Great Astronomers: Tycho Brahe
Great Astronomers in Modern English
by Sir Robert S. Ball, 1895 (paraphrased by Leslie Noelani Laurio)
To view the table of contents for the rest of this book, click here.
Tycho Brahe, 1546-1601
Developed astronomical instruments and catalogued over 770 stars.
The most colorful character in the history of astronomy is the famous Dutch astronomer, Tycho Brahe [he is usually referred to simply as Tycho -- which is pronounced TEE-koh]. He was just as infamous for his lively personality and quirks as he was for his scientific genius. He makes an ideal subject for any biographer because of his adventurous career as a philosopher, his inclination for luxury as a Danish noble, his fiercely devoted friendships, and his furious quarrels. But it's his magnificent work in astronomy that has given him enduring fame.
His life has been published in the book "Tycho Brahe" by John Louis Emil Dreyer [1890; online at archive.org and Wiki]. Dr. Dreyer is a Danish astronomer himself, although he currently directs the observatory at Armagh [Ireland]. His book is the authority on the subject of Tycho Brahe. Tycho came from a distinguished family. His ancestors had flourished both in Sweden and in Denmark, and many of his descendants are still there to this day. Tycho's father, Otto Brahe, was an advisor in the Danish government, and was promoted as the governor of Helsingborg Castle near the end of his life. His son Tycho was born in December, 1546. He was the second of ten children, and the oldest son.
Otto had a brother named Jørgen who was childless but wanted a son on whom he could lavish his affection and wealth. So, when Otto got married, the two brothers agreed that the first son born to Otto and his wife would be handed over to Jørgen to adopt and raise. But when Tycho was born, his parents didn't want to part with him. Tycho's Uncle Jørgen wasn't happy about this, but he bided his time -- and a year later, during the birth of his baby brother, Jørgen kidnapped little Tycho! Because of the deal that had been agreed on, he felt he was within his rights. His parents gave in and allowed Jørgen and his wife to keep the child -- so Tycho was raised by his Uncle Jørgen.
Tycho was enrolled at the University of Copenhagen at the age of 13, which was typical for that time and culture. This was not a higher level University like we think of now -- Dr. Dreyer writes in his biography that in the opening speech to his new students, one professor pointed out that even multiplication and division could be mastered by any student with some diligence!
Tycho's uncle wanted him to be educated in rhetoric and philosophy to prepare him to be a statesman. But Tycho made it clear to his teachers that, though he was a good student, he preferred the heavenly bodies rather than the subtle metaphysics of philosophy.
On October 21, 1560, there was a solar eclipse predicted that would be partially seen in Copenhagen. Even though Tycho was still pretty young [he would have been 14], he was very interested in the eclipse. The part that awed and astonished him the most was that the exact time it would happen could be predicted so accurately. He was eager to understand this more thoroughly, so he tried to get a book that would explain more about it. Books back then weren't easy to get, especially books about science. But there was an edition of Ptolemy's "Almagest" that had recently been published in Latin, and he managed to get a copy of this book. Ptolemy's work was considered the authority on astronomy. Even though Tycho was young, he studied hard -- though perhaps not always successfully -- to understand Ptolemy. His copy of the book, with his own annotations in his schoolboy's handwriting, is a highly valued treasure at the University at Prague's library.
After Tycho had been at the University of Copenhagen for about three years, his uncle decided to send him to school in a foreign country to complete his education. This was pretty common in those days. His uncle hoped to lure Tycho's attention away from stars and into something more useful. Sensible men of the time considered natural science a waste of time that could be better spent on rhetoric or logic. His uncle hired a tutor to accompany Tycho and hopefully persuade him to take up something more practical than astronomy [such as law]. The tutor, Anders Vedel [who would become Denmark's first great historian!], was four years older than Tycho, intelligent and responsible. By 1562, the tutor and his student were living at the University of Leipzig [in Germany].
But the tutor soon discovered how hopeless his task would be -- Tycho didn't have the slightest interest in law or any other useful subject. All he cared about were the stars. Whenever he got any money, he would secretly spend it on astronomy books and instruments. He learned the names of stars from a little globe that he hid from Vedel and only used when Vedel was out. This caused some conflict between the two of them, but later on, they learned to respect and appreciate each other, and became life-long friends.
