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

A faint comet with the shortest known period (about 3.30 years). Its semimajor axis is 2.21 AU and aphelion 4.1 AU. it is the parent body of the Taurids meteor shower. The comet was first observed in 1786 by the French astronomer Pierre Méchain.

Named after the German astronomer Johann Franz Encke (1791-1865), who in 1819 computed its orbit and proved that sightings of apparently different comets in 1786, 1795, 1805, and 1818 were in fact appearances of the same comet. → comet.

To convert (data, information) into another format by → encoding. See also → decode and → encrypt.

From en- "in; into" + → code.

Ramzândan, infinitive from ramz, → code. Ramz gozâštan, from ramz + gozâštan "to place, put," → nomenclature.

An electronic device or software program used to convert (a message, information, data) into a specialized digital format for efficient transmission or transfer.

→ encode; → -er.

A process used for transforming data into another format by means of a scheme that is publicly available so that it can easily be reversed. See also → decoding and → encryption.

→ encode; → -ing.

General: A meeting, especially one that is unplanned, unexpected, or brief. An often violent meeting; a clash.
Coming across of two bodies (as two stars in a cluster) which results in the deviation from original directions of motion. → close encounter; → strong encounter; → weak encounter.

From O.Fr. encountrer "confront," from encontre "against, counter to," from L.L. incontra "in front of," from L. in- "in" + contra "against."

Ruyâruyi "being face to face," from ru, ruy "face, countenance," variant rox (Mid.Pers. rôy, rôdh "face," Av. raoδa- "growth," in plural "appearance," from raod- "to grow, sprout, shoot," cf. Skt. róha- "rising, height") + euphonic interfix -â- + ruy + noun suffix -i.

To convert (information or data) into a system of symbols, especially to prevent unauthorized access. See also → decrypt and → encode.

From en- "in; into" + L. crypt, from Gk. kryptos "hidden, concealed, secret" + → -tion.

Darnahândan, from dar-, → in- + nahândan "to hide, conceal," from nahân "concealed, hid; clandestine;" Mid.Pers. nihân "secrecy, a secret place, a hiding place," nihânik "concealed;" Av. niδāti- "deposing, deposit."

A process that transforms data into another format in such a way that only specific individual(s) can reverse the transformation. Encryption is for maintaining data confidentiality. See also → decryption and → encoding.

→ encrypt; → -tion.

A combining form meaning "within, inside" used in the formation of compound terms such as → endomorphism and → endothermic.

From Fr., from Gk. endon "in, within, at home," from en "in" + -don, base of domos "house," → domain.

Darun "in, into, within;" Mid.Pers. andarôn "inside," from andar, → inter- + rôn "side, direction;" Av. ravan- "(course of a) river."

A nuclear or molecular process in which some of the energy of the incoming particle is absorbed by, or transferred to, the other particle.

→ endo- + -ergic, a combining form with the meanings "activated by, sensitive to, releasing, resembling the effect produced by the substance or phenomenon specified by the initial element," from → erg, → energy + → -ic; → process.

Farâravand, → process; kâružgir, from kâruž, → energy, + gir present stem of gereftan "to take, seize, catch" (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").

A → morphism from an → object to itself.

→ endo-; → morphism.

Process during which heat is absorbed by the system from outside.

→ endo- + -therm, from Gk. therme "heat," from PIE *ghwerm-/*ghworm- "warm;" cf. Pers. garm "warm," L. fornax "an oven," O.E. wearm "warm" + → -ic.

From garmâ "heat, warmth" (Mid.Pers. garm, O.Pers./Av. garəma- "hot, warm," cf. Skt. gharmah "heat," Gk. thermos "warm," L. formus "warm," P.Gmc. *warmaz, O.E. wearm, O.H.G., Ger. warm, PIE *ghworm-/*ghwerm-, as above) + gir present tense stem of gereftan "to take, seize, catch" (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) Remain in existence; last.
2) Suffer (something painful or difficult) patiently (OxfordDictionaries.com).

From L. indurare "make hard," from in- + durare "to harden," from durus "hard," → duration.

Pâyidan, → last (v.);
Tâb âvardan b"endure," from tâb "toleration, patience," related to tavân, tavânestan "to be able," → conserve, + âvardan "to bring, to cause, produce," → production.

1) Having a relatively high amount of energy.
2) Of or relating to energy.

→ energy + -t + → -ic.

Electrons and atomic nuclei ejected by solar flares, travelling with velocities amounting to a fraction of the velocity of light, and energies mostly in the range 1-100 million → electronvolts (eV), but occasionally as high as 15 billion eVs. Also known as solar → cosmic rays.

Energetic, from Gk. energetikos, from energe-, → energy, + -tikos a suffix, equivalent in meaning to → -ic, occurring in adjectives; → solar; → particle.

Zarrehâ plural of zarré, → particle; xoršidi, → solar; kâružmand from kâruž, → energy, + -mand possession suffix.

The total energy relations and transformations of energy within a particular physical, chemical, or biological system.

→ energy + -t + → -ics.

In physics, capacity for doing work.

From M.Fr. energie, from L.L. energia, from Gk. energeia "force in action, activity, operation," from energos "active, working," from en- "in, at" + ergon "work," from PIE base *werg- "to work" (cf. Av. varəz- "to work, do, perform, exercise;" Mod.Pers. varz-, varzidan "to labor, exercise, practise;" Arm. gorc "work;" Lith. verziu "tie, fasten, squeeze," vargas "need, distress;" Goth. waurkjan; O.E. wyrcan "work," wrecan "to drive, hunt, pursue").

Kâruž, literally "work strength," from kâr + už. The first component kâr "work," Mid.Pers kâr, Mod./Mid.Pers. kardan "to do, to work," 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." The second component, už, from Mid.Pers. ôž "strength" (ôžômand "strong"), Av. aogah-, aojah- "strength" (aojahvant- "strong") Skt. ojas- "strength" (ojasvant- "strong"); L. augustus "venerable," L.L. augmentare "to increase," from augere "to increase, enlarge, enrich;" Lith. augu "to grow;" Gk. auxo "increase;" Goth. aukan "to grow, increase;" O.E. eacien "to increase"); PIE *augos- "force," *aug- "to increase."

The → turbulent process whereby → kinetic energy is transformed into heat by the action of nonlinear coupling which transfers the energy from large eddies (→ eddy) to smaller and smaller eddies, finally arriving at → dissipative scales dominated by → viscosity (direct cascade). In the simplest case (3D homogeneous hydrodynamic turbulence), the resulting energy distribution is the → Kolmogorov spectrum. The reverse process also exists (inverse cascade) whereby energy is transferred to larger and larger eddies.

→ energy; → cascade.

The amount of energy in the form of radiation per unit volume, expressed in ergs cm^-3. In particular, the energy density of blackbody radiation at temperature T is aT⁴, where the radiation constant a = 7.56 × 10^-15 erg cm^-3 (K)^-4.

→ energy; → density.

Of a stellar → nuclear fusion, the equation describing the → energy generation rate as a function of → density and → temperature.

→ energy; → generation; → equation.

Of a stellar → nuclear fusion, the energy produced per unit mass per unit time, usually denoted ε (erg g^-1s^-1). The general form of the energy generation equation is: ε = ε₀ρ^λT^ν, where ε₀, ρ, and λ are constants over some efficiently restricted range of → temperature T, → density ρ, and → chemical composition. The temperature exponent ν is about 4, 15, and 40 for → proton-proton chain, → CNO cycle, and → triple alpha process, respectively.

→ energy; → generation; → rate.