The general Lorentz transformation,
the relationship between observations made in different frames, is a complicated
expression involving the 3 components of the relative velocity of the two frames,
and the three parameters describing the relative orientation of the frames.
A simpler description is known in which the six parameters are encoded in four
complex numbers subject to a single algebraic constraint. This simple description,
which is particularly useful for dealing with the aberration of light, is usually
introduced through rather advanced mathematical formulations. Here we show
that the basic idea, in addition to being useful, is actually quite simple.
We discuss at the end, the invisibility of the Lorentz transformation.