We all know there are various ways of visualizing sound waves. As good as any music program comes with feature to graphically outline sounds and tones. Windows Media Player, to name just one, has several dozen different notations ranging from simple stripes to more complex animations such as “red chaos”. What about photos of real sound waves? Well, the nice folks from NPRrecently published the video embedded below, introducing a method that enables photo and video shots of real sound waves.
The method is based on Schlieren Photography, developed by German chemist and physicist August Toepler. It has been used to make air movements caused by heat or kinetic energy visible. Some of the best-known examples are shock waves stemming from quickly-moving objects that are indispensable for the investigation of aerodynamics, and shots of sneezing people, that play a vital part in epidemiology.
