Diffraction: Why Waves Bend Around Obstacles

Diffraction is the bending and spreading of waves when they meet an obstacle or pass through an opening.
It shows that waves don’t just travel straight—they can curve into “shadows.”
Water waves clearly diffract when passing through gaps in harbor walls.
Sound waves diffract around corners, which is why you can hear someone without seeing them.
Light also diffracts, but because its wavelength is tiny, the effect is subtle unless the opening is very small.
The amount of diffraction depends on the relationship between the wavelength and the size of the opening.
Narrower gaps or longer wavelengths create stronger diffraction.
Diffraction patterns, like the rainbow rings on a CD or DVD, reveal light’s wave nature.
Engineers use diffraction in designing optical instruments and analyzing crystal structures.
From radio signals bending around mountains to shimmering light effects, diffraction shows waves’ flexibility in motion.