An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



Number of Results: 10 Search : fringe
došekast (#)

Fr.: biréfringence   

A property of some crystalline materials (e.g. calcite, quartz) which have different indices of refraction associated with different crystallographic directions. Therefore, the crystal splits incident transmitted light into two beams, each polarized perpendicularly to the other. Also called double refraction.

Birefringence, from → bi- + refringence, from L. refringere "to break up," from → re- "back" + combination form of frangere "to break."

Došekast, from do- "two," → bi- + šekast "breaking," from šekastan "to break up," Mid.Pers. škastan, Av. skand- "to break."

  دوشکستگر، دوشکستی   
došekastgar, došekasti (#)

Fr.: biréfringent   

Of or relating to → birefringence.

birefringent filter
  پالایه‌ی ِ دوشکستی، ~ دوشکستگر   
pâlâye-ye došekastgar, ~ došekasti

Fr.: filtre biréfringent   

A type of narrow-band filter that uses the birefringence to produce selective absorption of polarized light.

birefringent; → filter.

birefringent vacuum
  خلأ ِ دوشکستگر   
xala'-e došekastgar

Fr.: vide biréfringent   

Empty space undergoing → vacuum birefringence.

birefringent; → vacuum.

dark fringe
  فریز ِ تاریک   
fariz-e târik (#)

Fr.: frange noire   

One of the successive dark and light bands produced by diffraction or interference of light.

From O.Fr. frange, from V.L. *frimbia alteration by metathesis of L. fimbria "fringe, edge of garment."

Fariz, variants farviz, farâviz "fringe, edge of garment."

fariz (#)

Fr.: frange   

1) One of the alternating bright or dark bands produced by → interference or → diffraction.
2) Wavy patterns due to the layered structure of → CCDs. These interference effects are prominent when emission lines such as the night-sky emissions are present.

From M.E. frenge, from O.Fr. frange, from V.L. *frimbia, metathesis of L. fimbriæ "fibers, threads, fringe," of uncertain origin.

Fariz, contraction of farâviz "fringe, lace, edging," from far-, par-, variant pirâ- "around, about" (Mid.Pers. pêrâ; O.Pers. pariy "around, about," Av. pairi "around, over;" Skt. pari; Indo-Iranian *pari- "around;" PIE base *per- "through, across, beyond;" cf. Gk. peri "around, about, beyond;" L. per "through") + âviz "anything suspended; a place where things are hung up; a border, margin," from âvixtan, âvizidan "to hang, suspend;" Mid.Pers. âwextan "to hang;" Av. vij- "to shake, swing," frauuaēγa- "swinging forward;" cf. Skt. vej- "to dart up or back, move up;" Proto-Iranian *uij- "to shake, swing."

fringe visibility
  پدیداری ِ فریز   
padidâri-ye fariz (#)

Fr.: visibilité des franges   

Optics: If the intensity in an interference fringe pattern has the maximum and minimum values Imax and Imin, the visibility is defined by the relation ν = (Imax - Imin) / (Imax + Imin), where 0 ≤ ν ≤ 1. In terms of the intensities of the two interfering waves: ν = 2(I1 . I2)1/2 / (I1 + I2).

fringe; → visibility

Haidinger fringes
  فریز‌های ِ هایدینگر   
farizhâ-ye Haydinger (#)

Fr.: franges d'Haidinger   

The interference fringes seen with thick plates near normal incidence.

W. K. von Haidinger (1798-1871), Austrian mineralogist and geologist; → fringe.

interference fringe
  فریز ِ اندرزنشی   
fariz-e andarzaneši

Fr.: franges d'interférence   

One of the alternating bright or dark bands produced by optical interference.

interference; → fringe.

vacuum birefringence
  دوشکست ِ دوخلأیی   
došekast-e jala'i

Fr.: biréfringence du vide   

A highly → magnetized vacuum behaving as a prism for the propagation of light, as predicted by → quantum electrodynamics (QED). Attempts to detect this phenomenon in the laboratory have not yet succeeded in the 80 years since it was predicted (Heisenberg & Euler, 1936, Z. Physik, 98, 714). This effect can be detected only in the presence of enormously strong → magnetic fields, such as those around → neutron stars. Owing to the large inferred magnetic fields (B ~ 1013 G, → gauss), radiation from these sources is expected to be substantially polarized, independently of the mechanism actually responsible for the → thermal emission. The strongest magnetic field so far created in a laboratory is less than 106 G lasting only for several tens of milliseconds. A large observed → polarization degree is, however, expected only if QED polarization effects are present in the magnetized vacuum around the star. The detection of a strongly → linearly polarized signal would therefore provide the observational evidence of QED effects in the strong-field regime. Recently a team of astrophysicists (Mignani et al. 2016, arXiv/1610.08323) have detected → linear polarization toward the neutron star RXJ1856.5-3754 (at a significant degree of around 16%). This finding is likely due to the boosting effect of vacuum birefringence occurring in the area of empty space surrounding the neutron star.

vacuum; → birefringence.