volumes and surfaces is 3:2. (He was so proud of this last feat that he asked friends to have a sphere within a cylinder inscribed on his tombstone. Cicero, quaestor of Sicily in 75 B.C ., located and restored the tomb; it has since vanished.)
Marcellus’ invasion came while the Syracusans were celebrating the feast of Diana, traditionally an excuse for heavy drinking. Marcellus had ordered that no free citizens be injured, but his men had seen many of their compatriots killed by Archimedes’ war machines, and they were not in a conciliatory mood. As the story is told, Archimedes was absorbed in calculations when a Roman soldier approached and addressed him in an imperative tone. Archimedes was seventy-five years old and no fighter, but he was also one of the freest men who ever lived, and unaccustomed to taking orders. Drawing geometrical diagrams in the sand, Archimedes waved the soldier aside, or told him to go away, or otherwise dismissed him, and the angry man cut him down. Marcellus damned the soldier as a murderer, writes Plutarch, adding that “nothing afflicted Marcellus so much as the death of Archimedes.” 7
Greek science was mortal, too. By the time of Archimedes’ death the world center of intellectual life already had shifted from Athens to Alexandria, the city Alexander the Great had established a century earlier with the charter—inspired, I suppose, by his boyhood tutor Aristotle—that it be a capital of learning modeled on the Greek ideal. Here Ptolemy I, the Macedonian general and biographer of Alexander, established with the wealth of empire a vast library and a museum where scientists and scholars could carry on their studies, their salaries paid by the state. It was in Alexandria that Euclid composed his
Elements
of geometry, that Ptolemy constructed his eccentric universe, and that Eratosthenes measured the circumference of the earth and the distance of the sun to within a few percent of the correct values. Archimedes himself had studied at Alexandria, and had often ordered books from the library there to be sent to Syracuse. But the tree of science grew poorly in Alexandrian soil, and within a century or two had hardened into the dead wood of pedantry. Scholars continued to study and annotate the great books of the past, and roomfuls of copiers laboriouslyduplicated them, and historians owe a great debt to the anonymous clerks of the library of Alexandria, but they were the pallbearers of science and not its torchbearers.
The Romans completed their conquest of the known world on the day in 30 B.C . that Cleopatra, last of the Ptolemies, bared her breast to the asp. Theirs was a nonscientific culture. Rome revered authority; science heeds no authority but that of nature. Rome excelled in the practice of law; science values novelty over precedent. Rome was practical, and respected technology, but science at the cutting edge is as impractical as painting and poetry, and is exemplified more by Archimedes’ theorems than by his catapults. Roman surveyors did not need to know the size of the sun in order to tell time by consulting a sundial; nor did the pilots of Roman galleys concern themselves overmuch with the distance of the moon, so long as it lit their way across the benighted Mediterranean. Ceramic stars ornamented the ceilings of the elegant dining rooms of Rome; to ask what the real stars were made of would have been as indelicate as asking one’s host how the roast pig on the table had been slaughtered. When a student Euclid was tutoring wondered aloud what might be the use of geometry, Euclid told his slave, “Give him a coin, since he must gain from what he learns.” 8 This story was not popular in Rome.
Roman rule engendered among those it oppressed a growing scorn for material wealth, a heightened regard for ethical values, and a willingness to imagine that their earthly sufferings were but a preparation for a better life to come. The conflict between this essentially spiritual,