The Vacuum Attractor Hypothesis: A Restoring Force in Quantum Field Cavities

The quantum vacuum always returns to the same ground state no matter how you disturb it. Casimir cavities, photon cavities, different mechanisms every time but same result every time. This paper asks why and proposes an answer: the vacuum has a preferred energy density and actively resists departures from it. For a scalar field this is derived exactly. The restoring pressure is ΔP = λ(u - u₀) with λ = -1. Three experiments are proposed to test whether the same holds for electromagnetic fields. Wagner et al. 2018 already measured a 20% pressure anomaly in an optical cavity that fits this picture. That anomaly is motivation, not proof. The electromagnetic derivation is not finished. Everything else is.