By age sixteen, Tycho had already begun to calculate the movements of planets by marking down their positions from time to time. He was surprised to find that his own observations differed from the calculations that other astronomers had assigned to them in their records. He realized that it would be necessary to record the movements of heavenly bodies over an extended period of time to see why there was such a difference. To us, this sounds like an obvious step. But in Tycho's day, that kind of thinking was totally new and unusual. Tycho began his observations right away as well as he could. His instrument was nothing more than a couple of ordinary mathematical compasses. He would hold the hinge up to his eye and then open the legs of the compass so that they pointed to two different stars to find their distance. Then he would bring the compass to a circle marked to show various angles. With this primitive method, he was able to record the angular distances between heavenly bodies.
When he had more money, he purchased a cross-staff and used it to observe stars every chance he got. Telescopes hadn't been invented yet, so astronomers had to rely on their own unaided eye with some kind of measuring device. The most ingenious of these devices was the cross-staff [a fore-runner to the sextant].
If the angle between two stars isn't too great, it can be measured like this: the bar labeled AB is marked off like a ruler, in inches and fractions of inches. Another bar labeled CD slides up and down bar AB so that the two bars are always perpendicular to each other. There's a sight [an eye piece, like the sight on a rifle] at point A and at point C, and there's a pin at point D. By sliding bar CD along bar AB, you can bring the sights into a position where one star can be seen along DC, and another star can be seen along DE. Once the position is set, the length from point A to the cross-bar is noted and compared to a published table to identify the actual angular distance. If two stars were too far apart to position the cross-staff, then you could move the pin at point D along bar CD to bring the angular distance of the stars into a better range.
The cross-staff is primitive and clumsy, but when it's handled with someone as skilled as Tycho, it can be surprisingly accurate. Try making one yourself and see what kind of measurements you can take with it.
Yet Tycho had to take all his measurements secretly to evade his tutor, whose job was to persuade Tycho to give up his frivolous hobby of star-gazing. Tycho would wait until Vedel was asleep, and then sneak out with his cross-staff to take angular measurements of heavenly bodies. In spite of his youth and his secrecy, Tycho conducted his observations on solid principles that are still the foundation of modern astronomy [in 1895]. He recognized that an instrument as primitive as his would have inevitable errors in its workmanship, so he calculated how far off his measurements might be on account of this, and allowed for that difference in his records. This same principle [of recognizing a difference and allowing for that much "give or take" in the final calculations], practiced by a teenager with a cross-staff in 1564, is still being used by the Astronomer Royal at Greenwich, even though today's astronomer has the most "state of the art" instruments that modern opticians have been able to create.
Tycho's uncle died when he was 19, so there was no one to interfere with his choice of interests. Tycho had always been the restless type, so he moved to the University of Rostock [in Germany]. He had a bit of notoriety related to a lunar eclipse in October, 1566. Tycho, like other astronomers of the era, associated astronomy with astrology. He assumed that events in the sky had some connection with what was going on with humans. He was also a bit of a poet. He posted up some verses in the college announcing that the lunar eclipse was an omen foretelling the death of the Sultan of Turkey, whose doings were in the news at the time. And the Sultan did die! So Tycho was triumphant and commended -- until it was noted that the Sultan had died before the eclipse, and Tycho's prediction became a joke at his expense.
Tycho had a bit of a volatile disposition. While he was at the University of Rostock, he had an argument with another Danish nobleman, supposedly over which of them was a better mathematician, and it turned violent. They fought a duel in the dead of night under the stars -- which is fitting for two astronomers. The result was that Tycho's nose was cut off! So Tycho, with his experience at making astronomy instruments, made a substitute out of gold and silver. It was said [and recorded in Oliver Lodge's 1893 book "Pioneers of Science," online at Project Gutenberg] that his metal nose looked as good as the original -- although it's not clear whether this was said by one of his friends, or one of his enemies.
Tycho spent the next few years going to different schools learning about various things related to science. One time, he helped an alderman in Augsburg [Germany] to set up a huge wooden quadrant with a 19-foot radius for star-gazing. Another time, the King of Denmark recognized his talents and promised to give him an easy job as a canon [a church dignitary] with plenty of free time to pursue his own interests. At another time, he was enthusiastically doing experiments with chemistry. That shouldn't be too surprising, since all of the sciences were closely connected in the 1500's. Alchemists [scientists who hoped to find a way to chemically alter different materials into gold] and astrologers both taught that the different planets correlated in some mysterious way with various metals. So it's natural that Tycho, with his interest in astronomy, would have wanted to learn about the properties of different metals.
