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

The characteristic length of time that is required for a system undergoing → relaxation to move to its equilibrium state. If the system follows an exponential law G = G₀ exp(-t / τ), the relaxation time is the time required for G to obtain the fraction 1/e of its initial value G₀.

→ relaxation; → time.

A → dynamical system that has regained its → equilibrium. Especially a system in which the kinetic and potential energies obey a specific relationship known as the → virial theorem.

P.p. from relax, → relaxation.

General: The act of passing something along from one person, group, or device to another.
Electronics: An electronic or electromechanical switching device, typically operated by a low voltage, that controls a higher-voltage or higher-power circuit and turns it on or off.
A device consisting of a receiver and a transmitter, used to receive and retransmit signals.

M.E. relaien "to unleash fresh hounds in a hunt," from M.Fr. relai "reserve pack of hounds or other animals," from O.Fr. relaier "to exchange tired animals for fresh," literally "to leave behind," from → re- "back" + laier "to leave."

Ask "relay horse kept in stations for the use of messengers," maybe from asb→ horse.

The quality or condition of being → relevant.

Noun from → relevant; → -ance.

Closely related, connected, or pertinent to the matter at hand.

From Fr. relevant "depending upon," from M.L. relevantem (nominative relevans), from stem of L. relevare "to lessen, lighten," from intensive prefix → re- + levare "to lift up, lighten," from levis "not heavy;" from PIE root *leg^wh-

Dabuste, from Gilaki dabuste "tied, bound," from Gilaki dabustan "to tie, bind, close," variants dabastan, Mâzandarâni davəstən; Pers. bastan "to tie, bind, shut, close" (Mid.Pers. bastan/vastan "to bind, shut," Av./O.Pers. band- "to bind, fetter," banda- "band, tie," Skt. bandh- "to bind, tie, fasten," PIE *bhendh- "to bind," cf. Ger. binden, E. bind).

1) The state or quality of being reliable.
2) A statement of the error or precision.

→ reliable; → -ity.

Able to be trusted to be accurate or to provide a correct result.

From rely, from O.Fr. relier "fasten, rally, oblige," from L. religare "fasten, bind fast," from → re-, intensive prefix, + ligare "to bind" + → -able.

Ostigân, from Mid.Pers. ostigân "reliable, firm, sure," from ost "firm, reliable."

Data which are not affected by sampling error or bias.

→ reliable; → data.

The ratio of the magnetomotive force acting in a magnetic circuit to the magnetic flux. Also called magnetic resistance, it is analogous to resistance in an electrical circuit.

Reluctance "act of struggling against;" L. reluctari "to struggle against," from → re- "against" + luctari "to struggle."

Setehi "contention, litigation," related to setihidan "to quarrel, brawl," setiz, "battle, combat, conflict," setizidan "to fight;" Mid.Pers. stêzag "quarrel, strife;" Av. stij- "battle;" cf. Skt. steg- "to assail;" Gk. stizein "to prick, puncture," stigma "mark, puncture;" O.E. stician "to pierce, stab;" E. stick (v.); PIE *steig- "to sting, stab."

A unit used for measuring the effective dose of radiation received by a living organism. It is the quantity of radiation whose biological effect is equal to that produced by one → roentgen of → X-rays. 1 rem = 0.01 sievert (Sv) or 10 → millisieverts.

Rem, acronym for roentgen equivalent man. The unit was introduced in 1944 by Herbert M. Parker (1910-1984), a radiation physicist and co-inventor of the Paterson-Parker Radium Therapy System.

1) To continue in the same state.
2) To stay behind or in the same place.

M.E. remainen, from O.Fr. remain-, stressed stem of remanoir "to stay, dwell, remain," from L. remanere "to remain, to stay behind; be left behind," from → re- "back" + manere "to stay, remain" (from PIE root *men- "to remain," cf. Pers. mân-, mândan, as below.

Mândan "to remain, stay" (mân "house, home;" Mid.Pers. mândan "to remain, stay;" O.Pers. mān- "to remain, dwell;" Av. man- "to remain, dwell; to wait;" Gk. menein "to remain;" L. manere "to stay, abide" (Fr. maison, ménage; E. manor, mansion, permanent); PIE base *men- "to remain, wait for."

