Young Researcher / Outstanding Researcher* Award

Assoc Prof LI Baowen

Department of Physics

NUS acknowledges Assoc Prof Li Baowen as a Young Researcher for the impact his research is likely to have in helping physicists gain a better understanding of irreversible macroscopic phenomena. His recent finding puts a dampener on the long-held view that chaos is a necessary condition for Fourier's Law of heat conduction, strongly suggesting that microscopic chaos has no direct connection with irreversible behaviour.

Assoc Prof Li's promise as a researcher-to-watch-out-for is driven by a questioning and sceptical mind. For him, stated facts hold no water unless they can be proven. "Always prove a theory; don't take things at face value." And he did just that - turning the tables on the commonly-held view that chaos plays an essential role in the onset of macroscopic transport processes and hence in the origin of irreversible behaviour.

It takes courage and enthusiasm to challenge a conjecture that is supported by two decades of research. Following his passion for finding what governs natural laws, Assoc Prof Li took his favoured route of compressing complex systems to simplify them and introduced several ID systems in which the Lyapunov exponents were discovered to be zero, demonstrating no chaos. The results from computer simulations of heat transportation in his model showed that heat conduction obeys Fourier's Law only in the disordered channels. Both findings shed new light on the microscopic origin of irreversible macroscopic phenomena, a connection physicists hope to establish.

The impact of Assoc Prof Li's findings, published in Physical Review Letters (June 2002), can be immense. One referee commented, "The author's determination of the necessary conditions for normal heat transport in one dimension - disorder... is an important, fundamental result... solves at least a long-standing problem in non-equilibrium statistical mechanics."

The understanding of the heat conduction process can lead to the development of new materials to control heat flow with significant implications for the environment. Far-reaching results indeed from a man who believes that simplicity is beauty and cites nothing more simple than interest as the motivation for his achievement.