September 1999

Rewriting the Bible in 0's and 1's

Continued from page 2

By Steve Ditlea

Bad Breaks

In Knuth's Stanford talk, perfectability was again a theme. He followed the pages in his volume on Digital Typography beyond its introductory chapters to the longest section in the book, which attacks a crucial problem in typography. He calls his listeners' attention to "one of the main technical tricks in the TeX system: the question of how to break up paragraphs so that the lines are approximately equal and good."

Poor spacing between words and ugly choices for line breaks had been among the major computer typography gaffes that launched Knuth on his TeX crusade. Odd word chasms, ladders of hyphens, and orphaned bits of text resulted from the rigid algorithms used to program line breaks without regard for visual elegance. Knuth's solution: have the computer use trial-and-error methods to test how each paragraph of text can best be broken up. Instead of "greedy" algorithms packing in the most words on a line-standard in computer typography before and after TeX-Knuth's computation-intensive method evaluates beauty.

Knuth seems born to the task of promoting beauty on the printed page-via computational methods. "I had a love of books from the beginning," he tells his audience. "In my mother's collection, we found the first alphabet book I had. I had taken the letters and counted all the serifs." He is proud of his early literacy, telling a writer that he was the youngest member of the Book Worm Club at the Milwaukee Public Library. His interest in typographic reproduction also came early in life. One of his earliest memories of pre-desktop publishing was helping his father, Ervin, with the mimeograph stencils for printing the church newsletter in the basement. Like his father's newsletter, TeX was meant to be a homebrew project, on a manageable scale. "The original intent was that it would be for me and my secretary," he tells TR in an interview in his home's second-floor study. Leaning back in the black lounge chair, Knuth acknowledges that the long journey into TeX was intended to be a quick side trip: "I was going to finish it in a year."

Events took a different turn. In 1978, Sun's Steele-then an MIT grad student visiting Stanford-translated TeX for use on MIT's mainframe computer. Suddenly, Knuth recalls, "I had 10 users, then 100. Each time it went through different levels of error. In between the 1,000th and 10,000th user, I tore up the code and started over." Knuth says he realized then that TeX wasn't just a digression, it was itself part of the vision. "I saw that this fulfilled a need in the world and so I better do it right."

A key turning point in the spread of TeX was a lecture Knuth gave before the American Mathematical Society (AMS). Barbara Beeton, a staff specialist in composition systems for AMS and a longtime official of the Portland, Ore.-based TeX User's Group, remembers the occasion: "He was invited to deliver the Josiah Willard Gibbs Lecture. Albert Einstein and John von Neumann had been among the previous speakers. Knuth talked about his new typesetting system for the first time in public." Knuth was preaching to the choir; the assembled mathematicians were familiar with how printing quality had declined. Adds Beeton: "TeX was the first composition system meant to be used by the author of an article or book" as opposed to a publishing house. Soon after, AMS became the original institutional user of TeX, employing Knuth's system to publish all of its documents and journals.