Editing Johannes Kepler (section)

== Later life ==
=== Troubles ===
[[File:Karlova str No4, Prague Old Town.jpg|thumb|left|upright=0.8|Karlova street in Old Town, [[Prague]]&nbsp;– the house where Kepler lived, now a museum]]
In 1611, the growing political-religious tensions in Prague came to a head. Emperor Rudolf's health was failing, and he was forced to abdicate as [[List of rulers of Bohemia|King of Bohemia]] by his brother [[Matthias, Holy Roman Emperor|Matthias]]. Both sides sought Kepler's astrological advice, an opportunity he used to deliver conciliatory political advice (with little reference to the stars, except in general statements to discourage drastic action). However, it was clear that Kepler's future prospects in the court of Matthias were bleak.<ref>Caspar, ''Kepler'', pp.&nbsp;202–204</ref>

Also in that year, Kepler's wife Barbara contracted [[Hungarian spotted fever]] and began having [[seizure]]s. While she was recovering, all three of their children fell sick with smallpox; six-year-old Friedrich died. Following his son's death, Kepler sent letters to potential patrons in [[Württemberg]] and [[Padua]]. At the [[University of Tübingen]] in Württemberg, concerns over Kepler's perceived [[Calvinist]] heresies in violation of the [[Augsburg Confession]] and the [[Formula of Concord]] prevented his return. The [[University of Padua]]—on the recommendation of the departing Galileo—sought Kepler to fill the mathematics professorship, but Kepler, preferring to keep his family in German territory, instead travelled to Austria to arrange a position as teacher and district mathematician in [[Linz]]. However, Barbara relapsed into illness and died shortly after Kepler's return.<ref>Connor, ''Kepler's Witch'', pp.&nbsp;222–226; Caspar, ''Kepler'', pp.&nbsp;204–207</ref>

Postponing the move to Linz, Kepler remained in Prague until Rudolf's death in early 1612, though political upheaval, religious tension, and family tragedy (along with the legal dispute over his wife's estate) prevented him from doing any research. Instead, he pieced together a chronology manuscript, ''Eclogae Chronicae'', from correspondence and earlier work. Upon his succession as Holy Roman Emperor, Matthias re-affirmed Kepler's position (and salary) as imperial mathematician but allowed him to move to Linz.<ref>Caspar, ''Kepler'', pp.&nbsp;208–211</ref>

=== Linz (1612–1630) ===
[[File:Kepler Statue Linz.jpg|thumb|A statue of Kepler in [[Linz]]]]
In Linz, Kepler's primary responsibilities (beyond completing the ''Rudolphine Tables'') were teaching at the district school and providing astrological and astronomical services. In his first years there, he enjoyed financial security and religious freedom relative to his life in Prague—though he was excluded from [[Eucharist]] by his Lutheran church over his theological scruples. It was during his time in Linz that Kepler had to deal with the accusation and ultimate verdict of witchcraft against his mother [[Katharina Kepler|Katharina]] in the Protestant town of [[Leonberg]]. That blow, happening only a few years after his [[excommunication]], is not seen as a coincidence but as a symptom of the full-fledged assault waged by the Lutherans against Kepler.<ref>{{Cite book|url=https://books.google.com/books?id=GhamrvcsVyIC&q=mazer+waged+an+assault+against+kepler&pg=PT125|title=Shifting the Earth: The Mathematica Quest to Understand the Motion of the Universe|last=Mazer|first=Arthur|publisher=John Wiley & Sons, Inc.|year=2010|isbn=978-1-118-02427-0|location=Hoboken, NJ}}</ref>

