Can a value of a physical property be created instantaneously by a distant act of measurement? This paper develops an answer to that question by reconciling ideas expressed by Bohr in 1958 with the “standard” Copenhagen interpretation. The point of view thereby obtained is then applied to recently described correlation experiments of various sorts.

The inherent necessity of wave functions may be determined in either of two ways. One way, frequently presupposed, states that the fundamental validity of wave functions is determined generically: The nature of the system determines the assignability of inherently necessary wave functions. The other approach holds that it is the specific experiment which determines the systems for which description by use of wave functions is fundamentally valid. A guideline based on this contextual approach is proposed and tested in three experimental (...) situations. (shrink)