But then something happened in 1572 that changed his life. On November 11, he was returning home from the chemistry laboratory and he happened to look up at the sky. He saw a bright star he had never seen before! It was in the constellation of Cassiopeia, in a place where he had never seen a star before. He was so startled that he wondered if he was hallucinating. He called the servants who were with him to look up and tell him whether they could see the brilliant star, too. Yes, they saw it. Tycho became convinced that he was seeing a brand new star! Nowadays, we know that new stars can appear sometimes, but this one was brighter than any new star that has ever appeared that we know of -- as bright as the planet Jupiter.
Not only had Tycho discovered a new star -- but you might say that the new star had discovered Tycho! It sparked a passion for science in him that motivated him to give up his other pursuits and focus on astronomy as a career.
As soon as he got home, Tycho used his quadrant to measure the new star's position and try to determine how far away it was. He guessed (correctly) that if it was closer to the earth than other stars around it, then he should be able to figure out how far away it was by calculating changes in its distance from surrounding points. He figured out that it was farther away than the moon because its position, compared to the other stars around it, didn't change when it was below the pole every twelve hours [like the moon's does]. He was able to observe it every twelve hours because it was bright enough to see in full daylight! He concluded that it was too far away to be measured by its ratio with the earth's diameter. He wasn't the only astronomer who noticed this new star -- but the others thought that it must be closer to earth than the moon. Tycho found out as much as was possible to find out about this star with the tools he had access to at the time. He proved that it was too far away to determine its distance using the only objects he had available to measure it against. He showed that it wasn't moving, but was in one position, like other stars. He kept weekly records of its changes in brightness and color.
It seems strange to us that such a diligent scientist would have connected his observational data with astrology, but Tycho thought that the star's changes were omens of future events. J. L. E. Dreyer's biography of Tycho Brahe writes that the star looked like Venus and Jupiter at first, predicting a time of pleasantness. But then the star began to look more like Mars, which meant that a time of war and misery would follow, with cities being destroyed, drought, fiery comets in the sky, disease, and venomous snakes. Finally, the star began to look like Saturn, which foretold a time of sadness, poverty, captivity, and death. It wasn't just Tycho making these kinds of connections. All kinds of educated men thought the new star was an omen of dreadful events. One of the main ideas of the day was that the Star of Bethlehem announced the first coming of Christ, and this new star was announcing His second coming -- and the end of the world.
Tycho's research into the omens of the new star were the subject of his first book. Publication was delayed, though, when his friends urged him not to write a book because book publishing would be beneath his dignity as a nobleman! But Tycho decided to rebel against the traditions of nobility -- and his first book, De Nova Stella, was published in 1573.
[Tycho's new star was a supernova explosion that brightened for a few weeks and then faded away a few months later -- its remnants are now called SN 1572.]
Now he was a famous scientist, so the King of Denmark asked him to give a series of astronomy lectures at the University of Copenhagen. Tycho agreed reluctantly. His opening lecture was written down [probably in Danish]. In this lecture, he passionately praises the beauty and fascination of celestial phenomena. He emphasizes how urgently it was necessary to continue to record systematic observations in order to extend our knowledge. He talks about the practical use of astronomy in marking the passage of time. He says that studying celestial bodies "exalts the mind from earthly and trivial things to heavenly ones." He concludes by saying that astronomy helps us to discover the fate of humans [in other words, astrology].
Something else happened to change Tycho's life in 1572. He fell in love. His friends again urged him not to act because the girl, Kirsten Barbara Jørgensdatter, was from a lower class, and an unsuitable match for a nobleman. But Tycho was never one to give in. Perhaps he felt that a humble wife wouldn't make demands on his time to attend fashionable parties and buy expensive clothes, so he'd be able to devote himself to his science. So he married her. They seem to have been happily married. They had 8 children. Apparently none of the children inherited their father's scientific genius.
