Fields that live on themselves, without the need of a spacetime to serve as a substratum, as a support, and which are capable by themselves of generating spacetime, are called ‘covariant quantum fields’. The substance of which the world is made has been radically simplified in recent years. The world, particles, light, energy, space and time – all of this is nothing but the manifestation of a single type of entity: covariant quantum fields.
