Abstract: A rotating sphere (98) within a rotating sphere (20) device. The outer sphere (20) is a translucent earth globe. The slightly smaller inner sphere (98), consisting of one reflective white surfaced hemisphere (100) and one nonreflective black surfaced hemisphere (102), is the day-night, "terminator" line device. With normal levels of incident light, this inner sphere (98) reflects (or non-reflects) light back through the translucent earth globe (20) giving a day-night appearance to the outer earth globe (20). The inner sphere (98) is controlled by a set of outer control magnets (126A,B) that are "locked" to a set of inner magnets (114A,B) attached to the inner sphere (98). These outer magnets (126A,B), external to the earth globe (20), are rotated to achieve inner sphere (98) "terminator" line (104) rotation.