Tycho Brahe

Tycho Brahe

Overview
Tycho Brahe born Tyge Ottesen Brahe, was a Danish
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

 nobleman
Nobility
Nobility is a social class which possesses more acknowledged privileges or eminence than members of most other classes in a society, membership therein typically being hereditary. The privileges associated with nobility may constitute substantial advantages over or relative to non-nobles, or may be...

 known for his accurate and comprehensive astronomical and planetary
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 observations. Coming from Scania
Scania
Scania is the southernmost of the 25 traditional non-administrative provinces of Sweden, constituting a peninsula on the southern tip of the Scandinavian peninsula, and some adjacent islands. The modern administrative subdivision Skåne County is almost, but not totally, congruent with the...

, then part of Denmark, now part of modern-day Sweden, Tycho was well known in his lifetime as an astronomer
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 and alchemist
Alchemy
Alchemy is an influential philosophical tradition whose early practitioners’ claims to profound powers were known from antiquity. The defining objectives of alchemy are varied; these include the creation of the fabled philosopher's stone possessing powers including the capability of turning base...

.

In his De nova stella (On the new star) of 1573, he refuted the theory of the celestial spheres
Celestial spheres
The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus and others...

 by showing the celestial heavens were not in an immutable or unchanging state of perfection as previously assumed by Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...

 and Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

.
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Encyclopedia
Tycho Brahe born Tyge Ottesen Brahe, was a Danish
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

 nobleman
Nobility
Nobility is a social class which possesses more acknowledged privileges or eminence than members of most other classes in a society, membership therein typically being hereditary. The privileges associated with nobility may constitute substantial advantages over or relative to non-nobles, or may be...

 known for his accurate and comprehensive astronomical and planetary
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 observations. Coming from Scania
Scania
Scania is the southernmost of the 25 traditional non-administrative provinces of Sweden, constituting a peninsula on the southern tip of the Scandinavian peninsula, and some adjacent islands. The modern administrative subdivision Skåne County is almost, but not totally, congruent with the...

, then part of Denmark, now part of modern-day Sweden, Tycho was well known in his lifetime as an astronomer
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 and alchemist
Alchemy
Alchemy is an influential philosophical tradition whose early practitioners’ claims to profound powers were known from antiquity. The defining objectives of alchemy are varied; these include the creation of the fabled philosopher's stone possessing powers including the capability of turning base...

.

In his De nova stella (On the new star) of 1573, he refuted the theory of the celestial spheres
Celestial spheres
The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus and others...

 by showing the celestial heavens were not in an immutable or unchanging state of perfection as previously assumed by Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...

 and Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

. His precise measurements indicated that "new stars" (nova
Nova
A nova is a cataclysmic nuclear explosion in a star caused by the accretion of hydrogen on to the surface of a white dwarf star, which ignites and starts nuclear fusion in a runaway manner...

e or also now known as supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...

e), in particular that of 1572
SN 1572
SN 1572 , "B Cassiopeiae" , or 3C 10 was a supernova of Type Ia in the constellation Cassiopeia, one of about eight supernovae visible to the naked eye in historical records...

, lacked the parallax
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...

 expected in sub-lunar phenomena, and were therefore not "atmospheric" tail-less comets as previously believed, but occurred above the atmosphere and moon. Using similar measurements he showed that comets were also not atmospheric phenomena, as previously thought, and must pass through the supposed "immutable" celestial spheres.

Tycho Brahe was granted an estate on the island of Hven and the funding to build the Uraniborg
Uraniborg
Uranienborg was a Danish astronomical observatory operated by Tycho Brahe; built circa 1576-1580 on Hven, an island in the Øresund between Zealand and Scania, which at that time was part of Denmark. The observatory was shortly after its construction expanded with an underground facility,...

, an early research institute
Research institute
A research institute is an establishment endowed for doing research. Research institutes may specialize in basic research or may be oriented to applied research...

, where he built large astronomical instruments and took many careful measurements, and later Stjerneborg
Stjerneborg
Stjerneborg was Tycho Brahe's underground observatory next to his palace-observatory Uraniborg, located on the island of Hven in Oresund....

, underground, when he discovered that his instruments in the former were not sufficiently steady. Something of an autocrat on the island he nevertheless founded manufactories such as paper-making to provide material for printing his results. Something akin to a research institute
Research institute
A research institute is an establishment endowed for doing research. Research institutes may specialize in basic research or may be oriented to applied research...

 was founded which John Napier
John Napier
John Napier of Merchiston – also signed as Neper, Nepair – named Marvellous Merchiston, was a Scottish mathematician, physicist, astronomer & astrologer, and also the 8th Laird of Merchistoun. He was the son of Sir Archibald Napier of Merchiston. John Napier is most renowned as the discoverer...

 attended. After disagreements with the new Danish king in 1597, he was invited by the Bohemian
Kingdom of Bohemia
The Kingdom of Bohemia was a country located in the region of Bohemia in Central Europe, most of whose territory is currently located in the modern-day Czech Republic. The King was Elector of Holy Roman Empire until its dissolution in 1806, whereupon it became part of the Austrian Empire, and...

 king and Holy Roman
Holy Roman Empire
The Holy Roman Empire was a realm that existed from 962 to 1806 in Central Europe.It was ruled by the Holy Roman Emperor. Its character changed during the Middle Ages and the Early Modern period, when the power of the emperor gradually weakened in favour of the princes...

 emperor Rudolph II to Prague, where he became the official imperial astronomer. He built the new observatory at Benátky nad Jizerou
Benátky nad Jizerou
Benátky nad Jizerou is a town on the Jizera river in the Central Bohemian Region of the Czech Republic, between the cities Stará Boleslav and Mladá Boleslav.The city was the site of a castle and observatory built by astronomer Tycho Brahe.-External links:...

. Here, from 1600 until his death in 1601, he was assisted by 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...

. Kepler later used Tycho's astronomical results to develop his own theories of astronomy.

As an astronomer, Tycho worked to combine what he saw as the geometrical
Geometry
Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....

 benefits of the Copernican system with the philosophical benefits of the Ptolemaic system into his own model of the universe, 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...

. Furthermore, he was the last of the major naked eye
Naked eye
The naked eye is a figure of speech referring to human visual perception unaided by a magnifying or light-collecting optical device, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...

 astronomers, working without telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...

s for his observations.

Tycho is credited with the most accurate astronomical observations of his time, and the data were used by his assistant, 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...

, to derive the laws of planetary motion
Kepler's laws of planetary motion
In astronomy, Kepler's laws give a description of the motion of planets around the Sun.Kepler's laws are:#The orbit of every planet is an ellipse with the Sun at one of the two foci....

. No one before Tycho had attempted to make so many planetary observations.

Early years


Tycho was born at his family's ancestral seat of Knutstorp Castle
Knutstorp Castle
Knutstorp Castle is a castle in Svalöv Municipality, Scania, in southern Sweden. It was built in the 16th century by Otte Brahe. It is the birthplace of the famous astronomer Tycho Brahe ....

