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.
parâš-e Fresnel (#)
Fr.: diffraction de Fresnel
The diffraction effects obtained when either the source of light or observing screen, or both, are at a finite distance from diffracting aperture or obstacle. → Fraunhofer diffraction.
Named after Jean Augustin Fresnel (1788-1827), French physicist, a key figure in establishing the wave theory of light. His earlier work on interference was carried out in ignorance of that of Thomas Young (1773-1829), English physician and physicist, but later they corresponded and were allies; → diffraction.
Fr.: interaction fondamentale
Any of the four interactions in nature between bodies of matter and that are mediated by one or more particles. Also called the → fundamental force. In order of decreasing strength, the four fundamental interactions are the → strong interaction, the → electromagnetic interaction, the → weak interaction, and the → gravitational interaction.
Adjective of → galaxy.