Drunkard's Walk - Leonard Mlodinow [24]
GEROLAMO CARDANO was no rebel breaking forth from the intellectual milieu of sixteenth-century Europe. To Cardano a dog’s howl portended the death of a loved one, and a few ravens croaking on the roof meant a grave illness was on its way. He believed as much as anyone else in fate, in luck, and in seeing your future in the alignment of planets and stars. Still, had he played poker, he wouldn’t have been found drawing to an inside straight. For Cardano, gambling was second nature. His feeling for it was seated in his gut, not in his head, and so his understanding of the mathematical relationships among a game’s possible random outcomes transcended his belief that owing to fate, any such insight is futile. Cardano’s work also transcended the primitive state of mathematics in his day, for algebra and even arithmetic were yet in their stone age in the early sixteenth century, preceding even the invention of the equal sign.
History has much to say about Cardano, based on both his autobiography and the writings of some of his contemporaries. Some of the writings are contradictory, but one thing is certain: born in 1501, Gerolamo Cardano was not a child you’d have put your money on. His mother, Chiara, despised children, though—or perhaps because—she already had three boys. Short, stout, hot tempered, and promiscuous, she prepared a kind of sixteenth-century morning-after pill when she became pregnant with Gerolamo—a brew of wormwood, burned barleycorn, and tamarisk root. She drank it down in an attempt to abort the fetus. The brew sickened her, but the unborn Gerolamo was unfazed, perfectly content with whatever metabolites the concoction left in his mother’s bloodstream. Her other attempts met with similar failure.
Chiara and Gerolamo’s father, Fazio Cardano, were not married, but they often acted as if they were—they were known for their many loud quarrels. A month before Gerolamo’s birth, Chiara left their home in Milan to live with her sister in Pavia, twenty miles to the south. Gerolamo emerged after three days of painful labor. One look at the infant and Chiara must have thought she would be rid of him after all. He was frail, and worse, lay silent. Chiara’s midwife predicted he’d be dead within the hour. But if Chiara was thinking, good riddance, she was let down again, for the baby’s wet nurse soaked him in a bath of warm wine, and Gerolamo revived. The infant’s good health lasted only a few months, however. Then he, his nurse, and his three half brothers all came down with the plague. The Black Death, as the plague is sometimes called, is really three distinct diseases: bubonic, pneumonic, and septicemic plague. Cardano contracted bubonic, the most common, named for the buboes, the painful egg-size swellings of the lymph nodes that are one of the disease’s prominent symptoms. Life expectancy, once buboes appeared, was about a week.
The Black Death had first entered Europe through a harbor in Messina in northeastern Sicily in 1347, carried by a Genoese fleet returning from the Orient.9 The fleet was quickly quarantined, and the entire crew died aboard the ship—but the rats survived and scurried ashore, carrying both the bacteria and the fleas that would spread them. The