path-length difference
31telescope — /tel euh skohp /, n., adj., v., telescoped, telescoping. n. 1. an optical instrument for making distant objects appear larger and therefore nearer. One of the two principal forms (refracting telescope) consists essentially of an objective lens… …
32crystal — crystallike, adj. /kris tl/, n., adj., v., crystaled, crystaling or (esp. Brit.) crystalled, crystalling. n. 1. a clear, transparent mineral or glass resembling ice. 2. the transparent form of crystallized quartz. 3. Chem., Mineral. a solid body… …
33Crystal — /kris tl/, n. 1. a city in SE Minnesota, near Minneapolis. 25,543. 2. a female given name. * * * I Any solid material whose atoms are arranged in a definite pattern and whose surface regularity reflects its internal symmetry. Each of a crystal s… …
34Weather radar — in Norman, Oklahoma with rainshaft …
35Beer-Lambert law — In optics, the Beer–Lambert law, also known as Beer s law or the Lambert–Beer law or the Beer–Lambert–Bouguer law (in fact, most of the permutations of these three names appear somewhere in literature) is an empirical relationship that relates… …
36Tornado — This article is about the weather phenomenon. For other uses, see Tornado (disambiguation). For the current tornado season, see Tornadoes of 2011 …
37Ultrafast monochromator — In the diffraction of an ultrashort pulse (in the femtosecond, or lower, time scale) with a grating,apart spectral filtering, there occurs a time stretching due to the difference in the path length among the rays diffracted, even of equal… …
38Hydraulic head — is a specific measurement of water pressure or total energy per unit weight above a geodetic datum. It is usually measured as a water surface elevation, expressed in units of length, but represents the energy at the entrance (or bottom) of a… …
39Interferometric synthetic aperture radar — Interferometric synthetic aperture radar, also abbreviated InSAR or IfSAR, is a radar technique used in geodesy and remote sensing. This geodetic method uses two or more synthetic aperture radar (SAR) images to generate maps of surface… …
40Refractive index — Refraction of light at the interface between two media. In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum… …
