Ettore Majorana's legacy to contemporary physics

To celebrate the centennial of Ettore Majorana’s birth (1906—1938?), we survey the legacy of his scarce but fundamental scientific production to nearly all branches of physics, from atomic and molecular, to nuclear and subnuclear physics. In particular, we focus on a not so well known short communication by Majorana, where he critically discusses Fermi’s solution of the celebrated Thomas-Fermi equation for electron screening in atoms and positive ions. We argue that some of Majorana’s seminal contributions in molecular physics already prelude to the idea of exchange interactions (or Heisenberg-Majorana forces) in his later works on theoretical nuclear physics. We also describe a recent experiment on atomic confinement in magnetic traps, based on the ideas developed in Majorana’s paper on the behaviour of atoms in a varying magnetic field. In all his papers, Majorana emphasized the symmetries at the basis of a physical problem, as well as the limitations, rather than the advantages, of the approximations of the method employed.