Tycho had quite a few friends in Germany who admired his work. They were so much more encouraging to him than the people he knew in Denmark, that he decided to move permanently to Basle [also called Basel; it's right where Germany meets France and Switzerland]. King Frederick II of Denmark heard about his plans. Realizing what honour and fame it would bring to Denmark if Tycho stayed and did his great work within Denmark, he decided to induce him with a proposal. [Tycho's uncle had died of pneumonia in 1565 after rescuing King Frederick from drowning during a battle, so the king may also have had personal reasons for being Tycho's patron.] The king sent a messenger to travel day and night until he reached Tycho, and then bring Tycho to the castle. Tycho was in bed on February 11, 1576 when the messenger arrived. He read the message and left at once for Copenhagen. He told King Frederick that all he wanted was the means to study astronomy, so the king offered him Hven, a tiny island about 3 square miles between Denmark and Sweden where he could study in peace. The king promised to provide money to build him a house and the best observatory the world had ever known. Tycho consulted with his friends and thought it over before accepting the king's offer. The king granted him a salary and drew up a deed that formally allowed Tycho the use of the island for the rest of his life.
The foundation stone for the famous research facility of Uraniborg was laid in August, 1576. There was a grand, formal ceremony, imposing enough to suit Tycho's ideas of splendour. A group of his scientific friends was there, there was plenty of wine, and the date for this ceremony had been chosen to coincide with the time when the celestial bodies were in a favorable position. The foundation stone was placed with the appropriate solemnity. Many of the illustrations in this chapter show the character of this wonderful star-gazing temple.
One of the most interesting instruments that has ever been used for astronomy was the mural quadrant that Tycho installed in one of the rooms in Uraniborg. It allowed the altitudes of heavenly bodies to be observed more accurately. You can see it below. Notice that the walls of the room are decorated with lavish pictures -- unusual for a scientific establishment.
Within a few years, the observatory was famous enough to attract young men who wanted to study under Tycho. So another observatory was built on the island for them to use. The instruments were placed in rooms underground [where wind wouldn't affect them], with only the roofs visible above the ground. It was called Stjerneborg [star castle] and had a poetic inscription over the entrance expressing how surprised Urania [the muse of astronomy] must be to find this cavern under the earth devoted to studying his stars. Tycho had always been fond of writing poetry, and never lost an opportunity to indulge himself.
The walls of this underground observatory had pictures of eight astronomers with suitable comments under them. One picture was of Tycho himself, with an inscription inviting those who came after to judge his work. And the last one was to an unknown astronomer who was given the name "Tychonides." The inscription under that one hoped that when he arrived, he would be worthy of his great predecessor. King Frederick also helped pay for this building.
Tycho worked hard on his astronomy records at Uraniborg for twenty years. He mostly kept track of the positions of the moon, planets, and stars. The meticulous efforts he took to record his measurements as accurately as his instruments would allow are admirable. Living on the tiny island was great for his leisure time, too -- he was surrounded by his family and friends, a pet moose, and there was even a jester named Jeppe who lived on the island among his circle [although Tycho was apparently a tough landlord on the island]. When he wanted a change from his usual observations, he would work with his students in his chemistry laboratory. We don't know what he was working on specifically, although we do know that he was producing some medicines. Since he was giving them away, there was quite a demand!
Tycho's overbearing and ambitious character sometimes brought him difficulties, and he got worse with age. He hadn't treated one of his tenants at Hven very well, and when that tenant took him to court, the judge sided with the tenant. That made Tycho even more annoyed and added more frustration to his already irritable disposition. There were also changes at court that affected him. King Frederick II died in 1588 and his son Christian IV became king when he came of age in 1596. Christian IV refused to support Uraniborg. [Tycho thought he was more interested in war than science.] The young king gradually decreased funding until finally even Tycho's salary was stopped. Tycho was humiliated and abandoned Hven in a rage. He was invited to Prague [Bohemia, now called Czechoslovakia] by Rudolph II, the Holy Roman Emperor, where he built a new observatory and worked with Johannes Kepler during the last year of his life. He died fairly suddenly of a kidney ailment in October, 1601 at the age of 54. Before he died, he greatly desired that someone would carry on his work and complete the star charts he had started and planned to dedicate to Rudolph II. He was buried in the magnificent "Church of Our Lady before Tyn" in Prague.
Uraniborg was torn down for building material shortly after Tycho died, but the scientists who had worked there carried on the work they had started there under Tycho, spreading his influence all over Europe.
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[Shakespeare's play Hamlet, about a Danish prince, was published the same year that Tycho, the Danish astronomer, died. Was there a link between the two? Read more on the blog "Ophelia Gets a Life."]
