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

1) If f(x) is a continuous function on the interval from a to b, then:
∫ f(x) dx = f(c)(b - a) (summed from a to b) for at least one point in that interval.
2) More generally, If f(x) and g(x) are continuous functions on the interval from a to b and g(x)≥ 0, then:
∫ f(x)g(x) dx = f(c) ∫ g(x) dx (both integrals summed from a to b).

→ mean; → value; → theorem.

The sense or significance of a word, sentence, symbol, etc. The study dealing with meanings is called → semantics. See also → semiotics.

M.E., from mean; O.E. mænan "to mean, intend, signify" (cf. O.Fris. mena "to signify," O.S. menian "to intend, signify," M.Du. menen, Du. meenen, Ger. meinen "think, suppose"), related to Pers. maneš "disposition, temperament," mênidan "to think, consider," → idea; + → -ing.

Cemâr, from cem or cim "meaning, signification;" Mid.Pers. cim "meaning, reason, cause;" ultimately from Proto-Ir. *cahmāt "wherefore?" cf. Skt. kasmāt "why, where from? whence?," kim "what? how? why?" + âr short form of âvar present stem of âvardan "to cause or produce; to bring," → production, as in bonâr, → cause, used also as a nuance suffix; see also the verb → mean.

1) A unit or standard of → measurement; the act or process of ascertaining the extent, dimensions, or quantity of something; measurement; the quantity obtained by such a process.
2) To use standard units to determine the magnitude, extent, size, etc. of something. The quantity obtained by such a process.

From O.Fr. mesurer, from L.L. mensurare "to measure," from L. mensura "a measuring, a thing to measure by," from mensus, p.p. of metiri "to measure," → meter.

1) Andâzé "measure," from Mid.Pers. andâzag, handâcak "measure," handâxtan, handâz- "to measure," Manichean Mid.Pers. hnds- "to measure," Proto-Iranian *hamdas-, from ham-, → com-, + *das- "to heap, amass;" cf. Ossetic dasun/dast "to heap up;" Arm. loanword dasel "to arrange (a crowd, people)," das "order, arrangement."
2) Andâzé gereftan, compound verb, literally "to take measure," from andâzé, as above, + gereftan "to take, seize" (Mid.Pers. griftan; Av./O.Pers. grab- "to take, seize;" cf. Skt. grah-, grabh- "to seize, take," graha "seizing, holding, perceiving;" M.L.G. grabben "to grab;" from P.Gmc. *grab; E. grab "to take or grasp suddenly;" PIE base *ghrebh- "to seize").

1) The act of measuring; a measured quantity.
2) The determination of the magnitude or amount of a quantity by comparison (direct or indirect) with the prototype standards of the system of units employed (IEEE Standard Dictionary of Electrical and Electronics Terms). → absolute measurement, → measurement uncertainty, → Roemer's measurement.

Verbal noun of → measure.

The interval within which lies the actually measured value of a physical quantity and the true value of the same physical quantity.

→ measurement; uncertainty, from negation prefix un- + → certainty.

A person who repairs and maintains machinery, motors, etc. (Dictionary.com). Same as → mechanician.

→ mechanics.

1) Of, connected with, produced by → mechanics.
2) Like machines; automatic.

→ mechanic; → -al.

The energy that is possessed by an object due to its motion or due to its position. It is equal to the sum of the → kinetic energy and → potential energy.

→ mechanical; → energy.

1) The state of a → rigid body if, as viewed from an → inertial frame of rest: 1) the → linear acceleration of its → center of mass is zero, and 2) its → angular acceleration about any axis fixed in this reference frame is zero. The center of mass may be moving with constant velocity and the body may be rotating about a fixed axis with constant angular velocity.
2) In → thermodynamics, the state of a system in which → pressure is the same every where with no other forces acting on the system except a uniform external pressure.

→ mechanical; → equilibrium.

Same as → Joule's constant.

→ mechanical; → equivalent; → heat.

Any → mixing process that utilizes the → kinetic energy of relative → fluid motion.

→ mechanical; → mixing.

The → rate at which → work is done by a → force. In other words, → mechanical energy per unit time. Mechanical power is expressed in units of joules/sec (joules/s) or a watt (W) in the → mks system.

→ mechanical; → power.

1) Any system of elements that interact according to the laws of → mechanics (as distinguished from chemical, electrical, thermal, etc.).
2) A collection of → machines functioning together to achieve the transfer of motion.

→ mechanical; → system.

A process in which matter is shed into a → Keplerian disk from a star rotating at the → critical velocity. The disk is probably destroyed by the pressure exerted by the stellar radiation and finally matter is lost. Such a process seems to occur around → Be stars which are stars rotating at or very near the critical limit (Meynet et al. 2007, arXiv:0709.2275).

→ mechanical; → wind.

1) In a mechanical manner; by a mechanism.
2) In a machine-like manner; without feeling.

→ mechanical; → -ly.

A person skilled in constructing, working, or repairing machines; mechanic; machinist (Dictionary.com).

From → mechanic + -ian.

A branch of → physics that deals with motion and the → action of → forces on bodies. Mechanics may be divided into three areas, → kinematics, → dynamics, and → statics.

From mechanic, from L. mechanicus, from Gk. mekhanikos "an engineer," also "inventive," literally "pertaining to machines" (adj.), from mekhane, → machine, + → -ics.

Mekânik, loan from Fr. Sâzokârik, from sokâr, → mechanism, + -ik, → -ic.

1) The structure or arrangement of parts of a machine or similar device, or of anything analogous.
2) The agency or means by which an effect is produced or a purpose is accomplished.

From Mod.L. mechanismus, from Gk. mekhane, → machine.

Sâzokâr, literally "making and working," from sâz "apparatus; (musical) instrument," from sâzidan, sâxtan "to build, make, fashion; to adapt, adjust, be fit" (from Mid.Pers. sâxtan, sâz-, Manichean Parthian s'c'dn "to prepare, to form;" Av. sak- "to understand, to mark," sâcaya- (causative) "to teach") + kâr "work," from kardan "to do, to make" (Mid.Pers. kardan; O.Pers./Av. kar- "to do, make, build;" Av. kərənaoiti "he makes;" cf. Skt. kr- "to do, to make," krnoti "he makes, he does," karoti "he makes, he does," karma "act, deed;" PIE base k^wer- "to do, to make").

Statistics: The middle value in a sample sorted into ascending order. If the sample contains an even number of values, the median is defined as the mean of the middle two.
Geometry: The line from a vertex of a triangle to the midpoint of the opposite side.

From M.Fr. médian, from L. medianus "of the middle," from medius "middle;" akin to Pers. middle, → medium, → meddle; from PIE *medhyo-, from base *me- "between;" → medium.

Miyâné from miyân, → middle, + -é nuance suffix.

The art or science of restoring or preserving health or due physical condition, as by means of drugs, surgical operations or appliances, or manipulations (Dictionary.com).

M.E. medicin, from O.Fr. medecine "art of healing, cure," from L. medicina "the healing art; a remedy," feminine of medicinus (adj.) "of a doctor," from medicus "a physician;" PIE root *med- "to measure, limit, consider, advise," → dimension; cf. Av. vi-mad- "physician;" Gk. medein "to rule;" L. meditari "think or reflect on, consider," → meditation; Ir. miduir "judge;" O.E. metan "to measure out."

Pezeški, from pezešk "physician," from Mid.Pers. bizešk "physician," bêšâz "medicinal;" Av. bišaz- "to cure, heal;" cf. Skt. bhisaj- "healer, physician."