The Ericson fluctuations were first observed in 1964 by P. Von Brentano et al. in nuclear physics giving rise to a vigorous theoretical and experimental programme. They have the curious feature of being both reproducible and random at the same time. The fluctuations are universal and have later been observed in many other areas such as photoionization of hydrogen, uni-molecular dissociation (physical chemistry), perturbed atomic and molecular systems and micro wave billiards.