Wavelength facts for kids

A sine wave, with its wavelength

Periodic waves at shallow water, wavelength is denoted λ

A wavelength is the length of the shortest repeating part of a "sine wave". All waves can be formed by adding up sine waves. That is, every wave is a total of sine waves, which may be identified by Fourier analysis.

Examples of waves

Waves are everywhere. Examples of waves include:

• sound
• electromagnetic spectrum including
  • radio wave
  • light
• water waves such as ocean surface waves
• earthquake waves

"Length" of a sine wave

The sine wave has a pattern that repeats. The length of this repeating piece of the sine wave is called the wavelength. The wavelength can be found by measuring the length or distance between one peak of a sine wave and the next peak. The wavelength can be found in many other ways too.

There are other properties of waves and sine waves, such as their frequency, amplitude, phase, and speed.

A symbol used for wavelength most often is the Greek letter lambda (λ).

Images for kids

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  Wavelength is decreased in a medium with slower propagation.

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  Separation of colors by a prism (click for animation)

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  A sinusoidal wave travelling in a nonuniform medium, with loss

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  A wave on a line of atoms can be interpreted according to a variety of wavelengths.

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  A propagating wave packet

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  Pattern of light intensity on a screen for light passing through two slits. The labels on the right refer to the difference of the path lengths from the two slits, which are idealized here as point sources.

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  Diffraction pattern of a double slit has a single-slit envelope.

See also

In Spanish: Longitud de onda para niños