 (Danish: Knudstrup borg; Swedish: Knutstorps borg), about eight kilometres north of Svalöv
Svalöv Municipality
Svalöv Municipality is a municipality in Skåne County in southern Sweden. Its seat is located in the town Svalöv.The local government reform of 1952 grouped the 15 original entities into six larger municipalities...

 in then Danish Scania
Scania
Scania is the southernmost of the 25 traditional non-administrative provinces of Sweden, constituting a peninsula on the southern tip of the Scandinavian peninsula, and some adjacent islands. The modern administrative subdivision Skåne County is almost, but not totally, congruent with the...

, now Swedish, to Otte Brahe
Otte Brahe
Otte Brahe was a Danish nobleman who is best known for his son, Tycho Brahe.- Family life :Brahe was born in Tosterup to Tyge Brahe and Sophie Rud....

 and Beate Bille. His twin
Twin
A twin is one of two offspring produced in the same pregnancy. Twins can either be monozygotic , meaning that they develop from one zygote that splits and forms two embryos, or dizygotic because they develop from two separate eggs that are fertilized by two separate sperm.In contrast, a fetus...

 brother died before being baptized. Tycho wrote a Latin ode to his dead twin, which was printed in 1572 as his first published work. He also had two sisters, one older (Kirstine Brahe) and one younger (Sophia Brahe
Sophia Brahe
Sophie Brahe, or Sophia, was a Danish horticulturalist and student of astronomy, chemistry, and medicine, best known for assisting her brother Tycho Brahe with his astronomical observations.-Life:...

).

Otte Brahe, Tycho's father, was a nobleman and an important figure at the court of the Danish king. His mother, Beate Bille, came from an important family that had produced leading churchmen and politicians. Both parents are buried under the floor of Kågeröd Church, four kilometres east of Knutstorp. An epitaph
Epitaph
An epitaph is a short text honoring a deceased person, strictly speaking that is inscribed on their tombstone or plaque, but also used figuratively. Some are specified by the dead person beforehand, others chosen by those responsible for the burial...

, originally from Knutstorp, but now on a plaque near the church door, shows the whole family, including Tycho as a boy.

Tycho later wrote that when he was around age two, his uncle, Danish nobleman Jørgen Thygesen Brahe
Jørgen Thygesen Brahe
Jørgen Thygesen Brahe was a member of the Danish nobility.He was the son of Thyge Axelsen Brahe til Tostrup, Danish Councillor. He was also the uncle of the astronomer Tycho Brahe whom he raised as a little child and gave an education. He was married to Inger Johansdatter Oxe, sister of Peder...

, "without the knowledge of my parents took me away with him while I was in my earliest youth to become a scholar". Apparently, this did not lead to dispute, nor did his parents attempt to get him back. According to one source, Tycho's parents had promised to hand over a boy child to Jørgen and his wife, who were childless, but had not honoured this promise. Jørgen seems to have taken matters into his own hands and took the child away to his own residence, Tosterup Castle
Tosterup Castle
Tosterup Castle is a castle in Tomelilla Municipality, Scania, in southern Sweden. It is situated approximately north-east of Ystad....

. Jørgen Brahe inherited considerable wealth from his parents, which in terms of the social structure of the time made him eligible for a royal appointment as county sheriff
Sheriff
A sheriff is in principle a legal official with responsibility for a county. In practice, the specific combination of legal, political, and ceremonial duties of a sheriff varies greatly from country to country....

. He was successively sheriff to Tranekjær
Tranekær
Tranekær is a village in central Denmark, located in Tranekær municipality on the island of Langeland.-External links:*...

 (1542–49), Odensegaard (1549–52), Vordingborg Castle
Vordingborg Castle
The Vordingborg Castle ruins are located in the town of Vordingborg, Denmark and are the town's most famous attraction.-History:...

 (1552–57), and finally (1555 until his death in 1565) to Queen Dorothea
Dorothea of Saxe-Lauenburg
Dorothea of Saxe-Lauenburg , consort of Christian III from 1525 and Queen consort of Denmark and Norway. She was daughter of Duke Magnus I of Saxe-Lauenburg and Catherine, daughter of Henry IV, Duke of Brunswick-Lüneburg...

 at Nykøbing Castle on Falster
Nykøbing Falster
Nykøbing Falster is a southern Danish city, seat of the Guldborgsund kommune. It belongs to Region Sjælland. The city lies on Falster, connected by the 295-meter-long Frederick IX Bridge over the Guldborgsund waterway to the island of Lolland. The town has a population of 16,464...

.

Tycho attended Latin school from ages 6 to 12, but the name of the school is not known. At age 12, on 19 April 1559, Tycho began studies at the University of Copenhagen
University of Copenhagen
The University of Copenhagen is the oldest and largest university and research institution in Denmark. Founded in 1479, it has more than 37,000 students, the majority of whom are female , and more than 7,000 employees. The university has several campuses located in and around Copenhagen, with the...

. There, following his uncle's wishes, he studied law, but also studied a variety of other subjects and became interested in astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

. The solar eclipse of 21 August 1560
Solar eclipse of August 21, 1560
A total solar eclipse occurred on August 21, 1560. - Observations:The prediction of this solar eclipse helped to inspire Tycho Brahe's interest in astronomy at the age of 14....

, especially the fact that it had been predicted, so impressed him that he began to make his own studies of astronomy, helped by some of the professors. He purchased an ephemeris
Ephemeris
An ephemeris is a table of values that gives the positions of astronomical objects in the sky at a given time or times. Different kinds of ephemerides are used for astronomy and astrology...

 and books on astronomy, including Johannes de Sacrobosco
Johannes de Sacrobosco
Johannes de Sacrobosco or Sacro Bosco was a scholar, monk, and astronomer who taught at the University of Paris and wrote the authoritative mediaeval astronomy text Tractatus de Sphaera.-Origins:Although described as English, his birthplace is unknown because Sacrobosco is...

's De sphaera mundi
De sphaera mundi
De sphaera mundi is a medieval introduction to the basic elements of astronomy written by Johannes de Sacrobosco c. 1230...

, Petrus Apianus
Petrus Apianus
Petrus Apianus , also known as Peter Apian, was a German humanist, known for his works in mathematics, astronomy and cartography.The lunar crater Apianus and minor planet 19139 Apian are named in his honour....

's Cosmographia seu descriptio totius orbis and Regiomontanus
Regiomontanus
Johannes Müller von Königsberg , today best known by his Latin toponym Regiomontanus, was a German mathematician, astronomer, astrologer, translator and instrument maker....

's De triangulis omnimodis. Jørgen Thygesen Brahe, however, wanted Tycho to educate himself in order to become a civil servant, and sent him on a study tour of Europe in early 1562. Tycho was given the young Anders Sørensen Vedel
Anders Sørensen Vedel
Anders Sørensen Vedel was a Danish priest and historiographer. He translated the Gesta Danorum by Saxo Grammaticus into Danish in 1575, and published the influential "Hundredvisebogen" in 1591.-Biography:...

 as mentor, whom he eventually talked into allowing the pursuit of astronomy during the tour. At age 17, Tycho wrote:

I've studied all available charts of the planets and stars and none of them match the others. There are just as many measurements and methods as there are astronomers and all of them disagree. What's needed is a long term project with the aim of mapping the heavens conducted from a single location over a period of several years.


Tycho realized that progress in astronomy required systematic, rigorous observation, night after night, using the most accurate instruments obtainable. This program became his life's work. Tycho improved and enlarged existing instruments, and built entirely new ones. His sister Sophia assisted Tycho in many of his measurements. Tycho was the last major astronomer to work without the aid of a telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...

