Leuchs, GerdHawton, MargaretSánchez Soto, Luis Lorenzo2023-06-172023-06-172020-01-182624-817410.3390/physics2010002https://hdl.handle.net/20.500.14352/8097We present a new perspective on the link between quantum electrodynamics (QED) and Maxwell’s equations. We demonstrate that the interpretation of the electric displacement vector D=ε0E , where E is the electric field vector and ε0 is the permittivity of the vacuum, as vacuum polarization is consistent with QED. A free electromagnetic field polarizes the vacuum, but the polarization and magnetization currents cancel giving zero source current. The speed of light is a universal constant, while the fine structure constant, which couples the electromagnetic field to matter runs, as it should.engAtribución 3.0 Españahttps://creativecommons.org/licenses/by/3.0/es/journal articlehttps://doi.org/10.3390/physics2010002https://www.mdpi.com/2624-8174/2/1/2open accessquantum vacuumlinear responseQEDÓptica (Física)2209.19 Óptica Física