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.

---

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).

---

Example Sentences

See Examples For:

Casimir effect

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

To measure this force within their vacuum tube, the researchers will suspend two samples made of different materials from a two-meter-tall, 1.50-meter-wide balance and induce the Casimir effect within one.

From Scientific American ● Apr. 29, 2023

Now Calloni and his colleagues hope to use the Casimir effect to measure the energy of the void.

From Scientific American ● Apr. 29, 2023

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

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