, soon to be turned skyward by Galileo
Galileo Galilei
Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...

 and others.

Tycho jealously guarded his large body of celestial measurements, which Kepler "usurped" following Tycho's death.

Tycho's nose


While studying at University of Rostock
University of Rostock
The University of Rostock is the university of the city Rostock, in the German state of Mecklenburg-Vorpommern.Founded in 1419, it is the oldest and largest university in continental northern Europe and the Baltic Sea area...

 in Germany, on 29 December 1566 Tycho lost part of his nose
Human nose
The visible part of the human nose is the protruding part of the face that bears the nostrils. The shape of the nose is determined by the ethmoid bone and the nasal septum, which consists mostly of cartilage and which separates the nostrils...

 in a duel
Duel
A duel is an arranged engagement in combat between two individuals, with matched weapons in accordance with agreed-upon rules.Duels in this form were chiefly practised in Early Modern Europe, with precedents in the medieval code of chivalry, and continued into the modern period especially among...

 against fellow Danish nobleman Manderup Parsbjerg. Tycho had earlier quarrelled with Parsbjerg at a wedding dance at professor Lucas Bachmeister's house on the 10th, and again on the 27th. The duel two days later (in the dark) resulted in Tycho losing the bridge of his nose. From this event Tycho became interested in medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

 and alchemy
Alchemy
Alchemy is an influential philosophical tradition whose early practitioners’ claims to profound powers were known from antiquity. The defining objectives of alchemy are varied; these include the creation of the fabled philosopher's stone possessing powers including the capability of turning base...

. For the rest of his life, he was said to have worn a replacement made of silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

 and gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

, using a paste to keep it attached. Some people, such as Fredric Ihren and Cecil Adams
Cecil Adams
Cecil Adams is a name, possibly a pseudonym, designating the American author of The Straight Dope, a popular question and answer column published in The Chicago Reader since 1973. Ed Zotti is Adams' current editor....

 have suggested that the false nose also had copper. Ihren wrote that when Tycho's tomb was opened in 24 June 1901 green marks were found on his skull, suggesting copper. Cecil Adams
Cecil Adams
Cecil Adams is a name, possibly a pseudonym, designating the American author of The Straight Dope, a popular question and answer column published in The Chicago Reader since 1973. Ed Zotti is Adams' current editor....

 also mentions a green colouring and that medical experts examined the remains. Some historians have speculated that he wore a number of different prosthetics for different occasions, noting that a copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 nose would have been more comfortable and less heavy than a precious metal
Precious metal
A precious metal is a rare, naturally occurring metallic chemical element of high economic value.Chemically, the precious metals are less reactive than most elements, have high lustre, are softer or more ductile, and have higher melting points than other metals...

 one.

Death of his uncle


His uncle and foster father, Jørgen Brahe, died in 1565 of pneumonia
Pneumonia
Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...

 after rescuing Frederick II of Denmark
Frederick II of Denmark
Frederick II was King of Denmark and Norway and duke of Schleswig from 1559 until his death.-King of Denmark:Frederick II was the son of King Christian III of Denmark and Norway and Dorothea of Saxe-Lauenburg. Frederick II stands as the typical renaissance ruler of Denmark. Unlike his father, he...

 from drowning. In April 1567, Tycho returned home from his travels and his father wanted him to take up law, but Tycho was allowed to make trips to Rostock, then on to Augsburg
Augsburg
Augsburg is a city in the south-west of Bavaria, Germany. It is a university town and home of the Regierungsbezirk Schwaben and the Bezirk Schwaben. Augsburg is an urban district and home to the institutions of the Landkreis Augsburg. It is, as of 2008, the third-largest city in Bavaria with a...

 (where he built a great quadrant
Quadrant (instrument)
A quadrant is an instrument that is used to measure angles up to 90°. It was originally proposed by Ptolemy as a better kind of astrolabe. Several different variations of the instrument were later produced by medieval Muslim astronomers.-Types of quadrants:...

), Basel
Basel
Basel or Basle In the national languages of Switzerland the city is also known as Bâle , Basilea and Basilea is Switzerland's third most populous city with about 166,000 inhabitants. Located where the Swiss, French and German borders meet, Basel also has suburbs in France and Germany...

, and Freiburg. At the end of 1570 he was informed about his father's ill health, so he returned to Knutstorp Castle
Knutstorp Castle
Knutstorp Castle is a castle in Svalöv Municipality, Scania, in southern Sweden. It was built in the 16th century by Otte Brahe. It is the birthplace of the famous astronomer Tycho Brahe ....

, where his father died on 9 May 1571. Soon after, his other uncle, Steen Bille, helped him build an observatory and alchemical laboratory at Herrevad Abbey
Herrevad Abbey
Herrevad Abbey was a Cistercian monastery near Ljungbyhed in Klippan Municipality, Scania, in the south of present-day Sweden, but formerly in Denmark until 1658. It is now a country house known as Herrevad Castle .- History :...

.

Family life


Towards the end of 1571, Tycho fell in love with Kirsten, daughter of Jørgen Hansen, the Lutheran
Lutheranism
Lutheranism is a major branch of Western Christianity that identifies with the theology of Martin Luther, a German reformer. Luther's efforts to reform the theology and practice of the church launched the Protestant Reformation...

 minister in Knudstrup. She was a commoner, and Tycho never formally married her. However, under Danish law
Courts of Denmark
The Danish Supreme Court is the highest civil and criminal court responsible for the administration of justice in Denmark. The Kingdom of Denmark, consisting of Denmark, Greenland and the Faroe Islands, does not have a single unified judicial system – Denmark has one system, Greenland another, and...

, when a nobleman and a common woman lived together openly as husband and wife, and she wore the keys to the household at her belt like any true wife, their alliance became a binding morganatic marriage
Morganatic marriage
In the context of European royalty, a morganatic marriage is a marriage between people of unequal social rank, which prevents the passage of the husband's titles and privileges to the wife and any children born of the marriage...

 after three years. The husband retained his noble status and privileges; the wife remained a commoner. Their children were legitimate in the eyes of the law, but they were commoners like their mother and could not inherit their father's name, coat of arms
Coat of arms
A coat of arms is a unique heraldic design on a shield or escutcheon or on a surcoat or tabard used to cover and protect armour and to identify the wearer. Thus the term is often stated as "coat-armour", because it was anciently displayed on the front of a coat of cloth...

, or landholdings.

Kirsten Jørgensdatter gave birth to their first daughter, Kirstine (named after Tycho's late sister, who died at 13) on 12 October 1573. Together they had eight children, six of whom lived to adulthood. In 1574, they moved to Copenhagen where their daughter Magdalene was born. Kirsten and Tycho lived together for almost thirty years until Tycho's death.

Tycho's Elk (Moose)


Tycho was said to own one percent of the entire wealth of Denmark at one point in the 1580s and he often held large social gatherings in his castle. He kept a dwarf named Jepp (whom Tycho believed to be clairvoyant) as a court jester who sat under the table during dinner. Pierre Gassendi
Pierre Gassendi
Pierre Gassendi was a French philosopher, priest, scientist, astronomer, and mathematician. With a church position in south-east France, he also spent much time in Paris, where he was a leader of a group of free-thinking intellectuals. He was also an active observational scientist, publishing the...

 wrote that Tycho also had a tame elk
Moose
The moose or Eurasian elk is the largest extant species in the deer family. Moose are distinguished by the palmate antlers of the males; other members of the family have antlers with a dendritic configuration...

