Acoustic Casimir effect

Abstract

In 1948, Hendrick Brugt Gerhard Casimir predicted that two closely spaced uncharged conducting plates in vacuum would be mutually attracted. This attractive force is an indirect manifestation of the quantum electromagnetic zero point field (ZPF). When the indirect manifestations of the ZPF are interpreted as due to radiation pressure, acoustic noise can provide an excellent analog to investigate the Casimir effect as well as other effects due to the ZPF. Force measurements between two parallel plates are performed in an acoustic chamber with a broadband noise spectrum within a 5-15 kHz band and an intensity of 133 dB (re 20 %Pa). When the results are compared with the appropriate theory, very good agreement is obtained. Applications of the acoustic Casimir effect to noise transduction can provide new means to measure background noise. Because attractive or repulsive forces can be obtained by adjusting the noise spectrum or the plate geometry, a non-resonant method of acoustic levitation is also suggested