Felix Bloch was a pioneering Swiss-American physicist born on October 23, 1905, in Zürich, Switzerland, to a Jewish family. He initially studied engineering at ETH Zurich before switching to mathematics and physics, where he was influenced by prominent scientists including Peter Debye, Paul Scherrer, and Erwin Schrödinger. After completing his doctoral dissertation at the University of Leipzig in 1928, which established the quantum theory of solids and provided the basis for understanding electrical conduction, he taught at Leipzig until the rise of Nazi Germany forced his departure. In 1934, he emigrated to the United States and joined the faculty of Stanford University, where he would remain for most of his academic career, becoming the Max Stein Professor of Physics in 1961 and teaching until his retirement in 1971.
Bloch's most significant contribution came through his development of nuclear magnetic resonance (NMR), which he discovered independently and simultaneously with Edward Purcell at Harvard University. His 1939 work with Luis Alvarez to measure the magnetic moment of the neutron laid the foundation for this breakthrough, as did his earlier theoretical work on quantum mechanics in solids. The nuclear induction method he developed provided a purely electromagnetic procedure for studying nuclear moments in solids, liquids, or gases, enabling precise measurements of atomic structure and behavior. This groundbreaking work earned him the Nobel Prize in Physics in 1952, and his discoveries would later become fundamental to the development of nuclear magnetic resonance imaging (MRI), revolutionizing medical diagnostics and structural analysis in chemistry and materials science.
Beyond his Nobel Prize-winning work, Bloch served as the first Director-General of CERN (the European Organization for Nuclear Research) from 1954 to 1955, helping establish this pivotal international scientific collaboration. His theoretical contributions extended to multiple areas including electromagnetism, nuclear physics, and group theory, with influential papers such as Spectroscopic and Group Theoretical Models in Physics published throughout his career. The techniques he pioneered for measuring nuclear magnetic moments have become increasingly important in diagnostic medicine and materials characterization, with applications continuing to expand long after his death. Felix Bloch passed away on September 10, 1983, in Zürich, leaving a profound legacy that continues to shape physics, chemistry, and medical imaging through the widespread use of NMR and MRI technologies worldwide.
