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

The theory of → gravitation developed by Albert Einstein (1916) that describes the gravitation as the → space-time curvature caused by the presence of matter or energy. Mass creates a → gravitational field which distorts the space and changes the flow of time. In other words, mass causes a deviation of the → metric of space-time continuum from that of the "flat" space-time structure described by the → Euclidean geometry and treated in → special relativity. General relativity developed from the → principle of equivalence between gravitational and inertial forces. According to general relativity, photons follow a curved path in a gravitational field. This prediction was confirmed by the measurements of star positions near the solar limb during the total eclipse of 1919. The same effect is seen in the delay of radio signals coming from distant space probes when grazing the Sun's surface. Moreover, the space curvature caused by the Sun makes the → perihelion of Mercury's orbit advance by 43'' per century more than that predicted by Newton's theory of gravitation. The → perihelion advance can reach several degrees per year for → binary pulsar orbits. Another effect predicted by general relativity is the → gravitational reddening. This effect is verified in the → redshift of spectral lines in the solar spectrum and, even more obviously, in → white dwarfs. Other predictions of the theory include → gravitational lensing, → gravitational waves, and the invariance of Newton's → gravitational constant.

→ general; → relativity.

→ secretary-general.

→ general; → secretary.

The act or process of generalizing; → generalize.
A result of this process; a general statement, proposition, or principle.

Verbal noun of → generalize.

To make general, to include under a general term; to reduce to a general form.
To infer or form a general principle, opinion, conclusion, etc. from only a few facts, examples, or the like.

→ general; → -ize.

Made general. → generalized coordinates; → generalized velocities.

P.p. of → generalize

In a material system, the independent parameters which completely specify the configuration of the system, i.e. the position of its particles with respect to the frame of reference. Usually each coordinate is designated by the letter q with a numerical subscript. A set of generalized coordinates would be written as q₁, q₂, ..., q_n. Thus a particle moving in a plane may be described by two coordinates q₁, q₂, which may in special cases be the → Cartesian coordinates x, y, or the → polar coordinates r, θ, or any other suitable pair of coordinates. A particle moving in a space is located by three coordinates, which may be Cartesian coordinates x, y, z, or → spherical coordinates r, θ, φ, or in general q₁, q₂, q₃. The generalized coordinates are normally a "minimal set" of coordinates. For example, in Cartesian coordinates the simple pendulum requires two coordinates (x and y), but in polar coordinates only one coordinate (θ) is required. So θ is the appropriate generalized coordinate for the pendulum problem.

→ generalized; → coordinate.

In → Lagrangian dynamics, forces related to → generalized coordinates. For any system with n generalized coordinates q_i (i = 1, ..., n), generalized forces are expressed by F_i = ∂L/∂q_i, where L is the → Lagrangian function.

→ generalized; → force.

In → Lagrangian dynamics, momenta related to → generalized coordinates. For any system with n generalized coordinates q_i (i = 1, ..., n), generalized momenta are expressed by p_i = ∂L/∂q^._i, where L is the → Lagrangian function.

→ generalized; → momentum.

The time → derivatives of the → generalized coordinates of a system.

→ generalized; → velocity.

To bring into existence; create; produce.
Math.: To trace (a figure) by the motion of a point, straight line, or curve.

Generate, from M.E., from L. generatus "produce," p.p. of generare "to bring forth," from gener-, genus "descent, birth," akin to Pers. zâdan, Av. zan- "to give birth," as explained below.

Âzânidan, from â- nuance/strengthening prefix + zân, from Av. zan- "to bear, give birth to a child, be born," infinitive zazāite, zāta- "born;" Mod.Pers. zâdan, present stem zā- "to bring forth, give birth" (Mid.Pers. zâtan; cf. Skt. jan- "to produce, create; to be born," janati "begets, bears;" Gk. gignomai "to happen, become, be born;" L. gignere "to beget;" PIE base *gen- "to give birth, beget") + -idan infinitive suffix.

1) A coming into being.
2) The → production of → energy (→ heat or → electricity).

Verbal noun of → generate.

1) Capable of producing or creating.
2) Pertaining to the production of offspring.

→ generate; → -ive.

1) A machine for converting one form of energy into another.
2) Geometry: That which creates a line, a surface, a solid by its motion.

From L. generator "producer," from genera(re)→ generate + -tor a suffix forming personal agent nouns from verbs and, less commonly, from nouns.

Âzângar, from âzân the stem of âzânidan→ generate + -gar suffix of agent nouns, from kar-, kardan "to do, to make" (Mid.Pers. kardan; O.Pers./Av. kar- "to do, make, build," Av. kərənaoiti "makes;" cf. Skt. kr- "to do, to make," krnoti "makes," karma "act, deed;" PIE base k^wer- "to do, to make").

Pertaining or according to → genetics or → genes.

From Gk. genetikos, from genesis "origin," → gene; → -ic.

The study of heredity and inheritance, of the transmission of traits from one individual to another, of how genes are transmitted from generation to generation.

From → genetic and → -ics.

The → grammatical case that marks a noun or pronoun typically expressing "possession" or "origin." In English, the genitive case of a noun is shown in writing by adding an s together with an appropriately positioned apostrophe or creating it by using the pronoun of. For instance: "John's house," or "the house of John." A → synthetic language would express the same idea by putting the name "John" in the genitive case. Also called → possessive case.

From O.Fr. genitif or directly from L. (casus) genitivus "case expressing possession, source, or origin," from genitivus "of or belonging to birth," from genitus, p.p. of gignere "to beget, produce," → generate; → case.

Dârešti, → possessive; kâté, → case..

1) An exceptionally intelligent person or one with exceptional skill in a particular area of activity.
2) Exceptional intellectual or creative power or other natural ability (Oxford Dictionaries).

From L. genius "tutelary deity or genius of a person;" originally "generative power," from gignere "beget, produce," → generate.

Farhuš, from far- intensive prefix "much, abundant; elegantly," → perfect, + huš, → intelligence. Farhuši, from farhuš + -i.

The deliberate and systematic extermination of a national, racial, political, or cultural group (Dictionary.com).

From Gk. genos "race, kind," → generate, + → -cide.

Nežâdkoši, from nežâd, → race, + koši, → -cide.

1) Biology: The usual major subdivision of a family or subfamily in the classification of organisms, usually consisting of more than one species.
2) Logic: A class or group of individuals, or of species of individuals.
3) A kind; sort; class (Dictionary.com).

From L. genus "race, stock, kind, gender;" cognate with Gk. genos "race, kind," and gonos "birth, offspring, stock," → generate.

Sardé, from Mid.Pers. sardag "sort, kind;" Av. sarrəδa- "kind, type."

A combining form meaning "the earth," used in the formation of compound words.

Geo-, form Gk. ge "earth, land, ground, soil."

Zamin, zami "earth, ground," from Mid.Pers. zamig "earth;" Av. zam- "the earth;" cf. Skt. ksam; Gk. khthôn, khamai "on the ground;" L. homo "earthly being" and humus "the earth" (as in homo sapiens or homicide, humble, humus, exhume); PIE root *dh(e)ghom "earth."