axtaršenâi-ye ostar-kahkašâni, ~ borun-kahkašâni
Fr.: astronomie extragalactique
The branch of astronomy that deals with objects beyond the Milky Way, especially galaxies and quasars.
extragalactic background light (EBL)
nur-e paszimine-ye ostarkahkeši
Fr.: lumière du fond extragalactique
The integrated intensity of all of the light emitted throughout the history of the Universe across the whole of the → electromagnetic spectrum, including those which are not individually detected. The EBL spectrum includes cosmological backgrounds associated with either primordial phenomena, such as the → cosmic microwave background radiation (CMBR), or photons emitted by stars, galaxies and → active galactic nuclei (AGN) due to → nucleosynthesis or other → radiative processes, including → dust scattering, → absorption and reradiation. The EBL may also contain signals that are diffuse and extended, including high-energy photons associated with dark matter particle decays or annihilation.
bâšâ, budé (#)
Something that has actual existence; a piece of information presented as having objective reality. → scientific fact.
L. factum "event, occurrence," literally "something done, deed," from neut. p.p. of facere "to do" (cf. Fr. faire, Sp. hacer), from PIE base *dhe- "to put, to do" (cf. Mod.Pers. dâdan "to give;" O.Pers./Av. dā- "to give, grant, yield," dadāiti "he gives; puts;" Skt. dadáti "puts, places;" Hitt. dai- "to place;" Gk. tithenai "to put, set, place;" Lith. deti "to put;" Czech diti, Pol. dziac', Rus. det' "to hide," delat' "to do;" O.H.G. tuon, Ger. tun, O.E. don "to do").
Bâšâ, from bâš + -â agent suffix; bâš, present stem of budan "to be," from Mid.Pers. budan, from O.Pers./Av. bav- "to be; become, take place;" Av. buta- perf. ptcpl. pass., bavaiti "becomes" (cf. Skt. bhavati "becomes, happens," bhavah "becoming; condition, state;" PIE *bheu- "to be, come into being, become;" Gk. phu- "become," phuein "to bring forth, make grow;" L. fui "I was" (perf. tense of esse), futurus "that is to be, future;" Ger. present first and second person sing. bin, bist; E. to be; Lith. bu'ti "to be;" Rus. byt' "to be"); budé also from budan.
1) One that actively contributes to the production of a result.
M.Fr. facteur "agent, representative," from L. factor "doer or maker," from facere "to do" (cf. Fr. faire, Sp. hacer); from PIE base *dhe- "to put, to do;" cf. Skt. dadhati "puts, places;" Av. dadaiti "he puts;" Hitt. dai- "to place;" Gk. tithenai "to put, set, place;" Lith. deti "to put;" Rus. det' "to hide," delat' "to do;" O.H.G. tuon; Ger. tun; O.S., O.E. don "to do."
Karvand, from kar- root of Mod.Pers. verb kardan "to do, to make" (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 kwer- "to do, to make") + -vand a suffix forming adjectives and agent nouns.
Fr.: arbre des facteurs
A diagram representing a systematic way of determining all the prime factors of a number.
1) karvandeh; 2) karvandi
1) (n.) The product of all the positive integers from 1 to n, denoted by
karvandidan, karvand gereftan
The operation of resolving a quantity into factors.
Fr.: interaction de Fermi
An old explanation, proposed by Enrico Fermi, of the → weak interaction.
Fr.: facteur de remplissage
Of a molecular cloud or a nebula, the ratio of the volumes filled with matter to the total volume of the cloud.
Fr.: premier contact
1) The beginning of a → solar eclipse when the eastern part of
the lunar limb touches the western limb of the Sun, marking
the beginning of an eclipse.
Fr.: quatrième contact
The end of a solar eclipse marked by the disk of the Moon completely passing away from the disk of the Sun.
From M.E. fourthe, O.E. féowertha, from four, from O.E. feower, from P.Gmc. *petwor- (cf. Du. and Ger. vier, O.N. fjorir, Dan. fire, Sw. fyra), from PIE *qwetwor (cf. Mod.Pers. cahâr, Av. caθwar-, catur-, Skt. catvarah, Gk. tessares, L. quattuor) + -th a suffix used in the formation of ordinal numbers, from M.E. -the, -te, O.E. -tha, -the; cf. O.N. -thi, -di; L. -tus; Gk -tos; → contact.
Parmâs, → contact; cahârom cardinal form from cahâr "four," cognate with E. four, as above.
A geometrical or physical structure that repeats itself or nearly repeats itself on many different scales of magnification.
Fr.: cosmologie fractale
The postulate that the concentrations of matter in the Universe follow a → fractal structure over a wide range of scales.
Fr.: structure fractale
A → hierarchial structure that can be likened to fractals.
A rational number of the form a/b where a is called the numerator and b is called the denominator.
From L.L. fractionem (nom. fractio) "a breaking in pieces," from frangere "to break," from PIE base *bhreg- "to break" (cf. Goth. brikan, O.E. brecan "to break;" Lith. brasketi "crash, crack").
Barxé, from barx "lot, portion," variant bahr, from Mid.Pers. bahr "lot, share, portion," Av. baxəδra- "portion."
Fr.: fractionnaire, fractionné, partiel
1) Math.: Pertaining to fractions; constituting a fraction.
fractional sky coverage
pušeš-e barxe-yi-ye âsmân
Fr.: couverture partielle du ciel
The portion of the 4π → steradians of the sky that a radiotelescope can observe from a given location on Earth over a 24-hour time interval.
1) To break something up into smaller parts.
From → fraction + -ate a suffix forming verbs or nouns, from L. -atus, -ata, -atum.
Barxândan, from barx, barxé, → fraction, + -ândan suffix of transitive verbs.
1) Any of various methods of separating the components of a mixture into
fractions of different properties.
Verbal noun from → fractionate.
Fr.: réfracteur de Fraunhofer
The first modern refracting telescope which had an outstanding quality. It was built in 1824 by Fraunhofer for the Russian Imperial Observatory in Dorpat, now Tartu in Estonia. It had a 23-cm → achromatic lens and a German-type → equatorial mounting driven by a clockwork. Wilhelm Struve (1793-1864) used the refractor to observe many → visual binaries, and attempted to measure the distances of stars through their visual → parallaxes. He also obtaibned accurate values for the diameters of the → Galilean satellites of → Jupiter.
Named after Joseph von Fraunhofer (1787-1826), German optician and physicist; → refractor.