The "Big Bang" model is a good description of the Universe. In 2016, we know the value of the key parameters although we do not know what constitutes the majority of the matter and energy content of the Universe.Measurements of the cosmic microwave background radiation as well as of type Ia supernova explosions indicate that the dynamics of the Universe is determined by some kind of "dark energy" which causes the expansion of the Universe to accelerate.There are significant challenges to our understanding: We do not know the nature of key components and there appears to be insufficient time for the evolution of the stars, galaxies and structures that we see. While these might be just details to be worked out, it is instructive to remember that in 1900 Physics was considered a "complete and finished" science just before the Quantum revolution pulled the rug from under the "Classical" description.