What Is The Sound Of No Sounds Happening?
Figure 2. Scatterings and absorption coefficient of the flat panel composite absorber Applied Physics Letters 107, 104104 (2015) Think, for a moment, about the quietest quiet experience. Perhaps a still night in the desert, far from any of the sounds of civilization, or maybe a hike in a cave or catacomb, where the body of the Earth itself provides a strong barrier against intruding sounds. Whatever you imagined, it’s likely nowhere near as quiet as a lab at the Department of Physics of Hong Kong University of Science and Technology, where Min Yang et al. created almost perfect silence. Using a pair of resonators, their experiment absorbed 99.7 percent of ambient sound. Besides a librarian shhhhh-ing a room full of students, there are a few ways to create quiet. One is a material...