  We review the conceptual problems in quantum mechanics on a fundamental
level. It is shown that the proposed model of extended electrons and a clear
understanding of rotations in three dimensional space solve a large part of
these problems, in particular the problems related to the ontological status
and physical meaning of wavefunctions. It also solves the problem of
non-locality. The experimental results obtained in Yves Couder's group and
theoretical results by Gerdard Gr\"ossing indicate that the wave-like
distribution of trajectories of electrons in interference experiments are most
likely due to the quantized interactions leading to a discrete set of
transferred momenta. A separate experimental confirmation of this
interpretation for double-slit interferometry of photons has been given by the
group of Steinberg.