 (moose) and that his mentor the Landgrave
Landgrave
Landgrave was a title used in the Holy Roman Empire and later on by its former territories. The title refers to a count who had feudal duty directly to the Holy Roman Emperor...

 Wilhelm
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:...

 of Hesse-Kassel
Hesse-Kassel
The Landgraviate of Hesse-Kassel or Hesse-Cassel was a state in the Holy Roman Empire under Imperial immediacy that came into existence when the Landgraviate of Hesse was divided in 1567 upon the death of Philip I, Landgrave of Hesse. His eldest son William IV inherited the northern half and the...

 (Hesse-Cassel) asked whether there was an animal faster than a deer. Tycho replied, writing that there was none, but he could send his tame elk. When Wilhelm replied he would accept one in exchange for a horse, Tycho replied with the sad news that the elk had just died on a visit to entertain a nobleman at Landskrona
Landskrona
Landskrona is a locality and the seat of Landskrona Municipality, Skåne County, Sweden with 28,670 inhabitants in 2005.-History:The city of Landskrona was founded at the location of Scania's best natural harbour, as a means of King Eric of Pomerania's anti-Hanseatic policy, intended to compete...

. Apparently during dinner the elk had drunk a lot of beer, fallen down the stairs, and died.

Death



Tycho suddenly contracted a bladder or kidney ailment after attending a banquet in Prague, and died eleven days later, on 24 October 1601. According to Kepler's first hand account, Tycho had refused to leave the banquet to relieve himself because it would have been a breach of etiquette. After he had returned home he was no longer able to urinate, except eventually in very small quantities and with excruciating pain. The night before he died he suffered from a delirium during which he was frequently heard to exclaim that he hoped he would not seem to have lived in vain. Before dying, he urged Kepler to finish the Rudolphine Tables
Rudolphine Tables
The Rudolphine Tables consist of a star catalogue and planetary tables published by Johannes Kepler in 1627 using data from Tycho Brahe's observations.-Previous tables:...

and expressed the hope that he would do so by adopting Tycho's own planetary system, rather than that of Copernicus
Nicolaus Copernicus
Nicolaus Copernicus was a Renaissance astronomer and the first person to formulate a comprehensive heliocentric cosmology which displaced the Earth from the center of the universe....

. A contemporary physician attributed his death to a kidney stone
Kidney stone
A kidney stone, also known as a renal calculus is a solid concretion or crystal aggregation formed in the kidneys from dietary minerals in the urine...

, but no kidney stones were found during an autopsy performed after his body was exhumed in 1901, and the 20th century medical assessment is that it is more likely to have resulted from uremia
Uremia
Uremia or uraemia is a term used to loosely describe the illness accompanying kidney failure , in particular the nitrogenous waste products associated with the failure of this organ....

.

Recent investigations have suggested that Tycho did not die from urinary problems but instead from mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

 poisoning—extremely toxic levels of it have been found in hairs from his moustache. The results were, however, not conclusive. Prague City Hall approved a request by Danish scientists to exhume the remains in February 2010, and a team of Czech and Danish scientists from Aarhus University arrived in November 2010, to take bone, hair and clothing samples for analysis.

Tycho's body is currently interred in a tomb in the Church of Our Lady in front of Týn
Church of Our Lady in front of Týn
The Church of Our Lady before Týn is a dominant feature of the Old Town of Prague, Czech Republic, and has been the main church of this part of the city since the 14th century...

, in Old Town Square
Old Town Square (Prague)
Old Town Square is a historic square in the Old Town quarter of Prague in the Czech Republic at .Located between Wenceslas Square and the Charles Bridge, Prague's Old Town Square is often bursting at the seams with tourists in the summer. Featuring various architectural styles including the...

 near the Prague Astronomical Clock.

The 1572 supernova


On 11 November 1572, Tycho observed (from Herrevad Abbey
Herrevad Abbey
Herrevad Abbey was a Cistercian monastery near Ljungbyhed in Klippan Municipality, Scania, in the south of present-day Sweden, but formerly in Denmark until 1658. It is now a country house known as Herrevad Castle .- History :...

) a very bright star, now named SN 1572
SN 1572
SN 1572 , "B Cassiopeiae" , or 3C 10 was a supernova of Type Ia in the constellation Cassiopeia, one of about eight supernovae visible to the naked eye in historical records...

, which had unexpectedly appeared in the constellation Cassiopeia
Cassiopeia (constellation)
Cassiopeia is a constellation in the northern sky, named after the vain queen Cassiopeia in Greek mythology, who boasted about her unrivalled beauty. Cassiopea was one of the 48 constellations listed by the 2nd century Greek astronomer Ptolemy, and it remains one of the 88 modern constellations today...

. Because it had been maintained since antiquity
Ancient history
Ancient history is the study of the written past from the beginning of recorded human history to the Early Middle Ages. The span of recorded history is roughly 5,000 years, with Cuneiform script, the oldest discovered form of coherent writing, from the protoliterate period around the 30th century BC...

 that the world beyond the Moon's orbit was eternally unchangeable (celestial immutability was a fundamental axiom of the Aristotelian
Aristotelianism
Aristotelianism is a tradition of philosophy that takes its defining inspiration from the work of Aristotle. The works of Aristotle were initially defended by the members of the Peripatetic school, and, later on, by the Neoplatonists, who produced many commentaries on Aristotle's writings...

 world-view), other observers held that the phenomenon was something in the terrestrial sphere below the Moon. However, in the first instance Tycho observed that the object showed no daily parallax
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...

 against the background of the fixed stars. This implied it was at least farther away than the Moon and those planets that do show such parallax. He also found the object did not change its position relative to the fixed stars over several months as all planets did in their periodic orbital motions, even the outer planets for which no daily parallax was detectable. This suggested it was not even a planet, but a fixed star in the stellar sphere beyond all the planets. In 1573 he published a small book, De nova stella thereby coining the term nova
Nova
A nova is a cataclysmic nuclear explosion in a star caused by the accretion of hydrogen on to the surface of a white dwarf star, which ignites and starts nuclear fusion in a runaway manner...

 for a "new" star (we now classify this star as a supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...

 and we know that it is 7500 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...

s from Earth). This discovery was decisive for his choice of astronomy as a profession. Tycho was strongly critical of those who dismissed the implications of the astronomical appearance, writing in the preface to De nova stella: "O crassa ingenia. O caecos coeli spectatores" ("Oh thick wits. Oh blind watchers of the sky").

Tycho's discovery was the inspiration for Edgar Allan Poe
Edgar Allan Poe
Edgar Allan Poe was an American author, poet, editor and literary critic, considered part of the American Romantic Movement. Best known for his tales of mystery and the macabre, Poe was one of the earliest American practitioners of the short story and is considered the inventor of the detective...

's poem, "Al Aaraaf
Al Aaraaf
"Al Aaraaf" is an early poem by American writer Edgar Allan Poe, first published in 1829. It is based on stories from the Qur'an, and tells of the afterlife in a place called Al Aaraaf...

