When a beam of white light passes through a prism, its monochromatic components undergo refractions at slightly different angles: on exit, the light fans out into the complete visible spectrum, from red to violet. This is Newton’s historic experiment (1665, during the plague epidemic that closed Cambridge): with a second, inverted prism, he showed he could recombine white light starting from the spectrum of colours.
The prism separates white light into the visible spectrum: each colour, having a slightly different refractive index, exits at its own angle.
Key formula
White superposition of all visible frequencies. The prism separates them because each colour is refracted by its own angle.
Collegamenti
Argomenti: Ottica Concetti: Dispersione cromatica
Esercizi collegati: Esercizio svolto — Indice di rifrazione cromatico · Arcobaleno e dispersione · Problema — Raggi per oggetto oltre 2f (lente)