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Physics vocabulary · Waves, Oscillations and Sound

Diffraction

Meaning in physics, with examples

/dɪˈfrækʃən/nounCommon term

In physics, diffraction means: The spreading out of a wave when it passes through a gap or around the edge of an obstacle. It is strongest when the gap is about the same size as the wavelength.

In Turkish: kırınım

How it is used

Explains why you can hear someone round a corner without seeing them: sound waves are long enough to spread through a doorway, but light waves are far too short. A diffraction grating with many slits is used to measure the wavelength of light.

Example sentences

  1. Diffraction is easy to see when water waves pass through a narrow gap in a harbour wall.

  2. We used a diffraction grating to find the wavelength of the laser.

Common collocations

  • diffraction grating
  • diffraction pattern
  • single-slit diffraction
  • electron diffraction
  • interferenceThe effect produced when two or more waves meet and their displacements add together. They can reinforce each other (constructive) or cancel each other out (destructive).
  • wavelengthThe distance between two neighbouring points on a wave that are at the same stage of their cycle, such as two crests. It is shown by the Greek letter lambda (λ).
  • waveA disturbance that travels through a medium or through space and carries energy from one place to another without carrying matter with it.
  • wave-particle dualityThe idea that light and matter can behave both as waves and as particles, depending on the experiment. Electrons, for example, can produce interference patterns.
  • refractionThe change in direction of a wave as it passes from one material into another, caused by a change in its speed. It is why a straw looks bent in a glass of water.

More terms: Waves, Oscillations and Sound

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