Étienne Samuel Biéler (3 February 1895 – 25 July 1929) was a Swiss-born Canadian physicist who made important advances in the study of the strong interaction that holds the atomic nucleus together. A graduate of McGill University, he worked at the Cavendish Laboratory, where he studied the atomic nucleus under Sir Ernest Rutherford and James Chadwick. A 1921 paper with Chadwick has been hailed as "marking the birth of the strong interactions". In his doctoral thesis, Biéler explored the strong interaction, and showed that it varied with the fourth power of the distance. Biéler returned to Canada, where he was appointed assistant professor of physics at McGill. He became interested in geophysics, and he attempted to develop electrical methods for detecting hidden bodies of ore. He was given two years' leave from McGill to participate in an Imperial Geophysical Experimental Survey to try out various methods of ore detection. While in Australia he became ill and died of pneumonia on 28 July 1929. Biography Early life Étienne Samuel Biéler was born in Lausanne, Switzerland, on 3 February 1895, the second of five sons of Professor Charles Biéler and Blanche Merle-D'Aubigné. His father Charles was Director of Collège Gaillard and his mother Blanche was the daughter of the historian Jean-Henri Merle d'Aubigné. His younger brother André Charles Biéler later became a famous painter and professor of art at Queen's University. The family lived in Paris for twelve years before emigrating to Canada in 1908, where Charles became Professor of Theology at the Presbyterian College in Montreal. Biéler entered McGill University, which awarded him his Bachelor of Science (BSc) degree on Mathematics in 1915. During the First World War, he enlisted in the 38th Battalion (Ottawa), CEF on 29 March 1915. He transferred to Princess Patricia's Canadian Light Infantry on 17 July 1915. On 23 February 1916 he transferred to the Canadian Field Artillery, joining the 3rd Field Artillery Brigade on 23 February 1916, then the 12th Field Artillery Brigade on 28 June 1916, and finally the 1st Field Artillery Brigade on 20 March 1917. He was wounded twice, on 3 August 1916 and again on 29 April 1917, and rose to the rank of lieutenant. During the later part of the war, he worked in the Anti-Submarine Division of the British Admiralty, on methods for locating submarines. Nuclear physics After the war Biéler resumed his education, earning a Master of Science