Saturday, January 22, 2011

"Everything You Think You Know About the Dark Ages is Wrong" the title of an article featuring an interview with Nancy Marie Brown, who wrote The Abacus and the Cross: The Story of the Pope Who Brought the Light of Science to the Dark Ages

The Pope in question is Gerbert of Aurillac, known to history as Pope Sylvester II.


Nothing in my many years of reading about the Middle Ages had led me to suspect that the pope in the year 1000 was the leading mathematician and astronomer of his day.

Nor was his science just a sidelight. According to a chronicler who knew him, he rose from humble beginnings to the highest office in the Christian Church “on account of his scientific knowledge.”

To my mind, scientific knowledge and medieval Christianity had nothing in common. I was wrong.

I felt as if I had stumbled into a parallel universe, an alternate history of the Middle Ages that had been perfectly crafted for me: For most of my career, I have worked as a science writer, but my heart had first been captured by medieval sagas. The story of The Scientist Pope—one scholar called him “the Bill Gates of the end of the first millennium”—was a story I needed to tell.


A professor at a cathedral school for most of his career, Gerbert of Aurillac was the first Christian known to teach math using the nine Arabic numerals and zero. He devised an abacus, or counting board, that mimics the algorithms we use today for adding, subtracting, multiplying, and dividing. It has been called the first counting device in Europe to function digitally—even the first computer. In a chronology of computer history, Gerbert’s abacus is one of only four innovations mentioned between 3000 BC and the invention of the slide rule in 1622.

Like a modern scientist, Gerbert questioned authority. He experimented. To learn which of two rules best calculated the area of an equilateral triangle, he cut out square inches of parchment and measured the triangle with them. To learn why organ pipes do not behave acoustically like strings, he built models and devised an equation. (A modern physicist who checked his result calls it ingenious, if labor-intensive.)

Gerbert made sighting tubes to observe the stars and constructed globes on which their positions were recorded relative to lines of celestial longitude and latitude. He (or more likely his best student) wrote a book on the astrolabe, an instrument for telling time and making measurements by the sun or stars. You could even use it to calculate the circumference of the earth, which Gerbert and his peers knew very well was not flat like a disc but round as an apple.

You can always spot a cathophobe by his insistence that the Church was the enemy of science.