The simplest form of the Casimir effect was predicted in 1948 by H.B.G. Casimir and consists in the attraction between a pair of neutral, parallel conducting plates placed in the vacuum. This attractive force has a purely quantum origin and cannot be obtained using the classical description of electromagnetic field since it is a direct consequence of the existence of Zero-Point Fluctuations: a turmoil of virtual particles that come in and out of existence and that can violate the energy-momentum conservation of the system for very short periods of time, as described by Heisenberg’s uncertainty principle
