argument of periapsis
Fr.: argument du périastre
The angular distance between the → ascending node of an object orbiting a → primary and its periapsis measured from the primary. Argument of periapsis is measured in the → orbital plane in the direction of motion. It is one of the → orbital elements. See also → argument of perigee, → argument of perihelion.
argument of perigee
Fr.: argument du périgée
argument of perihelion
Fr.: argument du périhélie
The angular distance between the → ascending node of an object orbiting the Sun and its perihelion. Argument of perihelion is measured in the → orbital plane with respect to the Sun and in the direction of motion. It is one of the → orbital elements and usually shown with the symbol ω. See also: → argument of perigee, → argument of periapsis.
The presentation and elaboration of an argument or arguments.
Noun from → argument.
1) Fond of or given to argument and dispute.
Lacking sufficient water or rainfall.
L. aridus, from arere "to be dry, i.e. burnt up"; compare with Gk. azaleos "dry," PIE *as- "to burn, glow".
Kamâb, from Mod.P. kam "little, few, deficient, scarce" + âb "water".
A measure of the degree to which a climate lacks effective moisture.
Aridity, noun from → arid.
Kamâbi, noun from amâbi, → arid.
Ariel (Uranus I)
A satellite of → Uranus discovered by Lassell in 1851. It is orbiting at a mean distance of 192,000 kilometers with a period of 2.52 days.
Ariel, a spirit in William Shakespeare's The Tempest.
L. aries "ram," perhaps akin to Gk. eriphos "a kid, a young goat," O.Ir. heirp "she-goat;" cf. Lith. erytis, O.C.S. jarici, Arm. oroj "lamb."
Barré "ram, sheep; Aries" from Mid.Pers. warrag "lamb,
ram; Aries," compare with Av. varənâ- "wool," Skt.
urana, urabhra "wool-beared =
Fr.: inégalité d'Aristarque
Put in modern notation, if α and β are acute angles and if β <α, then sin α / sin β <α / β < tan α / tan β. Aristarchus probably used this inequality to show that the Sun is between 18 and 20 times as far from the Earth as the Moon is.
Aristarchus of Samos (c.310-c.230 BC); → inequality.
Fr.: forme aristotelienne
Any of the four main → proposition
forms treated in Aristotle's → syllogism:
Greek philosopher Aristotle (384-322 BC); → form.
A branch of mathematics that deals usually with integers, rational numbers, real numbers, or complex numbers under addition, subtraction, multiplication, and division. See also → compute, → computation, → count, → calculate, → calculus, → mathematics, → statistics.
O.Fr. arsmetique, from M.L. arithmetica, from Gk. arithmetike (tekhne) "(art, skill) of numbers," from arithmos "number."
Hesâb, from Ar. hisab.
miyângin hesâbi (#)
Fr.: moyenne arithmétique
Of n numbers a1, a2, ..., an, the quantity defined as: (a1 + a2 + ... + an)/n.
farâyâzi-yz hesâbi (#)
Fr.: progression arithmétique
A → sequence of n numbers or quantities such that the difference between any two successive terms is a constant. In particular, if a is the first term, the nth term is a + (n - 1)d, where d is the constant. Also called → arithmetic sequence.
Fr.: suite arithmétique
From O.E. earm "arm," from P.Gmc. *armaz (cf. M.Du., Ger. Arm, O.N. armr, O.Fris. erm), from PIE base *ar- "to fit, join;" cf. Mod.Pers. arm "arm, from the elbow to the shoulder;" Av. arma-, arəmo- "arm;" Skt. irma- "arm;" Gk. arthron "a joint;" L. armus "shoulder."
Bâzu "arm," from Mid.Pers. bâzûk "arm;" Av. bāzu- "arm;" Mod.Pers. bâhu "stick, staff; arm;" cf. Skt. bāhu- "arm, forearm;" Gk. pechys "forearm, arm, ell;" O.H.G. buog "shoulder;" Ger. Bug "shoulder;" Du. boeg; O.E. bôg, bôh "shoulder, bough;" E. bough " a branch of a tree;" PIE *bhaghu- "arm").
Fr.: sphère armillaire
An ancient instrument, used since ancient times until the Middle ages and later, to determine positions of celestial bodies. It consisted of an assemblage of rings, all circles of the same sphere, designed to represent the positions of the important circles of the celestial sphere.
L. armillarius, from armilla "arm ring, bracelet," from armus "arm" + → sphere.
Zâtolhelaq from Ar. "multi-ringed," from zât "holder, keeper" + helaq "rings," from halqah "ring."
Fr.: règle d'Arnett
Arnett, W. D. 1982, ApJ, 253, 785; → rule.
Chemistry: Of, relating to, or containing the six-carbon ring typical of the benzene (C6H6) series and related organic groups.
M.E. aromatyk, from M.Fr. aromatique, from L. aromaticus, from Gk. aromatikos, from aroma "seasoning, sweet spice," of unknown origin.
Fr.: composé aromatique
An organic compound which contains benzene rings in its structure. The simplest is therefore benzene (C6H6). Aromatic compounds have a planar ring of atoms linked by alternate single and double bounds.