Diffraction is a physics concept which occurs when waves bend around small obstacles, or spread out after they pass through small openings. Diffraction occurs with all waves, including sound waves, water waves, and electromagnetic waves such as light that the eye can see. The light wave has the ability to bend and then spread out itself this behavior of light can be distinguished as diffraction and dispersion. When the wavelength is similar to the dimensions of the object, as with low frequencies and buildings, or mid-range frequencies and the head, the wave diffracts around the object, using its edges as a focal point from which to generate a new wavefront of the same frequency but reduced intensity. Thus, diffraction may aid sound dispersion and DIFFUSION. Ĭompare: CANCELLATION, INTERFERENCE, PARABOLIC REFLECTOR, REFLECTION, REFRACTION. Īs a result of their capability of diffraction, low frequency sounds are difficult to localize or contain in an environment (see CANYON EFFECT, DIFFUSE SOUND FIELD ).Īn acoustic radiator must be specially designed for good dispersion of high frequencies since this does not occur naturally through diffraction. In addition, we will see that Huygens’s principle tells us how and where light rays interfere. 1: A transverse wave, such as an electromagnetic wave like light, as viewed from above and from the side. For instance, the TWEETER of a loudspeaker is shaped in the form of a fan for this purpose. 2: Huygens’s principle applied to a straight wavefront. Each point on the wavefront emits a semicircular wavelet that moves a distance s vt s v t. The new wavefront is a line tangent to the wavelets.
The direction of propagation is perpendicular to the wavefronts (or wave crests) and is represented by an arrow like a ray.
The Dutch scientist Christiaan Huygens (16291695) developed a useful technique for.