QR3.1.4 The Copenhagen Compromise

After centuries of dispute over whether light is a wave or a particle, Bohr devised the wave-particle compromise that holds today. He suggested in Copenhagen in the 1920’s that the two views are “complementary”, i.e. both true, and nothing better has been found since:

…nobody has found anything else which is consistent yet, so when you refer to the Copenhagen interpretation of the mechanics what you really mean is quantum mechanics.(Davies & Brown, 1999) p71.

Figure 3.4. a. Physical realism, b. Bohr’s dualism, c. Quantum realism

This don’t ask, don’t tell policy lets a photon be a wave when we don’t look as long as it is a particle when we do. It conveniently lets physics use particle or wave equations as required. Yet in no physical pond do rippling waves ever turn into particles and on no billiard table do the balls ever turn into waves. Convenience let Bohr successfully sell the big lie that light is a wavicle. As Gell-Mann said in his 1976 Nobel Prize speech:

Niels Bohr brainwashed a whole generation of physicists into believing that the problem (of the interpretation of quantum mechanics) had been solved fifty years ago.”

Bohr’s wave-particle dualism, like Descartes’ mind-body dualism, is a mystical marriage of convenience between incompatible domains, accepted by those who want to believe.

Quantum theory contradicts physical realism so it is not possible for a quantum world to exist within an objective physical reality (Figure 3.4a). Bohr’s Copenhagen statement that the quantum world could be assumed to exist alongside the physical world solely for the purpose of physics calculations was an admission of logical failure not a reality description (Figure 3.4b) (Audretsch, 2004) p14). Even as he publicly recognized that quantum equations require a quantum world to exist in some way, in private he denied the quantum world existed at all. One cannot have “the best of both worlds” when those worlds are incompatible.

Quantum realism rejects both physical realism and the Copenhagen compromise, proposing instead that physical events are a subset of quantum events so classical mechanics is a subset of quantum mechanics (Figure 3.4c). We now explore this alternative.