1) One of the principal lines through the center of a figure or a
solid, especially, the line which divides the figure or solid
L. axis "axle, pivot," akin to O.E. eax "axis, axle," Gk. axon "axle," Skt. aksa- "axle, axis, beam of a balance;" PIE base *aks- "axis."
Âsé, from Pers. dialects: Qâyeni asak "the shaft connecting the plough to the yoke," Lori esi "a pillar (used to put up a tribal tent)," variants hosi, hosin, Tabari âssen "the foot of a door on which it turns," cf. Skt. īṣā- "pole or shafts of a carriage or plough," Av. aêša "the two shafts," Mod.Pers. xiš "plough(share)," Gk. oiax "handle of rudder, tiller, helm," PIE base *ei-, *oi- "pole, thill."
axis of rotation
Fr.: axe de rotation
Same as → rotation axis and → rotational axis.
hamâmun-e âse-yi, âse-hamâmun
Having → axisymmetry.
hamâmuni-ye âse-yi, âse-hamâmuni
Same as → axial symmetry.
âse-ye âsmân (#)
Fr.: axe du monde
The Earth's axis extended to the → celestial pole.
Fr.: axe conjugué
One of the two diameters of a conic, so related that a tangent at the end of one is parallel to the other.
Fr.: axe de déclinaison
The axis to which the telescope tube is fastened in an → equatorial mounting.
→ declination; → axis.
inclination of axis
Fr.: inclinaison de l'axe
The angle between the rotation axis of a planet and the normal to the ecliptic.
→ inclination; → axis.
Fr.: axe magnétique
The imaginary straight line joining the two → poles of a → magnet.
Fr.: grand axe
The greatest diameter of an ellipse; it passes through the two foci.
Fr.: petit axe
The axis of an ellipse that is perpendicular to the major axis at a point equidistant from the foci.
non-principal axis (NPA) rotational motion
jonbeš-e carxeši be gerd-e âse-ye nâ-farin
Fr.: mouvement rotationnel autour de l'axe non-parincipal
A → tumbling motion of an → asteroid. See also → tumbling asteroid.
→ non-; → principal axis; → rotational; → motion.
off-axis optical system
râžmân-e nurik-e ap-âsé
Fr.: système optique hors axe
An → optical system in which the → optical axis of the → aperture is not coincident with the mechanical center of the aperture.
Fr.: axe optique
The direction in a doubly refracting crystal in which light is propagated without double refraction.
âse-ye nuri (#)
Fr.: axe optique
Line passing through the optical center and the center of curvature of a → spherical mirror or → lens. Same as → principal axis.
Fr.: axe orbital
The → perpendicular to the → orbital plane.
parallel axis theorem
farbin-e âsehâ-ye parâsu
Fr.: théorème des axes parallèles
The → moment of inertia of a body about any given axis is the moment of inertia about a parallel axis through the center of mass, plus the moment of inertia about the given axis if the mass were located at the center of mass. same as → Steiner's theorem.
perpendicular axis theorem
farbin-e âsehâ-ye pâlâr
Fr.: théorème des axes perpendiculaires
The → moment of inertia of a plane object (→ lamina) about an axis perpendicular to the plane is equal to the sum of the moments of inertia about any two perpendicular axes in the plane. Thus if x and y axes are in the plane, Iz = Ix + Iy.
→ perpendicular; → axis; → theorem.
âse-ye qotbi (#)
Fr.: axe polaire
The axis of an → equatorial mounting that is parallel to the Earth's axis, and consequently points to the celestial pole.
1) The practice and practical side of knowledge or skills, as opposed to the
M.L. praxis "practice, action," from Gk. praxis "practice, action, doing," from stem of prassein "to do, to act."
Varzidâr, from varzid past stem of varzidan, → practice, + -âr prefix forming nouns of action, such as kerdâr, raftâr, didâr, goftâr, jostâr, etc.