Fr.: période d'observation
A period of telescope time for observations allocated to a science project.
šekâf-e nepâheš, ~ gonbad
Fr.: fente d'observation
The long opening in the dome of a telescope through which observation is conducted.
zâviye-ye bâz (#)
Fr.: angle obtus
An angle whose measure is greater than 90° and less than 180°.
Obtuse, from M.Fr. obtus (fem. obtuse), from L. obtusus "blunted, dull," p.p. of obtundere "to beat against, make dull," from ob "against" + tundere "to beat," from PIE *(s)tud- "to beat, strike, push, thrust;" → angle.
Zâviyé, → angle; bâz "open," from Mid.Pers. abâz-, apâc-, O.Pers. apa- [pref.] "away, from;" Av. apa- [pref.] "away, from," apaš [adv.] "toward the back;" cf. Skt. ápāñc "situated behind."
1) A particular time, especially as marked by certain circumstances or occurrences.
M.E. occasioun from O.Fr. ochaison, ocasion "cause, reason, pretext; opportunity," from L. occasionem (nominative occasio) "appropriate time," from occasum, occasus "fall; sunset," p.p. of occidere "fall down, go down," from ob "down, away" + cadere "to fall," → case.
Âkatan, from prefix â- + katan "to fall," cf. Laki: katen "to fall," kat "he/she fell," beko! "fall!" (an insult); katyâ "fallen;" Lori: kat "event, error;" Kurd. (Soriani): kawtin "to fall, befall," kett "fallen;" Kurd. (Kurmanji): da.ketin "to fall down;" Lârestâni: kata "to fall;" Garkuyeyi: darkat, varkat "he/she fell (sudden death);" Gilaki (Langarud, Tâleš): katan "to fall," bakatam "I fell," dakatan "to fall (in a marsh, in a pit)," vakatan "to fall from tiredness, be exhausted," fakatan "to fall from (i.e., lose) reputation;" Tabari: dakətə "fallen," dakətən "to crash down," dakət.gu "stray cow;" Proto-Iranian *kat- "to fall;" cf. L. cadere "to fall," → case, Pers. kâté.
1) Occurring or appearing at irregular or infrequent intervals; occurring now and then.
Named after the Roman agriculture deity of harrowing, a method of leveling soil.
The blocking of light from an astronomical object, such as a star, by another object, such as the Moon or an asteroid, that passes in front of it. Also, the period of time for which this blocking takes place. A → solar eclipse is a particular case of occultation. Determining the moment of stellar occultation by the Moon is used to improve our knowledge of the lunar orbit. Moreover, the occultation of stars by asteroids or planetary satellites provide important data for better measuring the sizes of the occulting bodies. See also → grazing occultation.
M.E. from L. occultation- "a hiding," from occultat(us), p.p. of occultare "to conceal, keep something hidden," frequentative of occulere "to cover over, conceal," from ob "over" + a verb related to celare "to hide," from PIE base *kel- "to conceal."
Forupušân, from foru- "down, downward; below; beneath" (Mid.Pers. frôt "down, downward;" O.Pers. fravata "forward, downward;" cf. Skt. pravát- "a sloping path, the slope of a mountain") + pušân p.pr. of pušândan, accusative of pôšidan, pôš- "to cover; to wear" (related to pust "skin, hide;" Mid.Pers. pôst; O.Pers. pavastā- "thin clay envelope used to protect unbaked clay tablets;" Skt. pavásta- "cover," Proto-Indo-Iranian *pauastā- "cloth").
The act of occupying; the state of being occupied.
Verbal noun of → occupy.
Fr.: niveau occupé
The energy level adopted by a particle, atom, or molecule under quantum mechanical laws.
To take or fill up (space, time); to take possession and control of a place.
From O.Fr. occuper, from L. occupare "take over, seize, possess, occupy," from ob "over" + intensive form of capere "to grasp, seize, take;" PIE base *kap- "to grasp" (cf. Skt. kapati "two handfuls;" Gk. kaptein "to swallow," O.Ir. cacht "servant-girl," literally "captive;" Goth. haban "have, hold;" O.E. habban "to have, hold," probably Mod.Pers. qâp-, qâpidan "to seize;" Av. haf-, hap- "to keep, observe."
Hagidan, from dialectal Pers.: Šahmirzâdi hâgetan, Saraxsi hagiton, Tabari hâytan, haytan, Semnâni hâtan, Gilaki hâgitan, Lâsgardi agiton, degiton "to occupy;" maybe related to Av. haz- "to occupy;" Skt. sah- "to overcome, be victorious, prevail," saha- "victory," sahate "overcomes, masters;" Gk. ekhein "to have, hold;" PIE base *segh- "to have, to hold."
Fr.: avoir lieu
1) To happen; take place; come to pass.
M.Fr. occurrer "to happen unexpectedly" or directly from L. occurrere "run to meet, run against, present itself," from ob "against, toward" + currere "to run," → current.
Roxdâdan, literally "to appear," from rox "appearance; aspect; face," variant ruy "face, surface" + dâdan "to give," → event.
Verbal noun of → occur.
The intercommunicating body of salt water occupying the depressions of the Earth's surface, or one of its major primary subdivisions, bounded by the continents, or the equator, and other imaginary lines. A sea is subdivision of an ocean. the vast body of salt water that covers almost three fourths of the earth's surface.
M.E. ocean(e), from O.Fr. occean, from L. oceanus, from Gk. okeanos "the great river or sea surrounding the disk of the Earth, as opposed to the Mediterranean," of unknown origin. Personified as Oceanus, son of Uranus and Gaia and husband of Tethys.
Oqyânus, from Ar., ultimately from Gk., as above.
Fr.: planète océan
Of, living in, or produced by the ocean.
Fr.: croûte océanique
That part of the → Earth's crust underling most of the Earth's surface which is covered by the oceans. It has a remarkably uniform composition (mostly ~ 49% SiO2) and thickness (mostly ~ 7 km). The ocean floor is the most dynamic part of the Earth's surface. As a result, no part of the oceanic crust existing today is more than 200 million years old, which is less than 5% of the age of the Earth itself. New oceanic crust is constantly being generated from the → upper mantle by sea-floor spreading at → mid-ocean ridges, while other parts of the oceanic crust are being recycled back into the mantle at subduction zones.
Fr.: dorsale océanique
Any section of the narrow, continuous submarine mountain chain through all the world's oceans. The oceanic ridge constitutes the most extensive mountain ridge on Earth, more than 65,000 km. Perhaps the best-known part of the ridge system is the → Mid-Atlantic Ridge.
The study of the ocean, embracing and integrating all knowledge pertaining to the ocean's physical boundaries, the chemistry and physics of sea water, and marine biology.
M.E. oker, O.Fr. ocre, from L. ochra, from Gk. okhra, from okhros "pale yellow."
Oxrâ, loan from Gk.
ostare-ye Ockham (#)
Fr.: rasoir d'Ockham
The notion that any hypothesis should be stripped of all unnecessary assumptions. If two hypotheses fit the observations equally well, the one that makes the fewest assumptions should be chosen.
The doctrine was formulated by William of Ockham (c.1288-c.1347), an English Franciscan friar and scholastic philosopher. Razor from O.Fr. rasour "a razor," from raser "to scrape, shave."
Ostaré "razor," from sotordan "to shave, erase, remove;" Mid.Pers. ôstarak "removed, shaved," ôstârišn "wiping, shaving;" cf. Khotanese ustar- "to remove," Sogdian (prefixed *pari-) prtr- "to wipe off, dry up," from Proto-Iranian *us-tar- "to remove, wipe off."