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

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 412
 ortho-water   اردا-آب   adrdâ-âbFr.: eau ortho   The → water molecule in which the → nuclear spin of the constituent → hydrogen atoms are → parallel (→ orthohydrogen). In astrophysics the ratio between ortho- and → para-water is used to determine temperatures in → interstellar medium.→ ortho-; → water. orthocenter   اردامرکز   ardâmarkazFr.: orthocentre   Of a triangle, the point where the three → altitudes of the → triangle converge.→ ortho-; → center. orthogonal   ارداکنج   ardâkonjFr.: orthogonal   In elementary geometry, pertaining to or involving right angles or perpendiculars. Of a system of real functions, defined so that the integral of the product of any two different functions is zero. Of a linear transformation, defined so that the length of a vector under the transformation equals the length of the original vector. Of a square matrix, defined so that its product with its transpose results in the identity matrix.→ ortho- + gonia "angle," related to gony "knee;" L. genu "knee;" Mod.Pers. zânu "knee;" Av. žnav-, žnu- "knee;" Skt. janu-; PIE base *g(e)neu-, see below, + → -alArdâkonj, from ardâ-, → ortho-, + konj "angle, corner, confined place" (variants xong "corner, angle," Tabari kânj, Kurd. kunj, Hamadâni kom), maybe from the PIE base *g(e)neu-, as above, and related to Mod.Pers. zânu "knee" (Av. žnu-), Skt. kona- "angle, corner," Gk. gony, gonia, L. cuneus "a wedge," Albanian (Gheg dialect) kân "angle, corner," Albanian (Toks) kënd "angle, corner." orthogonal functions   کریاهایِ ارداکنج   karyâhâ-ye ardâkonjFr.: fonctions orthogonales   A set of functions, any two of which, by analogy to orthogonal vectors, vanish if their product is summed by integration over a specified interval.→ orthogonal; → function. orthogonal lines   خط‌هایِ ارداکنج   xatthâ-ye ardâkonjFr.: droites orthogonales   Perpendicular lines.→ orthogonal; → line. orthogonal trajectory   ترایشانه‌ی ِ ارداکنج   tarâyešâne-ye ardâkonjFr.: trajectoire orthogonale   Math.: An → isogonal trajectory where the family of curves are cut at right angles.→ orthogonal; → trajectory. orthogonal vectors   بردارهای ِ ارداکنج   bordârhâ-ye ardâkonjFr.: vecteurs orthogonaux   Two non-zero vectors which are perpendicular, i.e. their → scalar product is zero.→ orthogonal; → vector. orthogonality   ارداکنجی   ardâkonjiFr.: orthogonalité   1) The property of → orthogonal functions. 2) The following conditions satisfied by the → Fourier series: ∫ cos (mx) sin (nx) dx = 0 (summed from -π to +π) for all m, n∫ cos (mx) cos (nx) dx = 0 (summed from -π to +π) for all m ≠ n, = 2π for m = n = 0, = π for (m = n) > 0 ∫ sin (mx) sin (nx) dx = 0 (summed from -π to +π) for m ≠ n, = π for (m = n) > 0.→ orthogonal; → -ity. orthohydrogen   اردا-هیدروژن   ardâ-hidroženFr.: orthohydrogène   Molecular hydrogen in which the nuclei (protons) of the two hydrogen atoms contained in the molecule have spins in the same direction. → parahydrogen→ ortho-; → hydrogen. orthonormal vectors   بردارهای ِ ارداهنجارور   bordârhâ-ye ardâhanjârvarFr.: vecteurs orthonormaux   Two non-zero vectors that are → orthogonal and have magnitude 1.→ orthogonal; → vector. orthorhombic   اردالوزیک   ardâlowzikFr.: orthorhombique   Of or relating to a crystalline structure characterized by three mutually perpendicular axes of different length. → orthorhombic crystal system.→ ortho-; → rhombic. orthorhombic crystal system   راژمان ِ بلوری ِ اردالوزیک   râžmân-e boluri-ye ardâlowzikFr.: système cristallin orthorhombique   A → crystal system that has three mutually perpendicular axes, each of which is of a different length than the others.→ orthorhombic; → crystal; → system. orthoscopic   اردابینی   ardâbiniFr.: orthoscopique   Of or relating to an optical system corrected for → distortion.→ ortho-; → -scopic. orthoscopic eyepiece   چشمیِ اردابینی   cešmi-ye ardâbiniFr.: oculaire orthoscopique   A telescopic eyepiece that produces a wide field of view (between 40° and 50°). The eyepiece consists of a single element lens that is normally plano-convex, and a cemented triplet that is usually symmetrical.→ orthoscopic; → eyepiece. oscillate   نویدن   navidan (#)Fr.: osciller   To have, produce, or generate oscillations. → vibrate.From L. oscillatus, p.p. of oscillare "to swing," from oscill(um) "swing" + -ate a suffix forming verbs from L. words.Navidan "to swing, oscillate," from nâvidan, literally "to swing like a ship," from nâv "ship;" O.Pers./Av. *nāv-, O.Pers. nāviyā- "fleet;" Skt. nau-, nava- "ship, boat;" Gk. naus "ship;" PIE *nau- "boat." oscillating Universe   گیتیِ نونده   giti-ye navandéFr.: Univers oscillatoire   A cosmological model in which the Universe is closed and undergoes a series of oscillations, each beginning with a big bang and ending with a big crunch.Oscillating, verbal adj. of → oscillate; → universe. oscillation   نَوِش   naveš (#)Fr.: oscillation   The state of any quantity when the value of that quantity is continually changing so that it passes through maximum and minimum values.Verbal noun of → oscillate. oscillation mode   ترز ِ نَوِش، مُد ِ ~   tarz-e naveš, mod-e ~Fr.: modes d'oscillation   Same as → pulsation mode.→ oscillation; → mode. oscillator   نَوشگر   navešgar (#)Fr.: oscillator   A device for producing sonic or ultrasonic pressure waves in a medium. A device with no rotating parts for converting direct current into alternating current.Agent noun of → oscillate. oscillator strength   زورِ نوشگر   zur-e navešgarFr.: force d'oscillateur   A quantum-mechanical measure of the probability that a specific atomic transition will occur. It is used in the equation for the absorption coefficient of a spectral line. Also known as f value.→ oscillator; → strength.