Astronomy Tycho Brahe is noted as one of the most important astronomers of the late 16th century. Among other things he observed that the heavens were not constant, but instead consisted of complex systems not bound to celestial spheres has had been asserted by Ptolemy and others.
Upon his death in 1601 his work passed on to his pupil Johannes Kepler. At the time his death, while tragic, didn't raise any suspicions. Recently, however, questions have been raised about the circumstances of his death with some asserting foul play. Was he in fact murdered?
The Historical Account of His Death
According to his apprentice Johannes Kepler, Brahe died of a bladder ailment, probably either a ruptured bladder or bladder infection.
The story recorded by Kepler was that Brahe was at a banquet of the King and refused to excuse himself to use the restroom. This was customary etiquette; one would not leave the banquet room while the nobleman host was still seated at the table.
After returning home he was no longer able to urinate, expect with significant pain and only in small quantities. Passing 11 days after the banquet, a physician of the time recorded the cause of death as kidney stones. However, after exhuming the body in the early 1900's no evidence was found in support of that diagnosis.
Instead it was thought that the more likely explanation was either a severe bladder infection or, more likely, kidney failure.
Evidence of Mercury Poisoning
More recently, samples taken of the expired astronomers mustache have revealed high levels of mercury, suggesting mercury poisoning. However, these results have been refuted.
Then in late 2010 the body was again exhumed for examination by Czech and Danish researchers seeking to definitively identify the cause of death.
Could He Have Been Murdered?
The new results are still pending on whether Brahe suffered a death from mercury poisoning, but let's suppose that he did. Could he have accidently overdosed on the poisonous element, or is it more likely that he was intentionally assaulted?
Brahe was, in addition to being an accomplished astronomy, also an alchemist. Owning to this, he likely would have been familiar with mercury and its toxic effects. So he probably did not ingest the substance accidently.
If the banquet tale is true though, then he also probably experienced a delirium the nights before he died (as was reported by Kepler). In this delirium he may have taken the mercury, whether as an attempt at suicide or simply because he was absent of mind.
But there is another explanation. Historians have put forth the idea that Brahe and Kepler here more than teacher and pupil, but also scientific rivals, favoring different interpretations of the orbital mechanics data. Keen to make a name for himself, Kepler certainly had the motivation to eliminate his mentor.
Doing so would have meant the rights to Brahe's data would have passed to Kepler, as it did, allowing for Kepler to publish his own analysis and ideas. Kepler's laws of planetary motion are a key element to any introductory astronomy course. But had Brahe not passed when he did, would we instead learn of Brahe's laws?
Unfortunately, proving ill intent will be difficult, even if mercury poisoning is determined to be the ultimate cause of death. But it couldn't be ruled out as a possibility either.