Michael Maestlin

Michael Maestlin (also Mästlin, Möstlin, or Moestlin) (30 September 1550 – 26 October 1631)[1] was a German astronomer and mathematician, known for being the mentor of Johannes Kepler. He was a student of Philipp Apian and was known as the teacher who most influenced Kepler. Maestlin was considered to be one of the most significant astronomers between the time of Copernicus and Kepler.

Early life and family

Maestlin was born on September 30, 1550 in Göppingen, a small town in Southern Germany, about 50 kilometers east of Tübingen. The son of Jakob Maestlin and Dorothea Simon, Michael Maestlin was born into a Protestant family.[3] Maestlin had an older sister named Elisabeth and a younger brother named Matthäus. The original family name of the Maestlin was Leckher or Legecker and they lived in the village of Boll, just a few kilometers south of Göppingen (Decker 103).[4] In his autobiography, Maestlin recounts how the family name of Legecker became Mästlin.[4] He claims that one of his ancestors was given this as a nickname when an old blind woman touched him and exclaimed “Wie bist du doch so mast und feist! Du bist ein rechter Mästlin!” This roughly translates to “How are you so large and plump? You rightly are a fatso!

Maestlin married Margarete Grüniger on 9 April 1577.[3] There is little information on his children from this marriage. However, it is known that he had at least three sons, Ludwig, Michael and Johann Georg, and at least three daughters, Margareta, Dorothea Ursula and Anna Maria. In 1588, Margarete died at the age of 37, potentially due to complications from child birth.[3] This untimely death left several children under Maestlin's care and could have influenced his decision to remarry the following year. In 1589, Maestlin married Margarete Burkhardt. Maestlin and Burkhardt had eight children together. In a 1589 letter to Johannes Kepler, Maestlin recounts how the death of his month-old son, August, deeply troubled him.

Education

In 1565, when Michael was around 15 years old, he was sent to the nearby Klosterschule in Königbronn.[3] In 1567, Michael transferred to a similar school in Herrenalb.[5] Upon finishing his education at Herrenalb, Maestlin enrolled in university, matriculating on 3 December 1568 at the University of Tübingen.[6][3] When Maestlin entered the university in 1569 he did so as one of the beneficiaries of a scholarship from the duke of Württemberg.[7] He studied theology at the Tübinger Stift, which was founded in 1536 by Duke Ulrich von Württemberg, and was regarded as an elite institution of education.[8] He obtained his Baccalaureate in 1569 and his master's degree in 1571.[3] After receiving his masters degree Maestlin remained at the university as a student in theology and as a tutor in the theological seminary church located in Württemberg. In letters sent to Maestlin regarding his qualifications, it was revealed that he graduated summa cum laude and ranked third in his graduating class of twenty.[3] During the time he spent on earning his master's degree, Maestlin studied under Philipp Apian.[9] It is not certain, but it is believed that Apian taught courses on Frisius's Arithmetic, Euclid's Elements, Proclus's Sphera, Peurbach's Theoricae Novae Planetarus, and the proper use of geodetic instruments.[3] Apian's teachings evidently influenced Maestlin's paper on sundials as the contents of this essay involve elements of structured celestial globes and maps.

Career

Maestlin studied theology, mathematics, and astronomy/astrology at the University of Tübingen—the Tübinger Stift. (Tübingen was part of the Duchy of Württemberg.) He graduated as magister in 1571 and became in 1576 a Lutheran deacon in Backnang, continuing his studies there.[citation needed]

In 1580 he became a professor of mathematics, first at the University of Heidelberg, then at the University of Tübingen, where he taught for 47 years from 1583. In 1582 Maestlin wrote a popular introduction to astronomy.[citation needed] While teaching at the university Maetslin tho a Copernican taught traditional Ptolemaic astronomy in his courses. However, Maestlin did present Copernican's heliocentric astronomy to his advanced students.

Among his students was Johannes Kepler (1571–1630) who considered Maestlin not only a teacher, but also a lifelong mentor. Although he primarily taught the traditional geocentric Ptolemaic view of the solar system, Maestlin was also one of the first to accept and teach the heliocentric Copernican view. Maestlin corresponded with Kepler frequently and played a sizable part in his adoption of the Copernican system. Galileo Galilei's adoption of heliocentrism was also attributed to Maestlin.

The first known calculation of the (inverse) golden ratio as a decimal of "about 0.6180340" was written in 1597 by Maestlin on a letter he got from to Kepler about Kepler triangle

Michael Maestlin was one of the very few astronomers of the sixteenth century that fully adopted the Copernican hypothesis, that proposed that the Earth was a planet and that it moved around the sun. 1570 he acquired an edition of his main work De revolutionibus orbium coelestium (his edition with many commentaries is in Schaffhausen). Maestlin reacted to the thought of distant stars spinning around a fixed earth every 24 hours and taught everything that he could about Copernicus to Kepler.

