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Bibcode From Wikipedia, the free encyclopedia Jump to navigation Jump to search For the Wikipedia template to link to bibcoded articles, see Template:bibcode Bibcode Full name Bibliographic code Introduced 1990s No. of digits 19 Check digit none Example 1924MNRAS..84..308E The bibcode (also known as the refcode ) is a compact identifier used by several astronomical data systems to uniquely specify literature references. Contents 1 Adoption 2 Format 3 Examples 4 See also 5 References Adoption [ edit ] The Bibliographic Reference Code (refcode) was originally developed to be used in SIMBAD and the NASA/IPAC Extragalactic Database (NED), but it became a de facto standard and is now used more widely, for example, by the NASA Astrophysics Data System who coined and prefer the term "bibcode". [1] [2] Format [ edit ] The code has a fixed length of 19 characters and has the form YYYYJJJJJVVVVMPPPPA where YYYY is the four-digit yea

Sun glitter From Wikipedia, the free encyclopedia Jump to navigation Jump to search Sun glitter Sea otter and sun glitter Sun glitter is a bright, sparkling light formed when sunlight reflects from water waves. The waves may be caused by natural movement of the water, or by the movement of birds or animals in the water. Even a ripple from a thrown rock will create a momentary glitter. Light reflects from smooth surfaces by specular reflection. A rippled but locally smooth surface such as water with waves will reflect the sun at different angles at each point on the surface of the waves. As a result, a viewer in the right position will see many small images of the sun, formed by portions of waves that are oriented correctly to reflect the sun's light to the viewer's eyes. The exact pattern seen depends on the viewer's precise location. The color and the length of the glitter depend on the altitude of the Sun. The lower the sun,

Signal reflection From Wikipedia, the free encyclopedia Jump to navigation Jump to search This article does not cite any sources . Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (March 2007) (Learn how and when to remove this template message) It has been suggested that this article be merged with Reflections of signals on conducting lines . ([[Talk:Talk:Signal reflection#On merging|Discuss]]) Proposed since October 2018. Signal reflection occurs when a signal is transmitted along a transmission medium, such as a copper cable or an optical fiber. Some of the signal power may be reflected back to its origin rather than being carried all the way along the cable to the far end. This happens because imperfections in the cable cause impedance mismatches and non-linear changes in the cable characteristics. These abrupt changes in characteristics cause some of the tr

Ripple tank From Wikipedia, the free encyclopedia Jump to navigation Jump to search This article may require cleanup to meet Wikipedia's quality standards. No cleanup reason has been specified. Please help improve this article if you can. (December 2011) (Learn how and when to remove this template message) A simple ripple tank In physics and engineering, a ripple tank is a shallow glass tank of water used in schools and colleges to demonstrate the basic properties of waves. It is a specialized form of a wave tank. The ripple tank is usually illuminated from above, so that the light shines through the water. Some small ripple tanks fit onto the top of an overhead projector, i.e. they are illuminated from below. The ripples on the water show up as shadows on the screen underneath the tank. All the basic properties of waves, including reflection, refraction, interference and diffraction, can be demonstrated. Ripples may be generated b

Reflectance From Wikipedia, the free encyclopedia   (Redirected from Reflectivity) Jump to navigation Jump to search Spectral reflectance curves for aluminium (Al), silver (Ag), and gold (Au) metal mirrors at normal incidence. Reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at an interface. The reflectance spectrum or spectral reflectance curve is the plot of the reflectance as a function of wavelength. Contents 1 Mathematical definitions 1.1 Hemispherical reflectance 1.2 Spectral hemispherical reflectance 1.3 Directional reflectance 1.4 Spectral directional reflectance 2 Reflectivity 3 Surface type 4 Water reflectance 5 Grating efficiency 6 Applications 7 SI radiometry units 8 See also 9 References 10 External links Mathematical definitions [ edit ] Hemispherical reflectance [ edit ] The hemispherical reflectanc