virtual particle

noun

, Physics.

1. an elementary particle of transitory existence that does not appear as a free particle in a particular situation but that can transmit a force from one particle to another.

virtual particle

1. A short-lived subatomic particle whose existence briefly violates the principle of conservation of energy. The uncertainty principle of quantum mechanics allows violations of conservation of energy for short periods, meaning that even a physical system with zero energy can spontaneously produce energetic particles. The more energy a virtual particle has, the shorter its existence. Interactions between normal particles and virtual particles play a crucial role in quantum field theory analyses of interactions between real particles.
2. See also Casimir effect

Word History and Origins

Origin of virtual particle¹

First recorded in 1970–75

Example Sentences

In particle physics, virtual particles are ones that appear only for brief instants and don’t carry their normal masses.

From Science News

But, if experiment and theory don’t match, our understanding of the soup of virtual particles may be incomplete.

From Singularity Hub 

We talk about virtual particles, all this stuff — but it doesn’t go click, click, click in anyone’s detector.

From Quanta Magazine

When researchers compute the weights, they see that scenarios with the longest-lasting virtual particles — that is, cases in which the particles become essentially real — shape the outcome the most.

From Quanta Magazine