Anti-de Sitter space bell. It might be described as being the "opposite" of the surface of a sphere, which has a positive curvature. General relativity is a theory of the nature of time, space and gravity in which gravity is a curvature of space and time that results from the presence of matter or energy. Energy and mass are equivalent (as expressed in the equation "E" = "mc"), and space and time can be translated into equivalent units based on the speed of light ("c" in the "E" = "mc" equation). A common analogy involves the way that a dip in a flat
E-2 visa of origin, or change their status. The United States Department of State does not allow dual intent for this type of visa, although it is possible for E-2 visa holders to adjust their status to immigrant status. The holder of an E-2 visa may leave the United States at any time. Because there is no dedicated dependent visa class for E-2 visas, spouses and unmarried children (under 21) may receive derivative E-2 visas in order to accompany the principal immigrant. The duration of visa for a family member who is of a different nationality from the principal is determined by