Title: "Maxwell stress tensor. An elementary introduction in terms of differential forms"
It is well known that the two plates of the electric capacitor
attract each other. It can be interpreted that the electric field
between the plates exerts forces on the plates. The force is
proportional to the area of one of the plates. The linear mapping from
the surface bivector (of the plate) to the force one-form is a component
of the stress tensor of the electric field. It describes the tensional
stress. A reasoning applied to stretching the area of the plates allows
to derive the two other components of the stress tensor. They
describe the compressional stress.
If the time is left, similar considerations could be presented
for the magnetic field. In the whole presentation, the word
"perpendicular" will be never used, because it is a metric-independent
approach. Only the word "parallel" is allowed.