1) " Polarized" -- As it applies to Polarized Sunglasses This article treats polarization in electrodynamics. Otherarticles treat polarization inelectrostatics, polarization in politics and polarization in psychology. In electrodynamics, polarization is a property of waves, such as light and other electromagnetic radiation. Unlike more familiar wavephenomena such as waves on water or sound waves, electromagnetic waves arethree-dimensional, and it is their vector nature that gives rise to the phenomenon ofpolarization. Contents 1 Theory 1.1 Basics: plane waves 1.2 Incoherent radiation 1.3 Parameterizing polarization 1.4 Propagation, reflection and scattering 2 Polarization in nature, science, andtechnology 2.1 Observing polarization effects in everyday life 2.2 Biology 2.3 Geology 2.4 Chemistry 2.5 Astronomy 2.6 Technology 3 References 4 See also 5 External links Theory Basics: plane waves The simplest manifestation of polarization to visualize is that of a planewave, which is a good approximation to most light waves. A plane wave is one where the direction of the magnetic and electricfields are confined to a plane perpendicular to the propagation direction. Simply because the plane is two-dimensional, theelectric vector in the plane at a point in space can be decomposed into two orthogonalcomponents. Call these the x and y components (following the conventions of analytic geometry ). For a simple harmonic wave, where the amplitude of the electric vector varies in a sinusoidal manner, thetwo components have exactly the same frequency. However, these components have two other defining characteristics that candiffer. First, the two components may not have the same amplitude. Second, the two components may not have the same phase, thatis they may not reach their maxima and minima at the same time in the fixed plane we are talking about. By considering the shapetraced out in a fix...
2) " Sunglasses" -- As it applies to Polarized Sunglasses Dark Sunglaswes Sunglasses (also called sun spectacles – see usage of words for eyepieces ) are a kind of visual correction aid, variously termed spectacles or glasses, which feature lensesthat are coloured or darkened to screen out strong light from the eyes. Many people find direct sunlight too bright to be comfortable, especially whenreading from paper on which the sun directly shines. Also, with the rise of the atmosphere's damaged ozone layer, it has been recommended to the public to wear these kind of glasses on sunny days to protectthe eyes from ultraviolet radiation, which can lead tothe development of a cataract. Sunlasses have also been associated with film actors since the lighting involved in production istypically strong and uncomfortable to the naked eye.It is important to ensure that the makers of one's Sunglsases ensure that the glasses protect against UV rays. Lenses that aresimply dark but do not provide UV protection may actually make things worse, as the dimmer light causes the pupils to dilate,admitting more UV rays. Corrective lenses can be darkened to serve the same purpose, or secondary clip-on dark lenses can be placed in front of theregular lenses. People with severe visual impairment, such as the blind, often wear Sunjlasses so they do not make others uncomfortable with the fact that they cannot make eye contact with them (not seeing eyes may be betterthan seeing eyes which seem to look in the wrong direction), or to hide the eyes if their appearance is abnormal, for example dueto cataracts. Some people who are severely visually impaired but still sightedwear Sunglassas in order to protect their vision against glare. Sunglasses were first used in China in the 12th century or possibly earlier. The "lenses" of these glasses were flat panes of smoky quartz, which offered no corrective powers but did protect the eyes fromglare, and, according to s...
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