Interference
Quantum and Nuclear | Light Sound and Waves

Bending and spreading

Teaching Guidance for 14-16 Supporting Physics Teaching

Refraction's bending, diffraction's spreading

In our experience, students often confuse the terms, refraction and diffraction. With this in mind it's useful to practice the following mantra:

Teacher: So! Let's just remind ourselves, what's the difference between refraction and diffraction of light?

Esme: Refraction's bending, diffraction's spreading.

Teacher: Exactly! Refraction involves the bending of light at some interface between two media, such as air and glass. Diffraction involves the spreading of light around a barrier or through a gap.

Teacher Tip: Bend a beam  →  refraction.

Teacher Tip: Spread a beam  →  diffraction.

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