Whiteout (weather) moving. Local, short-duration whiteout conditions can be created artificially in the vicinity of airports and helipads due to aircraft operations. Snow on the ground can be stirred up by helicopter rotor down-wash or airplane jet blast, presenting hazards to both aircraft and bystanders on the ground. 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
Irrational number to show that π is irrational, whence it follows immediately that π is irrational also. The existence of transcendental numbers was first established by Liouville (1844, 1851). Later, Georg Cantor (1873) proved their existence by a different method, which showed that every interval in the reals contains transcendental numbers. Charles Hermite (1873) first proved "e" transcendental, and Ferdinand von Lindemann (1882), starting from Hermite's conclusions, showed the same for π. Lindemann's proof was much simplified by Weierstrass (1885), still further by David Hilbert (1893), and was finally made elementary by Adolf Hurwitz and Paul Gordan. The square root of 2