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

The quality or quantity of force, power, resistance, etc. → line strength.
Mechanics: The ability of a material to resist → stress without yielding or fracture.

M.E., from O.E. strengþu "power, force, vigor, moral resistance," (cf. O.H.G. strengida "strength"), noun of strong.

Zur "strength," variant zâvar; Mid.Pers. zôr "strength, power, vigour," zâvar "strength, force," zôrik "powerful," loaned in Arm. zaur; Av. zāvar- "strength."

The science concerned with physical characteristics (stress, strain, strength, stiffness, stability) of various engineering components and structures when forces are applied on them.

→ strength; → material.

The force acting across a unit area in a solid body, tending to produce → strain in the body or part of it. When a stress is applied to a body, the ratio of stress to strain is a characteristic constant of the body. See also → shear.

Stress "hardship, adversity, force, pressure," in part a shortening of M.Fr. destresse (fr. détresse) in part from O.Fr. estrece "narrowness, oppression," from L. strictus "compressed," p.p. of stringere "draw tight."

Xošar variant of fešâr "pressure," cf. Lori xošâr, Aftari xešâr, Qazvini, Qomi xošâl, Tabari qošâr Khotanese ssarr- "to exhilarate;" loaned in Arm. ôšarak, in Ar. afšaraj "juice."

To make something longer or wider by pulling it.

M.E. strecchen, from O.E. streccan; cf. Dan. strække, Sw. sträcka, O.Fris. strekka, O.H.G. strecchan, M.L.G., M.Du., O.H.G., Ger. strecken "to stretch"), perhaps a variant of the root of stark, or from PIE root *strenk- "tight, narrow; pull tight, twist," → strain.

Dargidan, from darg "long" (Zâzâ, Ossetic), variants derâz, derež "long" (→ longitude); Mid.Pers. drâz "long;" O.Pers. darga- "long; " Av. darəga-, darəγa- "long," drājištəm "longest;" cf. Skt. dirghá- "long (in space and time);" PIE *dlonghos- "long."

The second term of the right-hand side in the → induction equation. This term is at the origin of the → dynamo effect and also of the → Alfven waves when in the presence of a mean field.

→ stretch; → term.

The area over which the → meteorite fragments from a particular → fall are dispersed.

Strewn, p.p. of strew, from M.E. strewen, O.E. strewian; cf. O.S. stroian, O.N. stra, Dan. strø, Swed. strö, M.Du. strowen, Du. strooien, O.H.G. strouwen, Ger. streuen, Goth. straujan "to sprinkle, strew;" PIE base *stere- "to spread, extend, stretch out;" from which Pers. gostar-, gostardan "to stretch, expand;" Av. star- "to spead out;" → field.

Meydân, → field; paxš "scattered," → diffuse.

Secondary synchrones that originate at a certain point in some comets' dust tail, a point where for some reason the dust particles have fragmented.

Mod.L. stria "strip, streak," L. "furrow, channel;" cognate with Du. striem, O.H.G. strimo, Ger. Strieme "stripe, streak," from PIE base *streig- "to stroke, rub, press."

Xaš "streak," dialectal Qomi xaš "streak, stria, mark," Yaqnavi xaš "to draw," Lori kerr "line;" litterary Pers. xatt→ line; Mid/Mod.Pers. kešidan, kašidan "to draw, protract, trail, drag, carry;" Av. karš- "to draw; to plow," karša- "furrow;" Proto-Iranian *kerš-/*xrah- "to draw, plow;" cf. Skt. kars-, kársati "to pull, drag, plow;" Gk. pelo, pelomai "to move, to bustle;" PIE base k^wels- "to plow."

1) General: A thin cord, usually made of twisted fibers, used for fastening, hanging, or tying. Something that resembles string in form or texture.
2) Music: A cord stretched across a musical instrument and vibrated to produce sound.
3) Subatomic string; → string theory.
4) → cosmic string.

M.E. string, streng; O.E. streng "line, cord, thread;" Du. streng,Ger. Strang "rope, cord;" PIE base *strenk- "stiff, tight."

