One mystery leads to another. Pondering upon the enigma of the wave-particle duality of light, Louis DeBroglie asked himself the question: if light has this contra-intuitive dual nature of being waves and particles, is it possible that matter also has a similar duality? Could particles of matter also act like waves?! -- Indeed, scientists soon found that when electrons pass through a narrow opening they show 'diffraction' and 'interference' effects which were known to be exclusively wave phenomena. Thus, the particle-wave duality of matter was added to the wave-particle duality of light and modern physics declared the quadruplicity of Nature. The mathematical formalism that evolved from this hypothesis became the foundation of Quantum Mechanics.
Aethro-Kinematics tears down both dualisms!
In the all-pervading ideal gas of Aether all moving chunks or particles of matter create waves just like a fish or a boat in the water. When particles are driven through a narrow slit the reflecting Aether-waves destruct their straight line paths. This is the real kinematic cause of the diffraction of electrons.