[Read more about Tycho at Famous Scientists.org and Virginia Tech.]
by Sir Robert S. Ball, 1895 (paraphrased by Leslie Noelani Laurio)
To view the table of contents for the rest of this book, click here.
Tycho Brahe, 1546-1601
Developed astronomical instruments and catalogued over 770 stars.
The most colorful character in the history of astronomy is the famous Dutch astronomer, Tycho Brahe [he is usually referred to simply as Tycho -- which is pronounced TEE-koh]. He was just as infamous for his lively personality and quirks as he was for his scientific genius. He makes an ideal subject for any biographer because of his adventurous career as a philosopher, his inclination for luxury as a Danish noble, his fiercely devoted friendships, and his furious quarrels. But it's his magnificent work in astronomy that has given him enduring fame.
His life has been published in the book "Tycho Brahe" by John Louis Emil Dreyer [1890; online at archive.org and Wiki]. Dr. Dreyer is a Danish astronomer himself, although he currently directs the observatory at Armagh [Ireland]. His book is the authority on the subject of Tycho Brahe. Tycho came from a distinguished family. His ancestors had flourished both in Sweden and in Denmark, and many of his descendants are still there to this day. Tycho's father, Otto Brahe, was an advisor in the Danish government, and was promoted as the governor of Helsingborg Castle near the end of his life. His son Tycho was born in December, 1546. He was the second of ten children, and the oldest son.
Otto had a brother named Jørgen who was childless but wanted a son on whom he could lavish his affection and wealth. So, when Otto got married, the two brothers agreed that the first son born to Otto and his wife would be handed over to Jørgen to adopt and raise. But when Tycho was born, his parents didn't want to part with him. Tycho's Uncle Jørgen wasn't happy about this, but he bided his time -- and a year later, during the birth of his baby brother, Jørgen kidnapped little Tycho! Because of the deal that had been agreed on, he felt he was within his rights. His parents gave in and allowed Jørgen and his wife to keep the child -- so Tycho was raised by his Uncle Jørgen.
Tycho was enrolled at the University of Copenhagen at the age of 13, which was typical for that time and culture. This was not a higher level University like we think of now -- Dr. Dreyer writes in his biography that in the opening speech to his new students, one professor pointed out that even multiplication and division could be mastered by any student with some diligence!
Tycho's uncle wanted him to be educated in rhetoric and philosophy to prepare him to be a statesman. But Tycho made it clear to his teachers that, though he was a good student, he preferred the heavenly bodies rather than the subtle metaphysics of philosophy.
On October 21, 1560, there was a solar eclipse predicted that would be partially seen in Copenhagen. Even though Tycho was still pretty young [he would have been 14], he was very interested in the eclipse. The part that awed and astonished him the most was that the exact time it would happen could be predicted so accurately. He was eager to understand this more thoroughly, so he tried to get a book that would explain more about it. Books back then weren't easy to get, especially books about science. But there was an edition of Ptolemy's "Almagest" that had recently been published in Latin, and he managed to get a copy of this book. Ptolemy's work was considered the authority on astronomy. Even though Tycho was young, he studied hard -- though perhaps not always successfully -- to understand Ptolemy. His copy of the book, with his own annotations in his schoolboy's handwriting, is a highly valued treasure at the University at Prague's library.
After Tycho had been at the University of Copenhagen for about three years, his uncle decided to send him to school in a foreign country to complete his education. This was pretty common in those days. His uncle hoped to lure Tycho's attention away from stars and into something more useful. Sensible men of the time considered natural science a waste of time that could be better spent on rhetoric or logic. His uncle hired a tutor to accompany Tycho and hopefully persuade him to take up something more practical than astronomy [such as law]. The tutor, Anders Vedel [who would become Denmark's first great historian!], was four years older than Tycho, intelligent and responsible. By 1562, the tutor and his student were living at the University of Leipzig [in Germany].
But the tutor soon discovered how hopeless his task would be -- Tycho didn't have the slightest interest in law or any other useful subject. All he cared about were the stars. Whenever he got any money, he would secretly spend it on astronomy books and instruments. He learned the names of stars from a little globe that he hid from Vedel and only used when Vedel was out. This caused some conflict between the two of them, but later on, they learned to respect and appreciate each other, and became life-long friends.
