Fr.: corde noire
The extension of the → black hole concept in a → space-time with → dimensions higher than 4. Theoretically, it is possible to extend the 4D black hole with S2 horizon into the fifth dimension producing a hypercylindrical black hole S2× R. Black strings are unstable; it is not yet well understood whether they end up as black holes or different objects.
Same as → Abbe number.
Noun from → constrain.
Fr.: corde cosmique
A hypothetical → cosmic defect predicted to be infinitesimally small in cross section but enormously long and massive. Cosmic strings should not be confounded with → subatomic strings predicted by → string theory.
1) General: A thin cord, usually made of twisted fibers, used for fastening,
hanging, or tying. Something that resembles string in form or texture.
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").
Fr.: théorie des cordes
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.