Fr.: longueur d'onde pic
The wavelength at which the radiant intensity of a source is maximum.
→ peak; → wavelength.
derâzâ-ye Planck (#)
Fr.: longueur de Planck
The size limit, lP = √ (ħ G/ c3), about 10-33 cm, at which Einstein's notions of space-time are supposed to break down, and space is predicted to become "foam like."
Fr.: longueur de rayonnement
The mean distance traveled by a photon or particle in a given medium before its energy is reduced by a factor e due to its interaction with matter.
Fr.: longueur d'onde radio
The → electromagnetic radiation with a wavelength ranging from 1 mm to several 100 km. See so → radio wave.
→ radio; → wavelength.
Fr.: longueur de Sobolev
In the → Sobolev approximation, the length over which the conditions of the gas do not change and the approximation is valid. It is expressed by: ls = vth/(dv/dr), where vth is the thermal line width and (dv/dr) the velocity gradient. In other words, the length over which the profile function of a line is shifted through a distance equal to its own width by the macroscopic velocity gradients that exist in the moving medium.
→ Sobolev approximation; → length.
Fr.: longueur de Toomre
The scale beyond which for a thin, rotating disk, rotation stabilizes self-gravitational contraction. The Toomre length is given by: λT = 4π2GΣ / κ2, where G is the → gravitational constant, Σ is the mass → surface density, and κ is the → epicyclic frequency (Toomre 1964, ApJ 139, 1217).
→ Toomre parameter; → length.
tul-e mowj (#), mowj-tul (#)
Fr.: longueur d'onde
The distance between two successive points in the wave that are characterized by the same phase of oscillation; e.g. → de Broglie wavelength; → Compton wavelength; → blaze wavelength; → peak wavelength; → center wavelength; → central wavelength; → cutoff wavelength.