A Cosmic Coincidence, Part 1: The Players

About 400 years ago a seemingly unlikely cosmic coincidence occurred, that brought about the chance collaboration between two giants in the field of astronomy. The legacy of that teamwork was far greater than either person could have left on his own. It was as if they were destined to complement each other, and yet their encounter was about as coincidental and unimaginable as two strangers wandering through city streets and bumping into each other.

The first of these partners to enter the astronomical stage was Tycho Brahe (TEE-ko BRA-hay). He was of Danish noble birth, in 1546. The younger man was Johannes Kepler, a poor commoner, born in present-day Germany, 25 years later. Tycho was bold, brash, and loved to drink and party. Kepler was reserved, painfully modest, and deeply religious. He likely had no idea of what a party was!

Without their common passion for the night sky, these two folks would never have even wanted to be within sight of each other. Politics might make strange bedmates, but astronomy made it far stranger in this case. We even refer to them differently: by Brahe’s first name and Johannes’ last.

Prior to Tycho and Kepler entering the scene, astronomy was an odd mixture of observation and mythological beliefs. This blend caused most astronomers to sport two hats; one as an astrologer. It was people’s belief that the observed motions of the heavenly bodies were omens for them (especially for powerful leaders), portending future events.

All those points of light in the night sky were just that to them: illumination, heavenly lights. Some were brighter, some dimmer; but all of them just bright spots way off in the black sky. The stars were seen to be fixed and unchanging (residing in the “firmament”). The planets were no more than weird stars that rambled about the sky in devilishly unpredictable ways (planet = wanderer in Greek).

In the wake of Kepler’s and Tycho’s discoveries, astronomy was transformed from mythology into a science—it became an elegant and understandable dance of stars and planets across the heavens. It morphed from the Greek and Egyptian stories of gods and angels mysteriously pulling and pushing points of light across the skies (all circling the Earth), to a simple picture of stellar bodies moving through space in simple, beautiful circles around the sun. Just a few years later Newton showed that it was all guided by the invisible hand of universal gravity—an insight he’d never have been able to come to, if Tycho and Kepler had not paved the way. Newton himself described his work as being possible only because he “stood on the shoulders of giants.”

This post and the following three give the briefest story of the partnership between the extroverted Dane and the introverted German—key players in Europe’s Renaissance in science. Next time we’ll look at Tycho, then Kepler, and in the fourth installment, I’ll speculate on the meaning (if any) of this cosmic coincidence.