The ability of different types of computers, networks, operating systems, and software applications to work together by exchanging and sharing information in a standardized, accurate, and effective manner.
A colored form of natural silica, SiO2, which is a precious stone.
M.E. jaspe, jaspre, from M.Fr., O.Fr. jaspe, from L. iaspidem (nominative iaspis), from Gk. iaspis "jasper," via an Oriental language, probably an Eastern Iranian language, see below.
Yašm, variants, yasp, yasb, yašf "jasper;" Sogd. iešp "jasper," iešpênê "of jasper, crystalline."
damâ-ye jonbeši (#)
Fr.: température cinétique
The temperature of a gas defined in terms of the average kinetic energy of its atoms or molecules.
kamarband-e Kuiper (#)
Fr.: ceinture de Kuiper
A region of the → Solar System extending roughly from the orbit of → Neptune, or 30 → astronomical units (AU), to 50 AU from the Sun that contains many small icy bodies. The Kuiper belt is now considered to be the source of the → short-period comets.
Named after Gerard Peter Kuiper (1905-1973), a Dutch-born American astronomer, who predicted the belt in 1951. He is also considered the father of modern planetary science for his contributions to the study of our solar system; → belt.
Kuiper belt object (KBO)
barâxt-e kamarband-e Kuiper
Fr.: objet de la ceinture de Kuiper
Fr.: superamas Laniakea
A → supercluster of galaxies that includes our → Local Group and about 300 to 500 known → galaxy clusters and groups. Also called → Local Supercluster. If approximated as round, it has a diameter of 12,000 km s-1 in units of the → cosmic expansion or 160 megaparsecs, and encompasses about 1017 → solar masses. Our Local Group lies toward the outer regions of Laniakea. Its main components are the four previously known superclusters: → Virgo supercluster (the part where the → Milky Way resides), Hydra-Centaurus Supercluster (including the → Great Attractor, Antlia Wall, known as Hydra Supercluster, → Centaurus supercluster), Pavo-Indus Supercluster, and Southern Supercluster (including Fornax Cluster, Dorado and Eridanus clouds). The most massive galaxy clusters of Laniakea are Virgo, Hydra, Centaurus, Abell 3565, Abell 3574, Abell 3521, Fornax, Eridanus, and Norma. The Laniakea supercluster was discovered by Tully et al. (2014, Nature 513, 71).
From the Hawaiian words lani "heaven," and akea "spacious, immeasurable;" → supercluster.
Fr.: opérateur de Laplace
Same as → Laplacian.
linear perturbation theory
negare-ye partureš-e xatti
Fr.: théorie de perturbation linéaire
Assumption that the variations in the plasma parameters, due to the presence of waves, are small (to the first order) as compared to the undisturbed parameters. This makes it possible to linearize equations by dropping out second order (and higher) nonlinear terms.
haft xâharân (#), camce-ye kucak (#)
Little, from M.E., O.E. lytel, from W.Gmc. *lutila- (cf. Du. luttel, O.H.G. luzzil, Ger. lützel, Goth. leitils), from PIE *leud- "small;" dipper, from dip, O.E. dyppan "immerse," from P.Gmc. *dupjanan.
Haft xâharân "the seven sisters," from haft "seven"
(Mid.Pers. haft; Av. hapta; cf. Skt. sapta; Gk. hepta;
L. septem; P.Gmc. *sebun; Du. zeven; O.H.G. sibun;
Ger. sieben; E. seven; PIE *septm)
+ xâharân plural of xâhar "sister;" Mid.Pers. xwâhar
"sister;" Av. xvanhar- "sister;" cf. Skt. svásar- "sister;"
Sogdian xwār; Gk. eor; L. soror (Fr. soeur);
O.C.S., Rus. sestra; Lith. sesuo; O.Ir. siur; Welsh chwaer;
M.Du. suster; Du. zuster; O.H.G. swester;
Goth. swistar; Ger. Schwester;
Swed. sister; Dan. søster;
O.E. sweostor, swuster; E. sister.
abarxuše-ye mahali (#)
Fr.: superamas local
The supercluster to which the Local Group belongs. It is composed of some 100 clusters of galaxies, with the Virgo cluster of galaxies at its center.
