  The zero point field is an ordinary field existing in the dark, which cannot
be separated from the total electromagnetic field in an excited mode. The total
field is in equilibrium with matter that it polarizes temporarily and
reversibly. This polarisation is exceptionally large enough to allow the energy
of an atom reach and cross a pass between two minimums of potential,
stimulating an emission or an absorption.
  A paradox of quantum electrodynamics is explained classically: The nearly
plane wave generally used in stimulated emission experiments must be decomposed
into an efficient spherical wave and a scattered wave, so that the plane wave
is two times less efficient than the zero point component of the spherical
mode. The classical electromagnetism does not need the quantum postulate
"reduction of the wave packet" and it has no paradox such as EPR.
  De Broglie's waves may be the linear part of solitons of a field which may be
a high frequency electromagnetic field. These solitons may lead to a physical
interpretation of the superstrings theory.
