Wave-material interaction in radio science through the history of URSI

Radio science is the study of radio waves. The behavior of radio waves, as electromagnetic waves, is governed by Maxwell equations. In the real world, waves interact with material bodies and structures, and therefore the study of wave-material interaction connects to the fundamental interests of URSI. This presentation discusses the research on the interaction of radio waves with materials from the 19th century throughout the century-old history of URSI. The emphasis is on the electromagnetic characterization of complex media and metamaterials. Particular attention is given to the process in which the homogenization of a microscopic sample of medium leads to a macroscopic description which requires new and qualitatively different properties from those appearing in the microscopic scale.