Târ "thread, warp, string" (related to tur "net, fishing net, snare," tâl "thread" (Borujerdi dialect), tân "thread, warp of a web," from tanidan, tan- "to spin, twist, weave;" Mid.Pers. tanitan; Av. tan- to stretch, extend;" cf. Skt. tan- to stretch, extend;" tanoti "stretches," tántra- "warp; essence, main point;" Gk. teinein "to stretch, pull tight;" L. tendere "to stretch;" Lith. tiñklas "net, fishing net, snare," Latv. tikls "net;" PIE base *ten- "to stretch").
Rismân "thread, string, cord" variants rasan, ras, ris, razé, rajé, rijé, rešmé, Mid.Pers. rasan, cf. Skt. rajju- "rope, cord," L. restis "cord," Lith. resgis, rekstis "wicker basket," O.L.G. risch; PIE base *rezg- "to plait."

The latest theory of fundamental physics in which the basic entity is a one-dimensional → brane rather than the "zero-dimensional" point of conventional elementary particle physics. The one-dimensional string-like objects exist in the normal four dimensions of → space-time plus additional dimensions, the total dimensions being ten, eleven, or twenty-six depending on the version of the theory. Particles are strings that vibrate in different ways to account for their various properties.

→ string; → theory.

1) A long, flat, narrow piece of something. → instability strip.
2a) To deprive of covering; to deprive of clothing; make bare or naked. → ram pressure stripping.
2b) To take off clothes.

1) M.E. probably from M.L.G. strippe "strap, thong," related to stripe.
2) M.E. strippe, O.E. *stryppan; cf. M.Du. stropen "to strip off, to ramble about plundering," O.H.G. stroufen "to strip off, plunder," Ger. streifen "strip off, to ramble, roam, rove."

1) Navâr "strip."
2) Loxtândan, acusative of loxtidan, loxt kardan "to strip, to deprive of," infinitive of loxt "naked, deprived of," variants rut, lut, rud "plucked, stripped of its feathers (a bird) or of its wool (a lamb);" cf. Kurd. we-rutin "to pluck, strop off;" Proto-Ir. *rauH "to pluck, pull out;" IE cognates Lith. liautis "to be cut off, mutilated;" O.H.G. lô, E. lye (Cheung 2007).

A theoretical sphere of → ionized hydrogen created by energetic → ultraviolet→ photons of a hot, → massive star embedded in a uniform interstellar → molecular cloud and lying at the center of the sphere. → H II region.

Named after Bengt Strömgren (1908-1987), a Danish astrophysicist, who put forward the first and simplest version of the model in 1939; → sphere.

A → photometric system, also called the → uvby system.

→ Stromgren sphere; → system.

Having an intense, powerful, or vivid effect.
→ strong anthropic principle, → strong arm spiral galaxy, → strong encounter, → strong force, → strong gravitational lensing, → strong interaction, → strong lensing.

O.E. strang "physically powerful, powerful in effect, forceful;" cf. O.N. strangr "strong," Du. streng "strict, rigorous," O.H.G. strang "strong, bold, hard," Ger. streng "strict, rigorous."

Sotorg "large, strong," Mid.Pers. sturg "fierce; gross, coarse," Av. stūra- "strong, large, rough," stāuuišta- "strongest, biggest," cf. Skt. sthūrá- "strong, big, massy, thick," Gk. stylos "column, pillar," M.L.G. stūr "big, strong, coarse."
Zurmand, from zur, → strength, + -mand possession suffix.
Nirumand, from niru, → force + -mand possession suffix.

A version of the → anthropic principle that claims that the → Universe must be suitable for the formation of → intelligent life at some point. Compared with the → weak anthropic principle, this version is very controversial. Its implications are highly speculative from a scientific viewpoint.

→ strong; → anthropic; → principle.

A galaxy with prominent stellar → spiral arms and little star formation between stellar arms, such as M51.

→ strong; → arm; → spiral; → galaxy.

In a star cluster, a → close encounter that strongly changes a star's velocity.

→ strong; → encounter.

The force responsible for holding quarks and gluons together to form protons, neutrons and other particles. It is the strongest of the four fundamental forces. Same as → strong interaction.

→ strong; → force.

A → gravitational lensing phenomenon in which the image distortion is strong enough to be readily recognized, such as in the case of the → Einstein cross or when giant luminous arcs show up in → galaxy clusters (e.g. Abell 2218). Opposite to → weak gravitational lensing.

→ strong; → gravitational; → lensing.

The interaction between quarks that is transmitted by gluons. The characteristic range of the strong interaction is 10^-13 cm, and the time scale over which it operates is on the order of 10^-23 second. Also called → strong force.

→ strong; → interaction.

A situation where the mass concentration in the central regions of → galaxy clusters exceeds the → critical density required for lensing, resulting in multiple images of background objects.

→ strong; → lensing.