His first publication in Linz was ''De vero Anno'' (1613), an expanded treatise on the year of Christ's birth. He also participated in deliberations on whether to introduce [[Pope Gregory XIII|Pope Gregory]]'s [[Gregorian calendar|reformed calendar]] to Protestant German lands. On 30&nbsp;October 1613, Kepler married Susanna Reuttinger. Following the death of his first wife Barbara, Kepler had considered 11 different matches over two years (a decision process formalized later as the [[Secretary problem|marriage problem]]).<ref name="ferguson">{{cite journal |last=Ferguson |first=Thomas S. |author-link= Thomas S. Ferguson |title=Who solved the secretary problem ? |journal=Statistical Science |volume=4 |issue=3 |date=1989 |pages=282–289 |quote=When the celebrated German astronomer, Johannes Kepler (1571–1630), lost his first wife to cholera in 1611, he set about finding a new wife using the same methodical thoroughness and careful consideration of the data that he used in finding the orbit of Mars to be an ellipse&nbsp;... The process consumed much of his attention and energy for nearly 2 years&nbsp;... |jstor=2245639 |doi=10.1214/ss/1177012493 |doi-access=free }}</ref> He eventually returned to Reuttinger (the fifth match) who, he wrote, "won me over with love, humble loyalty, economy of household, diligence, and the love she gave the stepchildren."<ref>Quotation from Connor, ''Kepler's Witch'', p. 252, translated from an 23 October 1613 letter from Kepler to an anonymous nobleman</ref> The first three children of this marriage (Margareta Regina, Katharina, and Sebald) died in childhood. Three more survived into adulthood: Cordula (born 1621); Fridmar (born 1623); and Hildebert (born 1625). According to Kepler's biographers, this was a much happier marriage than his first.<ref>Caspar, ''Kepler'', pp.&nbsp;220–223; Connor, ''Kepler's Witch'', pp.&nbsp;251–254.</ref>

[[File:Regensburg Peterskirchlein Gedenktafel Kepler.jpg|thumb|upright=0.85|Regensburg, church {{lang|de|Peterskirchlein}}, memorial plate for the tomb of Johannes Kepler]]
On 8 October 1630, Kepler set out for Regensburg, hoping to collect interest on work he had done previously. A few days after reaching Regensburg, he became sick and progressively worsened. Kepler died on 15&nbsp;November 1630, just over a month after his arrival. He was buried in a Protestant churchyard in Regensburg, which was completely destroyed during the [[Thirty Years' War]].<ref>Caspar, ''Kepler'', pp.&nbsp;358–360</ref>

=== Christianity ===
Kepler's belief that God created the cosmos in an orderly fashion caused him to attempt to determine and comprehend the laws that govern the natural world, most profoundly in astronomy.<ref>{{Cite web | url=https://www.britannica.com/biography/Johannes-Kepler | title=Johannes Kepler &#124; Biography, Discoveries, & Facts| date=31 August 2023}}</ref><ref>{{Cite web | url=https://www.britannica.com/science/astronomy/The-techniques-of-astronomy#ref1211452 | title=Astronomy – the techniques of astronomy| date=26 July 2024}}</ref> The phrase "I am merely thinking God's thoughts after Him" has been attributed to him, although this is probably a capsulized version of a writing from his hand:
<blockquote>Those laws [of nature] are within the grasp of the human mind; God wanted us to recognize them by creating us after his own image so that we could share in his own thoughts.<ref>Letter (9/10 Apr 1599) to the Bavarian chancellor Herwart von Hohenburg. Collected in Carola Baumgardt and Jamie Callan, ''Johannes Kepler Life and Letters'' (1953), 50</ref></blockquote>Kepler advocated for [[Religious tolerance|tolerance]] among Christian denominations, for example arguing that Catholics and Lutherans should be able to take communion together. He wrote, "Christ the Lord neither was nor is Lutheran, nor Calvinist, nor Papist."<ref>{{Cite journal |last=Rothman |first=Aviva |date=1 January 2020 |title=Johannes Kepler's pursuit of harmony |url=http://physicstoday.scitation.org/doi/10.1063/PT.3.4388 |journal=Physics Today |language=en |volume=73 |issue=1 |pages=36–42 |doi=10.1063/PT.3.4388 |bibcode=2020PhT....73a..36R |s2cid=214144110 |issn=0031-9228}}</ref>