# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 6 Search : interval
 interval   اندروار   andarvâr (#)Fr.: intervalle   1) Math.: A portion of a real line (i.e. a line with a fixed scale so that every real number corresponds to a unique point on the line) between two designated endpoints. → span. 2) Music: Difference in pitch between two tones of a scale.From O.Fr. intervalle, from L.L. intervallum, originally "space between two palisades or ramparts," from → inter- "between" + vallum "rampart."Andarvâr, literally "between walls," from andar-→ inter- + vâr "wall," as in divâr "wall" (originally "fortress wall," from *dida-vāra-), variant bâru "wall, rampart, fortification; fort; tower;" Mid.Pers. bâr, var "enclosure, defences, fortress;" Av. var- "castle." lightlike interval   اندروار ِ نورسان   andarvâr-e nursânFr.: intervalle genre lumière   The space-time interval between two events if it is zero, i.e. ds2 = 0.→ lightlike; → interval. open interval   اندروارِ باز   andarvâr-e bâzFr.: intervalle ouvert   An interval that does not include its two endpoints.→ open; → interval. space-time interval   اندروار ِ فضا-زمان   andarvâr-e fazâ-zamânFr.: intervalle espace-temps   1) In Einstein's → theory of relativity, ds2 = c2dt2 - dx2 - dy2 - dz2. 2) In → Newtonian mechanics, time interval: dt; space interval at fixed time: dl2 = dx2 + dy2 + dz2.→ space-time; → interval. spacelike interval   اندروار ِ فضاسان   andarvâr-e fazâsânFr.: intervalle genre espace   The → space-time interval between two → events if it is imaginary, i.e. ds2< 0.→ spacelike; → interval. timelike interval   اندروار ِ زمانسان   andarvâr-e zamânsânFr.: intervalle genre temps   The → space-time interval between two → events if it is real, i.e. ds2 > 0.→ timelike; → interval.