Dark matter has been a controversial and mysterious topic since 1930s when Zwicky noticed a difference in the amount of mass obtained when computed in different manners. But much of the computations are based on what we knew about the Newtonian N-body problem 70 years ago. In this lecture, more recent results about the dynamics of the Newtonian N-body problem are described; it is shown how these results cast a new "light" on some of the dark matter assertions.