2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/140013In this paper we discuss the invariant thermal Proca - Klein - Gordon equation (PKG). We argue that for the thermal PKG equation the absolute velocity is equal v = alpha*c, where alpha is the fine stucture constant for electromagnetic interaction.4 pagesGeneral PhysicsOn the invariant thermal Proca - Klein - Gordon equationtext