heat transferred across a vacuum

The undulations of the first object’s surface exert a time-varying Casimir force (caused by quantum fluctuations) on the second object’s surface, which gives rise to phonons in the second object. Because phonons are heat carriers, heat is transferred from the first object to the second.

Heat transfer in a previously unknown way Physicists have managed to observe heat transferred across a vacuum by phonons. The effect joins conduction, convection and radiation as ways for heating to occur — but only across tiny distances. The heat is transferred by phonons — the energy-carrying particles of acoustic waves. The effect takes advantage of the Casimir effect, in which the quantum fluctuations in the space between two objects that are really, really close together result in physical effects not predicted by classical physics.