background brightness
61Compact fluorescent lamp — Low energy light bulb redirects here. For other low energy bulbs, see LED lamp. The tubular type compact fluorescent lamp is one of the most popular types in Europe …
62International Space Station — ISS redirects here. For other uses, see ISS (disambiguation). International Space Station …
63Olbers' paradox — in action In astrophysics and physical cosmology, Olbers paradox is the argument that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. It is one of the pieces of evidence for a non static… …
64eclipse — eclipser, n. /i klips /, n., v., eclipsed, eclipsing. n. 1. Astron. a. the obscuration of the light of the moon by the intervention of the earth between it and the sun (lunar eclipse) or the obscuration of the light of the sun by the intervention …
65Light-emitting diode — LED redirects here. For other uses, see LED (disambiguation). Light emitting diode Red, pure green and blue LEDs of the 5mm diffused type Type Passive, optoelectronic Working principle Electr …
66Color theory — For the American electronica/synthpop musician, see Color Theory. In the visual arts, color theory is a body of practical guidance to color mixing and the visual impacts of specific color combinations. Although color theory principles first… …
67Flatness problem — The local geometry of the universe is determined by whether the relative density Ω is less than, equal to or greater than 1. From top to bottom: a spherical universe with greater than critical density (Ω>1, k>0); a hyperbolic, underdense… …
68CIE 1931 color space — In the study of color perception, one of the first mathematically defined color spaces is the CIE 1931 XYZ color space, created by the International Commission on Illumination (CIE) in 1931.[1][2] The CIE XYZ color space was derived from a series …
69Methods of detecting extrasolar planets — Any planet is an extremely faint light source compared to its parent star. In addition to the intrinsic difficulty of detecting such a faint light source, the light from the parent star causes a glare that washes it out. For those reasons, only a …
70Star — For other uses, see Star (disambiguation) …
