  It is well known that a sequence of two non-collinear pure Lorentz
transformations (boosts) is not a boost again, but involves a spatial rotation,
the Wigner or Thomas-Wigner rotation. The formation of this rotation is
visually illustrated by moving a Born-rigid object on a closed trajectory in
several sections. Within each section the boost's proper time duration is
assumed to be the same and the object's centre accelerates uniformly.
Born-rigidity implies that the stern of this object accelerates faster than its
bow. It is shown that at least five boosts are required to return the object's
centre to its start position. With these assumptions, the Thomas-Wigner
rotation angle depends on a single parameter only, the maximum speed reached
within each boost section. The visualization highlights the close relationship
between the Thomas-Wigner rotation and the relativity of simultaneity.
Furthermore, it is illustrated that accelerated motion implies the formation of
an event horizon. The event horizons associated with the five boosts constitute
a boundary to the rotated Born-rigid object and ensure its finite size.
