The proposal that the inertial mass of a particle is determined by the gravitational effect of all the other matter in the Universe. Hence the concept of mass would be meaningless in an empty universe. The principle is named after the Austrian physicist Ernst Mach (1838–1916). A. Einstein was influenced by Mach’s principle, but his theory of general relativity failed to incorporate it. Many theorists have sought to remedy this failing, but with only limited success.