Radiating Ring of Electrons

Thomson found, however, that the more electrons were placed in each ring, the less radiation was emitted overall. In fact, the radiation from many electrons was deconstructively interfering. Especially if the electrons were orbiting at low velocities, the radiation drain could be reduced by several orders of magnitude for each new electron placed in the same orbit. 

Perhaps, Thomson speculated, atoms radiated continuously, but at such low levels that it was very difficult to observe.  And he discovered that if electrons were packed into an orbit to form a continuous ring of charge, the radiation drain would theoretically drop completely to zero.