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

A hypothetical → compact object composed of particles other than electrons, protons, and neutrons balanced against → gravitational collapse by → degeneracy pressure of corresponding quantum properties.

→ exotic; → star.

1a) To change (something) from a smaller form and/or size to a larger one.
1b) To increase the extent, number, volume or scope of (something).
1c) To express (something) at length and/or in detail.
1d) Math.: To write (a mathematical expression) as a sum of terms in an extended form.
2) to increase or grow in extent, bulk, scope; to spread out; unfold; develop.
See also → spread, → extend, → dilate.

M.E. expanden, from O.Fr. espandre "to spread, spread out," from L. expandere "to spread out, unfold, expand," from → ex- "out" + pandere "to spread, stretch," from nasalized form of PIE root *pete- "to spread," a Pers. offshoot of which is pahn "wide, broad," as below. from

Sopândan, "to stretch, to extend, open out" from so- "out," → ex-, + pân, from pan, variant of pahn "wide, large, broad, ample, extensive," from Mid.Pers. pah(a)n; Av. paθana- "broad, wide, spacious;" PIE root *pete- "to spread;" cf. L. patere "to be open," Gk. petannynai "to spread out," petalon "a leaf."
Alternatively, sopândan "to open up, to open out," from so- "out," → ex-, + pân "open," cf. Yaghnobi pen, peyn "to open, unroll," Sogd. pyn- "to open," ultimately from Proto-Ir. *apa- "off, away, from" + *hHai- "to chain, bind," from which Pers. gošâdan "to open, release" (Cheung 2007).

A → radio interferometer array consisting of 27 25-meter diameter antennas located on the Plains of San Agustin in West-Central New Mexico. EVLA will operate at any frequency between 1.0 and 50 GHz and will have a continuum sensitivity improvement over the → VLA by factors of 5 to 20.The EVLA project is expected to be completed in 2012. See also the EVLA homepage.

→ expand; → very; → large; → array.

The deduction based on the observational fact that the greater the → distance to a → galaxy, the greater the → redshift in its → spectral lines (→ Doppler effect). The observations strongly indicate that galaxies appear to be moving away from us with speeds proportional to their distance. This is in agreement with the overall → expansion of the → Universe.

→ expand; → -ing; → Universe.

1) General: The act or process of expanding; the state or quality of being expanded. → expansion of the Universe.
2) Math.: The process of expressing a quantity, or a quantity expressed, as a sum of a series of terms. For example the expression (2x - 1)(x + 3) can be expanded to: 2x² + 5x - 3. See also → binomial expansion.

Noun from → expand.

The receding of galaxies from one another at a speed proportional to their separation, as inferred by Edwin Hubble from the observed Doppler shift of distant galaxies. → Hubble constant describes the local rate of the expansion.

→ expansion; → universe.

A → scale factor that relates the size of the Universe R = R(t) at time t to the size of the Universe R₀ = R(t₀) at time t₀ by R = aR₀. The expansion parameter represents the history of expansion of the Universe.

→ expansion; → parameter.

Statistics: Same as → mathematical expectation, → expected value.

From L. expectare "to await, hope," from → ex- "thoroughly" + spectare "to look," from → specere "to look at," → -scope.

Bayusesš, verbal noun of bayusidan "to expect;" Mid.Pers. pyws- "to hope for, desire" (prefixed *pati-); O.Pers. vasiy "at will, greatly, utterly," vašna- "will, favor;" Av. vas- "to will, desire, wish, long for," vasəmi "I wish," vasna- "will, favor," ušti- "desire, wish, will," vasô, vasə "at one's will." This word is extant in several Mod.Pers. dialects, Tabari vessen "to wish, desire," Gilaki vâssan "to wish, desire," vâsti "desire," Kurd. wistin "to desire, wish," Lâri avessa "to desire," colloquial Tehrâni vâsé "for" (Mid.Pers. vasnâd "because"); cf. Skt. vaś- "to wish, want, desire," váśa- "wish, desire," vasēna "for, because;" Gk. ekon "voluntary;" PIE base *uek- "to wish."

Statistics: Same as → mathematical expectation, → expectation.

→ expectation; → value.

To use up. See also → spend, → consume.

