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

The rate with which the → mass loss process takes place, usually expressed in → solar mass per year. → radiation-driven mass loss. The mass loss rate and the → terminal velocity are anti-correlated, since the → wind momentum is constant, → bi-stability jump.

→ mass loss; → rate.

A → meteorite impact crater located about 55 km east of Flagstaff, near Winslow in the northern Arizona desert of the United States. Meteor Crater is about 1,200 m in diameter and some 170 m deep. It is thought to have formed between 20,000 to 50,000 years ago, by the impact of a small → asteroid about 25 m in diameter. Same as → Barringer Crater.

→ meteor; → crater.

1) To go from one country, region, or place to another.
2) To pass periodically from one region or climate to another, as certain birds, fishes, and animals.
3) Chem.: To move toward an electrode during electrolysis; (of atoms within a molecule) to change position (Dictionary.com).

From L. migratus p.p. of migrare "to move from one place to another," ultimately from PIE *meig^h- "to move, go;" cf. Gk. ameibein "to change," Iranian muž-, as below.

Mužidan, ultimately from Proto-Ir. *maij- "to move (to places);" cf. Parachi muž-, muš-, Yazghulami mûž- "to go," mex^w-/max^wt- "to move, shake," Gilaki maxtan "to stroll," Gonâbâdi mejon "ague, shivering, shaking chills," Sangesari moj; cognate with L. migrare "to move, go," as below, Skt. niméghanāna- "moving down;" PIE *meig^h- "to move, go."

To function or work; to make something function or work.

From L. operari "to work, labor," L. opus "a work, labor, exertion," Av. *āpah-, *apah- "to do, operate," see below, Skt. ápas- "work, action, religious act;" O.H.G. uoben "to start work, to practice, to honor;" Ger. üben "to exercise, practice;" Du. oefenen; O.E. æfnan "to perform, work, do," afol "power"); PIE base *op- "to work, perform."

Âpâridan, from âpâr-, from Av. *āp(ah)- "to do, operate," as above, + suffix -ar (as in vadar- "weapon," zafar- "jaw," baēvar- "thousand," and so on), shifted to -âr, + -idan suffix of infinitives. The Av. *āpah- "to do, operate," is extant in Mod.Pers. xub "good;" Mid.Pers. hwp, xub "good;" from Av. huuāpah- "doing good work, masterly," from huu-, hv- "good" → eu- + āpah- "work, deed," hauuapanha- "creativity;" cf. Skt. sv-ápas- "doing good work, skillful;" PIE base *op-, as above.

To make worse; to cause to deteriorate. To endow (a word) with a less favorable meaning.

Back formation from → pejorative.

Pastârdan, literally "to render low, vile, bring down" from past "low, vile, abject," → platykurtic, + ârdan, short for âvardan, "to cause or produce; to bring," → cause.

Any salt of perchloric acid.

→ per-; → chlorate.

Same as → PG 1159 star.

→ post-; → degenerate; → star.

The amount of change of some quantity during a time interval divided by the length of the time interval.

M.E. rate "monetary value," M.Fr. rate "price, value," from M.L. rata (pars) "fixed (amount)," from L. rata "fixed, settled," p.p. of reri "to reckon, think," → reason.

Nerx "rate, price, tariff."

The speed with which a → chemical reaction takes place. In other words, the change in → concentration of a → substance divided by the → time interval during which the change is observed.

→ reaction; → rate.

In computing and data processing, the number of words, characters, fields, etc. sensed by an input sensing device per unit of time.

Reading, verbal noun of read, from M.E. reden, O.E. rædan, redan "to counsel, read;" cf. Du. raden, Ger. raten "to advise, counsel, guess;" akin to Skt. rādh- "to succeed, accomplish;" Gk. arithmos "number amount;" L. ratio; Pers. rây, râ "because of, for the sake of;" → reason; → rate.

Nerx, → rate; xâneš verbal noun of xândan "to read; to sing; to call;" Mid.Pers. xwân- "to resound; to call;" Av. x^van- "to sound," Proto-Iranian *huan- "to call;" cf. Skt. svan-, sváranti "to sound, make a sound, sing;" L. sonus "sound," sonare "to sound;" O.E. swinn "music, song," PIE base *suen- "to sound" (Cheung 2007).

In → H II regions the rate at which free electrons recombine with → ionized hydrogen atoms (protons).

→ recombination; → rate.

1) To produce anew; bring into existence again; to bring new and more vigorous.
2) Biology: To renew or restore (a lost, removed, or injured part).
3) Physics: To restore (a substance) to a favorable state or physical condition.
4) Electronics: To magnify the amplification of, by relaying part of the output circuit power into the input circuit (Dictionary.com).

→ re-; → generate.

1) Chem.: To add as much of a liquid, solid, or gas to a solution as it can absorb at a given temperature.
2) To fill something with so many things that no more can be added.

From L. saturatus, p.p. of saturare "to fill full, sate, drench," from satur "sated, full," from PIE base *sā- "to satisfy."

Anjâlidan "to saturate, to fill" (Dehxodâ, Steingass), ultimately from Proto-Iranian *ham-gar-, from *ham- "together," denoting "much, many," → syn-, + *gar- "to soak, moisten;" cf. Sogdian wγyr- "to soak, steep," from *aua-gar-, from which derives Pers. âqâridan, âqeštan "to steep, soak; mix."

1) Chem.: The qualifier of a solution that has as much solute as possible.
2) (Of colors) Of maximum chroma or purity.

Past participle of → saturate (v..

Air that contains the maximum amount of → water vapor that is possible at the given → temperature and → pressure, i.e. air in which the → relative humidity is 100%.

→ saturated; → air.

A liquid whose temperature and pressure are such that any decrease in pressure without change in temperature causes it to boil.

→ saturate; → liquid.

A solution which can exist in equilibrium with excess of solute. The saturation concentration is a function of the temperature.

→ saturate; → solution.

A vapor at the pressure and temperature at which it can exist in dynamical equilibrium with its liquid. Any compression of its volume at constant temperature causes it to condense to liquid at a rate sufficient to maintain a constant pressure. The term "saturated" is a misnomer, since it does not have the same meaning as a → saturated solution in chemistry. There is no question of one substance being dissolved in another.

→ saturate; → vapor.

The scientific attempt to detect → intelligent extraterrestrial → life by surveying the sky to find the existence of → transmissions, especially → radio waves or → light, from a → civilization on a distant → planet. The SETI Institute, that carries out the project, is a private non-profit center founded in 1984. There are many methods that SETI scientific teams use to search for extraterrestrial intelligence. Many of these search billions of radio frequencies that reach Earth from all over the → Universe, looking for an intelligent → radio signal. Other SETI teams search by looking for signals in pulses of light emanating from the stars.

→ search; → extraterrestrial; → intelligence.

A crater formed by the relatively low-velocity impact of fragments ejected from a large primary crater. Secondary craters tend to cluster in a ring around the primary crater.

→ secondary; → crater.