Why does glass break light into colors?

Answer: Dispersion separates wavelengths

Glass contains colored layers — Wrong. Clear glass has no colored layers. Color separation occurs because different wavelengths refract at slightly different angles (dispersion).

Dispersion separates wavelengths ✓ — Correct! Dispersion! When white light enters glass, it slows and refracts. Different wavelengths slow by different amounts—refractive index varies with wavelength. Violet slows most (bends most), red slows least (bends least). When exiting, this difference creates angular separation—white light spreads into its component colors. Prisms, raindrops, and glass edges all produce dispersion!

Light speed creates spectrum — Wrong. Speed change in glass causes refraction, but wavelength-dependent speed differences (dispersion) separate colors, not speed change alone.