An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The greatest diameter of an ellipse; it passes through the two foci.

→ major; → axis.

The → merging of two spiral galaxies with roughly equal masses colliding at appropriate angles. The dynamical friction is so efficient that the galaxies merge after only a few perigalactic passages.

→ major; → merger.

A name used to describe any planet that is considerably larger and more massive than the Earth, and contains large quantities of hydrogen and helium. Jupiter and Neptune are examples of major planets.

→ major; → planète.

Logic: In a → categorical syllogism, the premise containing the → major term.

→ major; → premisse.

Logic: In a → syllogism, the → predicate of the → conclusion which occurs in the → major premise.

→ major; → term.

A function, or an element of a set, that dominates others or is greater than all others. In other words, for a function f defined on the interval I, the point M such that for each x on I, f(x)≤ M. See also → minorant.

From Fr. majorant, from majorer "to increase, raise," from L. → major.

Mehân, from mehidan, from meh "great, large," → major.

The greater number, part, or quantity of a whole.

→ major; → -ity.

The third largest known → dwarf planet after → Eris and → Pluto. Numbered 136472, and initially called 2005 FY_g, it belongs to the → Kuiper belt in the solar system. Discovered in 2005, Makemake is roughly three-quarters of Pluto in size and orbits the Sun in about 310 years.

Named after Makemake "the creator of humanity and god of fertility" in the mythology of the Rapanui, the native people of Easter Island.

Something put in a scale to complete a required weight.

→ make; → weight.

Pârsang, → counterweight.

A → reflecting telescope incorporating a deeply curved → meniscus, → lens, which corrects the → optical aberrations of the spherical → primary mirror to give high-quality → images over a wide → field of view.

Named for the Russian optical specialist Dmitri Maksutov (1896-1964), who developed the design; → telescope.

1) Belonging to the sex that typically has the capacity to produce gametes, especially spermatozoa which fertilize the eggs of a female.
2) A person, plant, or animal capable of fertilizing.

M.E. male, from O.Fr. malle, masle, from L. masculus "masculine, a male," → maculine.

Nar "male," from Mid.Pers. nar, "male; manly;" Av. nar- "male, man," nairya- "male, manly;" cf. Skt nara- "male, man."

A selection effect in observational astronomy. If a sample of objects (galaxies, quasars, stars, etc.) is flux-limited, then the observer will see an increase in average luminosity with distance, because the less luminous sources at large distances will not be detected.

Named after the Swedish astronomer Gunnar Malmquist (1893-1982); → bias.

A correction introduced into star counts distributed by apparent magnitude.

→ Malmquist bias; → correction.

If the light wave entering an → analyzer is → linearly polarized, the intensity of the wave emerging from the analyzer is I = k I₀ cos²φ, where k is the coefficient of transmission of the analyzer, I₀ is the intensity of the incident light, and φ is the angle between the planes of → polarization of the incident light and the light emerging from the analyzer.

Named after Etienne Louis Malus (1775-1812), French physicist who also discovered polarization by reflection at a glass surface (1808); → law.

A method for deriving the Earth's size based on measuring a length of meridian between two points corresponding to the difference between the respective latitudes. The Abbasid caliph al-Ma'mun (ruling from 813 to 833 A.D.), appointed two teams of surveyors to this task. They departed from a place in the desert of Sinjad (nineteen farsangs from Mosul and forty-three from Samarra), heading north and south, respectively. They proceeded until they found that the height of the Sun at noon had increased (or decreased) by one degree compared to that for the starting point. Knowing the variation of the Sun's → declination due to its apparent → annual motion, they could relate the length of the arc of meridian to the difference between the latitudes of the two places. They repeated the measurement a second time, and so found that the length of one degree of latitude is somewhat between 56 and 57 Arabic miles (Biruni, Tahdid). 360 times this number yielded the Earth's circumference, and from it the radius was deduced.
See also: → Eratosthenes' method, → Biruni's method.

The seventh Abbasid caliph Abu Ja'far Abdullâh al-Ma'mûn, son of Hârûn al-Rashîd (786-833 A.D.); → method.

1) An adult male person.
2) A member of the species Homo sapiens. See also → human, → anthropo-.

M.E., from O.E. man, mann "human being, person" (O.S., O.H.G. man, Ger. Mann, O.N. maðr, Goth. manna "man"), from PIE base *man-; cf. Skt. mánu-, más- "man, person, husband;" Av. manu- in proper noun Manus-ciθra- (Pers. Manucehr); O.C.S. moži, Russ. muž "man, male."

(Mid.Pers./Mod.Pers.) mard "man," mardom "mankind, people," cognate with mordan "to die," → death; Sogd. martu, marti "man, human;" O.Pers. martiya-; Av. marəta- "mortal, man," maša- "mortal;" cf. Skt. márta- "mortal, man;" Gk. emorten "died;" L. mortalis "subject to death;" PIE base *merto-, *morto-. Ensân, loan from Ar.

To direct or control the use of; to exercise executive, administrative, and supervisory direction of.

Probably from It. maneggiare "to handle, train (a horse)," from L. manus "hand."

Gonârdan, from Mid.Pers vinârtan, variant vinâristan "to organize, arrange, put in order," from vi- "apart, away from" (Av. vi- "apart, away from, out;" O.Pers. viy- "apart, away;" cf. Skt. vi- "apart, asunder, away, out;" L. vitare "to avoid, turn aside") + âristan, ârâstan "to arrange, adorn;" O.Pers. râs- "to be right, straight, true," râsta- "straight, true" (Mod.Pers. râst "straight, true"), râd- "to prepare," Av. râz- "to direct, put in line, set," Av. razan- "order," Gk. oregein "to stretch out," L. regere "to lead straight, guide, rule," p.p. rectus "right, straight," Skt. rji- "to make straight or right, arrange, decorate," PIE base *reg- "move in a straight line."

The act or manner of managing; handling, direction, or control.

Verbal noun of → manage.

A person who manages; a person who has controls or directs an institution, a team, a division, or part it.

Agent noun of → manage.

A set of points in the complex plane, the boundary of which forms a fractal with varying shapes at different magnifications. Mathematically, it is the set of all C values for which the iteration z_n+1 = z_n² + C, starting from z₀ = 0, does not diverge to infinity.

Discovered by Benoît Mandelbrot (1924-) a Polish-born French mathematician, best known as the "father of fractal geometry;" → set.