  The renormalization group method developed by Ken Wilson more than four
decades ago has revolutionized the way we think about problems involving a
broad range of energy scales such as phase transitions, turbulence, continuum
limits and bifurcations in dynamical systems. The theme issue provides articles
reviewing recent progress made using the renormalization group method in
atomic, condensed matter, nuclear and particle physics. In the following we
introduce these articles in a way that emphasizes common themes and the
universal aspects of the method.
