RT Journal Article T1 Physical mechanisms underpinning the vacuum permittivity A1 Leuchs, Gerd A1 Hawton, Margaret A1 Sánchez Soto, Luis Lorenzo AB The debate about the emptiness of space goes back to the prehistory of science and is epitomized by the Aristotelian 'horror vacui', which can be seen as the precursor of the ether, whose modern version is the dynamical quantum vacuum. In this paper, we suggest to change a common view to 'gaudium vacui' and discuss how the vacuum fluctuations fix the value of the permittivity, e(0), and permeability, mu(0), by modelling their dynamical response by three-dimensional harmonic oscillators. PB MDPI SN 2624-8174 YR 2023 FD 2023-03 LK https://hdl.handle.net/20.500.14352/72352 UL https://hdl.handle.net/20.500.14352/72352 LA eng NO © 2023 by the authors.This research was funded by the Spanish Ministerio de Ciencia e Innovación (Grant PGC2018-099183-B-I00). NO Ministerio de Ciencia e Innovación (MICINN) DS Docta Complutense RD 20 abr 2025