The forum discussion centers on the prediction of quantum fluctuations in the vacuum by relativistic quantum field theory (QFT), specifically illustrated by the Casimir Effect. Participants clarify that "vacuum fluctuation" is a misnomer, advocating for the term "vacuum energy" or "zero point energy" to describe the absence of particles. The Casimir Effect is attributed to electromagnetic forces between charged plates rather than fluctuations in the vacuum itself. The discussion emphasizes that energy differences, rather than absolute energy values, are crucial in understanding these phenomena.
PREREQUISITESPhysicists, particularly those specializing in quantum mechanics and field theory, as well as students seeking to deepen their understanding of vacuum energy and the Casimir Effect.
We do not. The Casimir effect can be explained purely as electromagnetic force between the electric charges in the plates: The Casimir Effect and the Quantum VacuumJrs580 said:We see this in the experiment proving the Casimir Effect so we know it's physical
In SR there is no physics in the absolute value of the total energy, and thus it's convenient to associate the values 0 of the Poincare-invariant vacuum state for all additive conservation laws. Formally you can achieve this with introducing "normal ordering" in the Hamiltonian/Lagrangian.malawi_glenn said:Vacuum fluctuation is not a good term, vacuum energy is better (zero point energy). Vaccum here means absence of particles.
The Casimir effect is due to fluctuations of charges and the em. field. The usual calculation you find in introductory chapters of some QFT books (e.g., in Itzykson, Zuber) is a limiting case for infinite (!) charges. For details seemalawi_glenn said:Hard to understand your "why" question, do you want to see the casimir effect calculation or what else are you referring to?