photon

[ foh-ton ]

noun

1. a quantum of electromagnetic radiation, usually considered as an elementary particle that is its own antiparticle and that has zero rest mass and charge and a spin of one. : γ

photon

/ ˈfəʊtɒn /

noun

1. a quantum of electromagnetic radiation, regarded as a particle with zero rest mass and charge, unit spin, and energy equal to the product of the frequency of the radiation and the Planck constant

photon

/ fō′tŏn′ /

1. The subatomic particle that carries the electromagnetic force and is the quantum of electromagnetic radiation. The photon has a rest mass of zero, but has measurable momentum, exhibits deflection by a gravitational field, and can exert a force. It has no electric charge, has an indefinitely long lifetime, and is its own antiparticle.
2. See Note at electromagnetic radiationSee Table at subatomic particle

photon

1. The quantum , or bundle of energy , in which light and other forms of electromagnetic radiation are emitted. ( See atom .)

Word History and Origins

Origin of photon¹

First recorded in 1900–05; phot- + -on ¹

Example Sentences

As with other live brain imaging systems that rely on "two-photon microscopy," this scanning light "excites" photon emission from brain cells that have been engineered to fluoresce when stimulated.

From Science Daily

"Our continued collaboration with the So lab and their expertise with microscope development has enabled in vivo studies that are unapproachable using conventional, out-of-the-box two photon microscopes," she added.

From Science Daily

The key to this study was optimizing the semiconductor material, which captures the photons, to broaden its preferred photon energies while aligning with the dominant energies produced by the heat source.

From Science Daily

This cavity helped trap photons with the right energies so that they entered the semiconductor and sent the rest back into the heat storage material, where the energy had another chance to be re-emitted as a photon the semiconductor could capture.

From Science Daily

By performing a series of mathematical calculations, the researchers found that one of a photon's basic properties is topological, meaning that it doesn't change even as the photon moves through different materials and environments.

From Science Daily