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

1) The position on the celestial sphere at which a heavenly body would be seen from the Earth at a particular time.
2) A position given by the coordinates calculated for a star, if it were seen from the Earth's centre, relative to the → real equator and the → real equinox, at a certain date. It includes the displacements from one heliocentric direction, given in a stellar catalogue, due to → precession, → nutation, → aberration, → proper motions, → annual parallax, and light gravitational deviation (M.S.: SDE).

→ apparent; → position.

In → propositional logic, a → sentence without any → connectives. See also → molecular proposition.

→ atomic; → proposition.

Same as catalog place and → mean catalog place.

→ catalog; → position.

In a → syllogism, a → proposition or statement that deals with inclusion or exclusion of members of → subject classes in → predicate classes. Categorical propositions are of four basic forms, see → Aristotelian form.

→ categorical; → proposition.

The identities, and relative abundances of the → chemical elements or → compounds that make up a substance.

→ chemical; → composition.

1) General: The act or manner of composing; the result or product of composing.
2) Chemistry: The proportion of the elements of which a substance is made up.
3) Mechanics: The determination of a force whose effect is the same as that of two or more given forces acting simultaneously.

Hamnehesh, from ham-, → com-, + neheš verbal noun from nehâdan "to put, place," → compose.

A statement formed from simple statements by the use of words such as "and," "or," "not," "implies," or their corresponding symbols.

→ compound; → proposition.

A compound → proposition in which one → clause asserts something as true provided that the other clause is true. A conditional statement consists of two parts, a hypothesis in the "if" clause and a conclusion in the "then"clause. For instance, "If it rains, then they cancel school." It rains is the hypothesis. "They cancel school" is the conclusion. The clause following if is traditionally called the → antecedent, whereas the clause following then is called the → consequent.

→ conditional; → proposition.

The process or the state of breaking down a physical entity or an organic material.

From → de- + → composition.

The process by which water vapor changes directly to ice without first becoming a liquid. This is how snow forms in clouds, as well as frost and hoar frost on the ground. The opposite of deposition is → sublimation. → condensation.

M.E., from O.Fr. deposition, from L. deposition- "putting aside, testimony, burial," from deposit(us) "laid down," p.p. of deponere "to put down," from → de- + ponere "to put, place."

Vâneheš, from vâ-→ de- + neheš verbal noun of nehâdan "to put, place," Mid.Pers. nihâtan, O.Pers./Av. ni- "down; into," → ni-, + dā- "to put; to establish; to give," dadāiti "he gives," cf. Skt. dadâti "he gives," Gk. didomi "I give," L. do "I give;" PIE base *do- "to give."

The position of an oscillating body at which no net force acts on it.

→ equilibrium; → position.

Complete set of points in any given space group which are obtained by performing the symmetry operations of the space group on a single point (x, y, z).

→ equivalent; → position.

1) The act of setting forth information or a viewpoint.
2) Public exhibition or show.

Verbal noun of → expose.

A coordinate positioning tool, using a combination of satellites that can rapidly and accurately determine the → latitude, → longitude, and the → altitude of a point on or above the Earth's surface. The GPS is based on a constellation of 24 Earth-orbiting satellites at an altitude of about 26,000 km. The system is a direct application of the thories of → special relativity and → general relativity.

→ global; → positioning; → system.

1) The laying on of something as a burden or obligation.
2) Something imposed, as a burden or duty; an unusual or extraordinarily burdensome requirement or task.
3) The act of imposing by or as if by authority (Dictionary.com).

→ impose; → -tion.

→ Einstein equivalence principle.

→ local; → position; → invariance.

Same as → mean place.

→ mean; → position.

In → propositional logic, a → sentence containing at least one → connectives. See also → atomic proposition.

→ atomic; → proposition.

1) The action of opposing, resisting, or combating.
2) A person or group of people opposing, criticizing, or protesting something, someone, or another group (Dictionary.com).
3) The position of a solar system body having its orbit outside that of the Earth when the Earth is in a line between the Sun and the body. At opposition the body has a solar → elongation of 180°, and is closest to the Earth. It will, in principle, be visible throughout the night. It will rise in the east as the Sun sets in the west and it will set as the Sun rises. This is because, at opposition, the body and the Sun are 12 hours apart. The inner planets can never be in opposition. The opposite of opposition is → conjunction.
4) Two periodic quantities of the same frequency are said to be in opposition when the → phase difference between them is one half of a → period.

Verbal noun of → oppose.

Pâdist "standing against," from pâd- "agaist, contrary to," → anti-, + ist present stem of istâdan "to stand" (Mid.Pers. êstâtan, O.Pers./Av. sta- "to stand; to set;" Av. hištaiti; cf. Skt. sthâ- "to stand;" Gk. histemi "put, place, weigh," stasis "a standing still;" L. stare "to stand;" Lith. statau "place;" Goth. standan; PIE base *sta- "to set, stand").
Pâdistân, from pâdist + -ân suffix of place and time.

1a) Condition with reference to place; location; situation.
1b) A place occupied or to be occupied. → mean position.
2a) To put in a particular or appropriate position; place.
2b) To determine the position of; locate.

M.E. posicioun, from O.Fr. posicion, from L. positionem "act or fact of placing, position, affirmation," from positus, p.p. stem of ponere "to put, place."

Neheš, verbal noun from nehâdan "to place, put; to set;" Mid.Pers. nihâtan, from ne-, ni- "down; into," → ni- (PIE), + dâ- "to put; to establish; to give," dadâiti "he gives;" cf. Skt. dadâti "he gives;" Gk. didomi "I give;" L. do "I give;" PIE base *do- "to give"). Neheš-dâdan, from neheš "position," + dâdan "to give, yield, put," → datum.