Casimir acoustics

Abstract

When the indirect manifestations of the electromagnetic ZPF are interpreted as due to radiation pressure, acoustic noise can render an excellent analog to probe previous as well as recently proposed behavior. An acoustic chamber for isotropic and homogeneous acoustic noise of controllable spectral shape has been built. The noise can be driven up to levels of 130 dB (re 20 microPa) in a band of frequencies up to 50 kHz wide. When driving the system with broadband noise, it will be used (1) to test the Galilean invariance of a spectral shape proportional to the square of the frequency, (2) the force of attraction between parallel plates (analog to Casimir force), (3) the acoustic radiation emitted by a cavity that is made to oscillate at high frequencies (analog to the proposed Casimir radiation), (4) the change in the frequency of oscillation of a pendulum as the noise intensity is varied (analog to the proposed origin of inertia), and (5) the force of attraction between two spheres due to the acoustic shadow that each one casts onto the other (analog to van der Waals force and the proposed origin of gravitation).