Yibao Xu of Plainsboro, one of the newest members of the West Windsor-Plainsboro Board of Education, had an unusual work experience this summer, contributing to a research project that explored the worlds of archaeology and mathematics. What made the project even more unusual was its location: Beijing, China, where a unique turn of events led to Xu’s opportunity.
A few of years ago there was a theft in China where bamboo strips were stolen and smuggled into Hong Kong. An antiques dealer there sold the strips to the highest bidder, and the person who bought them was an alumnus of Tsinghua University. In July of 2008, the alumnus donated the bamboo strips along with some wooden tablets, to the university. Xu says Tsinghua University inherited a major find.
“These bamboo strips are very important. First, their dating has been traced to 2,200 years ago, during the first dynasty of China (Qin Dynasty, 221 B.C. to 207 B.C.). A substantial part of these bamboo strips is about Chinese classicals and history, but a tiny part of this is about mathematics. Twenty of the strips put together form a perfect and complete multiplication table,” Xu said.
According to Chinese magazine Beijing Review, archaeologists say the bamboo strips (now known as the Tsinghua Bamboo Slips, TBS, or Shuihudi bamboo strips) were unearthed from a tomb of the Qin Dynasty at Shuihudi in Yunmeng County, China. The strips’ value is significant to studying the history of mathematics in Pre-Qin Dynasty China.
In 2010 Xu was invited by one of his colleagues to work on a research paper titled the “Chinese Multiplication Table.” He says the collection of bamboo strips were to be one focus of the paper, along with other archaeological findings.
“This is a very exciting period for doing research on Chinese mathematics. Another set of bamboo strips has been preserved at Yuelu Academy, the secondary college of Hunan University. Also, more than 250 strips will go through mathematical tests, and part of which deals with the operation of refractions and multiplication tables. Yet another collection is now at Beijing University, and they also have some counting rods — a tool used to do calculations – plus certain strips devoted to multiplication tables, including one complete wooden tablet for multiplication tables,” Xu said.
His goal is to incorporate all the historical items, “the newly discovered primary sources,” with transmitted written documents to form a synthetic research paper on Chinese multiplication tables.
Xu is still working on a final version of his research paper, but the information should be published soon. He says Tsinghua University intends to send a research paper about the collection of bamboo strips and wooden tablets to international science journals. “As soon as that general paper is published, I am ready to send out my paper to top journals such as Historia Mathematica or Archive for History of Exact Sciences,” he said.
Xu has traveled to Beijing many times. His first visit to China’s capital city was in 1988 as a graduate student. He went to see the bamboo strips in August of 2010 and was immediately intrigued. But with a college teaching career and his older son Jonathan (a 2011 graduate of High School South) about to enter his senior year of high school, Xu’s interest in taking part in research at Tsinghua was delayed.
Xu teaches college mathematics at the Borough of Manhattan Community College, so he could not find time to go to Beijing for more than a month, let alone the entire semester or school year. “They offered me but I could not get the release time from BMCC, so the best time for me to go was during the summer,” he said. While U.S. colleges’ winter break periods are short, one main advantage of summer break is its overlap with the Chinese university calendar.
“Our summer ends in May, but at Tsinghua University the summer break starts at the end of June. As soon as my spring courses here ended I flew to Beijing, and as a visiting scholar I was offered six weeks of residency,” Xu explained.
Tsinghua University often places either first or second in the rankings of mainland China’s best universities. In 2010, Tsinghua was listed as the top college in China for computer science and technology. With his colleagues at the university, Xu says he had discussions about the differences between China’s multiplication tables the mathematical models of other ancient civilizations such as Mesopotamia, the Babylonians and the Egyptians. The professors also spent time comparing various historical multiplication tables.
On Thursday, August 16, Xu wrapped up teaching summer courses at BMCC in basic algebra and introduction to statistics. He is happy to be back, as he says the six weeks he spent in China this summer were a marathon. On top of the extensive research, Xu traveled to several Chinese colleges for speaking engagements.
“I was invited to give talks at Tsinghua University, the University of the Chinese Academy of Science, the Institute for the History of Natural Science, Shanghai Jiao Tong University,” he said.
At each of the four institutions Xu lectured on “George Sarton and Chinese Science or Chinese Mathematics.” Sarton (1884-1956) was the Belgian chemist and historian known as “founding father of the history of science in the United States,” Xu said. At each university he tailored the lecture to either be more science-based or math-based depending on the audiences, which varied from graduate students to professionals or postdoctoral research fellows.
“I went through his archive and dug out some correspondence between him and Chinese scholars in his time, looking at bibliographies and historiographies from research, Basically I talked about George Sarton and Chinese mathematics. When he wrote his monumental work `Introduction to the History of Science’ part of the book dealt with Chinese science. I focused on how he wrote accounts of Chinese science and mathematics,”
Towards the end of his stay in China, Xu visited the inland city of Hohhot and lectured at Inner Mongolia Normal University. He spoke about Chinese nuclear elements and their English sources, which was the basis of research work Xu did over 10 years ago.
“They are still interested in that subject,” Xu says.
It appears that Dr. Xu’s latest research will also capture people’s attention over a long time, on both sides of the globe.
