Meanings
plural Arago spots
- engineeringA bright point that appears at the centre of a circular object's shadow due to Fresnel diffraction.
The Arago spot played an important role in the discovery of the wave nature of light and is a common way to demonstrate that light behaves as a wave.
Synonyms: Fresnel spot, Poisson spot
Synonyms & antonyms
nounA bright point that appears at the centre of a circular object's shadow due to Fresnel diffraction.
Origin
Named after Dominique-François-Jean Arago, who performed an experiment demonstrating the spot's existence.
Full word history & related roots →Cite this entry
Arago spot. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/Arago%20spot
“Arago spot.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Arago%20spot. Accessed November 4, 2026.
WatkinsX Dictionary, s.v. “Arago spot,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/Arago%20spot.
Source: Arago spot on Wiktionary, CC BY-SA 4.0.