At the end of the First World War, physicist Ernest Rutherford carried out a series of experiments consisting on bombing nitrogen atoms with alpha particles. He saw the appearance of a radiation which was less ionizing than those particles and with a greater range. Rutherford noted that this radiation was formed by hydrogen ions, which he named protons, and which should be the constituents of atomic nucleus. With the exhibition “100 anys del descobriment del protó. Rutherford, pare de la física nuclear”, the annual exhibition of the Physics and Chemistry CRAI Library commemorates the 1919 publication of this important discovery, the first nuclear reaction that was artificially created, and which marks the birth of nuclear physics.

The exhibition, commissioned by the lecturer José M Fernández Varea, from the Department of Quantum Physics and Astrophysics, will open on November 27, at 12 noon, in the Aula Magna Enric Casassas at the faculties of Physics and Chemistry. Visitors will see works and facsimiles by Rutherford on the atomic structure and works on the English scientist, as well as classic books on nuclear physics. Also, the exhibition includes radioactivity-related instruments.

Ernest Rutherford received the Nobel Prize in Chemistry in 1908 for his research studies on disintegration of elements and chemistry of radioactive substances, conducted in McHill University (Montreal). That same year, he moved to the University of Manchester, where he supervised the research study by several excellent young researchers. The Geiger and Marsden experiment (1909) on the dispersal of particles, whose results were interpreted by Rutherford in 1911 –based on a new atomic model- is well known. In this experiment, the positive charge and almost the whole mass of the atom are concentrated in a small nucleus surrounded by light and negatively-charged electrons. Despite being less known, the experiment that took him to discover the proton is one of the big milestones in physics.

Theatre play: Cent anys després

During the opening of the exhibition, there will be a theatre play: Cent anys després, which treats aspects related to social perception of science on the occasion of some 1919 discoveries in physics. The play has been written for this occasion by Enric Pérez Canals, lecturer at the Department of Condensed Matter Physics, who also directs it. Other members of the Faculty of Physics take part in the theatrical production.