Commemoration of ancient Chinese mathematical master Liu Hui marks his timeless influence on mathematics and civilization exchanges

A year-long global commemoration of Liu Hui, a prominent figure in ancient Chinese mathematics, kicked off in Paris on Tuesday local time.

Co-hosted by the China Association for Science and Technology (CAST), and the Chinese National Commission for UNESCO (The United Nations Educational, Scientific, and Cultural Organization), the commemoration celebrates Liu, whose works and theories not only have a profound impact on ancient Chinese mathematics, but also continue to provide a source of inspiration for scientific and technological progress and civilization exchanges in today's world.

In November 2023, UNESCO held the 42nd session of the General Conference and approved the proposal made by the CAST to celebrate the anniversary of Liu's birth. It was the first time China had successfully applied for a birthday anniversary event for a scientist at UNESCO, said the CAST.

"We hope that through such events, we can showcase to a global audience the remarkable scientific achievements, exceptional ideas, and significant contributions to human civilization made by ancient Chinese scholars like Liu Hui," said He Junke, executive president of the CAST, in a speech he delivered at the launch ceremony of the commemoration on Tuesday local time, at the headquarters of UNESCO in Paris.

An ancient Chinese mathematical master

Liu, who lived in the 3rd century, was one of the founders of classical Chinese mathematical theory.

Liu had a profound influence on ancient Chinese mathematics and a direct influence on mathematics in the whole East Asia region, and he also indirectly influenced other regions in the world, said Zou Dahai, a research fellow at the Institute for History of Natural Sciences, Chinese Academy of Sciences (CAS).

Liu's commentary in China's mathematical classic Nine Chapters on the Mathematical Art inspired numerous mathematicians and mathematical works in later generations.
"Emerging during the mid-1st century BC and having been passed down to present day, Nine Chapters on the Mathematical Art contains numerous universal algorithms and corresponding mathematical problems," Zou, who attended the Tuesday commemoration events online as an expert representative, told the Global Times. "The book has extremely rich content, featuring many significant academic achievements. But it doesn't provide explanations of how the algorithms and formulas were derived."

Liu's commentary was then an essential complement to the book, giving a comprehensive demonstration of mathematical methods in it. "Also, he made original and significant achievements in various areas, such as the theory of lü (ratio), the method of infinite division, volume theory, indirect surveying, the ratio of circumference to diameter, and decimals," Zou said.

Mathematics plays a crucial role in the modern scientific framework, He said at the launch ceremony on Tuesday. In ancient China, mathematics was one of the most advanced disciplines, deeply embedded in everyday life, he said.

"The mathematical system outlined in 'The Nine Chapters' serves as a bridge connecting abstract mathematical theories with practical applications," noted He. "From land measurement to urban planning, from building houses to constructing levees, it not only introduces precise calculation methods but also provides rigorous mathematical proof."

A light of wisdom spanning two millennia

Weeks ago, the International Astronomical Union Minor Planet Naming Committee officially named an asteroid discovered in China the "Liu Hui Star," paying tribute to this precious cultural heritage of all humanity, He mentioned at the launch ceremony of the commemoration.

Many Chinese and international scholars invited to the commemoration told the Global Times that Liu's thoughts and his contributions to mathematics not only have great historical value, but also a profound enlightenment in contemporary mathematical learning, scientific research, and youth science education.

"The achievements, thoughts, and methods of ancient Chinese mathematics have long been integrated into the mathematics that we study today, and Liu's contributions are also part of this integration, having both tangible and intangible effects on the development of Chinese mathematics," Zou said. He explained that many kinds of knowledge of proportions that (modern Chinese people) learn, including the idea of viewing fractions as the ratio of two numbers, were actually influenced by Liu.

"Apart from Liu's specific mathematical achievements, his scholarly attitude and scientific spirit are worth our study and promotion," added Zou.

Jeff Chen, a professor of mathematics at US St. Cloud State University who attended the commemoration in Paris on Tuesday, emphasized how Liu's work can inspire and benefit the science education of today's youth.

"Liu's works clearly demonstrated that he had a curious and logical mind," Chen told the Global Times via email. "Although the mathematical knowledge in the Nine Chapters on the Mathematical Art may be considered elementary or even rudimentary, Liu's thinking and modes of reasoning are definitely not. They help us to make sense of the knowledge and lead us to utilize the tools at our disposal, applying them in ways beyond the conventions."

"In short, Liu's works really train students to think for themselves - the ultimate goal of education," Chen noted.

A bridge connecting Eastern and Western civilizations

Following the launch ceremony, an international symposium on Liu's academic thought was also held at the headquarters of UNESCO on Tuesday afternoon, where global experts in the history of science and technology, and the history of mathematics, made multi-dimensional interpretations and held discussions on Liu's academic contributions and scientific heritage, as well as their modern value.

Furthermore, they delved into the global dissemination of Liu's mathematical ideas, and proposed suggestions to further promote China's classical mathematical heritage.

Earlier, as another highlight of this series of commemorative events, a themed exhibition featuring Liu's achievements in mathematics kicked off at the Réfectoire des Cordeliers in Paris on Monday, so as to showcase Liu's mathematical achievement, and to deepen the civilization exchanges and mutual understanding between China and the world, read the exhibition's foreword.

Zhou Xiaohan, an associate research fellow at the Institute for History of Natural Sciences, CAS, believes that the exhibition is an opportunity to show Liu's important contributions, as well as the efforts made by Chinese and foreign scholars to study ancient scientific thought in China and their in-depth cooperation over the last century.

"Liu's achievements are not only a treasure to China, but also a great legacy of human thought for the world," he told the Global Times.

"I wish there were exhibitions and presentations [in commemoration of Liu] in more major cities around the world," said Chen. "With the backing of UNESCO, such occasions will encourage more international interest in his works and attract students into the field of the history of mathematics in China. It will promote dialogue, discussions, and cultural exchanges between China and the rest of the world."

One of the themes of our time is exchange and mutual learning among different civilizations, Zou said in a speech he delivered at the launch ceremony. "Indeed, our commemoration of Liu Hui today, as well as the academic achievements supporting these activities are exactly the product of civilizational exchanges and mutual learning," he said.

The commemoration event in honor of Liu further conveys China's outstanding scientific achievements and scientific culture to the international community, which showcases both the characteristics and the universality of Chinese mathematics, Zou told the Global Times on Monday, ahead of the ceremony.

"This is a model case showing the diversity and accommodation of Eastern and Western cultures," Zou said.