". In 1998, Sky & Telescope
Sky & Telescope
Sky & Telescope is a monthly American magazine covering all aspects of amateur astronomy, including the following:*current events in astronomy and space exploration;*events in the amateur astronomy community;...

magazine published an article by Donald W. Olson, Marilynn S. Olson and Russell L. Doescher arguing, in part, that Tycho's supernova was also the same "star that's westward from the pole" in Shakespeare's Hamlet
Hamlet
The Tragical History of Hamlet, Prince of Denmark, or more simply Hamlet, is a tragedy by William Shakespeare, believed to have been written between 1599 and 1601...

.

Tycho's observatories


In 1574, Tycho published the observations made in 1572 from his first observatory at Herrevad Abbey
Herrevad Abbey
Herrevad Abbey was a Cistercian monastery near Ljungbyhed in Klippan Municipality, Scania, in the south of present-day Sweden, but formerly in Denmark until 1658. It is now a country house known as Herrevad Castle .- History :...

. He then started lecturing on astronomy, but gave it up and left Denmark in spring 1575 to tour abroad. He first visited 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:...

's observatory at Kassel, then went on to Frankfurt, Basel and Venice. Upon his return he intended to relocate to Basel, but King
Monarch
A monarch is the person who heads a monarchy. This is a form of government in which a state or polity is ruled or controlled by an individual who typically inherits the throne by birth and occasionally rules for life or until abdication...

 Frederick II of Denmark
Frederick II of Denmark
Frederick II was King of Denmark and Norway and duke of Schleswig from 1559 until his death.-King of Denmark:Frederick II was the son of King Christian III of Denmark and Norway and Dorothea of Saxe-Lauenburg. Frederick II stands as the typical renaissance ruler of Denmark. Unlike his father, he...

, desiring to keep the distinguished scientist, offered Tycho the island of Hven
Hven
Ven is a small Swedish island in the Öresund strait, between Scania and Zealand . It is situated in Landskrona Municipality, Skåne County. The island has 371 inhabitants and an area of . During the 1930s, the population was at its peak, with approximately 1,300 inhabitants...

 in Oresund
Oresund
The Sound , is the strait that separates the Danish island Zealand from the southern Swedish province of Scania. Its width is just at the narrowest point between Helsingør, Denmark, and Helsingborg, Sweden...

 and funding to set up an observatory. Tycho first built Uraniborg
Uraniborg
Uranienborg was a Danish astronomical observatory operated by Tycho Brahe; built circa 1576-1580 on Hven, an island in the Øresund between Zealand and Scania, which at that time was part of Denmark. The observatory was shortly after its construction expanded with an underground facility,...

 in 1576 (with a laboratory for his alchemical
Alchemy
Alchemy is an influential philosophical tradition whose early practitioners’ claims to profound powers were known from antiquity. The defining objectives of alchemy are varied; these include the creation of the fabled philosopher's stone possessing powers including the capability of turning base...

 experiments in its cellar) and then Stjerneborg
Stjerneborg
Stjerneborg was Tycho Brahe's underground observatory next to his palace-observatory Uraniborg, located on the island of Hven in Oresund....

 in 1581. Unusual for the time, Tycho established Uraniborg as a research centre, where almost 100 students and artisans worked from 1576 to 1597.

After Frederick died in 1588 and his 11-year-old son, Christian IV
Christian IV of Denmark
Christian IV was the king of Denmark-Norway from 1588 until his death. With a reign of more than 59 years, he is the longest-reigning monarch of Denmark, and he is frequently remembered as one of the most popular, ambitious and proactive Danish kings, having initiated many reforms and projects...

, succeeded him, Tycho's influence steadily declined. After several unpleasant disagreements, Tycho left Hven in 1597.

He moved to 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...

 in 1599. Sponsored by Rudolf II, Holy Roman Emperor
Rudolf II, Holy Roman Emperor
Rudolf II was Holy Roman Emperor , King of Hungary and Croatia , King of Bohemia and Archduke of Austria...

, Tycho built a new observatory in a castle in Benátky nad Jizerou
Benátky nad Jizerou
Benátky nad Jizerou is a town on the Jizera river in the Central Bohemian Region of the Czech Republic, between the cities Stará Boleslav and Mladá Boleslav.The city was the site of a castle and observatory built by astronomer Tycho Brahe.-External links:...

, 50 km from Prague, and worked there for one year. The emperor then brought him back to Prague, where he stayed until his death. Tycho received financial support from several nobles in addition to the emperor, including Oldrich Desiderius Pruskowsky von Pruskow, to whom he dedicated his famous "Mechanica". In return for their support, Tycho's duties included preparing astrological
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...

 charts and predictions for his patrons on events such as births, weather
Weather
Weather is the state of the atmosphere, to the degree that it is hot or cold, wet or dry, calm or stormy, clear or cloudy. Most weather phenomena occur in the troposphere, just below the stratosphere. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate...

 forecasting, and astrological interpretations of significant astronomical events, such as the supernova of 1572
SN 1572
SN 1572 , "B Cassiopeiae" , or 3C 10 was a supernova of Type Ia in the constellation Cassiopeia, one of about eight supernovae visible to the naked eye in historical records...

 (sometimes called Tycho's supernova) and the Great Comet of 1577
Great Comet of 1577
The Great Comet of 1577 was a comet that passed close to Earth during the year 1577 AD. It was viewed by people all over Europe, including famous Danish astronomer Tycho Brahe. From his observations of the comet, Brahe was able to discover that comets and similar objects travel above the Earth's...

.

Tycho's observational astronomy


Tycho's observations of stellar
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

 and planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...

ary positions were noteworthy both for their accuracy and quantity. His celestial positions were much more accurate than those of any predecessor or contemporary. Rawlins (1993, §B2) asserts of Tycho's Star Catalog D, "In it, Tycho achieved, on a mass scale, a precision far beyond that of earlier catalogers. Cat D represents an unprecedented confluence of skills: instrumental, observational, & computational—all of which combined to enable Tycho to place most of his hundreds of recorded stars to an accuracy of ordermag 1'!"

He aspired to a level of accuracy in his estimated positions of celestial bodies of being consistently within 1 arcminute
Minute of arc
A minute of arc, arcminute, or minute of angle , is a unit of angular measurement equal to one sixtieth of one degree. In turn, a second of arc or arcsecond is one sixtieth of one minute of arc....

 of their real celestial locations, and also claimed to have achieved this level. But in fact many of the stellar positions in his star catalogues were less accurate than that. The median errors for the stellar positions in his final published catalog were about 1'.5, indicating that only half of the entries were more accurate than that, with an overall mean error in each coordinate of around 2'. Although the stellar observations as recorded in his observational logs were more accurate, varying from 32.3" to 48.8" for different instruments, systematic errors of as much as 3' were introduced into some of the stellar positions Tycho published in his star catalog - due for instance, to his application of an erroneous ancient value of parallax and his neglect of polestar refraction. Incorrect transcription in the final published star catalogue, by scribes in Brahe's employ, was the source of even larger errors, sometimes by many degrees.

