Hot topics in physical acoustics

From the astronomical to the molecular, acoustics is central to phenomena across a vast spectrum of length scales. This talk provides an overview of recent developments in physical acoustics across the size continuum, while looking more in depth in three areas. At the larger end of the scale, the generation of the infrasound by cyclonic storms is considered, specifically looking at the infrasonic signatures that can be used to track and characterize these systems. At intermediate length scales, advances in acoustic metamaterial (AM) research are examined. Specific examples will include energy-harvesting metasurfaces and soft matter systems. Moving to the small end of the scale, phoxonic crystals (PxC) are discussed. PxC’s possess both optical and acoustic band gaps and can be used to trap light and sound together, enhancing the strength of acousto-optic interactions.