October 02, 2017, BY Matt Hughes

poster art for Fibonacci at Bucknell

Fibonacci's Liber Abaci, or Book of Calculation, is one of the most influential mathematical treatises in human history, and a work that still reverberates more than eight centuries after its composition. But for all its influence, a full understanding of this monumental achievement wasn't accessible to English speakers until it was made available through the extraordinary work of a Bucknell professor and his wife.

The first-ever English translation of Liber Abaci, a work that introduced the Hindu­-Arabic number system to the West and included the famous Fibonacci Numbers, was completed by Professor Laurence Sigler in 1995 and published posthumously in 2002, exactly 800 years after the its original publication. Sigler's translation remains the only version of Fibonacci's text in any modern language. Bucknell's Department of Mathematics will celebrate the connection between the Italian mathematician and the University with "Fibonacci at Bucknell," a one-day conference scheduled for Oct. 14 from 10 a.m. until 2:30 p.m. in the Elaine Langone Center. || Click here for a campus map.

Speakers will include:

  • Keith Devlin, "The Math Guy" of NPR's Weekend Edition, Stanford University mathematician and author of Finding Fibonacci: The Quest to Rediscover the Forgotten Mathematical Genius Who Changed the World, which devotes a chapter to Sigler's translation
  • Mario Livio, an astrophysicist, speaker and author of popular science books, including The Golden Ratio: The Story of Phi, the World's Most Astonishing Number
  • William Goetzmann, director of the International Center for Finance at the Yale School of Management and author who has written about the importance of Fibonacci in the history of finance

Also attending and participating in a panel discussion will be Sigler's widow, Judith Sigler Fell, whose work saved Sigler's translation from being lost forever.

"Liber Abaci is one of the most influential books of mathematics ever," said Professor Tom Cassidy, chair of Bucknell's Department of Mathematics. "Its impact on western civilization has only been fully understood in the wake of Professor Sigler's translation. It is wonderful that Bucknell plays a crucial role in the modern understanding of Fibonacci's contributions."

Professor Lawrence Sigler, mathematics, during the 1980s

According to Devlin's book on Fibonacci, Laurence Sigler became interested in the Italian mathematician in the early 1980s, while working on a college-level mathematics textbook in which he wanted to introduce Fibonacci sequences. In the process, he discovered that no English translation existed of any of Fibonacci's books, and was so frustrated by this fact that he put his textbook aside and set out to create the first English translation of all three of Fibonacci's surviving major works — and to teach himself Latin in order to do so.

Sigler succeeded in translating and publishing the first, Liber Quadratorum, in 1987, but his work on Liber Abaci was interrupted in 1992, when he was diagnosed with terminal leukemia. After retiring from Bucknell to focus on the book, Sigler completed his translation in 1995, and shipped it on floppy disks to his editor at Harcourt Brace, eager to see it published in his lifetime.

An enormous challenge
Unfortunately, the editor was in the process of starting his own publishing house around the same time and wanted to take the book with him, which left the text in limbo when Sigler died in 1997. It stayed with the editor until 2000, when Sigler's colleagues convinced Judith to find a new publisher for her husband's work.

The editor returned the disks and with the help of Bucknell faculty members Judith found a new publisher, but technology had since made floppy disks obsolete. Though she was able to recover most of the lost data from the disks, all of the text formatting, mathematical layout instructions, graphics and about 80 pages of the manuscript were lost. In addition to reconstructing the lost formatting and the missing sections from her husband's handwritten manuscript, for the book to see publication Judith would have to reformat the entire document using the mathematical typesetting language TeX — an effort Devlin calls "an enormous challenge."

"In effect, she would have to become yet another translator of Liber abbaci," Devlin writes, "this time translating her late husband's English translation of Boncompagni's nineteenth-century printed version of a thirteenth-century handwritten copy of [Fibonacci's] original handwritten Latin manuscript into the computer language TeX."

It took Judith around six months to reconstruct the manuscript, which would be published in 2002. She received significant aid in her efforts from other members of the Bucknell mathematics department, including Greg Adams, Paul McGuire, George Exner and Karl Voss.

"The world finally had a version of Liber abacci, one of the most influential books ever written, in an international modern language," Devlin writes. "But it had taken an amazing sequence of events, and the efforts of a number of people, to produce it."

Attendance of Bucknell's commemoration of the Siglers' work and the University's connection to Fibonacci is free and open to the public. Lunch will be provided. Attendees are asked to RSVP by contacting the math department at 570-577-1343 or math@bucknell.edu.