After his death, his records of the motion of the planet Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

 provided evidence to support Kepler's discovery of the ellipse and area laws of planetary motion
Kepler's laws of planetary motion
In astronomy, Kepler's laws give a description of the motion of planets around the Sun.Kepler's laws are:#The orbit of every planet is an ellipse with the Sun at one of the two foci....

. Kepler's application of these two laws to obtain astronomical tables of unprecedented accuracy (the Rudolphine Tables) provided powerful support for his heliocentric model of the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

.

Tycho himself was not a Copernican, but proposed a system in which the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

 and Moon orbited the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

, while the other planets orbited the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

. His system provided a safe position for astronomers who were dissatisfied with older models but were reluctant to accept the Earth's motion. It gained a considerable following after 1616 when Rome decided officially that the heliocentric model was contrary to both philosophy and Scripture, and could be discussed only as a computational convenience that had no connection to fact. His system also offered a major innovation: while both the geocentric model
Geocentric model
In astronomy, the geocentric model , is the superseded theory that the Earth is the center of the universe, and that all other objects orbit around it. This geocentric model served as the predominant cosmological system in many ancient civilizations such as ancient Greece...

 and the heliocentric model as set forth by Copernicus relied on the idea of transparent rotating crystalline spheres to carry the planets in their orbits, Tycho eliminated the spheres entirely.

Celestial objects observed near the horizon and above appear with a greater altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...

 than the real one, due to atmospheric refraction
Refraction
Refraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...

, and one of Tycho's most important innovations was that he worked out and published the very first tables for the systematic correction of this possible source of error. But as advanced as they were, they attributed no refraction whatever above 45 degrees altitude for solar refraction, and none for starlight above 20 degrees altitude.

To perform the huge number of multiplications needed to produce much of his astronomical data, Tycho relied heavily on the then-new technique of prosthaphaeresis
Prosthaphaeresis
Prosthaphaeresis was an algorithm used in the late 16th century and early 17th century for approximate multiplication and division using formulas from trigonometry. For the 25 years preceding the invention of the logarithm in 1614, it was the only known generally-applicable way of approximating...

, an algorithm for approximating products based on trigonometric identities that predated logarithms.

Tycho's geo-heliocentric astronomy




Kepler tried, but was unable, to persuade Tycho to adopt the heliocentric model
Heliocentrism
Heliocentrism, or heliocentricism, is the astronomical model in which the Earth and planets revolve around a stationary Sun at the center of the universe. The word comes from the Greek . Historically, heliocentrism was opposed to geocentrism, which placed the Earth at the center...

 of the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

. Tycho advocated for geocentrism for reasons of physics, astronomical observations of stars, and religion.

In regards to physics, Tycho held that the Earth was just too sluggish and heavy to be continuously in motion. According to the accepted Aristotelian physics of the time, the heavens (whose motions and cycles were continuous and unending) were made of “Aether” or “Quintessence”
Aether (classical element)
According to ancient and medieval science aether , also spelled æther or ether, is the material that fills the region of the universe above the terrestrial sphere.-Mythological origins:...

; this substance, not found on Earth, was light, strong, unchanging, and its natural state was circular motion. By contrast, the Earth (where objects seem to have motion only when moved) and things on it were composed of substances that were heavy and whose natural state was rest. Accordingly, Tycho said the Earth was a “lazy” body that was not readily moved. Thus while Tycho acknowledged that the daily rising and setting of the sun and stars could be explained by the Earth's rotation, as Copernicus had said, still
such a fast motion could not belong to the earth, a body very heavy and dense and opaque, but rather belongs to the sky itself whose form and subtle and constant matter are better suited to a perpetual motion, however fast.


In regards to the stars, Tycho also believed that if the Earth orbited the Sun annually there should be an observable stellar parallax
Stellar parallax
Stellar parallax is the effect of parallax on distant stars in astronomy. It is parallax on an interstellar scale, and it can be used to determine the distance of Earth to another star directly with accurate astrometry...

 over any period of six months, during which the angular orientation of a given star would change thanks to Earth's changing position (this parallax does exist, but is so small it was not detected until 1838, when Friedrich Bessel
Friedrich Bessel
-References:* John Frederick William Herschel, A brief notice of the life, researches, and discoveries of Friedrich Wilhelm Bessel, London: Barclay, 1847 -External links:...

 discovered a parallax of 0.314 arcseconds of the star 61 Cygni
61 Cygni
61 Cygni,Not to be confused with 16 Cygni, a more distant system containing two G-type stars harboring the gas giant planet 16 Cygni Bb. sometimes called Bessel's Star or Piazzi's Flying Star, is a binary star system in the constellation Cygnus...

 in 1838). The Copernican explanation for this lack of parallax was that the stars were such a great distance from Earth that Earth's orbit was almost insignificant by comparison. However, Tycho noted that this explanation introduced another problem: Stars as seen by the naked eye appear small, but of some size, with more prominent stars such as Vega appearing larger than lesser stars such as Polaris, which in turn appear larger than many others. Tycho had determined that a typical star measured approximately a minute of arc in size, with more prominent ones being two or three times as large. In writing to Christoph Rothmann, a Copernican astronomer, Tycho used basic geometry to show that, assuming a small parallax that just escaped detection, the distance to the stars in the Copernican system would have to be 700 times greater than the distance from the sun to Saturn. Moreover, the only way the stars could be so distant and still appear the sizes they do in the sky would be if even average stars were gigantic — at least as big as the orbit of the Earth, and of course vastly larger than the sun. And, Tycho said, the more prominent stars would have to be even larger still. And what if the parallax was even smaller than anyone thought, so the stars were yet more distant? Then they would all have to be even larger still. Tycho said
Deduce these things geometrically if you like, and you will see how many absurdities (not to mention others) accompany this assumption [of the motion of the earth] by inference.
Copernicans offered a religious response to Tycho's geometry: titanic, distant stars might seem unreasonable, but they were not, for the Creator could make his creations that large if He wanted.

Religion played a role in Tycho's geocentrism also – he cited the authority of scripture in portraying the Earth as being at rest. He rarely used Biblical arguments alone (to him they were a secondary objection to the idea of Earth's motion) and over time he came to focus on scientific arguments, but he did take Biblical arguments seriously.

Tycho advocated an alternative to the Ptolemaic geocentric system: A “geo-heliocentric” system now known as 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 he developed in the late 1570s. In such a system, the sun, moon, and stars circle a central Earth, while the five planets orbit the Sun. The essential difference between the heavens (including the planets) and the Earth remained: Motion stayed in the aethereal heavens; immobility stayed with the heavy sluggish Earth. It was a system that Tycho said violated neither the laws of physics nor sacred scripture — with stars located just beyond Saturn and of reasonable size.

Tycho was not the first to propose a geoheliocentric system. It used to be thought that Heraclides
Heraclides Ponticus
Heraclides Ponticus , also known as Herakleides and Heraklides of Pontus, was a Greek philosopher and astronomer who lived and died at Heraclea Pontica, now Karadeniz Ereğli, Turkey. He is best remembered for proposing that the earth rotates on its axis, from west to east, once every 24 hours...

 in the 4th century BC had suggested that Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...

 and Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...

 revolve around the Sun, which in turn (along with the other planets) revolves around the Earth. Macrobius Ambrosius Theodosius (395–423 AD) later described this as the "Egyptian System," stating that "it did not escape the skill of the Egyptians
Egyptians
Egyptians are nation an ethnic group made up of Mediterranean North Africans, the indigenous people of Egypt.Egyptian identity is closely tied to geography. The population of Egypt is concentrated in the lower Nile Valley, the small strip of cultivable land stretching from the First Cataract to...

