An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 63 Search : part
test particle
  ذره‌ی ِ آزمون   
zarre-ye âzmun

Fr.: particule-test   

In → plasma physics, → fluid dynamics, and → self-gravitating systems, a particle or ensemble of particles which are affected by the evolution of the rest of the system, but do not affect the rest of the system. The test particle concept is used, e.g., for revealing a flow, describing the path of fluid elements, and so on.

test; → particle.

virtual particle
  ذرّه‌یِ ویر‌آگین   
zarr-ye virâgin

Fr.: particule virtuelle   

A subatomic particle that, according to the uncertainty principle, comes into being out of energy fluctuations of the "vacuum" and lasts for extremely short periods of time. An electron-positron pair can exist only about 4 x 10-21 seconds. The lifetime increases as the mass and energy involved decreases. Virtual particles are real and have measurable effects, but cannot be directly observed, according to the uncertainty principle. → vacuum polarization.

virtual; → particle

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.

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