Most people know Tycho Brahe as the silver-nose-wearing, elk-owning astronomer that they'd love to drink with. He was also an implacable grudge-holder. His bitterest fight involved three famous astronomers of the 16th century, and their battle over the best theory about how Earth was at the center of the universe.

Tycho Brahe and Nicolaus Reimarus

In 1588, Tycho Brahe, the swaggering aristocrat with a silver nose and a reputation for debauchery, published a geoheliocentric version of the universe, with both the Earth and Sun at the center of the solar system. The "system of the world" was well-received, and an improvement on the existing geocentric model. It was not unique. Nicolaus Reimarus also published a book, titled "Fundamentals of Astronomy," that replaced the geocentric model.

The dual publication was bound to cause bad feelings. Tycho Brahe was a great drinking buddy, but he did not have an even temper when it came to academic debate. He'd lost part of his nose in a duel with his third cousin over a difference in their appraisal of mathematical formula. He was also a dyed-in-the-wool aristocrat who avoided marrying a woman because she was a commoner, despite the fact that they lived together for 30 years and had eight children.

Reimarus started his life lower, and arguably rose higher. As a child he was a pig herder. (Confusingly, this seemed to earn him the nickname of "Bear" or "Ursus.") His academic performance helped him rise quickly, and his book on the true shape of the universe earned him a position as the Imperial Astronomer to the Holy Roman Emperor, Rudolph II.


The Fight Was On!

Because of the time period and the subject matter, the feud lasted for the better part of a decade. Brahe first launched the attack in 1592. After studying Reimarus' work, he found striking similarities between Reimarus' theory and an early version of his own idea. Digging through his papers, he found the early draft and circulated it, in a letter, among the other imperial scientists. He also alleged that Reimarus must have first come up with the idea for the theory after a dinner he had attended at Brahe's home. After the dinner, Brahe and a fellow scientists talked over the theory and drew it up in chalk on a tablecloth. Brahe claimed that "long-nosed Ursus" must have snooped on them, and "sniffed" out the theory.


Five years later, Reimarus replied to the allegations in an astronomy journal. His response might be summed up as "bold words for a man without a nose." Not one to let the mention of the long nose go, he made fun of Brahe for his lack of a nose, and brought up his unconventional common law marriage. Then he did something he lived to regret – if only briefly. He mentioned that Johannes Kepler, another famous astronomer, had sided with him in this little dispute. He even included a letter from Kepler, full of extravagant praise, in which Kepler declared that good old Ursus had taught him everything he knew about brilliant mathematics. When one of the most famous astronomers and mathematicians of the age was on his side, how could he be wrong?

Enter Johannes Kepler


Johannes Kepler regretted that letter long before he realized Reimarus had published it. Kepler was a brilliant astronomer and mathematician. In modern times he's more famous that Brahe or Reimarus, and his works on planetary motion set the stage for Newton's laws of gravitation. Even in his own time he was revered, and so the person who actually did teach him had bragging rights. Those rights belonged to Michael Maestlin, Kepler's math teacher at his university. When Maestlin heard that Kepler was making the Reimarus claim, he was understandably peeved, and fired off a letter to Kepler. Kepler replied contritely, and claimed that, "Those who know me well will be surprised that I honored Ursus as my teacher instead of Maestlin."

Brahe also knew Kepler, of course, and angrily wrote to him about his apparent alliance with Reimarus. Kepler's letter, however complimentary, was never meant to back Reimarus' claim. Kepler had to miserably write to Brahe, and then to the general public, declaring that his letter was not an endorsement.

The whole thing ended in a book burning. Brahe won, in part, because he outlived Reimarus. Ursus died in 1600. Tycho Brahe struggled along for another year, during which he destroyed all the copies of Reimarus' insulting rebuttal.


[Via Scientific Feuds, Kepler's Defense of Tycho Against Ursus]