," though there is no other evidence it was known in ancient Egypt
Ancient Egypt
Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...

. The difference was that Tycho's system had all the planets (with the exception of Earth) revolving around the Sun, instead of just the interior planets of Mercury and Venus. In this regard, he was anticipated in the 15th century by the Kerala school astronomer Nilakantha Somayaji
Nilakantha Somayaji
Kelallur Nilakantha Somayaji was a major mathematician and astronomer of the Kerala school of astronomy and mathematics. One of his most influential works was the comprehensive astronomical treatise Tantrasamgraha completed in 1501...

, whose geoheliocentric system also had all the planets revolving around the Sun. The difference to both these systems was that Tycho's model of the Earth does not rotate daily, as Heraclides and Nilakantha claimed, but is static.

Another crucial difference between Tycho's 1587 geo-heliocentric model and those of other geo-heliocentric astronomers, such as 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...

, Reimarus Ursus
Reimarus Ursus
Nicolaus Reimers Baer , also Reimarus Ursus, Nicolaus Reimers Bär or Nicolaus Reymers Baer was an astronomer and imperial mathematician to Emperor Rudolf II...

, Helisaeus Roeslin
Helisaeus Roeslin
Helisaeus Roeslin was a German physician and astrologer who adopted a geoheliocentric model of the universe. He was one of five observers who concluded that the Great Comet of 1577 was located beyond the moon...

 and David Origanus
David Origanus
David Origanus or David Tost was a German astronomer and professor for Greek language and Mathematics at the University of Frankfurt , where he had also studied....

, was that the orbits of Mars and the Sun intersected. This was because Tycho had come to believe the distance of Mars from the Earth at opposition (that is, when Mars is on the opposite side of the sky from the Sun) was less than that of the Sun from the Earth. Tycho believed this because he came to believe Mars had a greater daily parallax than the Sun. But in 1584 in a letter to a fellow astronomer, Brucaeus, he had claimed that Mars had been further than the Sun at the opposition of 1582, because he had observed that Mars had little or no daily parallax. He said he had therefore rejected Copernicus's model because it predicted Mars would be at only two-thirds the distance of the Sun. But he apparently later changed his mind to the opinion that Mars at opposition was indeed nearer the Earth than the Sun was, but apparently without any valid observational evidence in any discernible Martian parallax. Such intersecting Martian and solar orbits meant that there could be no solid rotating celestial spheres, because they could not possibly interpenetrate. Arguably this conclusion was independently supported by the conclusion that the comet of 1577 was superlunary, because it showed less daily parallax than the Moon and thus must pass through any celestial spheres in its transit.

Tychonic astronomy after Tycho


Galileo's
Galileo Galilei
Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...

 1610 telescopic discovery that Venus shows a full set of phases refuted the pure geocentric Ptolemaic model. After that it seems 17th century astronomy then mostly converted to geo-heliocentric planetary models that could explain these phases just as well as the heliocentric model could, but without the latter's disadvantage of the failure to detect any annual stellar parallax
Stellar parallax
Stellar parallax is the effect of parallax on distant stars in astronomy. It is parallax on an interstellar scale, and it can be used to determine the distance of Earth to another star directly with accurate astrometry...

 that Tycho and others regarded as refuting it. The three main geo-heliocentric models were the Tychonic, the Capellan with just Mercury and Venus orbiting the Sun such as favoured by Francis Bacon, for example, and the extended Capellan model of Riccioli with Mars also orbiting the Sun whilst Saturn and Jupiter orbit the fixed Earth. But the Tychonic model was probably the most popular, albeit probably in what was known as 'the semi-Tychonic' version with a daily rotating Earth. This model was advocated by Tycho's ex-assistant and disciple Longomontanus in his 1622 Astronomia Danica that was the intended completion of Tycho's planetary model with his observational data, and which was regarded as the canonical statement of the complete Tychonic planetary system.

A conversion of astronomers to geo-rotational geo-heliocentric models with a daily rotating Earth such as that of Longomontanus may have been precipitated by Francesco Sizzi's 1613 discovery of annually periodic seasonal variations of sunspot trajectories across the sun's disc. They appear to oscillate above and below its apparent equator over the course of the four seasons. This seasonal variation is explained much better by the hypothesis of a daily rotating Earth together with that of the sun's axis being tilted throughout its supposed annual orbit than by that of a daily orbiting sun, if not even refuting the latter hypothesis because it predicts a daily vertical oscillation of a sunspot's position, contrary to observation. This discovery and its import for heliocentrism, but not for geo-heliocentrism, is discussed in the Third Day of Galileo's 1632 Dialogo. However, prior to that discovery, in the late 16th century the geo-heliocentric models of Ursus and Roslin had featured a daily rotating Earth, unlike Tycho's geo-static model, as indeed had that of Heraclides in antiquity, for whatever reason.

The fact that Longomontanus's book was republished in two later editions in 1640 and 1663 no doubt reflected the popularity of Tychonic astronomy in the 17th century. Its adherents included John Donne
John Donne
John Donne 31 March 1631), English poet, satirist, lawyer, and priest, is now considered the preeminent representative of the metaphysical poets. His works are notable for their strong and sensual style and include sonnets, love poetry, religious poems, Latin translations, epigrams, elegies, songs,...

 and the atomist and astronomer Pierre Gassendi.


The ardent anti-heliocentric French astronomer Jean-Baptiste Morin devised a Tychonic planetary model with elliptical orbits published in 1650 in a simplified, Tychonic version of the Rudolphine Tables. Some acceptance of the Tychonic system persisted through the 17th century and in places until the early 18th century; it was supported (after a 1633 decree about the Copernican controversy) by "a flood of pro-Tycho literature" of Jesuit origin. Among pro-Tycho Jesuits, Ignace Pardies declared in 1691 that it was still the commonly accepted system, and Francesco Blanchinus reiterated that as late as 1728. Persistence of the Tychonic system, especially in Catholic countries, has been attributed to its satisfaction of a need (relative to Catholic doctrine) for "a safe synthesis of ancient and modern". After 1670, even many Jesuit writers only thinly disguised their Copernicanism. But in Germany, Holland, and England, the Tychonic system "vanished from the literature much earlier".

James Bradley
James Bradley
James Bradley FRS was an English astronomer and served as Astronomer Royal from 1742, succeeding Edmund Halley. He is best known for two fundamental discoveries in astronomy, the aberration of light , and the nutation of the Earth's axis...

's discovery of stellar aberration, published in 1729, eventually gave direct evidence excluding the possibility of all forms of geocentrism including Tycho's. Stellar aberration could only be satisfactorily explained on the basis that the Earth is in annual orbit around the Sun, with an orbital velocity that combines with the finite speed of the light coming from an observed star or planet, to affect the apparent direction of the body observed.

