Consider a free real scalar field. The quadratic term in field of spacetime implies that a universe of these free particles is created, annihilated, recreated, and so on moment by moment. In this video Susskind explains the quadratic term in the Lagrangian youtu.be/D7yXoNAg3J8 (At minute 32:0) How they "absorb and emit" an undisturbed particle at the same point or neighboring points of spacetime. Yet we are under the false impression that the particles exist continuously in spacetime. The question is does this observation alone imply the existence of some extra or hidden dimensions in which the particle exists when annihilated in the four dimensional universe?