Brahe and Kepler: the original science bros

Through my research on Dee and Kelley, I’ve enjoyed discovering other colorful figures from Rudolf II’s court. Tycho Brahe and Johannes Kepler interested me the most, as much for their “odd couple” dynamic as for their accomplishments.

Statue of Brahe and Kepler
Statue of Brahe and Kepler outside Strahov Monastery, author’s own

Brahe, a Danish nobleman, pursued astronomy despite the ridicule of most of his family. Of a somewhat extravagant personality, he famously lost his nose in a duel (over a mathematical formula) and replaced it with a metal one. His entertainments for his noble patrons included his pet drunk elk and a court jester that lived under his dining room table.

When not partying like a rockstar he made a log of precise celestial measurements, all without the aid of a telescope(!). Of several personal facilities his largest was Uraniborg, his observatory/alchemical lab/research institute, which he ruled like a king until the actual Danish king stopped funding him.

contemporary engraving of Uraniborg
Contemporary engraving of Uraniborg, courtesy Armagh Observatory

If Brahe was larger than life, Kepler was…not. Noble but impoverished, he almost became a minister before taking a post teaching mathematics in what is now Austria. Though interested in astronomy from an early age, poor eyesight prevented him making celestial observations of his own.

Plate from Kepler's De Stella Nova
Plate of a planetary conjunction from Kepler’s De Stella Nova, courtesy Bill Blair’s site

So, a flamboyant genius with a personal scientific playground and a mild mannered, nearsighted professor…sounds familiar…

Robert Downey Jr. and Mark Ruffalo as Tony Stark and Bruce Banner
Kepler may not have turned into a green rage monster, but Brahe would have loved the Iron Man suit. Courtesy Collider

But I digress. How did the Renaissance science bros come to work together?

Partly through correspondence – they exchanged letters for years on astronomical questions. They finally met in Prague. Brahe arrived in 1599 at Rudolf II’s invitation, to become his imperial astronomer. A year later Brahe invited Kepler to work as his assistant. After several months of Kepler’s uncertain employment and an argument over access to Brahe’s logs, they formalized a commission to work together.

Not a month later Brahe died. Kepler inherited both his post as imperial astronomer and Brahe’s logs – the latter not without a fight. Brahe’s family wanted to lock them up, but after acrimonious negotations Kepler finally gained access to the data. He used it to create the Rudolphine Tables, the most accurate star and planetary tables of their time. The precision of the measurements also allowed him to prove that planets travel in an ellipse and improve upon Copernicus’ heliocentric model of the solar system.

(My understanding of physics and complex astronomy is limited and beyond the scope of this blog post. Corrections are welcome in the comments section!)

Circling back to my book: Neither Brahe nor Kepler appear in it as they were active in Prague long after my 1580s timeframe. It’s also unlikely Dee or Kelley met either of them, though Brahe corresponded with Dee about the 1572 supernova and a 1577 comet. But, they are another example of the great minds attracted by Prague’s scientific golden age.