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) need to look no further than its title. Long live the Diva." Caryn Ganz from "Rolling Stone" questioned why she limited her vocal abilities throughout the record, "nearly every song confines Carey to four-note verses, offering little room for her glorious range." Journalist Eric Henderson, writing for "Slant Magazine", graded the album three out of five stars, and concluding with, "Such are the rewards of an album like 'E=MC²', in which one does reach a solution, but not before Mariah bends over backward to show her work." The album finished in the top-ten of several "best of 2008" lists, ending