Literally meaning: “that carry light”
Origin: Anc Greek
φως/phos(=light) > (genitive φωτός/photos=of light)
by Gilbert Lewis in 1926, though the concept of light in the form of discrete particles had been known.
- (physics) photon is defined as a quantum of electromagnetic energy
- (biology) Photon is a unit of retinal illumination, equal to the amount of light that reaches the retina through 1 square millimeter of pupil area from a surface having a brightness of 1 candela per square meter.