Phrase guide

Arago spot

noun · 1 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

No pronunciation record was provided for this word.

1

noun

Meaning 1

A bright point that appears at the centre of a circular object's shadow due to Fresnel diffraction.

Definition source: English Wiktionary via Wiktextract

Topics: engineering, natural-sciences, optics, physical-sciences, physics

Examples

  • 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.

Meaning relationships

Synonyms: Fresnel spot, Poisson spot

Antonyms: none provided

History

Etymology

Named after Dominique-François-Jean Arago, who performed an experiment demonstrating the spot's existence.