On the Foundations of Quantum Mechanics: Wave-Particle Non-Duality and the Nature of Physical Reality (original) (raw)

The Schrödinger's wave function can naturally be realized as an 'instantaneous resonant spatial mode' in which quantum particle moves and hence the Born's rule is derived after identifying its origin. This realization facilitates the visualization of 'what's really going on?' in the Young's double-slit experiment which is known to be the central mystery of quantum mechanics. Also, an actual mechanism underlying the 'spooky-action-at-a-distance', another mystery regarding the entangled quantum particles, is revealed. Wheeler's delayed choice experiments, delayed choice quantum eraser experiment and delayed choice entanglement swapping experiments are unambiguously and naturally explained at a single quantum level without violating the causality. The reality of Nature represented by the quantum mechanical formalism is conceptually intuitive and is independent of the measurement problem. Quantum mechanics is an extremely successful theoretical description of Nature, especially in the sub-atomic world where the classical mechanistic concepts seem to fail completely. Nevertheless, for more than ninety years, there is no consensus about what kind of physical reality is being revealed by the quantum formalism irrespective of its ability to predict accurately the exact outcomes of various experiments. According to Prof. Feynman, the central mystery of quantum mechanics is contained in the Young's double-slit experiment which is about the wave-particle duality of a single quantum [1]. Twenty years later, he once again declared that the entanglement of two or more particles is one more deep mystery in the quantum world [2]. It is not only important but also unavoidably necessary to conceptually visualize the true picture of reality described by the quantum formalism not only for solving the above mentioned mysteries, but also for further progress in fundamental physics like quantum gravity, unification of fundamental forces, quantum cosmology e.t.c. In Young's double-slit experiment, a monochromatic source emits coherent light which passes through a double-slit assembly to a detector screen where an interference pattern reminiscent of wave nature is formed. On the other hand, photoelectric effect, Compton effect, Raman effect, e.t.c., strongly suggests the existence of particle nature of light. The usual intuition about particle is that it is a localized entity present at some definite position in space, whereas the wave is a delocalized one and hence they are incompatible with each other. But, light seems to possess both natures simultaneously; however, only one nature seems to be observable at a given moment. These mutually exclusive natures of light's behavior is generally known as wave-particle duality. Not only light, but all material particles like electrons, protons, atoms, molecules e.t.c., are known to exhibit the wave-particle duality [3–7]. The quantum formalism itself never imposes any limitations on its validity only to microscopic objects and it can, in principle, be applied to materials of any scale. See the Fig. 1 below representing the Youngs's double-slit experiment. Consider the single particles to be photons. In this case, each photon is fired at the double-slit one-at-a-time such that the time interval between consecutively fired photons may be greater than the time of arrival of any one photon from the source to the screen. This assures that, each and every photon is really independent and they don't know each other. As a large number of photons are being collected on the screen, an interference pattern gradually emerges. If slit-1 (slit-2) is blocked, then a clump pattern corresponding to single slit diffraction of slit-2 (slit-1), supposed to be of particle nature, appears on the screen. This suggests that every individual photon is aware of whether one or both slits are open. The interference pattern suggests to infer that a single particle-like photon 'somehow' passes through both the slits simultaneously. A surprise occurs when a detector observes through which slit a photon is really passing through. It always appears as going through slit-1 or slit-2 like a particle but never through both the slits simultaneously like a wave. However, now the interference pattern disappears and two clump patterns appear which look like a proof for the observed particle behavior at the respective slits. This is generally known as quantum enigma i.e., when photons are watched, they appear to go through only one slit like particles. But, when they are not watched, then they seem to go through both the slits simultaneously like a wave. Now, consider the Wheeler's delayed-choice situation [8]. The screen is removed quickly exposing the twin telescopes, after a photon has already passed through the double slits. The interference pattern which would have occurred on * Electronic address: dr.n.gurappa@gmail.com