Diffraction
The bending of waves around obstacles or through apertures when the wavelength is comparable to the obstacle/aperture size. Single slit diffraction produces a diffraction pattern with a central maximum and weaker secondary maxima. Diffraction is evidence for the wave nature of light and matter.
Formula
Single-slit minima: a sinθ = nλ
Real World
Radio astronomers use large dish arrays like the Square Kilometre Array because radio waves (~1 m wavelength) diffract so strongly through small apertures that a tiny dish would produce no usable image.
Exam Focus
For single-slit questions, note that the central maximum is twice as wide as secondary maxima — a common sketch error.
How well did you know this?