  The evolution of the luminosity distance in a contracting universe is
studied. It is shown that for quite a lot of natural dynamical evolutions, its
behavior is far from trivial and its value can even decrease with an increasing
time interval between events. The consequences are investigated and it is
underlined that this could both put stringent consistency conditions on
bouncing models and open a new observational window on "pre Big Bang" physics
using standard gravitational waves.
