The Malus-Dupin theorem, a result in geometrical optics discovered by Etienne-Louis Malus in 1808 and clarified by Charles Dupin in 1822, states that if a pencil of light rays perpendicular to some surface undergoes any sequence of reflections and refractions through homogeneous media, the resulting pencil of rays remains perpendicular to some other surface. William Rowan Hamilton later gave an independent proof of the theorem using his own Hamiltonian formulation of optics.
Facts
StatementA pencil of light rays perpendicular to some surface, after any number of reflections and refractions, remains perpendicular to some other surface. 1 Classification
Statement FormCharacterization Theorem 1 Connections
Has Statement Form
Entity-backed identity for the statement-form enum value this theorem already carries, resolved to a mathematics concept by an explicit value-to-entity map (phase 3 bucket conversion, docs\design_entity_backed_browse_buckets_20260928.md). The statement-form fact itself stays on the theorem unchanged.
Sources
1. Malus-Dupin theorem - Wikipedia
Introduction, paragraph 2, last sentenceQuote, Introduction, paragraph 2, last sentence
The theorem states that the resulting pencil of light rays is still perpendicular to some other surface.
Reader Challenges (0)
No disputes yet. Spotted an error or a better source? Open the first one.
Sign in to dispute this or suggest a correction.