In quantum mechanics, the consistent histories or simply "consistent quantum theory" interpretation generalizes the complementarity aspect of the conventional Copenhagen interpretation. The approach is sometimes called decoherent histories and in other work decoherent histories are more specialized.

The blurred unchanging appearance of a physical system in motion does not imply the immateriality of the particles making it up. Thus the Copenhagen Interpretation is wrong because its based upon Bohr and his associates jumping to unjustified conclusions.

Einstein saw Quantum Theory as a means to describe Nature on an atomic level, but he doubted that it upheld "a useful basis for the whole of physics." He thought that describing reality required firm predictions followed by direct observations.

Originated by US physicist Hugh Everett in the late 1950s, this envisions our Universe as just one of numerous parallel worlds that branch off from each other, nanosecond by nanosecond, without intersecting or communicating.