A peculiar lecture by Ettore Majorana

We give, for the first time, the English translation of a manuscript by Ettore Majorana, which probably corresponds to the text for a seminar lecture delivered at the University of Naples in 1938, where he lectured on theoretical physics. Some passages reveal a physical interpretation of quantum mechanics which anticipates for several years the Feynman approach in terms of path integrals, independent of the underlying mathematical formulation. From January to March 1938, Ettore Majorana delivered his only lectures on quantum mechanics at the University of Naples, where he obtained a position as a full-time professor of theoretical physics, a few months before he mysteriously disappeared. Although the scientific personality of such a physicist is widely recognized, here we only mention that Majorana obtained that position in the 1937 Italian national competition for three full professorships for ‘great and well-deserved fame’, independent of the competition itself, upon recommendation of the judging committee chaired by Enrico Fermi [1]. The interest in the course on theoretical physics, delivered by Ettore Majorana at the University of Naples in 1938, has been recently revived by the discovery of the Moreno paper [2], which is a faithful transcription of the lecture notes prepared by Majorana himself made by the student Eugenio Moreno1. Such a paper, in fact, includes some previously unknown lecture notes, whose original manuscripts seem to be missing. The handwritten notes by Majorana were reproduced some years ago [3] along with some papers initially interpreted as the notes prepared for a forthcoming lecture that, however, Majorana never delivered due to his mysterious disappearance. Here, however, we do not focus on the university lecture notes (delivered to students) but, rather just on the last mentioned spare papers that cannot be considered as notes for academic lectures, even for an advanced course such as that by Majorana. This is testified mainly by an accurate analysis of the scientific content present in those notes, referring to 1 This document is owned by the Moreno family in Naples and, at the moment, is kept by the present author. 0143-0807/06/051147+10$30.00 c © 2006 IOP Publishing Ltd Printed in the UK 1147