An animation of the destruction of an electric field.
We start out with five negative electric charges and
five positive charges, separated by a distance L in
space. An external agent moves one of the positive charges
at constant velocity from its initial position to the
position of the negative charges. After doing that,
the agent moves the second positive charge in the same
manner. The agent continues on with the rest of the
positive charges, until all the positive charges are
sitting on top of the negative charges. We have color
coded the "grass seeds" representation to
represent the strength of the electric field. Very strong
fields are white, very weak fields are black, and fields
of intermediate strength are yellow.
The field lines move in the direction of the energy
flow of the electromagnetic field. Over the course of
the animation, the strength of the electric field decreases
as each positive charge is moved into place. That energy
flows into the path along which the charges move, and
is being provided to the agent moving the charges at
constant speed with the electric field of the other
charges. The work done by this agent at the end of this
process is equal in magnitude and opposite in sign to
the energy originally stored in the electric field.