Fr.: dérive de continents
A hypothesis proposed by Alfred Wegener (1912) suggesting that the → continents are not stationary, but drift through time. Wegener's hypothesis has since been developed and included in a new theory called → plate tectonics.
1) delek; 2) delekidan
Fr.: 1) dérive; 2) dériver
1a) General: A driving movement or force; impulse; impetus; pressure.
From M.E. drift, from O.E. drifan "to drive," or from O.N. or M.Du. drift, from P.Gmc. *driftiz, related to *dribanan "to drive."
Delek from Lori, Laki, Hamadâni, Malâyeri "push, shove, drive;" variants Gilaki duko, Tâleši dako, Baluchi dhakkk(a) "push, shove, blow," Choresmian dh- "to hit," Kurd. dân/di- "to beat, hit," Proto-Iranian *daH- "to beat, hit, strike" (Cheung 2007); PIE base *dhen- "to hit, push;" delekidan, verb from delek.
Fr.: courbe de passage
In radio astronomy, the output response as a function of position for a given filter as the source passes through the beam.
Fr.: taux de dérive
The amount of drift, in any of its several senses, per unit time.
Fr.: vitesse de dérive
The average velocity of a charged particle in a plasma in response to an applied electric field.
Fr.: dérive de l'éther
1) The hypothetical motion of the supposed → ether relative to
the Earth. The → Michelson-Morley experiment found no
ether drift. An analogy is given by a boat drifting in a fast-flowing river due
to the river's current. With the same power, the speed would be slower
when sailing across the stream. Moreover, in order to reach
directly opposite the starting point, the boat would have to be headed
somewhat upstream. See also the → ether drag.
Fr.: dérive de fréquence
An undesired progressive change in an oscillator's frequency with time.
Fr.: dérive de radiant
A mound or bank of snow deposited as sloping surfaces and peaks, often behind obstacles and irregularities, due to eddies in the wind field.
Barf-rând "snowdrift, drfited snow" from barf, → snow, + rând "driving, drfit; drifted," from rândan "to push, drive, cause to go," causative of raftan "to go, walk, proceed" (present tense stem row-, Mid.Pers. raftan, raw-, Proto-Iranian *rab/f- "to go; to attack"); barf-e bâd âvard "snow brought by wind," from barf + bâd→ wind + âvard, short for âvardé "brought," p.p. of âvardan "to bring; to cause, produce" (Mid.Pers. âwurtan, âvaritan; Av. ābar- "to bring; to possess," from prefix ā- + Av./O.Pers. bar- "to bear, carry," bareθre "to bear (infinitive)," bareθri "a female that bears (children), a mother;" Mod.Pers. bordan "to carry;" Skt. bharati "he carries;" Gk. pherein; L. fero "to carry").
Fr.: dérive stellaire
The relative motion of two groups of stars in the Galaxy moving in opposite directions.