Fascinated by spatiotemporal hierarchy: From soft matter to liquids and glasses

Looking back, my research has ranged across critical phenomena, polymers, phase separation, colloids, hydrodynamics, the glass transition, crystallization, water anomalies, liquid-liquid transitions, and, more recently, the mechanics of amorphous solids. The subjects spanned diverse fields, but the question that attracted me remained remarkably persistent: how do microscopic constituents generate structures and collective dynamics on much larger spatial and temporal scales? The idea of spatiotemporal hierarchy, which first impressed me as a graduate student studying critical phenomena, later reappeared in many forms-as dynamic asymmetry and viscoelastic phase separation in soft matter, as hidden many-body structural order in liquids, and as mechanical self-organization in glasses and gels. This article is therefore not intended as a chronological catalog of results. Rather, I look back on several turning points that changed how I thought about condensed matter, the people who encouraged those changes, and the recurring physical ideas that gradually connected apparently different problems.