In one minute

Bressi, Carugno, Onofrio and Ruoso start from a basic consequence of the uncertainty principle: the vacuum is not empty. The evidence for an accelerating universe gives a compelling reason to understand how the quantum vacuum contributes to spacetime curvature, and forces between neutral bodies are a direct probe of it. They measure the Casimir force between two conducting surfaces held parallel, the geometry of Casimir's original prediction. The force acts between a chromium-coated silicon cantilever and a similar rigid surface. It is detected through shifts in the cantilever's resonant frequency as the surfaces approach. Its scaling with distance was tested from 0.5 to 3.0 µm, and the force coefficient was determined to 15% precision.

Measurement of the Casimir force between parallel metallic surfaces