An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 6 Search : cascade
cascade
  آبشار، پی‌شار   
âbšâr (#), peyšâr

Fr.: cascade   

1) A waterfall or a succession of small waterfalls.
2) A succession of stages or processes, as in → cascade shower, → cascade error, → cascade transition.

From Fr., from It. cascata "waterfall," from cascare "to fall," from V.L. *casicare, from L. casum, p.p. of cadere "to fall," → case.

Âbšâr, from âb "water," → Aquarius, + šâr "pouring of water and liquids, waterfall;" peyšâr "waterfall succession," from pey "step, succession," as in peyâpey, + šâr. This word maybe related to Skt. sar- "to flow, run, hurry," Gk. iallo "I send out," L. salio "I jump." It may also be variant of Mod.Pers. cal-, calidan "to walk, be going," car-, caridan "to pasture, graze," Av. car- "to come and go," Skt. cari- "to move, walk, wander."

cascade error
  ایرنگ ِ پی‌شاری، ~ آبشاری   
irang-e peyšâri, ~ âbšâri

Fr.: erreur en cascade   

An error that amplifies as the process of calculation goes on.

cascade; → error.

cascade shower
  رگبار ِ پی‌شاری، ~ آبشاری   
ragbâr-e peyšâri, ~ âbšâri

Fr.: gerbe   

Multiple generations of secondary cosmic rays when the primary particles produce a succession of secondaries which have the same effects as the primary.

cascade; → shower.

cascade transition
  گذرش ِ پی‌شاری   
gozareš-e peyšâri

Fr.: transition en cascade   

A photon generation mechanism in an atom in which a transition initiates a series of secondary transitions from lower electronic levels.

cascade; → transition.

energy cascade
  پی‌شار ِ کاروژ   
peyšâr-e kâruž

Fr.: cascade d'énergie   

The → turbulent process whereby → kinetic energy is transformed into heat by the action of nonlinear coupling which transfers the energy from large eddies (→ eddy) to smaller and smaller eddies, finally arriving at → dissipative scales dominated by → viscosity (direct cascade). In the simplest case (3D homogeneous hydrodynamic turbulence), the resulting energy distribution is the → Kolmogorov spectrum. The reverse process also exists (inverse cascade) whereby energy is transferred to larger and larger eddies.

energy; → cascade.

Richardson cascade
  پی‌شار ِ ریچاردسون   
peyšâr-e Richardson

Fr.: cascade de Richarson   

Same as → energy cascade

Named after L. F. Richardson (1922), Weather Prediction by Numerical Process (Cambridge Univ. Press); → cascade.