The Casimir effect is not caused by "vacuum energy" - it is a van der Waals force

Our previous blog post suggests that vacuum energy is zero. Thus, vacuum energy cannot be responsible for the Casimir effect, which has been empirically measured at the precision of 1% already.

https://arxiv.org/abs/hep-th/0503158

Robert L. Jaffe (2005) from MIT writes about the derivation of the Casimir effect in QED.

Hendrik Casimir and Dirk Polder calculated in 1948 the van der Waals force between two polarizable molecules. 

                +     -                        +     -

          molecule 1             molecule 2

Configurations where the molecules are polarized and attract each other are energetically favored over configurations in which they are polarized and repel each other. This creates a weak attractive force. There is no reference to vacuum energy in this. It is common sense that an attractive force forms between the molecules. The force is a van der Waals force.

Casimir and Polder noticed that if we do not assume the van der Waals force between the molecules, we can still derive an attractive force by assuming "vacuum energy" and its pressure on the molecules. The derived force has the correct numerical value.

This observation created the myth that the Casimir effect somehow proves that there exists vacuum energy.

Our previous blog post suggests an explanation for the coincidence that the exact same force can be derived in two different ways. The vacuum energy derivation calculates the complement of the true physical effect. The true physical effect is the attractive van der Waals force.

Robert Jaffe explains in his paper that in the configuration with two metal plates, the fact that the plates are made of a polarizable material (metal) is obfuscated by establishing a boundary condition for assumed "vacuum fluctuations". The dipole explanation for the force is thus hidden from plain sight.