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: 378
orthogonality
  ارداکنجی   
ardâkonji

Fr.: 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-hidrožen

Fr.: 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 ardâhanjârvar

Fr.: vecteurs orthonormaux   

Two non-zero vectors that are → orthogonal and have magnitude 1.

orthogonal; → vector.

orthorhombic
  اردالوزیک   
ardâlowzik

Fr.: 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 ardâlowzik

Fr.: 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   
ardâbini

Fr.: orthoscopique   

Of or relating to an optical system corrected for → distortion.

ortho-; → -scopic.

orthoscopic eyepiece
  چشمیِ اردابینی   
cešmi-ye ardâbini

Fr.: 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 navandé

Fr.: 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 navešgar

Fr.: 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.

osculate
  آبوسیدن   
âbusidan

Fr.:   

Geometry: Of a curve, to touch another curve so as to have the same tangent and curvature at the point of contact.

From L. osculatum p.p. of osculari "to kiss," from osculum "kiss," literally "little mouth," diminutive of os "mouth;" PIE *os-/*ous- "mouth;" cf. Av. āh- "mouth;" Skt. ās-, āsán- "mouth;" Hittite aiš- "mouth;" O.Ir. á "mouth;" O.N. oss "mouth."

Âbusidan, from â- a nuance prefix + busidan "to kiss," related to buyidan "to smell," buy "smell, scent;" Mid.Pers. bôy, bôd "smell, scent; consciousness," bôyidan "to smell," Mod./Mid.Pers. bustân "garden," Parthian (prefixed *pati-) pdbws- "to desire; to hope for;" Av. baod- "to perceive, notice, become aware of; to smell of," baoδi- "smell, fragrance," baozdri- "who gets to know sexually;" cf. Skt. bodh- "to wake, awaken; to perceive, pay attention," Buddha "awakened, enlightened;" Gk. peuthomai "to learn, hear;" Lith. budeti "to wake;" O.C.S. bljusti "to take care;" PIE base *bheudh- "to be aware, to make aware."

osculating
  آبوسنده   
âbusandé

Fr.: osculateur   

Relating to → osculate.

Participial adjective of → osculate.

osculating circle
  پرهونِ آبوسنده   
parhun-e âbusandé

Fr.: cercle osculateur   

The circle that touches a curve (on the concave side) and whose radius is the radius of curvature.

osculating; → circle.

osculating elements
  بن‌پارهایِ آبوسشی   
bonpârhâ-ye âbuseš

Fr.: éléments orbitaux osculateurs   

The orbital elements of an osculating orbit.

osculating; → element.

osculating orbit
  مدارِ آبوسنده   
madâr-e âbusandé

Fr.: orbite osculatrice   

The Keplerian orbit that a satellite would follow after a specific time t if all forces other than central inverse-square forces ceased to act from time t on. An osculating orbit is tangent to the real, perturbed, orbit and has the same velocity at the point of tangency.

osculating; → orbit.

osculating plane
  هامُنِ آبوسنده   
hâmon-e âbusandé

Fr.: plan osculateur   

For a curve C at a point p, the limiting plane obtained from taking planes through the tangent to C at p and containing some variable point p' and then letting p' approach p along C.

osculating; → plane.

osculating sphere
  سپهرِ آبوسنده، کره‌یِ آبوسنده   
sepehr-e âbusandé, kore-ye ~

Fr.: sphère osculatrice   

For a curve C at a point p, the limiting sphere obtained by taking the sphere that passes through p and three other points on C and then letting these three points approach p independently along C.

osculating; → sphere.

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