and 1949 Technology and science Gray (unit), the SI unit of energy for absorbed dose of radiation Gray code, an encoding method used to minimise bit change between adjacent values Grey box testing, a step in software development Other uses Grey aliens, an alleged race of extraterrestrial aliens Grey College, Durham, a college of the University of Durham The Gray, another name for the Astral Plane or Spirit World See also Justice Gray (disambiguation) The Grey (disambiguation)