By age sixteen, Tycho had already begun to calculate the movements of planets by marking down their positions from time to time. He was surprised to find that his own observations differed from the calculations that other astronomers had assigned to them in their records. He realized that it would be necessary to record the movements of heavenly bodies over an extended period of time to see why there was such a difference. To us, this sounds like an obvious step. But in Tycho's day, that kind of thinking was totally new and unusual. Tycho began his observations right away as well as he could. His instrument was nothing more than a couple of ordinary mathematical compasses. He would hold the hinge up to his eye and then open the legs of the compass so that they pointed to two different stars to find their distance. Then he would bring the compass to a circle marked to show various angles. With this primitive method, he was able to record the angular distances between heavenly bodies.
When he had more money, he purchased a cross-staff and used it to observe stars every chance he got. Telescopes hadn't been invented yet, so astronomers had to rely on their own unaided eye with some kind of measuring device. The most ingenious of these devices was the cross-staff [a fore-runner to the sextant].
If the angle between two stars isn't too great, it can be measured like this: the bar labeled AB is marked off like a ruler, in inches and fractions of inches. Another bar labeled CD slides up and down bar AB so that the two bars are always perpendicular to each other. There's a sight [an eye piece, like the sight on a rifle] at point A and at point C, and there's a pin at point D. By sliding bar CD along bar AB, you can bring the sights into a position where one star can be seen along DC, and another star can be seen along DE. Once the position is set, the length from point A to the cross-bar is noted and compared to a published table to identify the actual angular distance. If two stars were too far apart to position the cross-staff, then you could move the pin at point D along bar CD to bring the angular distance of the stars into a better range.
The cross-staff is primitive and clumsy, but when it's handled with someone as skilled as Tycho, it can be surprisingly accurate. Try making one yourself and see what kind of measurements you can take with it.
Yet Tycho had to take all his measurements secretly to evade his tutor, whose job was to persuade Tycho to give up his frivolous hobby of star-gazing. Tycho would wait until Vedel was asleep, and then sneak out with his cross-staff to take angular measurements of heavenly bodies. In spite of his youth and his secrecy, Tycho conducted his observations on solid principles that are still the foundation of modern astronomy [in 1895]. He recognized that an instrument as primitive as his would have inevitable errors in its workmanship, so he calculated how far off his measurements might be on account of this, and allowed for that difference in his records. This same principle [of recognizing a difference and allowing for that much "give or take" in the final calculations], practiced by a teenager with a cross-staff in 1564, is still being used by the Astronomer Royal at Greenwich, even though today's astronomer has the most "state of the art" instruments that modern opticians have been able to create.
Tycho's uncle died when he was 19, so there was no one to interfere with his choice of interests. Tycho had always been the restless type, so he moved to the University of Rostock [in Germany]. He had a bit of notoriety related to a lunar eclipse in October, 1566. Tycho, like other astronomers of the era, associated astronomy with astrology. He assumed that events in the sky had some connection with what was going on with humans. He was also a bit of a poet. He posted up some verses in the college announcing that the lunar eclipse was an omen foretelling the death of the Sultan of Turkey, whose doings were in the news at the time. And the Sultan did die! So Tycho was triumphant and commended -- until it was noted that the Sultan had died before the eclipse, and Tycho's prediction became a joke at his expense.
Tycho had a bit of a volatile disposition. While he was at the University of Rostock, he had an argument with another Danish nobleman, supposedly over which of them was a better mathematician, and it turned violent. They fought a duel in the dead of night under the stars -- which is fitting for two astronomers. The result was that Tycho's nose was cut off! So Tycho, with his experience at making astronomy instruments, made a substitute out of gold and silver. It was said [and recorded in Oliver Lodge's 1893 book "Pioneers of Science," online at Project Gutenberg] that his metal nose looked as good as the original -- although it's not clear whether this was said by one of his friends, or one of his enemies.
Tycho spent the next few years going to different schools learning about various things related to science. One time, he helped an alderman in Augsburg [Germany] to set up a huge wooden quadrant with a 19-foot radius for star-gazing. Another time, the King of Denmark recognized his talents and promised to give him an easy job as a canon [a church dignitary] with plenty of free time to pursue his own interests. At another time, he was enthusiastically doing experiments with chemistry. That shouldn't be too surprising, since all of the sciences were closely connected in the 1500's. Alchemists [scientists who hoped to find a way to chemically alter different materials into gold] and astrologers both taught that the different planets correlated in some mysterious way with various metals. So it's natural that Tycho, with his interest in astronomy, would have wanted to learn about the properties of different metals.
