Mickey Mouse universe to Duckburg, the city in which Donald Duck lives (see Donald Duck universe). According to traditional continuity, both cities are located in the fictional U.S. state of Calisota – analogous to Northern California. The most consistent aspect of the Mickey Mouse universe is the characters. The most well-known include Mickey's girlfriend Minnie, pet dog Pluto, friends Horace Horsecollar, Clarabelle Cow, Donald Duck, Daisy Duck and Goofy, and nemesis Pete. Some Disney productions incorporate characters from Disney's animated feature films, such as "Bath Day" (1946; in which Figaro from "Pinocchio" appears as Minnie's cat), "Mickey's Christmas Carol" (1983), and – most
Random walk fact that the boundary of the trajectory of a Wiener process is a fractal of dimension 4/3, a fact predicted by Mandelbrot using simulations but proved only in 2000 by Lawler, Schramm and Werner. A Wiener process enjoys many symmetries random walk does not. For example, a Wiener process walk is invariant to rotations, but the random walk is not, since the underlying grid is not (random walk is invariant to rotations by 90 degrees, but Wiener processes are invariant to rotations by, for example, 17 degrees too). This means that in many cases, problems on a random walk are