Science & TechnologyGreek → English
Photon
/ˈfoʊtɒn/noun
The quantum of electromagnetic radiation, a particle of light with no mass.
The Greek roots
φῶς
phôs
light
Literally: “light-particle”
Follow a root:φῶς13 words
The story of the word
Gilbert Lewis put the word into Nature in 1926, but for a different object: a persistent atom of radiant energy that was not created or destroyed. Physicists kept the name and discarded the concept, attaching it to Einstein's light quantum of 1905. At least four earlier authors had used photon for other things, including a unit of illumination at the retina. The genitive φωτός, not the nominative, is what shows up in photograph and photosynthesis.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 1926
The same roots elsewhere
Other languages reached for exactly the same Greek pieces.
Same family
photographphotosynthesisphosphorusphotometer
In a sentence
A single photon is enough to trip the detector.