An effect that remains in a system for a while after the physical cause has been removed. For example the light remaining in a detector after elimination of the source, or the magnetic induction that remains in a material after removal of the magnetizing field.

From reman(ent), → remanent + -ence a noun suffix.

Noun of → pasmân.

Possessing → remanence.

M.E. from L. remanent- (stem of remanens), pr.p. of remanere "to remain, stay behind," from → re- "back" + manere "to stay, remain," cognate with Pers. mândan "to stay, remain," as below.

Pasmân, from pas- "behind," variant pošt "back; the back; behind" (Mid.Pers. pas "behind, before, after;" O.Pers. pasā "after;" Av. pasca "behind (of space); then, afterward (of time);" cf. Skt. paścā "behind, after, later;" L. post, as above; O.C.S. po "behind, after;" Lith. pas "at, by;" PIE *pos-, *posko-) + mân present stem of mândan "to remain, stay" (mân "house, home;" Mid.Pers. mândan "to remain, stay;" O.Pers. mān- "to remain, dwell;" Av. man- "to remain, dwell; to wait;" Gk. menein "to remain;" L. manere "to stay, abide" (Fr. maison, ménage; E. manor, mansion, permanent); PIE base *men- "to remain, wait for").

Something that cures or relieves a disease or bodily disorder; a healing medicine, application, or treatment (Dictionary.com).

M.E. remedie, O.Fr. remede "remedy, cure" and directly from L. remedium "a cure, remedy, medicine, antidote," from → re-, + mederi "to heal."

Darmân, Mid.Pers. darmân "remedy, medicine," related to O.Pers. duruva- "firm, certain, immune;" Av. druua- "healthy;" cf. Skt. dhruva- "fixed, firm;" related to Mid.Pers. drôd (Pers. dorud) "thriving," durust (Pers. dorost) "whole, right, healthy," Baloci durâh "healthy, whole;" Khotanese drunna- "healthy," → integral.

A usually small part of something that is left after the rest of it has been used, removed, or destroyed. → supernova remnant.

M.E., from O.Fr. remnant, pr.p. of remenoir "to remain," from L. remanere "to remain, stay behind," from → re- "back" + manere "to stay, remain," cognate with Pers. mândan "to stay, remain," as below.

Bâzmândé "remnant," from bâz-, → re-, + mândé p.p. of mândan "to remain, stay" (mân "house, home;" Mid.Pers. mândan "to remain, stay;" O.Pers. mān- "to remain, dwell;" Av. man- "to remain, dwell; to wait;" Gk. menein "to remain;" L. manere "to stay, abide" (Fr. maison, ménage; E. manor, mansion, permanent); PIE base *men- "to remain, wait for").

Situated at some distance away.

M.E. from L. remotus "afar off, remote," p.p. of removere "move back or away," from → re- "back, away" + movere "to move."

Dur, from Mid.Pers. dūr "far, distant, remote;" O.Pers. dūra- "far (in time or space)," dūraiy "afar, far away, far and wide;" Av. dūra-, dūirē "far," from dav- "to move away;" cf. Skt. dūrá- "far; distance (in space and time);" PIE base *deu- "to move forward, pass;" cf. Gk. den "for a long time," deros "lasting long."

The ability to connect to a computer from a remote location and to control the machine once the connection has been made.

→ remote; → access.

1) Control of the operation or performance of an apparatus from a distance, as the control of a guided missile by radio signals.
2) A device used to control the operation of an apparatus or machine, as a television set, from a distance.

→ remote; → control.

A mode of astronomical observation in which the observer is situated in a remote place from the telescope. The data are collected through assistants in contact with the telescope, and are transmitted along some communication pathway for local processing and interpretation.

→ remote; observing, verbal noun of → observe.

Technique that utilizes electromagnetic waves to detect, measure, and obtain information about an object that is not in contact with the sensing apparatus.

→ remote; → sense.

Hesgari, noun from hesgar, → sensor; dur, → remote.