For a given dependence
D[E],H[B] (and given boundary conditions, see below) the Maxwell
equations uniquely specify the fields in terms of the charges. Reciprocally, the fields exert influence
on the charge distribution. Responsible for this feedback mechanism is the Lorentz force (density)
http://www.thp.uni-koeln.de/alexal/pdf/electrodynamics.pdf
Consequence of the mutual influence of fields on matter: a new understanding of
forces
between particles
. Newtonian mechanics: the interaction between two (charged) particles A and B is
instantaneous
; contradiction with the principle of relativity, i.e. the existence of a maximal speed of
signal propagation (the velocity of light), see below. In ED, the interaction between
A and B is mediated
by a field: the charge of particle
A creates an electromagnetic field (via the Maxwell equations) which
then influences
B (via the Lorentz force.) This indirect interaction is retarded (by the speed of field
propagation which will turn out to be the speed of light.) History: the experimentally observed forces
between charges could not be understood in terms of an instantaneous Newtonian interaction and
required
the introduction of non–matter fields into our description of nature. Modern physics describes all four
fundamental iqnteractions as indirect processes matter
$ (gauge) field $ matter.
Indeed, we will see that ED is compatible with the principles of special relativity
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