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autumn pâyiz (#) Fr.: automne The season of the year between summer and winter; it begins in the northern hemisphere at the → autumnal equinox and ends at the → winter solstice. O.Fr., from L. autumnus, a word probably of Etruscan origin. Pâyiz, from Mid.Pers. pâdiz or pâtez, from Proto-Iranian *pâti-z(a)ya- "near winter," from pâti "near" + *z(a)ya- "winter," compare with Av. zyan- or zyam- "winter" (Skt. heman, Gk. xeimon, L. hiems). |
autumnal equinox hamugân-e pâyizi Fr.: équinoxe d'automne One of the two points where the → ecliptic crosses the → celestial equator. At the autumnal equinox the Sun appears to be moving across the equator from the northern celestial hemisphere to the southern celestial hemisphere. The instant of the event. |
average miyângin (#) Fr.: moyenne A number representing a group of quantities, obtained by adding each quantity of the group and dividing the total by the number of quantities. Same as → arithmetic mean. From O.Fr. avarie "damage to ship," from It. avaria or maybe avere, O.Fr. aveir "property, goods," from L. habere "to have." Meaning shifted to "equal sharing of such loss by the interested parties." Miyângin "the middle; middle-sized; the middle pearl in a string," from miyân, → middle, + -gin a suffix forming adjectives of possession. |
average acceleration šetâb-e miyângin Fr.: accélération moyenne Of a body traveling from A to B, the change of → velocity divided by the time interval: ā = (v_{2} - v_{1}) / (t_{2} - t_{1}). → average; → acceleration. |
average velocity tondâ-ye miyângin Fr.: vitesse moyenne The ratio of the displacement (Δx) of a particle, as it moves from point A to point B, to the corresponding time interval: v = Δx/Δt. |
averted vision negâh-e kaž (#) Fr.: regard oblique The technique of looking slightly to the side of a faint object being studied while continuing to concentrate on the object. The technique helps bring out details which otherwise would be missed by looking directly at an object. The reason is that the portion of the eye's retina that best detects dim light (fovea) is located all around the edges rather than the center. Averted p.p. from avert, from O.Fr. avertir, from L. avertere "to turn away," from → ab- "from, away" + vertere "to turn" (cognate with Pers. gardidan "to turn"); → vision. Negâh, → vision; kaž "averted." |
Avogadro constant pâyâ-ye Avogâdro (#) Fr.: constante d'Avogadro The number of units in one → mole of any → substance (defined as its → molecular weight in grams), equal to 6.022 140 857 × 10^{23}. The units may be electrons, atoms, ions, or molecules, depending on the nature of the substance. Named after Amedeo Avogadro (1776-1856), whose law allowed other physicists to calculate Avogadro's number; → number. |
Avogadro's law qânun-e Avogâdro (#) Fr.: loi d'Avogadro A statement according to which equal volumes of different gases contain an equal number of molecules under the same conditions of temperature and pressure. After Amedeo Avogadro (1776-1856), Italian chemist and physicist, who advanced the hypothesis in 1811. |
Avogadro's number adad-e Avogâdro (#) Fr.: nombre d'Avogadro Named after Amedeo Avogadro (1776-1856), whose law allowed other physicists to calculate Avogadro's number; → constant. |
aware âgâh (#) Fr.: conscient Having knowledge; conscious; informed; alert. → awareness. M.E., variant of iwar, O.E. gewær; cf. O.S. giwar, M.Du. gheware, O.H.G. giwar, Ger. gewahr. Âgâh "aware, knowing," related to negâh "look, attention;" Mid.Pers. âkâh; Av. ākas- "to look;" Proto-Iranian *kas- "to look, appear;" cf. Skt. kāś- "to become visible, appear;" Gk. tekmar, tekmor "sign, mark;" |
awareness âgâhi (#) Fr.: conscience The state or condition of being aware; having knowledge; consciousness
(Dictionary.com). |
axial âse-yi (#) Fr.: axial Of, pertaining to, characterized by, or forming an axis. |
axial inclination darkil-e âsé Fr.: inclinaison de l'axe The angle at which a planet's axis of rotation is tilted, with respect to that of the planet's orbit. → axial; → inclination. |
axial precession pišâyân-e âse-yi Fr.: précession axiale 1) A change in the orientation of the → rotation axis
of a non-spherical, spinning body caused by → gravity.
A rotating top will precess in a direction determined by the
→ torque exerted by its → weight.
The precession
→ angular velocity is
inversely proportional to the spin angular velocity, so that the
precession is faster and more pronounced as the top slows down. → axial; → precession. |
axial symmetry hamâmuni-ye âse-yi Fr.: symmétrie axiale A symmetry with respect to a line. A geometric configuration is said to have axial symmetry if it remains unchanged when rotated about a given line. |
axial tilt gerâ-ye âsé Fr.: inclinaison de l'axe The angle between an object's → rotation axis and its → orbital axis. In other words, the angle between its → equatorial plane and → orbital plane. Same as → axial inclination and → obliquity, but not to be confounded with → orbital inclination. |
axiom bondâšt (#), arzâqâzé (#) Fr.: axiome In any system of mathematics or logic, a statement or proposition from which secondary statements or propositions are derived. The truth of an axiom is either taken for granted or assumed. In modern practice, axiom and → postulate have the same meaning. M.Fr. axiome, from L. axioma, from Gk. axioma "authority," literally "something worthy," from axioun "to think worthy," from axios "worthy," from PIE adj. *ag-ty-o- "weighty," from base *ag- "to drive, draw, move." Bondâšt, literally "taking as the base," from bon
"root, origin, base" + dâšt "held," from dâštan "to have,
to hold, to maintain, to consider." |
axiom of constraints bondâšt-e pâvandhâ Fr.: axiome des contraintes An axiom in → statics, stating that any → constrained body can be treated as a → free body detached from its → constraints, provided the latter are represented by their → reactions. → axiom; → constraint. |
axiomatic bondâšti Fr.: axiomatique Of, relating to, or resembling an → axiom. |
axiomatic system râžmân-e bondâšti Fr.: système axiomatique Any system of → logic which explicitly states → axioms from which → theorems can be → deduced. |
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