But then something happened in 1572 that changed his life. On November 11, he was returning home from the chemistry laboratory and he happened to look up at the sky. He saw a bright star he had never seen before! It was in the constellation of Cassiopeia, in a place where he had never seen a star before. He was so startled that he wondered if he was hallucinating. He called the servants who were with him to look up and tell him whether they could see the brilliant star, too. Yes, they saw it. Tycho became convinced that he was seeing a brand new star! Nowadays, we know that new stars can appear sometimes, but this one was brighter than any new star that has ever appeared that we know of -- as bright as the planet Jupiter.
Not only had Tycho discovered a new star -- but you might say that the new star had discovered Tycho! It sparked a passion for science in him that motivated him to give up his other pursuits and focus on astronomy as a career.
As soon as he got home, Tycho used his quadrant to measure the new star's position and try to determine how far away it was. He guessed (correctly) that if it was closer to the earth than other stars around it, then he should be able to figure out how far away it was by calculating changes in its distance from surrounding points. He figured out that it was farther away than the moon because its position, compared to the other stars around it, didn't change when it was below the pole every twelve hours [like the moon's does]. He was able to observe it every twelve hours because it was bright enough to see in full daylight! He concluded that it was too far away to be measured by its ratio with the earth's diameter. He wasn't the only astronomer who noticed this new star -- but the others thought that it must be closer to earth than the moon. Tycho found out as much as was possible to find out about this star with the tools he had access to at the time. He proved that it was too far away to determine its distance using the only objects he had available to measure it against. He showed that it wasn't moving, but was in one position, like other stars. He kept weekly records of its changes in brightness and color.
It seems strange to us that such a diligent scientist would have connected his observational data with astrology, but Tycho thought that the star's changes were omens of future events. J. L. E. Dreyer's biography of Tycho Brahe writes that the star looked like Venus and Jupiter at first, predicting a time of pleasantness. But then the star began to look more like Mars, which meant that a time of war and misery would follow, with cities being destroyed, drought, fiery comets in the sky, disease, and venomous snakes. Finally, the star began to look like Saturn, which foretold a time of sadness, poverty, captivity, and death. It wasn't just Tycho making these kinds of connections. All kinds of educated men thought the new star was an omen of dreadful events. One of the main ideas of the day was that the Star of Bethlehem announced the first coming of Christ, and this new star was announcing His second coming -- and the end of the world.
Tycho's research into the omens of the new star were the subject of his first book. Publication was delayed, though, when his friends urged him not to write a book because book publishing would be beneath his dignity as a nobleman! But Tycho decided to rebel against the traditions of nobility -- and his first book, De Nova Stella, was published in 1573.
[Tycho's new star was a supernova explosion that brightened for a few weeks and then faded away a few months later -- its remnants are now called SN 1572.]
Now he was a famous scientist, so the King of Denmark asked him to give a series of astronomy lectures at the University of Copenhagen. Tycho agreed reluctantly. His opening lecture was written down [probably in Danish]. In this lecture, he passionately praises the beauty and fascination of celestial phenomena. He emphasizes how urgently it was necessary to continue to record systematic observations in order to extend our knowledge. He talks about the practical use of astronomy in marking the passage of time. He says that studying celestial bodies "exalts the mind from earthly and trivial things to heavenly ones." He concludes by saying that astronomy helps us to discover the fate of humans [in other words, astrology].
Something else happened to change Tycho's life in 1572. He fell in love. His friends again urged him not to act because the girl, Kirsten Barbara Jørgensdatter, was from a lower class, and an unsuitable match for a nobleman. But Tycho was never one to give in. Perhaps he felt that a humble wife wouldn't make demands on his time to attend fashionable parties and buy expensive clothes, so he'd be able to devote himself to his science. So he married her. They seem to have been happily married. They had 8 children. Apparently none of the children inherited their father's scientific genius.
