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

The velocity with which an object moves away from another object or a reference point.

→ recession; → velocity.

1) General: Any theorem that expresses various reciprocal relations for the behavior of some physical systems, in which input and output can be interchanged without altering the response of the system to a given excitation.
2) In classical electromagnetism, the theorem stating that the current in a detector divided by the voltage at the source remains constant when source and detector are interchanged, as long as the frequency and all the impedances are left unchanged.

Reciprocity, from L. reciproc(us) "returning the same way, alternating" + → -ity; → theorem.

Farbin, → theorem; dosuyegi, quality noun of dosuyé nuanced term of dosu "two-sided," from do, → two, + su "direction, side," from Mid.Pers. sôk "direction, side."

An act of recognizing or the state of being recognized.

Verbal noun of → recognize.

1) To identify as something or someone previously seen, known, etc.
2) To identify from knowledge of appearance or characteristics (Dictionary.com).

→ re-; → cognition; → -ize.

1) To draw back; to rebound or fly back.
2) An act of recoiling. → Compton recoil.

M.E. recoilen, reculen, from O.Fr. reculer "to go back, recede, retreat," from V.L. *reculare, from L. → re- "back" + culus "backside."

Paszadan, from pas-, → back-, + zadan "to strike, beat, dash against," from Mid.Pers. zatan, žatan, O.Pers./Av. jan-, gan- "to strike, hit, smite, kill" (jantar- "smiter"), Skt. han- "to strike, beat" (hantar- "smiter, killer"), cf. Gk. theinein "to strike," L. fendere "to strike, push," Gmc *gundjo "war, battle;" PIE *g^when- "to strike, kill."

1) The process or result of combining again.
2) The capture of an electron by a positive ion. It is the inverse process to → ionization.

Verbal noun of → recombine.

A measure of the specific rate at which oppositely charged ions join to form neutral particles. It is given by the rate at which those ions recombine, divided by the product of the densities of the two species involved.

→ recombination; → coefficient.

A recombination radiation that is continuous over a range of frequencies. Same as → continuum emission.

→ recombination; → continuum.

Same as → recombination era.

→ recombination; → epoch.

The era some 380,000 years after the → Big Bang (at a → redshift of about 1,100), when the Universe had cooled sufficiently so that protons and electrons combined to form → neutral hydrogen in a process called → recombination. The temperature was about 3,000 K and the ionization fraction low enough for Universe to become transparent to light. Consequently matter and radiation decouple from one another because no further → scattering of the radiation occurs. The observation of the → cosmic microwave background radiation provides a means of studying the Universe at the recombination era. Also called recombination epoch and → decoupling era.

→ recombination; → era.

An → emission line in a spectrum produced in an → H II region when a free electron combines with an ionized atom to form a neutral atom or an ion of lower → ionization stage. Same as → free-bound emission.

→ recombination; → line.

Radiation produced when a free electron in a plasma is captured by an ionized atom.

→ recombination; → radiation.

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

→ recombination; → rate.

The time period necessary for a cloud of atomic hydrogen to be → ionized by the ultraviolet photons of a central → massive stars.

→ recombination; → time.

To combine or put together again. To undergo or cause recombination.

→ re- + → combine.

1) To cause (a person) to accept or be resigned to something not desired.
2) To win over to friendliness; cause to become amicable.
3) To compose or settle (a quarrel, dispute, etc.); to bring into agreement or harmony; make compatible or consistent (Dictionary.com).

Infinitive of → reconciliation.

1) An act of reconciling, as when former enemies agree to an amicable truce.
2) The state of being reconciled, as when someone becomes resigned to something not desired.
3) The process of making consistent or compatible (Dictionary.com).

From O.Fr. reconciliacion and directly from L. reconciliationem noun of action from p.p. stem of reconciliare. "to bring together again; regain," from → re- "again" + concilare "make friendly"

šti, from Mid.Pers. âštêh "peace;" Av. āšti- "peace, treaty of peace; agreement," āxšta-- "pacified, appeased."

1a) An act of recording.
1b) The state of being recorded, as in writing.
1c) Something on which sound or images have been recorded for subsequent reproduction, as a grooved disk that is played on a phonograph or an optical disk for recording sound (audiodisk) or images (videodisk).
2a) To set down in writing or the like, as for the purpose of preserving evidence.
2b) To set down or → register in some permanent form, as on a seismograph.
2c) To set down, register, or fix by characteristic marks, incisions, magnetism, etc., for the purpose of reproduction by a phonograph or magnetic reproducer; to make a recording of.

From M.E. recorden "to repeat, to report," from O.Fr. recorder "to get by heart," from L. recordari "to call to mind, remember," from → re- "back, again" + cor "heart" (as the metaphoric seat of memory, as in learn by heart).

Vâgat literally "to take, seize, to take back," cf. Ger. aufnehmen "to record," from nehmen "to take;" E. "take down" "to note down;" Šahmirzâdi vagatan "to take," Lâhijâni vitan, "to take, seize," Aftari veytu "to take," Delijâni bitan "to take," Tâleši gate, Târi gata/ger, Sorxeyi gil, all variants of gereftan, → concept.

A → quadrilateral all of whose angles are → right angles.

M.Fr. rectangle, from M.L. rectangulum "a triangle having a right angle," from rect-, combining form of rectus→ right + angulum, → angle.

Râstgušé, from râst, → right, + gušé "corner, angle;" Mid.Pers. gôšak "corner."

Having the base or section in the form of a rectangle. Shaped like a rectangle.

Adj. of → rectangle.