Einstein believed that spacetime and objects exist and have definite properties whether or not they are observed. More precisely, he believed in local realism. Realism is the claim that physical objects have definite values of physical properties—such as position, momentum, spin, charge, and polarization—even when unobserved. Locality is the claim that physical objects cannot influence each other faster than the speed of light. Local realism asserts that both realism and locality are true.
