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?
Field fluctuations in the vacuum refer to the spontaneous and temporary changes in the strength and direction of electromagnetic fields that occur in empty space. These fluctuations are a result of the uncertainty principle in quantum mechanics.
Field fluctuations can affect particles by causing them to spontaneously appear and disappear, a process known as particle-antiparticle pair production. This can also lead to changes in the energy and momentum of particles.
Field fluctuations cannot be directly observed, as they occur at a very small scale and are constantly changing. However, their effects can be observed through experiments and calculations, such as the Casimir effect.
Yes, field fluctuations have practical applications in areas such as quantum computing and cosmology. They also play a crucial role in our understanding of the fundamental laws of physics.
Currently, field fluctuations cannot be controlled or manipulated, as they are a natural phenomenon. However, scientists are researching ways to harness and utilize these fluctuations for various purposes, such as energy generation and communication.