The online science magazine Nautilus is now also an offline science magazine. Its first issue has just come off the press. To mark the occasion, the editors asked me to write a brief essay about the resilience of paper as a reading medium.
Gutenberg we know. But what of the eunuch Cai Lun?
A well-educated, studious young man, a close aide to the Emperor Hedi in the Chinese imperial court of the Eastern Han Dynasty, Cai invented paper one fateful day in the year 105 A.D. At the time, writing and drawing were done primarily on silk, which was elegant but expensive, or on bamboo, which was sturdy but cumbersome. Seeking a more practical alternative, Cai came up with the idea of mashing bits of tree bark and hemp fiber together in a little water, pounding the resulting paste flat with a stone mortar, and then letting it dry into sheets in the sun. The experiment was a success. Allowing for a few industrial tweaks, Cai’s method is still pretty much the way paper gets made today.
Cai killed himself some years later, having become entangled in a palace scandal from which he saw no exit. But his invention took on a life of its own. …