This book presents in full the work of the Italian theoretical physicist Ettore Majorana and explains its impacts, which are still being felt. It opens with a contribution by A. Zichichi that considers in depth the scientific genius of Majorana. This introductory chapter is followed, in chronological order, by the eleven scientific papers by this great scientist, in most cases translated into English for the first time. Each paper is accompanied by a comment from an expert in the field in question. Although very few in number, Majorana's papers constitute a heritage of undeniable value and extraordinary scientific meaning, since they laid the foundations for research fields that remain topical today. With this in mind, two additional contributions on ongoing developments in these research fields are included: one on neutrino physics and the other on Majorana fermions in condensed matter. The volume closes with a note on Majorana's life until his ill-fated disappearance.

Presents a collection of Majorana's scientific notes, many of which translated into English for the first time

Preface.- Brief biography.- Scientific Paper no. 1a "Rendiconti dell'Accademia dei Lincei", vol. 8, 1928, pp. 229-233.- On the splitting of the Roentgen and optical terms caused by the electron rotation and on the intensity of the cesium lines.- G. Gentile and E. Majorana.- Comment on the Scientific Paper no. 1a - E. Arimondo.- Scientific Paper no. 1b Talk given at the 22nd General Meeting of the Italian Physical Society "Il Nuovo Cimento", vol. 6, 1929, pp. XIV-XVI.- Majorana dr. Ettore: Search for a general expression of Rydberg corrections, valid for neutral atoms or positive ions.- Comment on the Scientific Paper no. 1b - F. Guerra and N. Robotti.- Scientific Paper no. 2 "Il Nuovo Cimento", vol. 8, 1931, pp. 22-28.- On the formation of molecular helium ion - E. Majorana.- Comment on the Scientific Paper no. 2 - A. Sasso.- Scientific Paper no. 3 "Il Nuovo Cimento", vol. 8, 1931, pp. 78-83.- On the possible anomalous terms of helium - E. Majorana.- Comment on the Scientific Paperno. 3 - M. Inguscio and F. Minardi.- Scientific Paper no. 4 "Rendiconti dell'Accademia dei Lincei", vol. 13, 1931, pp. 58-61.- Pseudopolar reaction of hydrogen atoms - E. Majorana.- Comment on the Scientific Paper no. 4 - A. Sasso.- Scientific Paper no. 5 "Il Nuovo Cimento", vol. 8, 1931, pp. 107-113.- Theory of the incomplete P_ triplets - E. Majorana.- Comment on the Scientific Paper no. 5 - E. Arimondo.- Scientific Paper no. 6.- "Il Nuovo Cimento", vol. 9, 1932, pp. 43-50.- Oriented atoms in a variable magnetic field - E. Majorana.- Comment on the Scientific Paper no. 6 - M. Inguscio.- Scientific Paper no. 7 "Il Nuovo Cimento", vol. 9, 1932, pp. 335-344.- Relativistic theory of particles with arbitrary intrinsic angular momentum - E. Majorana.- Comment on the Scientific Paper no. 7 - N. Cabibbo.- Scientific Paper no. 8 8a - "Zeitschrift f¿ur Physik", Bd. 82, 1933, pp. 137-145.- 8b - "La Ricerca Scientifica", vol. 4 (1) 1933, pp. 559-563.- ¿Uber die Kerntheorie - E. Majorana.- On nuclear theory - E. Majorana.- Comment on the Scientific Paper no. 8 - L. A. Radicati di Brozolo.- Scientific Paper no. 9 "Il Nuovo Cimento", vol. 14, 1937, pp. 171-184.- A symmetric theory of electrons and positrons - E. Majorana.- Comment on the Scientific Paper no. 9 - L. Maiani.- Scientific Paper no. 10 "Scientia", vol. 36, 1942, pp. 58-66.- The value of statistical laws in physics and social sciences - E. Majorana.- Comment on the Scientific Paper no. 10 - R. N. Mantegna.- The Inaugural Lecture University of Naples, 13 january 1938.- Preliminary notes of the inaugural lecture - E. Majorana.- Comment on the "Preliminary notes of the inaugural lecture" - B. Preziosi and E. Recami.