In November 1572 Maeslin and many others around the world witnessed a strange light in the sky that we now know was a galactic supernova. Maeslin attempted to explain this phenomenon in his tract entitled Demonstratio astronomica loci stellae novae, tum respectu centri mundi, tum respectu signiferi & aequinoctialis. This tract of Maeslin's was a short mathematical and astronomical appendix detailing the nova and was published in Tübingen in March or April of 1573. This nova was called the Nova of Cassiopeia and was the first galactic supernova to be observed in Europe. Maeslin's treatise attracted the attention of Tycho Brahe, who reproduced it in its entirety, along with his criticism, in one of the best known publications on the nova, in his posthumously printed Astronomiae instauratae progymnasmata. Maestlin's treatise is available in manuscript format in Stuttgart and in Marburg.

The programme of Maestlin's treatise of 1573 over the supernova was practically identical to that of Tycho Brahe's longer treatise De stella nova, which published in the same year two or three months later. Tycho's Progymnasmata, was also nearly identical to Maeslin's treaties, which was finished latter in 1592 but published only in 1602, a year after Tycho Brahe's death

Maestlin in following the copernicium solar system believed that the ‘movement of commutation’ (or ‘parallactic motion’) of the superior planets, those being planets with a farther distance from the sun compared to the earth, and the lack of parallactic motion in the nova meant that the nova had to occur outside the planetary rings and in the ring of fixed stars. This nova occurring in the ring of fixed stars contradicted the previous understandings of Ptolemaic and Aristotelian. Maestlin also concluded that the nova helped to prove the heliocentric solar system as he said unless people concede that comets can be placed in the stellar orb, whose altitude is immense and whose extension we do not know, to which also the distance between the Sun and the Earth is incomparable, as witnessed by Copernicus

In 1580, Maestlin observed another comet and began to gather up some ideas on how it formed. Nine years later in 1589, Maestlin shared his conclusions about the appearance of the comet with his friend the astrologer, Helisaeus Roeslin, who said that the moon was located in front of the Great Comet of 1577, Also this same year, Maestlin published a dissertation on the fundamental principles of astronomy and the first edition of his book Epitome Astronomiae (Epitome of Astronomy).[3] Epitome Astonomiae consisted of six editions and used works like Ptolemy's famous geocentric model to create his descriptions of astronomy.

The preface in the 1596 republication of Rheticus' Narratio Prima was also written by Maestlin. This preface was an introduction to the work of Copernicus. Additionally, Maestlin made many contributions to tables and diagrams in Kepler's Mysterium Cosmographicum. Kepler's publication of Mysterium Cosmographicum was supervised by Maestlin, in which he added his own appendix to the publication over Copernican planetary theory with help from Erasmus Reinhold's Prutenic Tables.[20] The information Maestlin used for his appendix from the Prutenic Tables, by Erasmus Reinhold, was used to help readers that were not well educated in astronomy to be able to read Johannes Kepler's Mysterium Cosmographicum as not much information over the basics was included. A discussion of the great sphere and the lunar sphere, as well as more discussion and conclusions to his descriptions of the Copernican planetary theory was also added by Maestlin in Kepler's book.[20] Maestlin's appendix was written more than once, and in the final version he wrote the appendix in correspondence to “the needs of a hypothetical educated reader.” However, Maestlin also answered the questions Kepler had while writing the Mysterium Cosmographicum in his appendix.

Maestlin and Kepler communicated through a series of letters about Kepler's book the Mysterium Cosmographim in which Maestlin added his appendix “On the Dimensions of the Heavenly Circles and Spheres, according to the Prutenic tables after the theory of Nicolaus Copernicus” This appendix contained a set of planetary distances in addition to a method of deriving them from the Prutenic tables. Maestlin also added his own understanding of Nicolaus Copernicus’ geometry to Kepler's book. When. Maestlin and Kepler were communicating through letters regarding Kepler's book the discussed such topics such as the inaccuracy of the values that Copernicus used when calculating the spheres of the cosmos With the help of Maeslin in 1595, Kepler believed that he had discovered the relationship between the planets period and the distance from the sun. He did so by first assuming equal velocity of each planet and then observing that the planets did not just revolve just according to the length of their radii. Kepler observed that the sun exerted a force that was progressively attenuated as planets are farther and farther away from the sun itself. Maeslin even provided the geometry to help visualize Kepler's theory of the sun force and its effects of the other planets