Bell, John (1928-1990).

British physicist who in 1964 devised a test to verify a point in quantum theory: whether two particles that were once connected are always afterwards interconnected even if they become widely separated. As well as investigating fundamental problems in theoretical physics, Bell contributed to the design of particle accelerators.
Bell worked for 30 years at CERN, the European research laboratory near Geneva, Switzerland. He demonstrated how to measure the continued interconnection of particles that had once been closely connected, and put forward mathematical criteria that had to be obeyed if such a connection existed, as required by quantum theory. In the early 1980s, a French team tested Bell's criteria, and a connection between widely separated particles was detected.