CasimirEffekt

CasimirEffekt, commonly known as the Casimir effect, is a physical manifestation of quantum vacuum fluctuations that results in a force between neutral, macroscopic bodies. It was predicted in 1948 by Dutch physicist Hendrik B. G. Casimir. In the canonical setup, two parallel, perfectly conducting plates in vacuum experience an attractive force arising from the restriction of electromagnetic field modes between them. For plates of area A separated by distance a, the force is F = - (π^2 ħ c A) / (240 a^4), and the corresponding pressure is F/A = - π^2 ħ c /(240 a^4). Real materials and finite temperature modify this ideal result; Lifshitz theory extends the description to dielectrics with finite conductivity and includes thermal corrections.

Experimental verification progressed from crude measurements in the 1950s to precise determinations in the 1990s and 2000s, using torsion balances, atomic force microscopes, and microelectromechanical systems. Typical forces are tiny but measurable at separations in the hundreds of nanometers to a few micrometers for microscale devices. The Casimir effect is of practical relevance in nanotechnology, where it can cause stiction or alter operation of MEMS/NEMS, and it motivates designs that tailor or counteract the force, including proposals of repulsion with specific materials or geometries.

From a theoretical perspective, the Casimir effect is interpreted as the change in zero-point energy of the quantized electromagnetic field due to boundary conditions, and is related to van der Waals forces at short range. It is described in quantum electrodynamics and quantum field theory, and continues to be a testbed for precision measurements and fundamental physics.