👉 In physics and quantum mechanics, an "apheliotropic" is a type of wave that exhibits a phase velocity (the speed at which light or other waves travel in one direction) greater than the speed of sound. This property can be useful for various applications such as optics, acoustics, and information theory. For example, in optical communications, an "apheliotropic" wave may be used to transmit signals that have a longer wavelength than the visible light or other waves that are