ruk-e miyân Atlasi
Fr.: dorsale médio-atlantique
An immense chain of underwater mountains that runs down the middle of the Atlantic Ocean. The MAR, approximately 500-1000 km wide, extends 16,000 km from Iceland to the Antarctic Circle. The MAR is so high that it actually rises above sea level in many places, forming volcanic islands. The Azores, Ascension, St. Helena, and Iceland all arise from this great Atlantic range. The chain results from the movement of the continental plates. As these plates slowly separate, they leave gaps in the → Earth's crust. This allows molten rock from beneath the Earth's crust to reach the surface and forms a ridge. The MAR is a part of the global → mid-ocean ridge system.
forusorx-e miyâni (#)
Fr.: infrarouge moyen
The portion of the → electromagnetic radiation lying between the → near-infrared and the → far-infrared. This covers the wavelength range approximately from 8 to 30 → microns. See also: → infrared radiation, → submillimeter radiation.
Fr.: dorsale médio-océanique
Any of submarine mountain ranges that stretch around the world through the Atlantic Ocean and across the Pacific and Indian Oceans. Such ridges generally stand about 1000 m to 3000 m above the adjacent ocean floor and are about 500-1000 km in width.
The middle of the day; noon or the time centering around noon.
1) (n.) miyân; 2) (adj.) miyâni
Fr.: 1) milieu; 2) du milieu
The point, part, position, etc., equidistant from extremes or limits.
M.E., O.E. middel; cf. M.L.G., Du. middel, Ger. mittel, variant mid; cognate with Pers. miyân, as below; from PIE *medhyo-.
1) Miyân "within, between, center," from
Mid.Pers. mayân "middle; among, between," Av. maidiia- "middle, the middle,"
maiδiiāna- "middle, center,"
maδəma- [adj.] "middle, being in the middle;
middling, of a middling size or quality," maiδim "in the midst of,"
cf. Skt. mádhya-
"middle, located in the middle;" O.H.G. mitti "located in the middle."
havâsepehr-e miyâni, javv-e ~
Fr.: atmosphère moyenne
forusorx-e miyâni (#)
Fr.: infrarouge moyen
Same as → mid-infrared.
Fr.: latitudes moyennes
The latitude belt roughly between 35 and 65 degrees North and South. Also referred to as the temperate region.
Fr.: moyen terme
Generally, the middle of the night as indicated by twelve o'clock at night.
Nimšab, from nim "mid-, half" (Mid.Pers. nêm, nêmag "half;" Av. naēma- "half;" cf. Skt. néma- "half") + šab, → night
xoršid-e nimšab (#)
Fr.: Soleil de minuit
The phenomenon occurring when the Sun is visible above the horizon at midnight. This phenomenon can be seen at positions north of the Arctic Circle and south of the Antarctic Circle when the Sun is circumpolar (around the summer solstice in the northern hemisphere and the winter solstice in the southern hemisphere respectively).
Fr.: diffusion de Mie
The scattering of → electromagnetic waves by → particles of → size comparable to the radiation → wavelength. Mie scattering depends weakly upon the wavelength, hence the → scattered light spectrum is similar to that of the → incident light. Mie scattering explains the → white color of clouds when scattering is due to → water droplets having a size of few microns. Cloud → droplets with a diameter of around 20 microns or so are large enough to scatter all visible wavelengths more or less equally. Because all wavelengths are scattered, clouds appear to be white. When clouds become very deep, less and less of the incoming solar radiation makes it through to the bottom of the cloud, which gives these clouds a darker appearance.
Named after Gustav Adolf Mie (1868-1957), a German physicist, whose theory of 1908 explains the process; → scattering.
Fr.: théorie de Mie
The explanation of the → scattering of → electromagnetic waves by → homogeneous spheres of arbitrary → size and → composition using analytical solutions of → Maxwell's equations. See also: → Mie scattering, → Rayleigh scattering.
Fr.: émigrer, immigrer
1) To go from one country, region, or place to another.
From L. migratus p.p. of migrare "to move from one place to another," ultimately from PIE *meigh- "to move, go;" cf. Gk. ameibein "to change," Iranian muž-, as below.
Mužidan, ultimately from Proto-Ir. *maij- "to move (to places);" cf. Parachi muž-, muš-, Yazghulami mûž- "to go," mexw-/maxwt- "to move, shake," Gilaki maxtan "to stroll," Gonâbâdi mejon "ague, shivering, shaking chills," Sangesari moj; cognate with L. migrare "to move, go," as below, Skt. niméghanāna- "moving down;" PIE *meigh- "to move, go."
mužeš, kuc (#)
1) The process or act of migrating; a migratory movement.
Migrating; periodically migrating; pertaining to migration.
→ migrate + -ory, an adj.-forming suffix.
Fr.: cycles de Milankovitch
The theory according to which variations in the elements of Earth-Sun geometry are responsible for the sequence of ice ages during the Pleistocene era. The main elements are the varying tilt of the Earth's rotational axis, and the varying eccentricity of the Earth's orbit.
Named after the Serbian mathematician Milutin Milankovitch (1879-1958), who introduced the concept during the first half of the twentieth century.
An opaque white fluid secreted by female mammals for the nourishment of their young.
M.E.; O.E. meol(o)c, (Anglian) milc; cf. Gr. Milch, Goth. miluks; akin to L. mulgere, Gk amelgein "to milk;" PIE base *melg- "wiping, stroking;"
Šir "milk;" Mid.Pers. šir; cf. Skt. ksira- "milk."
Râh-e Širi (#)
Fr.: Voie lactée
The diffuse glowing band of light seen on dark nights spanning the sky as a great circle. It is produced by light from stars and nebulae in the → Galactic plane. The apparent form of the Milky Way in the sky results from a geometrical effect created by our location in the outlying regions of a huge, flattened disk of stars. → Milky Way galaxy.
From L.L. galaxias "Milky Way," from Gk. galaxis kyklos
"emilky circle," from gala (gen. galaktos) "milk."
Râh, → way; širi, adj. of šir "milk;" Mid.Pers. šir; cf. Skt. ksira- "milk."
Milky Way galaxy
kahkešân-e râh-e širi (#)
Fr.: Voie lactée
A → spiral galaxy, of which the
→ solar system is a small part.
It is the second largest in our → Local Group of galaxies.
The Milky Way is a disk-shaped system,
with a diameter of between 80,000 and 100,000 → light-years
and a thickness of about 2,000 light-years, containing more than
1011 stars. The stars are divided into two main categories,
→ Population II stars and
→ Population I stars.