Fr.: périodogramme de Lomb-Scargle
An algorithm for detecting and characterizing periodic signals in unevenly-sampled data. The Lomb-Scargle periodogram has a particularly wide use within the astronomy community. This method allows efficient computation of a Fourier-like → power spectrum estimator from such unevenly-sampled data, resulting in an intuitive means of determining the period of oscillation (see VanderPlas, 2017, astro-ph/1703.09824 and references therein).
Named after Lomb, N. R. 1976, Ap&SS 39, 447 and Scargle, J. D. 1982, ApJ 263, 835; → periodogram.
domdâr-e derâz dowré
Fr.: comète à longue période
vartande-ye derâz dowré
Fr.: variable à longue période
lunar sidereal orbital period
dowre-ye madâri-ye axtari-ye mâng
Fr.: période orbitale sidérale de la Lune
Same as → sidereal month.
tarâvâyi-ye meqnâtisi (#)
Fr.: perméabilité magnétique
The ratio of the → magnetic induction, B, in the substance to the external magnetic field, H, causing the → induction: μ = B/H. It is measured in henry/meter and is known as absolute permeability. The relative permeability is equal to the ratio of absolute permeability to the permeability of the free space. Thus μr = μ/μ0, where μ0, the permeability of free space has the value 4π x 10-7 henry/meter.
method of small perturbations
raveš-e parturešhâ-ye kucak
Fr.: méthode des petites perturbations
The linearization of the appropriate equations governing a system by the assumption of a steady state, with departures from that steady state limited to small perturbations. Also called perturbation method.
âzmâyeš-e Michelson-Morley (#)
Fr.: expérience de Michelson-Morley
An experiment performed in 1887 to establish the presence or absence of an → ether, a medium through which light was supposed to travel. The experiment aimed to measure the speed of light coming from different directions. However no → ether drift was found. The null results obtained showed that the ether hypothesis was incorrect. Consequently, the theory of → special relativity, with its hypothesis that the speed of light is the same in all → inertial frames, reconciled the results of the Michelson-Morley experiment with the rest of physics.
→ Michelson interferometer; Michelson received the Nobel Prize in 1907 for his work, the first American to receive the Prize in science. Edward Williams Morley (1838-1923), an American chemist; → experiment.
Fr.: expérience de Miller-Urey
A chemical experiment conducted in 1953 that aimed at checking Alexander Oparin's and J. B. S. Haldane's hypothesis that under putative conditions present in the atmosphere of the early Earth inorganic molecules would spontaneously form organic molecules. Miller and Urey filled a sterile flask with a mixture of water, ammonia, methane, and hydrogen. The mixture was heated to evaporate water to produce water vapor. High-voltage electric sparks were passed through the mixture to simulate lightning. After a week, contents were analyzed. Amino acids, the building blocks for proteins, were found.
Named after Stanley L. Miller (1930-2007) and Harold C. Urey (1893-1981); → experiment.
Millikan's oil-drop experiment
âzmâyeš-e Millikan (#)
Fr.: expérience de Millikan
A precision experiment for measuring the → electron charge. By studying the falling speed of small charged droplets in the gravitational field of the Earth subjected to an adjustable electric field, Millikan (1909) was able to demonstrate conclusively the discrete nature of electric charge, and moreover measure the charge of an individual electron.
Robert Andrews Millikan (1868-1953); → experiment.
Mirfak (α Persei)
The brightest star of Perseus, with a visual magnitude of 1.8. It is a giant of spectral type F5 lying some 590 light-years away.
From Ar. al-Mirfaq (
Merfaq, from Ar. al-Mirfaq, as above.