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

A lexical form derived from a verb, that has some of the characteristics and functions of both verbs and adjectives. In most Indo-European languages participles are used to express participation in an action (present participle) or relate to a completed action (past participle). They can also appear in attributive form as adjectives.

M.E., from O.Fr. participle, variant of participe, from L. participium, literally "a sharing, partaking," from particeps "sharing, partaking," → participate.

Pârgerté, from pârgert present stem of pârgertidan, → participate, + nuance suffix -é.

1) A unit of → matter smaller than the → atom or its main components. The term particle also includes any (currently hypothetical) new particles that might be discovered, such as the supersymmetric partners of the → quarks and → leptons and → bosons.
2) Mechanics: A material body (a body possessing mass) the size of which can be neglected in investigating its motion.
3) Grammar: In some languages, a word that has a grammatical function but does not fit into the main parts of speech (i.e. → noun, → verb, → adverb, → preposition). For example, in English, off, on, out, and up in call off, pass on, rule out, and grow up, respectively.
See also:
→ alpha particle, → antiparticle, → astroparticle physics, → beta particle, → charged particle, → elementary particle, → energetic solar particle, → exchange particle, → Lagrangian particle, → nanoparticle, → particle horizon, → particle nature, → particle physics, → relativistic particle, → resonance particle, → sink particle, → Smoothed Particle Hydrodynamics, → strange particle, → subatomic particle, → test particle, → virtual particle, → wave-particle duality.

From L. particula "little bit or part," diminutive of pars (genitive partis), from PIE base *per- "to assign, allot;" cf. Mid.Pers. pârag "gift, offering, bribe;" Mod.Pers. pâreh "gift" (→ partial); Gk. porein "to provide, give, grant," peprotai "it has been granted;" Skt. purtá- "gift, pay, reward."

Zarré, from Ar. dharrat "particle." Pârul, from pâr, → part, + -ul, → -ule.

For an observer at a given epoch t₀, the boundary between the observable and the unobservable regions of the → Universe. Therefore, the distance to the particle horizon at t₀ defines the size of the → observable Universe. Same as → cosmic horizon.

→ particle; → horizon.

A general term to describe → light involving the following phenomena: → reflection, → refraction, and → photoelectric effect. Compare → wave nature.

→ particle; → nature.

The branch of physics that deals with the smallest known structures of matter and energy in order to understand the fundamental particles and forces of nature.

→ particle; → physics.

1) (adj.) Of or pertaining to a single or specific person, thing, group, class, occasion, etc., rather than to others or all; special rather than → general.
2a) (n.) An individual or distinct part, as an item of a list or enumeration.
2b) (n.) Logic: An individual or a specific group within a general class (Dictionary.com).

M.E., from O.Fr. particuler and directly from L.L. particularis "of a part, concerning a small part," from L. particula, → particle, + -ar, → -al.

Pâruli, adj. from pârul, → particle; pârulé, from pârul + nuance adj. -é.

An → astrolabe that serves only a limited number of → latitudes.

→ particular; → astrolabe.

Of partial differential equations, the solution which can be obtained from the general solution by particular choice of the arbitrary functions. → general solution; → singular solution.

→ particular; → solution.

1) Of or relating to minute separate → particles.
2) A particulate → substance.

From Mod. L. particulatus, from particula, → particle.

From pârul, → particle, + suffix -é or -mand.

Meteorology: A complex → mixture of → microscopic → particles and → liquid droplets suspended in the → atmosphere, especially pollutants.

→ particulate; → matter.

1a) A division into or distribution in portions or shares.
1b) A separation; something that separates or divides; a part, division, or section.
2a) The act or process of dividing something into parts. The state of being so divided.
2b) Math.: → integer partition; → set partition.
2c) Computers: → disk partition.
3) To divide into parts or portions. To divide or separate by a partition.

M.E., from O.Fr. particion, from L. partition- "division, partition, distribution," from p.p. stem of partire "to part, divide," from PIE root *per- "to grant, allot," related to → part and akin to pake, as below.

Parke, from Kermâni parke "piece, part, fragmant," related to pâr "→ part;" parkidan, infinitive from parke; parkeš, verbal noun of parkidan.

See → integer partition.

→ partition; → function.

The ratio of the → concentration of a → solute in a single definite form in the stationary phase to its concentration in the same form in the other phase at equilibrium.

→ partition; → ratio.

A chemical separation process whereby a solute is distributed between two phases.

→ partition; → -ing.

The act or fact of being partitioned.

→ partition; → -ment.

In particle physics, a constituent of the hadron originally postulated in the theoretical analysis of high-energy scattering of particles off hadrons. In modern usage, the term parton is often used to mean a quark or a gluon.

Coined by the American physicist Richard Feynman (1918-1988), from part, from → particle + → -ion

A fraction of a whole number in units of 1/1000,000. It is usually used to describe chemical concentrations, very small amounts of pollutants in air, water, body fluids, and uncertainty. For example 30 ppm is 3 x 10^-5 or 0.003%.

→ part; → per; → million.

A → participle that indicates a completed action or state.

→ past; → participle.

A diagram involving → formal compactification of → space-time used in → general relativity to describe the causal properties of the space-time. Only two of the space dimensions are shown and horizontal lines represent space, while vertical lines belong to time. The → null geodesicss are at 45°, which facilitates the visualization of → light cones. The major feature of Penrose-Carter diagram is representing the whole space-time on a finite surface, while putting → spacelike and → timelike infinities at finite distance.

Named for Roger Penrose (1931-) and Brandon Carter (1942-) who introduced it independently; → diagram.

A → participle that indicates an ongoing action or state in the present.

→ present; → participle.