Page "Casimir effect" Paragraph 4

Dutch physicists Hendrik B. G. Casimir and Dirk Polder at Philips Research Labs proposed the existence of a force between two polarizable atoms and between such an atom and a conducting plate in 1947, and, after a conversation with Niels Bohr who suggested it had something to do with zero-point energy, Casimir alone formulated the theory predicting a force between neutral conducting plates in 1948 ; the former is called the Casimir-Polder force while the latter is the Casimir effect in the narrow sense.

Predictions of the force were later extended to finite-conductivity metals and dielectrics by Lifshitz and his students, and recent calculations have considered more general geometries.

It was not until 1997, however, that a direct experiment, by S. Lamoreaux, described above, quantitatively measured the force ( to within 15 % of the value predicted by the theory ), although previous work van Blockland and Overbeek ( 1978 ) had observed the force qualitatively, and indirect validation of the predicted Casimir energy had been made by measuring the thickness of liquid Helium films by Sabisky and Anderson in 1972.

Subsequent experiments approach an accuracy of a few percent.