Quantum Optics for Engineers

21

Interpretational Issues in Quantum Mechanics

21.1  Introduction

In 1935 Einstein, Podolsky, and Rosen (EPR) (1935) wrote a famous paper entitled Can quantum mechanical description of physical reality considered complete? This is a cleverly crafted document that argues that in quantum mechanics “when the momentum of a particle is known, its coordinate has no physical reality” (Einstein et al., 1935).

Subsequently, the authors go on to conclude that “the quantum mechanical description of reality given by the wave function is not complete” (Einstein et al., 1935).

In a reply also entitled Can quantum mechanical description of physical reality considered complete? Bohr (1935) uses the Heisenberg uncertainty principle and the principle of ...