An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 215
wave collapse
  رمبش ِ موج   
rombeš-e mowj

Fr.: effondremenr d'onde   

In the → Copenhagen Interpretation of → quantum mechanics, the change undergone by the → wave function of a particle when a measurement is performed on the particle. The wave function collapses to one that has a definite value for the quantity measured. If the → position of the matter wave is measured, it collapses to a localized → pulse. If → momentum is measured, it collapses to a wave with a definite momentum. Same as → collapse of the wave function.

wave; → collapse.

wave equation
  هموگش ِ موج   
hamugeš-e mowj

Fr.: équation d'onde   

The partial differential equation 2U / ∂2x + ∂2U / ∂2y + ∂2U / ∂2z = (1/c2) ∂2U / ∂2t or its counterparts in one or two dimensions or in other coordinates, the solution of which represents the propagation of displacementU as waves with velocity c.

wave; → equation.

wave function
  کریای ِ موج   
karyâ-ye mowj

Fr.: fonction d'onde   

In → quantum mechanics, the function of space and time that satisfies → Schrodinger equation. The square of the modulus of its amplitude at any point represents the probability of finding a particle there.

wave; → function.

wave mechanics
  مکانیک ِ موجی   
mekânik-e mowji (#)

Fr.: mécanique ondulatoire   

One of the forms of quantum mechanics, due to Louis de Broglie and extended by E. Schrödinger. It originated in the suggestion that light consists of corpuscles as well as of waves and the consequent suggestion that all elementary particles are associated with waves.

wave; → mechanics

wave nature
  زاستار ِ موجی   
zâstâr-e mowji

Fr.: nature ondulatoire   

A general term to describe → light involving the following phenomena: → reflection, → refraction, → interference, → diffraction, and → polarization. Compare → particle nature.

wave; → nature.

wave number
  عدد ِ موج   
adad-e mowj (#)

Fr.: nombre d'onde   

The reciprocal of → wavelength, which represents the number of waves per unit length. Wave number is often defined as k = 2π/λ. Same as → propagation number.

wave; → number

wave optics
  نوریک ِ موجی   
nurik-e mowji

Fr.: optique ondulatoire   

The branch of optics that analyzes the electromagnetic radiation in terms of its wave characteristics. Also called → physical optics.

wave; → optics.

wave packet
  بسته‌ی ِ موج   
baste-ye mowj (#)

Fr.: paquet d'onde   

A traveling → waveform consisting of the → superposition of several → waves of different → wavelengths and → phases.

wave; packet from M.E. pak "bundle" + diminutive suffix -et; maybe from M.Fr. pacquet.

Basté "packet," literally "bound, tied; set," p.p. of bastan "to form, bind, tie" (Mid.Pers. bastan/vastan "to bind, shut;" Av./O.Pers. band- "to bind, fetter," banda- "band, tie;" cf. Skt. bandh- "to bind, tie, fasten;" Ger. binden; E. bind; PIE base *bhendh- "to bind").

wave plate
  تیغه‌ی ِ موج   
tiqe-ye mowj (#)

Fr.: lame à retard   

An optical element that retards the phase of one plane of vibration of light relative to the plane at right angles. The two beams then recombine to form a single beam with new polarization characteristics. A typical wave plate is a birefringent crystal with a carefully chosen orientation and thickness. Also known as → retardation plate. A → half-wave plate creates a half-wave retardation. See also → quarter-wave plate.

wave; → plate.

wave theory of light
  نگره‌ی ِ موجی ِ نور   
negare-ye mowji-ye nur

Fr.: théorie ondulatoire de la lumière   

The theory that describes light as waves that spread out from the source that generates the light. It contradicts the → corpuscular theory of light proposed by Newton (1704). The idea of the wave nature of light was first put forward by Robert Hooke (1660). The wave theory was originally stated by Huygens (1690), who showed reflection and refraction could be explained by this theory. It was supported by → Young's experiment (1802) and established by the work of Fresnel (1814-1815). The wave theory received its most important support from Maxwell's → electromagnetic theory. See also → Huygens-Fresnel principle.

wave; → theory; → light.

wave train
  قطار ِ موج، موج-ترن   
qatâr-e mowj (#), mowj-teran

Fr.: train d'onde   

A series of successive waves spaced at regular intervals.

wave; → train.

wave vector
  بردار ِ موج   
bordâr-e mowj (#)

Fr.: vecteur d'onde   

A vector whose direction is that of propagation of a wave and whose magnitude is given by the → wave number, 2π/λ, where λ is the → wavelength, or ω/c, where ω is the → angular frequency and c is the speed of propagation.

wave; → number.

wave-particle duality
  دوگانگی ِ موج-ذره   
dogânegi-ye mowj-zarré

Fr.: dualité onde-particule   

The principle admitted in → quantum mechanics that all particles have a wave-like nature and that waves have a particle aspect. The wave-particle duality is of fundamental importance in obtaining a realistic picture of the → elementary particles.
See also: → particle nature, → wave nature, → de Broglie hypothesis, → Davisson-Germer experiment.

wave; → particle; → duality.


Fr.: bande de longueur d'onde   

A portion of the electromagnetic spectrum which is defined because of its characteristics or for its use.

wave; → band.


Fr.: forme d'onde   

A graphical representation of the shape of a wave for a given instant in time.

wave; → form.

waveform analysis
  آنالس ِ موجدیس   
ânâlas-e mowjdis

Fr.: analyse de forme d'onde   

The resolution of a complex waveform into a sum of simple periodic waves, usually by computer means.

waveform; → analysis.

  پیشان ِ موج، موج-پیشان   
pišân-e mowj, mowj-pišân

Fr.: front d'onde   

The locus of adjacent points possessing the same phase in the path of a wave motion. Its surface is uniform (spherical or plane) and normal to propagation direction in an isotropic medium. → wavefront distortion.

wave; → front.

wavefront correction
  ارشایش ِ پیشان ِ موج   
aršâyeš-e pišân-e mowj

Fr.: correction de front d'onde   

In → adaptive optics, eliminating the effects of atmospheric turbulence on the wavefront of the object being observed. → wavefront distortion.

wavefront; → correction.

wavefront distortion
  چولگی ِ پیشان ِ موج   
cowlegi-ye pišân-e mowj

Fr.: distortion de front d'onde   

The disruption of the spherical shape of a wavefront due to atmospheric turbulence which makes the adjacent points in the wavefront out of phase.

wavefront; → distortion.

wavefront sensor
  حسگر ِ پیشان ِ موج   
hessgar-e pišân-e mowj

Fr.: analyseur de front d'onde   

In adaptive optics, a device that analyzes the light sample coming from the wavefront and determines the error in each part of the beam. The wavefront sensor used in adaptive optics is a → Shack-Hartmann type, which works in conjunction with a deformable mirror.

wavefront; → sensor.

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