Tycho had quite a few friends in Germany who admired his work. They were so much more encouraging to him than the people he knew in Denmark, that he decided to move permanently to Basle [also called Basel; it's right where Germany meets France and Switzerland]. King Frederick II of Denmark heard about his plans. Realizing what honour and fame it would bring to Denmark if Tycho stayed and did his great work within Denmark, he decided to induce him with a proposal. [Tycho's uncle had died of pneumonia in 1565 after rescuing King Frederick from drowning during a battle, so the king may also have had personal reasons for being Tycho's patron.] The king sent a messenger to travel day and night until he reached Tycho, and then bring Tycho to the castle. Tycho was in bed on February 11, 1576 when the messenger arrived. He read the message and left at once for Copenhagen. He told King Frederick that all he wanted was the means to study astronomy, so the king offered him Hven, a tiny island about 3 square miles between Denmark and Sweden where he could study in peace. The king promised to provide money to build him a house and the best observatory the world had ever known. Tycho consulted with his friends and thought it over before accepting the king's offer. The king granted him a salary and drew up a deed that formally allowed Tycho the use of the island for the rest of his life.
The foundation stone for the famous research facility of Uraniborg was laid in August, 1576. There was a grand, formal ceremony, imposing enough to suit Tycho's ideas of splendour. A group of his scientific friends was there, there was plenty of wine, and the date for this ceremony had been chosen to coincide with the time when the celestial bodies were in a favorable position. The foundation stone was placed with the appropriate solemnity. Many of the illustrations in this chapter show the character of this wonderful star-gazing temple.
One of the most interesting instruments that has ever been used for astronomy was the mural quadrant that Tycho installed in one of the rooms in Uraniborg. It allowed the altitudes of heavenly bodies to be observed more accurately. You can see it below. Notice that the walls of the room are decorated with lavish pictures -- unusual for a scientific establishment.
Within a few years, the observatory was famous enough to attract young men who wanted to study under Tycho. So another observatory was built on the island for them to use. The instruments were placed in rooms underground [where wind wouldn't affect them], with only the roofs visible above the ground. It was called Stjerneborg [star castle] and had a poetic inscription over the entrance expressing how surprised Urania [the muse of astronomy] must be to find this cavern under the earth devoted to studying his stars. Tycho had always been fond of writing poetry, and never lost an opportunity to indulge himself.
The walls of this underground observatory had pictures of eight astronomers with suitable comments under them. One picture was of Tycho himself, with an inscription inviting those who came after to judge his work. And the last one was to an unknown astronomer who was given the name "Tychonides." The inscription under that one hoped that when he arrived, he would be worthy of his great predecessor. King Frederick also helped pay for this building.
Tycho worked hard on his astronomy records at Uraniborg for twenty years. He mostly kept track of the positions of the moon, planets, and stars. The meticulous efforts he took to record his measurements as accurately as his instruments would allow are admirable. Living on the tiny island was great for his leisure time, too -- he was surrounded by his family and friends, a pet moose, and there was even a jester named Jeppe who lived on the island among his circle [although Tycho was apparently a tough landlord on the island]. When he wanted a change from his usual observations, he would work with his students in his chemistry laboratory. We don't know what he was working on specifically, although we do know that he was producing some medicines. Since he was giving them away, there was quite a demand!
Tycho's overbearing and ambitious character sometimes brought him difficulties, and he got worse with age. He hadn't treated one of his tenants at Hven very well, and when that tenant took him to court, the judge sided with the tenant. That made Tycho even more annoyed and added more frustration to his already irritable disposition. There were also changes at court that affected him. King Frederick II died in 1588 and his son Christian IV became king when he came of age in 1596. Christian IV refused to support Uraniborg. [Tycho thought he was more interested in war than science.] The young king gradually decreased funding until finally even Tycho's salary was stopped. Tycho was humiliated and abandoned Hven in a rage. He was invited to Prague [Bohemia, now called Czechoslovakia] by Rudolph II, the Holy Roman Emperor, where he built a new observatory and worked with Johannes Kepler during the last year of his life. He died fairly suddenly of a kidney ailment in October, 1601 at the age of 54. Before he died, he greatly desired that someone would carry on his work and complete the star charts he had started and planned to dedicate to Rudolph II. He was buried in the magnificent "Church of Our Lady before Tyn" in Prague.
Uraniborg was torn down for building material shortly after Tycho died, but the scientists who had worked there carried on the work they had started there under Tycho, spreading his influence all over Europe.
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[Shakespeare's play Hamlet, about a Danish prince, was published the same year that Tycho, the Danish astronomer, died. Was there a link between the two? Read more on the blog "Ophelia Gets a Life."]
[Read more about Tycho at Famous Scientists.org and Virginia Tech.]
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