A demonstration
White is
a crowd.
One beam goes in. Inside the glass, every wavelength takes a slightly different road. What leaves is a disagreement we call colour.
Apex angle60.0°
Incoming tilt−12°
Dispersion28°
SelectedFull spectrum
Drag the glass · optical bench
Tilt−12°
Dispersion28°
Drag a ray or choose a band400 → 700 nm