Whiteout (weather) Whiteout (weather) Whiteout is a weather condition in which visibility and contrast are severely reduced by snow or sand. The horizon disappears from view while the sky and landscape appear featureless, leaving no points of visual reference by which to navigate. Whiteout has been defined as: "A condition of diffuse light when no shadows are cast, due to a continuous white cloud layer appearing to merge with the white snow surface. No surface irregularities of the snow are visible, but a dark object may be clearly seen. There is no visible horizon." A whiteout may be due simply to extremely
Irrational number rely on deductive reasoning for proof.” This method of exhaustion is the first step in the creation of calculus. Theodorus of Cyrene proved the irrationality of the surds of whole numbers up to 17, but stopped there probably because the algebra he used could not be applied to the square root of 17. It was not until Eudoxus developed a theory of proportion that took into account irrational as well as rational ratios that a strong mathematical foundation of irrational numbers was created. Geometrical and mathematical problems involving irrational numbers such as square roots were addressed very early during the