This “zero-point” energy is real, and can be measured in the ‘Casimir effect’. There is a force between two metallic plates in a vacuum, because moving them would change the wavelength/energy of the z...This “zero-point” energy is real, and can be measured in the ‘Casimir effect’. There is a force between two metallic plates in a vacuum, because moving them would change the wavelength/energy of the zero-point quantised electromagnetic waves between them: this change in energy in response to a move equates to a force. The wavefunction for transverse standing electromagnetic waves between plates of area A separated by a in the z-direction is:
