Celestial Ships

Celestial Ships

Tycho Brahe, like Johannes Kepler, was far from hostile to astrology, although he carefully distinguished his own secret version of astrology from the more common variants of his time, which he thought conducive to superstition. In his book Astronomiae Instauratae Mechanica, published in 1598, he argued that astrology is “really more reliable than one would think” if charts of the position of the stars were properly improved. Brahe wrote: “I have been occupied in alchemy, as much as by the celestial studies, from my 23rd year.” But both of these pseudosciences, he felt, had secrets far too dangerous for the general populace (although entirely safe, he though, in the hand of those princes and kings from whom he sought support). Brahe continued the long and truly dangerous tradition of some scientists who believe that only they and the temporal and ecclesiastical powers can be trusted with arcane knowledge: “It serves no useful purpose and is unreasonable, to make such things generally known”.

Kepler, on the other hand, lectured on astronomy in schools, published extensively and often at his own expense, and wrote science fiction, which was certainly not intended primarily for his scientific peers. He may not have been a popular writer of science in the modern sense, but the transition in attitudes in the single generation that separated Tycho and Kepler is telling.

I prefer the hard truth to my dearest illusions. Image: As Stars Shine Bright by © Elena

But it was a Thirty Years’ War epoch. As soon as Kepler learned about his mother’s fate, in the midst of other grave personal problems, hi rushed to Würtemberg to find his seventy-four-year-old mother chained in a Protestant secular dungeon and threatened, like Galileo in a Catholic dungeon, with torture. He set about, as a scientist naturally would, to find natural explanations for the various events that had precipitated the accusations of witchcraft, including minor physical ailments that the burghers of Württemberg had attributed to her spells. The research was successful, a triumph, as was much of the rest of his life, of reason over superstition. His mother was exiled, with a sentence of death passed on her should she ever return to Wüttemberg; and Kepler’s spirited defense apparently led to a decree by the Duke forbidding further trials for witchcraft on such splender evidence.

The upheavals of the war deprived Kepler of much of his financial support, and the end of his life was spent fitfully, pleading for money and sponsors. He cast horoscopes for the Duke of Wallenstein, as he had done for Rudolf II, and spent his final years in a Silesian town controlled by Wallenstein and called Sagan.

Kepler’s epitaph, which he himself composed, was: “I measured the skies, now the shadows I measure. Sky-bound was the mind, Earth-bound the body rests”. The Thirty Years’ War obliterated his grave. If a marker were to be erected today, it might read, in homage to his scientific courage: “He preferred the hard truth to his dearest illusions”.

Johannes Kepler believed that there would one day be “celestial ships with sails adapted to the winds of heaven” navigation the sky, filled with explorers “who would not fear the vastness” of space. And today those explorers, human and robot, employ as unerring guides on their voyages through the vastness of space the three laws of planetary motion that Kepler uncovered during a lifetime of personal travail and ecstatic discovery.