Quantum Mechanics: From Bohr to Bohm

Quantum numbers and electron configurations of chemical elements form an important part of the physical science curriculum and textbooks devote considerable amount of space to these topics. These topics are closely related to students' understanding of quantum mechanics and various studies have reported students' difficulties in grasping the fundamental issues involved (Shiland, 1995, 1997; Tsaparlis, 1997, 2001; Johnston et al., 1998; Dobson et al., 2000; Hadzidaki et al., 2000; Ireson, 2000; Michelini et al., 2000; Pospiech, 2000; Ardac, 2002; Wittmann et al., 2002; Kalkanis et al., 2003; Taber, 2005; Niaz, 2008; Niaz & Fernández, 2008). Interestingly, physicists have also recognized the difficulties involved in understanding quantum mechanics (Feynman, 1985; Styer, 2000; Laloë, 2001). Feynman (1965) was quite categorical: “I can safely say that nobody understands quantum mechanics” (p. 129). On the other hand, philosophers of science have argued that quantum mechanics is particularly difficult to understand, due to the controversial nature of the different interpretations (e.g., Bohr's Copenhagen “indeterminacy” and Bohm's “hidden variables”). According to physicist-philosopher Abner Shimony (1985), “I must confess that after 25 years of attentive — and even reverent — reading of Bohr, I have not found a consistent and comprehensive framework for the [Copenhagen] interpretation of quantum mechanics” (p. 109). In contrast, in a recent critical review a physicist has conceded that:

At the turn of the century, it is probably fair to say that we are no longer sure that the Copenhagen interpretation is the only possible consistent attitude for physicists.… Alternative points of view are considered as perfectly consistent: theories including additional variables (or “hidden variables”). (Laloë, 2001, p. 656)

Cushing (1991) has expressed the crux of the issue in cogent terms:

The question is whether we are capable of truly understanding (or comprehending) quantum phenomena, as opposed to simply accepting the formalism and certain irreducible quantum correlations. The central issue is that of understanding versus merely redefining terms to paper over our ignorance. (p. 337, original italics)