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

Same as → metric.

→ distance + → function.

The difference between the → apparent magnitude (m) of a star or galaxy and its → absolute magnitude (M). It is given by m - M = 5 log d - 5, where d is the distance in → parsecs. For an object that is 10 pc away, the distance modulus is zero.

→ distance; → modulus.

The distance separating an observer and the → apparent horizon of the place. Neglecting the → atmospheric refraction, it is given by: d = (2Rh)^1/2, where R is the radius of the Earth and h is the observer's height. This can be approximated to: d (km) = 3.57(h)^1/2 for a typical value of R = 6378 km. The atmospheric refraction, however, makes the thing more complex, depending on the temperature and density variations along the line of sight. Generally, refraction pushes the apparent horizon about 10% farther.

→ distance; → horizon.

1) Readily distinguishable from all others.
2) Clearly defined; unquestionable (TheFreeDictionary.com).

Past-participle adjective from obsolete distincten "to distinguish one thing from another; make distinct," from O.Fr. distincter, from L. distinctus, p.p. of distinguere "to separate between, mark off."

Bažnâ, literally "high," from Kurd. bažn "height, stature," variants baž, baš "height," bašn, → stature, faš, baš "a horse's mane."

1) The act or an instance of distinguishing or differentiating.
2) A distinguishing feature.
3) The state of being different or distinguishable.
4) Special honor, recognition, or fame (The FreeDictionary.com).

→ distinct; → -tion.

Serving to identify; distinguishing or characteristic.

→ distinct; → -ive.

In a clear and noticeable way; clearly.

→ distinct; → -ly.

The state or quality of being distinct.

→ distinct; → -ness.

1) To perceive as being different or distinct.
2) To demonstrate or describe as being different or distinct.

ME. distingwen, from O.Fr. distinguer, from L. distinguere "to separate between, divide, mark off," perhaps literally "separate by pricking," from assimilated form of → dis- "apart" + -stinguere "to prick."

Bažnâyidan, verb from bažnâ, → distinct.

1) Characterized by excellence or distinction; eminent.
2) Dignified in conduct or appearance (TheFreeDictionary.com).

Past participle of → distinguish.

To twist awry or out of shape; make crooked or deformed (Dictionary.com).

From L. distortus, p.p. of distorquere "to distort," from → dis-, + torquere "to twist."

Cowlé "distorted, crooked, bent," variants [Mo'in] kowlé, kal, kil, Lori cowel, Laki hoval, hol, Malâyeri caval, hol, Tabari, Aftari val, Mid.Pers. xwahl "bent, crooked;" PIE base *klei- "to lean, incline" from which is also derived Gk. klinein "to cause to slope, slant, incline," L. clinare "to bend," → declination.

1) Extent to which a system, optical, acoustic, or electronic, fails to reproduce accurately at its output the characteristics of the input.
2) Optics: An optical imperfection caused by a → lens or → system of lenses which results in → magnification differences between different points on the → image. The points on the → object are misplaced in the image relative to the → center of the → field. See also → barrel distortion; → pincushion distortion.

Verbal noun of → distort.

1) (v.tr.) To divide and dispense in portions; to disperse through a space or over an area.
2) (v.intr.) Math.: To be → distributive. → distribution.

Distribute, from L. distributus p.p. of distribute "deal out in portions," from → dis- + tribuere "to pay, assign, allot," from tribus "tribe."

Vâbâžidan, infinitive of vâbâž, from vâ-→ dis- + bâž "tribute, toll, impost," from Mid.Pers. bâj, bâž "tribute, tax," baxtan "to distribute," baxt "luck, fate," O.Pers. bāji- "tribute, tax," Av. bag- "to distribute, divide, allot," cf. Skt. bhaj- "to share, distribute, apportion," Gk. phagein "to eat (to have a share of food)"; PIE base *bhag- "to share out, apportion;" → division.

An act or instance of distributing; the state or manner of being distributed; something that is distributed. → binomial distribution, → Bose-Einstein distribution, → brightness distribution, → chi-square distribution, → cumulative distribution function, → distribution function, → Gaussian distribution, → Gibbs canonical distribution, → lognormal distribution, → Maxwell-Boltzmann distribution, → normal distribution, → Poisson distribution, → power-law distribution, → probability distribution, → spectral energy distribution.

Verbal noun of → distribute

A function that gives the relative frequency with which the value of a statistical variable may be expected to lie within any specified interval. For example, the Maxwellian distribution of velocities gives the number of particles, in different velocity intervals, in a unit volume.

→ distribution; → function.

Characterized by or relating to → distribution. → distributive law.

→ distibution; → -ive.

Math.: In multiplication, the principle that permits the multiplier to be applied separately to each term in the multiplicand: x(y + z) = xy + xz. → associative law; → commutative law.

→ distributive; → law.

The state or quality of being distributive.

Noun of → distributive.

1) To interfere with; interrupt; hinder.
2) To interfere with the arrangement, order, or harmony of; disarrange (Dictionary.com).

M.E., from O.Fr. destorber, from L. disturbare "to throw into disorder," from → dis- "completely" + turbare "to disorder, disturb," from turba "turmoil," → turbid.

Parišândan, infinitive from parišân "dispersed, scattered," also parišidan "to disperse, get disturbed," ultimately from Proto-Ir. *parišan- literally "disperse around," from *pari-, Pers. par-, pirâ-, → peri-, + *šan- "to shake;" cf. afšândan, → volcano; Choresmian šny- "to tremble;" Zazaki šânâyiš/šânen- "to shake, scatter;" Kurd râšândin "to spread;" Tabari šanne "he shakes" (Cheung 2007).

The act of disturbing. The state of being disturbed.

Verbal noun of → disturb.