## Encyclopedia > Wavelength

Article Content

# Wavelength

The wavelength is the distance between repeating units of a wave pattern. It is commonly designated by the greek letter lambda (λ).

In a sine wave, the wavelength is the distance between peaks:

The x axis represents distance, and I would be some varying quantity (for instance air pressure for a sound wave or strength of the electric or magnetic field for light), at a given point in time as a function of x.

Wavelength has an inverse relationship frequency, the number of peaks to pass a point in a given time. The wavelength is equal to the speed of the wave divided by the frequency of the wave. When dealing with electromagnetic radiation in a vacuum, this speed is the speed of light c, so the conversion becomes,

$\lambda = \frac{c}{\nu}$

where:

For radio waves this relationship is easily handled with this formula: meters of wavelength = 300/frequency in megahertz (MHz)

Louis-Victor de Broglie discovered that all particles with momentum have a wavelength, called the de Broglie wavelength. For a relativistic particle, this wavelength is given by

$\lambda = \frac{h} {mv} = \frac {h} {m_0v} \sqrt{1 - \frac{v^2}{c^2}}$

where h is the Planck constant, m0 is the particle's rest mass, and v is the particle's velocity.

Wavelength is the title of a 1978 album by Van Morrison.

All Wikipedia text is available under the terms of the GNU Free Documentation License

Search Encyclopedia
 Search over one million articles, find something about almost anything!

Featured Article
 Ocean Beach, New York ... median age is 42 years. For every 100 females there are 126.2 males. For every 100 females age 18 and over, there are 120.4 males. The median income for a household in ...