We saw in this chapter that the universe was composed of
approximately a not-baryon third of matter, and of a baptized component
even more mysterious black energy. The other identified components (let
us baryons and photons) contribute probably marginally to the
assessment of energy. We will see in the next chapter how measurements
of distance and in particular those of distance from luminosity make it
possible to force the cosmological parameters and the nature of black
energy.