absolute boundary
121Apparent horizon — An apparent horizon is a surface defined in general relativity as the boundary between light rays which are directed outwards and moving outwards, and those which are directed outwards but moving inwards.Apparent horizons are not invariant… …
122Europe, history of — Introduction history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …
123Land-Tenure in the Christian Era — • The way in which land has been held or owned during the nineteen hundred years which have seen in Europe the rise and establishment of the Church is a matter for historical inquiry. Strictly speaking, the way in which such ownership or tenure… …
124Eigenvalues and eigenvectors — For more specific information regarding the eigenvalues and eigenvectors of matrices, see Eigendecomposition of a matrix. In this shear mapping the red arrow changes direction but the blue arrow does not. Therefore the blue arrow is an… …
125PROSODY, HEBREW — This article is a survey of the history of Hebrew poetic forms from the Bible to the present time. The entry is arranged according to the following outline: introduction the variety of formal systems the specific nature of hebrew literary history …
126Central Atlantic Magmatic Province — The Central Atlantic magmatic province (CAMP) was formed during the breakup of Pangaea during the Mesozoic Era. The initial breakup of Pangaea in early Jurassic time provided a legacy of basaltic dikes, sills, and lavas over a vast area around… …
127Potential flow — streamlines around a NACA 0012 airfoil at 11° angle of attack, with upper and lower streamtubes identified. In fluid dynamics, potential flow describes the velocity field as the gradient of a scalar function: the velocity potential. As a result,… …
128Surface weather analysis — A surface weather analysis is a special type of weather map that provides a view of weather elements over a geographical area at a specified time based on information from ground based weather stations. [ Air Apparent: How Meteorologists Learned… …
