- the pressure exerted on a surface by electromagnetic radiation or by sound waves.
Origin of radiation pressure
First recorded in 1900–05
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- Force per unit area exerted by waves or particles of radiation, especially photons. Though photons have no mass, they do have momentum, and can transfer that momentum to other particles upon impact. The amount of pressure exerted by a given amount of radiation depends on whether the radiation is absorbed or reflected. Radiation pressure is responsible for the Casimir effect; solar radiation pressure is exploited in the design of solar sails.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.