# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

Homepage

Number of Results: 674
 electromagnetic signal   نشال ِ برقامغناتی   nešâl-e barqâmeqnâtiFr.: signal électromagnétique   Information transmitted by means of a modulated current or an electromagnetic wave and received by telephone, radio, television, etc. electromagnetic spectrum   بیناب ِ برقامغناتی   binâb-e barqâmeqnâtiFr.: spectre électromagnétique   The range of frequencies over which electromagnetic waves are propagated. → electromagnetic radiation. electromagnetic theory   نگره‌ی ِ برقامغناتی   negare-ye barqâmeqnâtiFr.: théorie électromagnétique   The description of combined electric and magnetic fields mainly by → Maxwell's equations. Same as → electromagnetism. electromagnetic theory of light   نگره‌ی ِ برقامغناتی ِ نور   negare-ye barqâmeqnâti-ye nurFr.: théorie électromagnétique de la lumière   The theory describing light as a wave phenomenon resulting from the combination of two electric and magnetic fields vibrating transversely and mutually at right angles. → electromagnetic radiation; → electromagnetic wave; → Maxwell's equations.→ electromagnetic; → theory; → light. electromagnetic wave   موج ِ برقامغناتی   mowj-e barqâmeqnâtiFr.: onde électromagnétique   A wave produced by oscillation or acceleration of an electric charge. → electromagnetic radiation.→ electromagnetic; → wave. electromagnetism   برقامغنات، برقامغناتیس   barqâmeghnât, barqâmeghnâtisFr.: électromagnétisme   1) The science dealing with the physical relations between → electricity and → magnetism. Same as → electromagnetic theory. 2) One of the four fundamental forces of nature, governing the electric and magnetic interaction between particles.→ electro-; → magnetism. electromotive force (EMF)   نیروی ِ برقران   niru-ye barqrân (#)Fr.: force électromotrice   The force, analogous to a pressure, which maintains a flow of electricity through a closed circuit. It is the algebraic sum of the → potential differences acting in the circuit. The unit of electromotive force is the → volt.From → electro- + motive, from M.E., from M.Fr., from O.Fr. motif, from M.L. motivus "moving, impelling," from L. motus, p.p. of movere "to move," → motion; → force.Niru, → force; barqrân, literally "driving electricity," from barq, → electro- + rân present stem of rândan, → drive. electron   الکترون   elektron (#)Fr.: électron   The → elementary particle that possesses the smallest possible negative → electric charge. This structureless particle has an intrinsic → spin (1/2), a mass of 9.109 382 91 (40) x 10-31 kg, and an electric charge of 1.602 176 565(35) × 10-19 → coulombs, or 4.803 204 51(10) × 10-10 → esu.Term first suggested in 1891 by Irish physicist G. J. Stoney (1826-1911); from electr-, from → electric + -on, a suffix used in the names of subatomic particles, probably extracted from → ion. electron affinity   کرونی ِ الکترونی   karvani-ye elektroniFr.: affinité électronique   The amount of energy released or absorbed in the process in which an electron is added to a neutral atom or molecule in gaseous state to form a negative ion.→ electron; → affinity. electron capture   گیر‌افت ِ الکترون   giroft-e elektronFr.: capture d'électron   A process whereby an → unstable atom becomes stable. In this process, an → electron in an atom's inner shell is drawn into the → nucleus where it combines with a → proton, forming a → neutron and a → neutrino. The neutrino escapes from the atom's nucleus. The result is an element change, because the atom loses a proton. For example, an atom of → carbon (with 6 protons) becomes an atom of → boron (with 5 protons). Electron capture is also called K-capture since the captured electron usually comes from the atom's K-shell. See also → neutronization.→ electron; → capture. electron charge   بار ِ الکترون   bâr-e elektron (#)Fr.: charge de l'électron   The charge of one electron, e = -1.602 176 × 10-19→ coulombs or -4.803 204 51 × 10-10→ statcoulombs.→ electron; → charge. electron configuration   همپیکرش ِ الکترونی   hampeykareš-e elektroniFr.: configuration électronique   Of an atom, a form of notation which shows how the electrons are distributed among the various atomic orbital and energy levels. The format consists of a series of numbers, letters and superscripts. For example, 1s2 2s2 2p3 means: 2 electrons in the 1s subshell, 2 electrons in the 2s subshell, and 3 electrons in the 2p subshell. electron degeneracy   واگنی ِ الکترون   vâgeni-ye elektron (#)Fr.: dégénérescence des électrons   A → degenerate matter in which electrons are very tightly packed together, as in a white dwarf, but cannot get closer than a certain limit to each other, because according to quantum mechanics laws (→ Pauli exclusion principle) the lowest energy levels can be occupied by only one electron. Therefore, electrons are forced into high energy states. And the significant pressure created by these high energy electrons supports white dwarf stars against their own gravity.→ electron; → degeneracy. electron density   چگالی ِ الکترونی   cagâli-ye elektroni (#)Fr.: densité électronique   The number of electrons per unit volume in an ionized medium, like an → H II region, as determined from → emission lines.→ electron; → density. electron diffraction   پراش ِ الکترونی   parâš-e elekroni (#)Fr.: diffraction des électrons   A diffraction phenomenon resulting from the passage of electrons through matter, analogous to the diffraction of visible light. This phenomenon is the main evidence for the existence of waves associated with elementary particles; → de Broglie wavelength.→ electron; → diffraction. electron mass   جرم ِ الکترون   jerm-e elekron (#)Fr.: masse de l'électron   The mass of an electron, which is 9.109 382 91 × 10-28 g.→ electron; → mass. electron radius   شعاع ِ الکترون   šo'â'-e elektronFr.: rayon de l'électron   The classical size of the electron given by re = e2/mec2 = 2.81794 × 10-13 cm, where e and me are the → electron charge and → electron mass, respectively, and c is the → speed of light.→ electron; → radius. electron shell   پوسته‌ی ِ الکترونی   puste-ye elekroni (#)Fr.: couche éléctronique   Any of up to seven energy levels on which an electron may exist within an atom, the energies of the electrons on the same level being equal and on different levels being unequal. The number of electrons permitted in a shell is equal to 2n2. A shell contains n2 orbitals, and n subshells.→ electron; → shell. electron temperature   دمای ِ الکترونی   damâ-ye elektroni (#)Fr.: température électronique   1) The temperature of electrons in an interstellar ionized nebula (e.g. in → H II regions and → planetary nebulae) as determined by characteristic → emission lines (optical → forbidden lines or → radio recombination lines). 2) In the → solar wind, the temperature derived from the mean → thermal agitation of the electrons. More specifically, electric field receivers on board space probes carry out the spectroscopy of the → thermal noise due to the potential fluctuations produced by the thermal agitation of the electrons, yielding the electron temperature in certain conditions (N. Meyer-Vernet, 2007, Basics of the Solar Wind, Cambridge Univ. Press). See also → proton temperature.→ electron; → temperature. electron volt (eV)   الکترون-ولت   elektron-volt (#)Fr.: électron-volt   → electron; → volt.