From L. expendere "to pay out, weigh out money," from → ex- "out" + pendere "to pay, weigh."

Hazinidan, back formation from haziné, → expenditure.

1) The act of expending something, especially funds; disbursement; consumption.
2) Something that is expended; expense (Dictionary.com).

From → expend.

Mid.Pers. uzên, uzênag "expense;" ultimately from Proto-Ir. *uz-ayana- literally "going out" (cf. Awromani ziāy-/-zia- "to go out"), from uz-, → ex-, + *Hai- "to go," → efficiency.

An act or operation for the purpose of discovering something unknown or of testing a principle, supposition. See: → Aspect experiment, → Carnal-Mlynek experiment, → Davisson-Germer experiment, → double-slit experiment, → Eratosthenes experiment, → Hafele-Keating experiment, → Hertz experiment, → Michelson-Morley experiment, → Millikan's oil-drop experiment, → Pascal's barrel experiment, → random experiment, → Stern-Gerlach experiment, → thought experiment, → toothed-wheel experiment, → Trouton-Noble experiment, → Young's experiment.

From O.Fr. experiment, from L. experimentum "a trial, test," from experiri "to test, try," from → ex- "out of" + peritus "experienced, tested."

Âzmâyeš, verbal noun of âzmudan, âzmây- "to try, experiment, test;" Mid.Pers. uzmudan, ôzmutan "to test, try, prove;" from O.Pers./Av. *uz-māy-, from uz-, → ex- + mā(y)- "to measure," Proto-Ir. *maH- "to measure;" PIE *meH- "to measure;" cf. Skt. mati "measures," matra "measure;" Gk. metra "lot, portion;" L. metri "to measure."

1) To make plain or clear; to render understandable or intelligible.
2) To make clear the cause or reason of; to account for.
3) To assign a meaning to; → interpret.

From L. explanare "to make level, smooth out; make clear," from → ex- "out" + planus "flat; clear."

Ostâhidan, literally "to unfold, spread out" (on the model of Fr. expliquer, Sp. explicar, from L. → ex- "out" + plicare "to lay, fold, twist," from PIE base *plek- "to plait, twist;" cf. Gk. plekein "to plait," L. plectere "to plait, braid, intertwine," O.C.S. plesti "to braid, plait, twist," Goth. flahta "braid"), from os- "out," → ex- + tâh "fold, plait, ply;" Mid.Pers. tâg "piece, part" + -idan infinitive suffix.

1) The act or process of explaining.
2) A statement made to clarify something and make it understandable.

Verbal noun of → explain.

1) General: Precisely and clearly expressed.
2) Math.: → explicit function.

From Fr. explicite, from L. explicitus "unobstructed," variant p.p. of explicare "unfold, unravel, explain," → explain.

Ostâhi, from ostâh present stem of ostâhidan, → explain, + -i adj. suffix.

The most usual form of a function in which the dependent variable (written on the left hand side of the Same as → equality sign) is expressed directly in terms of independent variables written on the left (on the right hand side). See also → implicit function.

→ explicit; → function.

Verbal form of → explosion.

From L. explodere "drive out or off by clapping," originally theatrical, "to drive an actor off the stage by making noise," from → ex- "out" + plaudere "to clap, beat," of uncertain origin.

Oskaftidan, from os-, → ex- + kaftidan "to burst; to split," variants kaftan, kâftan "to split; to dig," Parthian Mid.Pers. q'f- "to split;" Sogdian kβ "to spli;" Chorasmian kf- "to split, be split;" Proto-Iranian *kap-, *kaf- "to split."

1) An act or instance of exploring or investigating; examination.
2. The investigation of unknown regions.
3) The process of searching for minerals by means of geological studies.
4) Medicine: An examination or investigation for diagnostic purposes, usually involving endoscopy or a surgical procedure.

Verbal noun of → explore.

1) To travel to or in a place for the purpose of discovery.
2) To make a careful investigation or study of something.

From L. explorare "investigate, search out;" said to be originally a hunters' term meaning "set up a loud cry," from → ex- "out" + plorare "to cry."

Puyidan, originally "to run, trot; wander," from Mid.Pers. pôy-, pwd- "to run;" cf. Gk. speudein "to hasten;" Lith. spudinti.

A person or thing that explores.

Agent noun of → explore.