#### 1.3.6 Dynamic visualization of the interaction between
two charged particles

Let us now consider a system made up of two charges, to
show
the interaction between them. First by means of the field lines

Start the simulation to dynamically visualize the
interaction.

The system consists of two identical positive
charges.
The field lines seem to belong separately to one charge or the other,
but
let us take into account that the field which is plotted is the total
field,
due to *both* charges.

Next, let us look at the interaction between two
charges
of opposite sign and the same magnitude, forming a system known as a
dipole

Load
another experiment

Start the experiment to see it dynamically.
In this case, the same number of field lines begin
at
the positive charge and end at the negative one, because both charges
are
of the same magnitude. The field seems now to belong to both charges as
a whole. It should be noticed, however, that the situation is exactly
the
same as when the two charges are of the same sign.

We show the system with the two charges of same sign
again,
but in terms of an equipotential surface.

Load
another experiment

set
desiredPotentialValue = 47000.0

Start the simulation to see it dynamically.
We approach now the interaction from a new
perspective.
When the two charges are close to each other, so that the interaction
is
strong, the equipotential surface encloses (embraces) the two charges.
When they separate far away, and then the interaction is weak, the
equipotential
surface breaks up in two sheets, each enclosing independently one of he
interacting charges. Nevertheless, this situation is a special case,
associated
to the system of two identical charges.