“Most people think of mathematics as something dry and theoretical, with little connection to the real world,” says Yibao Xu. “But if you can look at math in its historical context, you can see its relevance — and richness.”
An assistant professor in BMCC’s department of mathematics, Xu overlays a historical perspective on each of the three math courses he teaches — Pre-Algebra, Fundamentals of Modern Mathematics and Introduction to Statistics.
“I’ve taught the fundamentals course every semester that I’ve been at BMCC and it’s one I especially enjoy,” says Xu, who joined the faculty in 2003. “It has something for everyone — set theory, logic, group theory, the history of numeration systems.”
The course can also be something of an eye-opener.
Other cultures, other numbering systems
“Most people, including my students, take our western decimal-based counting system for granted,” Xu says. “But over the course of history, there have been many other systems, all valid. For example, the ancient Mayans created a base-20 system; the Babylonians used a base-60 system.”
Vestiges of the Babylonian numbering scheme are evident in the Western approach to measuring time, “with each hour divisible into 60 minutes, and each minute further divisible into 60 seconds,” he says.
Born in China, Xu studied mathematics and the history of mathematics at Inner Mongolia Normal University, from which he received his MS degree, and earned his Ph.D. at the CUNY Graduate Center. A member of several academic organizations, including the American Mathematical Society, Xu has authored more than 30 articles and book chapters and has delivered lectures at numerous conferences in the U.S. and abroad.
Why did China lag?
Xu’s fascination with the history of mathematics originated in the teachings of Joseph Needham, a scholar and biochemist best known for his writings on the history of Chinese science and mathematics. At Cambridge University, Xu notes, Needham oversaw an ambitious study devoted to answering a single question: Why didn’t the scientific revolution originate in China?
“Prior to the 1400s, China led Europe in science and technology, but lagged behind Europe afterwards. That question, which later became widely known as ‘the Needham puzzle,’ is what inspired my interest in the history of mathematics.”
Other puzzles abound. One that especially intrigues Xu relates to the very origins of mathematics. “No one agrees on who actually invented mathematics and it remains a very hard question to answer.” A case in point: the Pythagorean Theorem, conventionally attributed to the Greek philosopher Pythagoras, “was actually known in ancient China and Babylonia, many centuries earlier.”
