In physics, wavelength is the distance between repeating units of a propagating wave of a given frequency. It is commonly designated by the Greek letter lambda (λ). Examples of wave-like phenonomena are light, water waves, and sound waves. Wavelength may refer to: Wavelength, a property of a wave Wavelength (album), an album by Van Morrison Wavelength (song), a song on the album Wavelength by Van Morrison Wavelength (1966 film), a film by Michael Snow Wavelength (1983 film), a film by Mike Gray Wavelength (club), a club in Toronto... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... A wave is a disturbance that propagates through space or spacetime, transferring energy and momentum and sometimes angular momentum. ... For other uses, see Frequency (disambiguation). ... For other uses, see Letter (disambiguation). ... Look up Λ, λ in Wiktionary, the free dictionary. ... This article does not cite any references or sources. ... Waves breaking on rocks at La Jolla Waves Ocean surface waves are surface waves which occur at the surface of an ocean. ... This article is about compression waves. ...

Wavelength of a sine wave.

In a wave, a property varies with the position. For example, this property can be the air pressure for a sound wave, or the magnitude of the electric or the magnetic field for light. The wavelengths of frequencies audible to the human ear (20 Hz–20 kHz) are between approximately 17 m and 17 mm, respectively. Visible light ranges from deep red, roughly 700 nm to violet, roughly 400 nm (430–750 THz). For other examples, see electromagnetic spectrum. Image File history File links Wavelength. ... Image File history File links Wavelength. ... Sound pressure is the pressure deviation from the local ambient pressure caused by a sound wave. ... Sound is a disturbance of mechanical energy that propagates through matter as a wave. ... In physics, the space surrounding an electric charge or in the presence of a time-varying magnetic field has a property called an electric field. ... Magnetic field lines shown by iron filings In physics, the space surrounding moving electric charges, changing electric fields and magnetic dipoles contains a magnetic field. ... This article does not cite any references or sources. ... Legend γ = Gamma rays HX = Hard X-rays SX = Soft X-Rays EUV = Extreme ultraviolet NUV = Near ultraviolet Visible light NIR = Near infrared MIR = Moderate infrared FIR = Far infrared Radio waves EHF = Extremely high frequency (Microwaves) SHF = Super high frequency (Microwaves) UHF = Ultra high frequency VHF = Very high frequency HF = High...

Relationship with frequency

Wavelength λ is inverse proportional with the frequency ν (Greek "nu"), the number of wave periods per time unit passing a given point, as in For other uses, see Frequency (disambiguation). ...

where v_w is the propagation velocity of the wave. In the case of electromagnetic radiation, such as light, in a vacuum, this speed is the speed of light, 299,792,458 m/s or about 10⁹ km/h. For sound waves in air, this is the speed of sound, 344 m/s (1238 km/h) in air at room temperature. Usually, SI units are used, where the wavelength is expressed in meters, the frequency in Hz, and the propagation velocity in meters per second. Electromagnetic waves can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. ... The speed of light in vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning swiftness.[1] It is the speed of all electromagnetic radiation, including visible light, in a vacuum. ... An order of magnitude is the class of scale or magnitude of any amount, where each class contains values of a fixed ratio to the class preceding it. ... This article is about compression waves. ... This page is about the physical speed of sound waves in a medium. ... Look up si, Si, SI in Wiktionary, the free dictionary. ... The metre, or meter (symbol: m) is the SI base unit of length. ... This article is about the SI unit of frequency. ...

In non-vacuum media

The speed of light in most media is lower than in vacuum, which means that the same frequency will correspond to a shorter wavelength in the medium than in vacuum. The wavelength in the medium is

where n is the refractive index of the medium. Wavelengths of electromagnetic radiation are usually quoted in terms of the vacuum wavelength, unless specifically indicated as the "wavelength in the medium". In acoustics, unless otherwise specified, the term wavelength is used to mean the wavelength in the medium. The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ...

De Broglie wavelength of particles

Louis de Broglie postulated that all particles with momentum have a wavelength Louis-Victor-Pierre-Raymond, 7th duc de Broglie, generally known as Louis de Broglie (August 15, 1892–March 19, 1987), was a French physicist and Nobel Prize laureate. ... This article is about momentum in physics. ...

where h is Planck's constant, and p is the momentum of the particle. This hypothesis was at the basis of quantum mechanics. Nowadays, this wavelength is called the de Broglie wavelength. For example, the electrons in a CRT display have a De Broglie wavelength of about 10^-13 m. A commemoration plaque for Max Planck on his discovery of Plancks constant, in front of Humboldt University, Berlin. ... This article is about momentum in physics. ... For a less technical and generally accessible introduction to the topic, see Introduction to quantum mechanics. ... The wavelength is the distance between repeating units of a wave pattern. ... For other uses, see Electron (disambiguation). ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT: 1. ...

See also

• Amplitude
• Angular frequency
• Frequency
• Fraunhofer lines, spectral lines traditionally used as standard optical wavelength references
• Periodic function
• Wavevector

It has been suggested that pulse amplitude be merged into this article or section. ... It has been suggested that this article or section be merged into Angular velocity. ... For other uses, see Frequency (disambiguation). ... Solar Fraunhofer lines In physics and optics, the Fraunhofer lines are a set of spectral lines named for the German physicist Joseph von Fraunhofer (1787--1826). ... In mathematics, a periodic function is a function that repeats its values after some definite period has been added to its independent variable. ... A wave vector is a vector representation of a wave. ...

External links

• Conversion: Wavelength to Frequency and vice versa - Sound waves and radio waves
• Teaching resource for 14-16yrs on sound including wavelength