magnetic south pole
qotab-e daštar-e meqnâtisi
Fr.: pôle sud magnétique
tâbeš-e doqotbe-ye meqnâtisi (#)
Fr.: rayonnement du dipôle magnétique
Radiation emitted by a rotating magnet.
Fr.: pôle moyen
The direction of the Earth's axis at a particular epoch if the nutation is ignored.
An entity consisting of several poles.
Fr.: indice multipolaire
A variable used in → spherical harmonic expansions. Each spherical harmonic is characterized by its multipole index l: l = 0 for a → monopole, l = 1 for a → dipole, and so on. It is used in particular to describe the → cosmic microwave background anisotropy: ΔT/T0 (θ,φ) = Σ almYlm(θ,φ), where θ and φ are the → spherical polar coordinates, Ylm is the → spherical harmonic functions, and the sum runs over l = 1, 2, ..., ∞ and m = -l, ..., l, where the multipole index l corresponds to angular scales ≅ 180°/l.
Fr.: moment multipolaire
The quantity that gives the electric potential field due to a distribution of charges, such as a → dipole, → quadrupole, → octupole, etc. A multipole moment usually involves powers of the distance to the origin, as well as some angular dependence.
north celestial pole
qotb-e âsmâni-ye hudar
Fr.: pôle nord céleste
The point in the → northern hemisphere where the → rotation axis of Earth touches the → celestial sphere. The star → Polaris, also called the Pole Star, is located very near this point, at an angular separation of 42 degrees (about 1.4 lunar diameters).
Fr.: pôle nord
1) An → imaginary → point
in the → northern hemisphere representing the intersection
of the → Earth's → rotation axis
with the → globe or with the
→ celestial sphere.
1) Either extremity of the axis of the Earth or of any spherical body.
M.E., from L. polus "end of an axis, the sky," from Gk. polos "pivot, pole," polein "move around;" from PIE base *kwel- "to turn, move around, sojourn, dwell;" cognate with Pers. carx "every thing performing a circulatory motion; a wheel; a cart;" Av. caxra- "wheel," caraiti "he moves, approaches;" cf. Skt. cakra- "wheel, circle; cycle," carati "he moves, wanders;" Gk. kyklos "circle, wheel" (loaned L.L. cyclus); L. colere "to dwell in, to cultivate, move around," colonus "farmer, settler;" O.E. hweol "wheel;" Rus. koleso "wheel."
Qotb, from Ar. quTb.
pole of a mirror
Fr.: pôle de mirroir
The point where the → principal axis passes through the mirror.
setâre-ye qotbi (#)
Fr.: étoile polaire
A star that lies in the direction pointed to by the Earth's → rotation axis. The term usually refers to the star → Polaris, which is the current → north celestial pole star. The → south celestial pole is not associated with any bright star.
A set of either two → electric dipoles or two → magnetic dipoles in close proximity to each other arranged with alternating polarities and acting as a single unit. Quadrupole interactions are much smaller than dipole interactions, but can allow transitions forbidden in dipole moment transitions.
Fr.: anisotropie quadrupolaire
The → anisotropy which is at the origin of the → cosmic microwave background polarization. The quadrupole anisotropy could arise from three types of perturbations: → scalar perturbation, → vector perturbation, and → tensor perturbation
Fr.: lentille quadrupôle
Fr.: moment quadrupolaire
A quantity characterizing an electric charge distribution, determined by the product of the charge density, the second power of the distance from the origin, and a spherical harmonic over the charge distribution.
south celestial pole
qotb-e âsmâni-ye daštar
Fr.: pôle sud céleste
Fr.: pôle Sud
1) An → imaginary point in the
→ southern hemisphere representing the intersection of the
→ Earth's → rotation axis with the
→ globe with the → celestial sphere.
From M.E. taddepol, from tadde "toad" + polle "head," from M.L.G. or M.Du. pol "head, top."
Vagiz, from Tabari vag "→ frog" + -iz, -ize diminutive suffix (variants -ce, -že, -ak, Mid.Pers -cak).
Fr.: orbite en forme de têtard