The Copenhagen interpretation is the standard textbook interpretation of quantum mechanics. The term covers a range of divergent views, loosely related to Bohr's complementarity interpretation. The consensus of the physics community is that Einstein lost the debate to Bohr about the "completeness" of quantum mechanics at the Solvay conference of October 1927, and that Bohr's analysis of the experimental situation in quantum mechanics in terms of the notion of complementarity allows one to make sense of a universe that is indeterministic 'all the way down,' so that quantum states (that in general assign probabilities between 0 and 1 to the outcomes of experiments) are as complete as they can be.

It is difficult to pin down the Copenhagen interpretation. Heisenberg—who seems to have coined the term "Copenhagen interpretation" (see Howard's "Who Invented the Copenhagen Interpretation" for a discussion)—concedes differences between his own position and Bohr's, but...