In one minute

R. L. Jaffe examines what a measurement of the Casimir force tells us about the quantum vacuum. The measured attraction between conducting objects can be calculated as a quantum electromagnetic interaction involving charges and currents, without assigning the result to zero-point energy. His argument concerns the interpretation of the force, whose existence the paper accepts. He shows that the force disappears as the electromagnetic coupling approaches zero, although the familiar ideal-conductor formula hides that dependence. The properties of the material and assumptions used to derive the formula therefore matter when interpreting its apparent universality. The paper asks whether Casimir measurements uniquely establish the reality of vacuum zero-point energy; it leaves the broader question of that energy's existence outside its scope.

The Casimir Effect and the Quantum Vacuum