Can the Most Abstract Math Make the World a Better Place?
Columnist Natalie Wolchover explores whether applied category theory can be “green” math. The post Can the Most Abstract Math Make the World a Better Place? first appeared on Quanta Magazine

In the realm of mathematics, where abstract concepts often seem removed from the tangible world, a group of mathematicians is exploring the potential of category theory to address real-world challenges. Columnist Natalie Wolchover delves into this intriguing intersection of abstract mathematics and practical applications in her article "Can the Most Abstract Math Make the World a Better Place?" published on Quanta Magazine.
The story begins with John Baez, a renowned mathematical physicist who splits his time between the University of California, Riverside and the University of Edinburgh. In 2011, Baez expressed a shift in his interests, writing on his blog, "I've spent a long time exploring the crystalline beauty of traditional mathematics, but now I'm feeling an urge to study something slightly more earthy." This sentiment reflects a broader trend among mathematicians who are increasingly drawn to applied category theory, a branch of mathematics that seeks to model complex systems and processes.
Category theory, a field that originated in the 1940s, is known for its abstract nature. It deals with the relationships between mathematical structures, such as sets, groups, and rings, rather than the structures themselves. Traditionally, category theory has been viewed as a purely theoretical endeavor, but in recent years, it has gained traction as a tool for solving practical problems.
One of the key figures driving this shift is Brendan Fong, a mathematician at the University of Pennsylvania. Fong's work focuses on applying category theory to model ecological systems, such as food webs and nutrient cycles. By using category theory, Fong and his colleagues can create models that capture the intricate interactions within these systems, providing insights into how they function and how they might respond to environmental changes.
The appeal of category theory lies in its ability to handle complexity. Many real-world systems are inherently complex, with multiple interacting components and feedback loops. Traditional mathematical models often struggle to capture this complexity, leading to oversimplifications or inaccuracies. Category theory, with its focus on relationships and transformations, offers a more flexible framework for modeling such systems.
Another area where category theory is being applied is in network theory. Researchers are using it to study everything from transportation networks to social networks. By modeling these networks through category theory, they can gain a deeper understanding of their structure and dynamics, which can inform more effective design and management strategies.
The potential applications of category theory extend beyond ecology and networks. It is being explored in fields as diverse as computer science, physics, and even economics. In computer science, category theory is being used to develop new programming languages and to better understand the principles underlying software design. In physics, it has been applied to quantum mechanics and general relativity, offering fresh perspectives on long-standing problems. In economics, category theory is being used to model financial systems and to understand the dynamics of market interactions.
Despite its growing popularity, category theory remains a niche area of study. Many mathematicians and scientists are still unfamiliar with its concepts and techniques. However, as researchers continue to uncover its potential, there is growing interest in bridging the gap between abstract mathematics and practical applications.
One initiative aiming to foster this connection is the "Applied Category Theory" (ACT) school, which was founded in 2012. This annual event brings together mathematicians, physicists, computer scientists, and other researchers to share their work and explore new directions in applied category theory. The school has become a hub for interdisciplinary collaboration, driving the development of new theories and models that can be applied to real-world problems.
The potential of category theory to make the world a better place is not just theoretical. It is already being harnessed to tackle some of the most pressing challenges of our time. From understanding the impacts of climate change to designing more efficient transportation systems, category theory offers a powerful tool for modeling and understanding complex systems.
In conclusion, the most abstract of maths is not merely a pursuit of intellectual curiosity. It has the potential to make a tangible difference in the world. As mathematicians like John Baez and Brendan Fong continue to explore the applications of category theory, we are witnessing a fascinating convergence of abstract mathematics and practical problem-solving. Whether it be in ecology, networks, or economics, category theory is proving to be a valuable ally in our quest to understand and improve the world around us.










