The Penrose stairs or Penrose steps, also dubbed the impossible staircase, is an impossible object created by Lionel Penrose and his son Roger Penrose. A variation on the Penrose triangle, it is a two-dimensional depiction of a staircase in which the stairs make four 90-degree turns as they ascend or descend yet form a continuous loop, so that a person could climb them forever and never get any higher. This is clearly impossible in three dimensions.
A taxicab geometry, considered by Hermann Minkowski in 19th-century Germany, is a form of geometry in which the usual distance function or metric of Euclidean geometry is replaced by a new metric in which the distance between two points is the sum of the absolute differences of their Cartesian coordinates.
Restyle the web with Stylish, a user styles manager. Stylish lets you easily install themes and skins for Google, Facebook, YouTube, Tumblr, and many, many other sites. You can even customize Firefox and other programs themselves.
We are interested in the transport of energy by ocean waves. It is important to realise that under the assumptions of linear theory, there is no net motion of particles, but there is a transport of energy (as would be expected). The energy consists of two parts, one kinetic due to the motion of the fluid and the other potential due to the variation in the fluid height. It is the resonance between these two energies which gives rise to the wave motion. The situation is analogous to Simple Harmonic Motion but more complicated.