is the redirection of a wave as it passes from one transmission medium, medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commo ...
, believed that
comet A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...
s were messengers of evil, and imagined that he had squared the circle. He found that the circle whose diameter is 43 has for its circumference the square root of 18252 which gives 3.14185... for the value of π. John Pell and others tried in vain to convince him of his error. In 1632 he started the construction of the ''
Rundetårn The Round Tower () is a 17th-century tower in Copenhagen, Denmark, one of the many architectural projects of Christian IV. Built as an astronomical observatory, it is noted for its equestrian staircase, a 7.5-turn helical corridor leading to th ...
'' (a stately astronomical tower in Copenhagen), but did not live to witness its completion. King
Christian IV of Denmark Christian IV (12 April 1577 – 28 February 1648) was King of Denmark and King of Norway, Norway and List of rulers of Schleswig-Holstein, Duke of Holstein and Schleswig from 1588 until his death in 1648. His reign of 59 years and 330 days is th ...
, to whom he dedicated his ''Astronomia Danica'', an exposition of the Tychonic system of the universe, conferred upon him the
canonry Canon () is a Christian title usually used to refer to a member of certain bodies in subject to an canon law, ecclesiastical rule. Originally, a canon was a cleric living with others in a clergy house or, later, in one of the houses within the p ...
of Lunden in
Schleswig The Duchy of Schleswig (; ; ; ; ; ) was a duchy in Southern Jutland () covering the area between about 60 km (35 miles) north and 70 km (45 mi) south of the current border between Germany and Denmark. The territory has been di ...
. Longomontanus's major contribution to science was to develop Tycho's geoheliocentric model of the universe empirically and publicly to common acceptance. When Tycho died in 1601, his program for the restoration of astronomy was unfinished. The observational aspects were complete, but two important tasks remained, namely the selection and integration of the data into accounts of the motions of the
planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...
s, and the presentation of the results on the entire program in the form of a systematic treatise. Longomontanus assumed the responsibility and fulfilled both tasks in his voluminous ''Astronomia Danica'' (1622). Regarded as the testament of Tycho, the work was eagerly received in seventeenth-century astronomical literature. The book was highly accredited and many famous owners included Christopher Wren, Christiaan Huygens as well as the
Royal Greenwich Observatory The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, temporarily moved south from Greenwich to Herstmonceux) is an observatory situated on a hill in G ...
in England. The book mainly compared the three world systems of the time, these included the Copernicus, Tycho Brahe and Ptolemy schools of thought. But unlike Tycho's, the geoheliocentric model of Longomontanus gave the Earth a proper daily rotation (as in the models of Ursus and Roslin). It is therefore sometimes called the 'semi-Tychonic' system. The book was reprinted in 1640 and 1663, which indicates its popularity and the interest in the semi-Tychonic system in this period. Having originally worked on calculating the
Martian Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. Trends in the planet's portrayal have largely been influenced by advances in planetary science. It became the most popular celes ...
orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...
for Tycho with
Kepler Johannes Kepler (27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws of p ...
, he had already modelled its orbit in his geoheliocentric model to an error in
longitude Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lett ...
of under 2
arcminute A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a tu ...
s when Kepler had still only achieved 8 arcminutes error in his
heliocentric Heliocentrism (also known as the heliocentric model) is a Superseded theories in science#Astronomy and cosmology, superseded astronomical model in which the Earth and Solar System, planets orbit around the Sun at the center of the universe. His ...
system, as he had not yet used elliptical orbits. Some historians claim Kepler's 1627 ''
Rudolphine Tables The ''Rudolphine Tables'' () consist of a star catalogue and planetary tables published by Johannes Kepler in 1627, using observational data collected by Tycho Brahe (1546–1601). The tables are named in memory of Rudolf II, Holy Roman Emper ...
'', based on Tycho Brahe's observations, were more accurate than any previous tables. But nobody has ever demonstrated they were more accurate than Longomontanus's 1622 ''Danish Astronomy'' tables, also based upon Tycho's observations.


Publications

His major works in mathematics and astronomy were: * ''Systematis Mathematici, etc.'' (1611) * ''Cyclometria e Lunulis reciproce demonstrata'', etc. (1612) * ''Disputatio de Eclipsibus'' (1616) * ''Astronomia Danica'', etc. (1622) * * ''Disputationes quatuor Astrologicae'' (1622) * ''Pentas Problematum Philosophiae'' (1623) * ''De Chronolabio Historico, seu de Tempore Disputationes tres'' (1627) * ''Geometriae quaesita XIII. de Cyclometria rationali et vera'' (1631) * ''Inventio Quadraturae Circuli'' (1634) * ''Disputatio de Matheseos Indole'' (1636) * ''Coronis Problematica ex Mysteriis trium Numerorum'' (1637) * ''Problemata duo Geometrica'' (1638) * ''Problema contra Paulum Guldinum de Circuli Mensura'' (1638) * ''Introductio in Theatrum Astronomicum'' (1639) * ''Rotundi in Plano, etc.'' (1644) * ''Admiranda Operatio trium Numerorum 6, 7, 8'', etc. (1645) * ''Caput tertium Libri primi de absoluta Mensura Rotundi plani'', etc. (1646)


Eponymy

*The
lunar crater Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, all of which were formed by impacts. The International Astronomical Union currently recognizes 9,137 craters, of which 1,675 have been dated. History The wo ...
Longomontanus was named after him. It is located near the Tycho crater.This is not a coincidence
as explains Giambattista Riccioli, who named it.


References

*


External links


Biography from ''Dansk Biografisk Lexicon''
(1887–1905 – in Danish) * Longomontanus'
'Astronomia Danica'
in its original Latin, at the internet archive. {{DEFAULTSORT:Longomontanus, Christen Sorensen 1562 births 1647 deaths 16th-century Danish astronomers Rectors of the University of Copenhagen 17th-century Danish astronomers