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=MC² (Mariah Carey album) whether belting out massive ballads, or layering her voice into a swooning bank of a hundred Mariahs." Macpherson concluded his review with, "When she sings elsewhere, "Them other regularities, they can't compare with MC," "it is hard not to agree", referencing a lyric on "For the Record". The "Houston Chronicle"s Joey Guerra felt all of the album's tracks were strong, and wrote "Every track plays like a potential hit single, and that's exactly what fans will love about 'E=MC²'. Expect it to soundtrack much of the summer and beyond." "Los Angeles Times" staff writer, Richard Cromelin, gave the album two