polar optical effect
81Solar variation — Solar variations are changes in the amount of solar radiation emitted by the Sun. There are periodic components to these variations, the principal one being the 11 year solar cycle (or sunspot cycle), as well as aperiodic fluctuations. Solar… …
82Life on Mars — For other uses, see Life on Mars (disambiguation). An artist s impression of what Mars surface and atmosphere may look like if Mars were terraformed. Scientists have long speculated about the possibility of life on Mars owing to the planet s… …
83History of film — This article is about the history of cinema. For other uses, see History of photography. Years in film 1870s 1880s 1890s …
84Ionosphere — The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner …
85Polarization — ( Brit. polarisation) is a property of waves that describes the orientation of their oscillations. For transverse waves, it describes the orientation of the oscillations in the plane perpendicular to the wave s direction of travel. Longitudinal… …
86Binary star — For the hip hop group, see Binary Star (band). Hubble image of the …
87Polythiophene — The monomer repeat unit of unsubstituted polythiophene …
88cell — cell1 cell like, adj. /sel/, n. 1. a small room, as in a convent or prison. 2. any of various small compartments or bounded areas forming part of a whole. 3. a small group acting as a unit within a larger organization: a local cell of the… …
89Astronomy on Mars — Mosaic of two different Mars Global Surveyor Mars Orbiter Camera (MOC) exposures of Earth, the Moon, and Jupiter from 2003 …
90reaction mechanism — Introduction in chemical reactions (chemical reaction), the detailed processes by which chemical substances are transformed into other substances. The reactions themselves may involve the interactions of atoms (atom), molecules (molecule),… …
