Geometric models of particles - the missing ingredient
  Einstein's dream of describing elementary particles as solutions of a classical field theory is severely limited by our current understanding of Nature. Quantum theory is inconsistent with any local realistic theory such as evolving topological structures in space. It is shown that allowing time reversal as an intrinsic part of the structure of elementary particles allows general relativity to explain quantum theory in principle. Such structures may also explain electric charge and spin-half. 
Mark J Hadley