Casimir effect

American  

[kaz-uh-meer-i-fekt] / ˈkæz əˌmɪər ɪˌfɛkt /

noun

1. the effect produced by an attractive force (Casimir force) between objects in close proximity to each other, caused by a disparity in quantum vacuum fluctuations.

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Casimir effect Scientific  

/ kăz′ə-mîr′ /

1. The effect of a net attractive force between objects in a vacuum, caused by quantum mechanical vacuum fluctuations creating radiation pressure. The radiation can be thought of as an atmosphere of virtual particles. The amount of radiation pressure on the objects is decreased in the gap between them, due to limits on the wavelength of the radiation in the gap. The gap is thus an area of lower radiation pressure, drawing the objects toward it. This force is strong enough to be of great importance at scales encountered in nanotechnology. The Casimir effect is named after Dutch physicist Hendrik Casimir (1909–2000).

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Example Sentences

The attractive force, known as the Casimir effect, causes the gold flakes to draw closer together and toward the substrate.

From Science Daily • Oct. 23, 2025

In planning the experiment, the scientists needed to find a suitable material that could be heated and cooled uniformly and quickly and that exhibited a strong Casimir effect.

From Scientific American • Apr. 29, 2023

But “a missing signal could also be because there is no Casimir effect in cuprates, or it is very weak,” says experimental physicist Markus Aspelmeyer of the University of Vienna.

From Scientific American • Apr. 29, 2023

That vacuum fluctuations and virtual particles exist has been widely accepted at least since the Casimir effect was demonstrated.

From Scientific American • Apr. 29, 2023

It is a tiny force and very difficult to measure, but in 1995 the physicist Steven Lamoreaux measured the Casimir effect directly.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife