We investigate nature of the wavefunction collapse in a welcher weg experiment by observing physical effects of the so-called “Empty Waves,” specifically their ability to interfere with real photons to generate spatial or temporal interference.
The 'collapse' of the wave function in a general measuring process is analyzed by a pure quantum mechanical (QM) approach. The problem of the delayed choice and Welcher-Weg (WW) experiments is analyzed for Mach-Zehnder (MZ) interferometer. The WW effect is related to complementarity principle and orthogonality of wavefunctions although it produces small momentum changes between the electromagnetic (EM) field and the beam-splitters (BS's). For QM states for which we have a superposition of states and interference effects there is no reality before measurement, but by excluding such effects the system gets a real meaning already before measurement.
Early on, Albert Einstein and Niels Bohr heatedly debated wave-particle duality. To explain duality Bohr postulated his principle of complementarity, which is now widely accepted, but has mystifying metaphysical implications. Albert Einstein disagreed. Richard Feynman called it the “only mystery�? in quantum mechanics. Ingenious experiments including those using entanglement have confirmed Bohr’s complementarity. In this paper a new Duality Theorem is presented with proof which explains duality with particle always remaining particle and wave always remaining wave throughout, without using wave-particle complementarity or “which way�? (welcher-weg) observation. We explain results of reported experiments by showing the equivalence: Coherence and alignment ≡ Interference ≡ No “which way�? observation; No coherence or alignment ≡ No interference ≡ “which way�? observation That is, complementarity is redundant; conventional criteria of alignment and coherence alone suffice for interference. Our explanation does not require that photon somehow “know�? about the test setup or “which way�? observation and change its behavior from particle to wave and vice versa. No new assumptions are made, only new reasoning. In the context of entanglement we also help explain non-local action at a distance, and rephrase Albert Einstein’s unanswered question “Is quantum mechanics complete?�? at a more fundamental level.
This paper proposes a spectral reinterpretation of wavefunction collapse based on the electromagnetic nature of the electron. In this framework, the electron is not a point particle but a confined electromagnetic wave. The so-called “collapse of the wavefunction” is not a mysterious or observer-induced process, but a real physical phenomenon — a destructive spectral interaction between the electron’s wave field and the electromagnetic field of the measuring device. This interaction destroys the spectral coherence of the electron wave, transforming it from a complex interference-capable field into a linear mode that manifests as a localized detection event. The model provides a tangible physical mechanism for the disappearance of interference in the double-slit experiment when measurement occurs.