Tycho's lunar theory


Tycho's distinctive contributions to lunar theory
Lunar theory
Lunar theory attempts to account for the motions of the Moon. There are many irregularities in the Moon's motion, and many attempts have been made over a long history to account for them. After centuries of being heavily problematic, the lunar motions are nowadays modelled to a very high degree...

 include his discovery of the variation
Variation (astronomy)
"Variation" is a generic word in astronomy as in other fields: many observable astronomical quantities can show variations of some kind. But the term variation also has a specific meaning in astronomy, referring to the variation of the Moon...

 of the Moon's longitude. This represents the largest inequality of longitude after the equation of the center
Equation of the center
For further closely related mathematical developments see also Two-body problem, also Gravitational two-body problem, also Kepler orbit, and Kepler problem...

 and the evection
Evection
Evection , in astronomy, is the largest inequality produced by the action of the Sun in the monthly revolution of the Moon around the Earth. The evection, formerly called the moon's second anomaly, was approximately known in ancient times, and its discovery is attributed to Ptolemy...

. He also discovered librations in the inclination of the plane of the lunar orbit, relative to the ecliptic (which is not a constant of about 5° as had been believed before him, but fluctuates through a range of over a quarter of a degree), and accompanying oscillations in the longitude of the lunar node. These represent perturbations in the Moon's ecliptic latitude. Tycho's lunar theory doubled the number of distinct lunar inequalities, relative to those anciently known, and reduced the discrepancies of lunar theory to about 1/5 of their previous amounts. It was published posthumously by 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...

 in 1602, and Kepler's own derivative form appears in Kepler's Rudolphine Tables
Rudolphine Tables
The Rudolphine Tables consist of a star catalogue and planetary tables published by Johannes Kepler in 1627 using data from Tycho Brahe's observations.-Previous tables:...

 of 1627.

Legacy


Although Tycho's planetary model was soon discredited, his astronomical observations were an essential contribution to the scientific revolution
Scientific revolution
The Scientific Revolution is an era associated primarily with the 16th and 17th centuries during which new ideas and knowledge in physics, astronomy, biology, medicine and chemistry transformed medieval and ancient views of nature and laid the foundations for modern science...

. The traditional view of Tycho is that he was primarily an empiricist who set new standards for precise and objective measurements. This appraisal originated in Pierre Gassendi
Pierre Gassendi
Pierre Gassendi was a French philosopher, priest, scientist, astronomer, and mathematician. With a church position in south-east France, he also spent much time in Paris, where he was a leader of a group of free-thinking intellectuals. He was also an active observational scientist, publishing the...

's 1654 biography, Tychonis Brahe, equitis Dani, astronomorum coryphaei, vita. It was furthered by Johann Dreyer's biography in 1890, which was long the most influential work on Tycho. According to historian of science Helge Kragh, this assessment grew out of Gassendi's opposition to Aristotelianism
Aristotelianism
Aristotelianism is a tradition of philosophy that takes its defining inspiration from the work of Aristotle. The works of Aristotle were initially defended by the members of the Peripatetic school, and, later on, by the Neoplatonists, who produced many commentaries on Aristotle's writings...

 and Cartesianism
Cartesianism
Cartesian means of or relating to the French philosopher and mathematician René Descartes—from his name—Rene Des-Cartes. It may refer to:*Cartesian anxiety*Cartesian circle*Cartesian dualism...

, and fails to account for the diversity of Tycho's activities.

Tycho considered astrology to be a subject of great importance. In addition to his contributions to astronomy, he was famous in his own time also for his contributions to medicine; his herbal medicines were in use as late as the 1900s.
Although the research community Tycho created in Uraniborg did not survive him, while it existed it was both a research center and an institution of education, functioning as a graduate school for Danish and foreign students in both astronomy and medicine. Tycho's success as a scientist also depended on his adroit political skills, to obtain patronage and funding for his work.

The crater Tycho
Tycho (crater)
Tycho is a prominent lunar impact crater located in the southern lunar highlands, named after the Danish astronomer Tycho Brahe . To the south is the crater Street; to the east is Pictet, and to the north-northeast is Sasserides. The surface around Tycho is replete with craters of various sizes,...

 on the Moon is named after him, as is the crater Tycho Brahe
Tycho Brahe (crater)
Tycho Brahe is a crater on Mars named after the Danish astronomer Tycho Brahe. It is located in the Cerberus hemisphere of Mars, around 49.8° south and 213.9° west, in an area which is southeast of the Martz crater and east of the Hellas Basin....

 on Mars. The Tycho Brahe Planetarium
Tycho Brahe Planetarium
The Tycho Brahe Planetarium is located in Copenhagen, Denmark, at the southern end of Skt. Jørgens Sø. It is named after astronomer Tycho Brahe. It was designed by MAA Knud Munk and opened on November 1, 1989....

 in Copenhagen is also named after him.

HEAT1X-TYCHO BRAHE is the name of a manned private spacecraft to be launched by Copenhagen Suborbitals
Copenhagen Suborbitals
Copenhagen Suborbitals is a non-profit organization working towards suborbital manned spaceflight. Founded in 2008 by Kristian von Bengtson and Peter Madsen the project has accomplished a successful sea launch of a test hybrid rocket, carrying a full scale human model...

. Other things named after him include a bar in Zagreb
Zagreb
Zagreb is the capital and the largest city of the Republic of Croatia. It is in the northwest of the country, along the Sava river, at the southern slopes of the Medvednica mountain. Zagreb lies at an elevation of approximately above sea level. According to the last official census, Zagreb's city...

 and a ferry operating between Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

 and Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

.

See also


  • December 1573 lunar eclipse
    December 1573 lunar eclipse
    A total lunar eclipse occurred on December 8, 1573.It was predicted and then observed by a young Tycho Brahe at Knutstorp Castle. He said "I cannot but be very surprised that even at this youthful age of 26 years, I was able to get such accurate results."- External links:* Tycho observes a lunar...

  • History of trigonometry
  • Regiomontanus
    Regiomontanus
    Johannes Müller von Königsberg , today best known by his Latin toponym Regiomontanus, was a German mathematician, astronomer, astrologer, translator and instrument maker....


Further reading

  • Kitty Ferguson: The nobleman and his housedog: Tycho Brahe and Johannes Kepler: the strange partnership that revolutionised science. London: Review, 2002 ISBN 0-7472-7022-8 (published in the US as: Tycho & Kepler: the unlikely partnership that forever changed our understanding of the heavens. New York: Walker, 2002 ISBN 0-8027-1390-4)
  • Joshua Gilder and Anne-Lee Gilder Heavenly intrigue. New York: Doubleday, 2004 ISBN 0-385-50844-1
  • Arthur Koestler
    Arthur Koestler
    Arthur Koestler CBE was a Hungarian author and journalist. Koestler was born in Budapest and, apart from his early school years, was educated in Austria...

    : The Sleepwalkers: A History of Man's Changing Vision of the Universe. Hutchinson, 1959; reprinted in Arkana, 1989
  • Godfred Hartmann. Urania. Om mennesket Tyge Brahe. Copenhagen: Gyldendal, 1989 ISBN 87-00-62763-1
  • Wilson & Taton. Planetary astronomy from the Renaissance to the rise of astrophysics 1989 CUP (articles by Thoren, Jarell and Schofield on the nature and history of the Tychonic astronomical model) (analysis of individual instrument accuracies) (critical analysis of Tycho's 1004-star catalogue D. Printing date: 2009\1\12)

External links