Edward Purcell. Portrait of Edward Mills Purcell (born 1912), American physicist. Purcell helped to develop nuclear magnetic resonance (NMR) during the 1940s. Purcell developed the technique so that the magnetic fields of the nuclei of atoms could be measured in solids and liquids; previously only gaseous atoms could be measured in this way. In 1951 Purcell was the first to detect microwave emission at the wavelength of 21 centimetres from interstellar hydrogen atoms. This discovery allowed the mapping of much of our Galaxy. In 1952 Purcell shared the Nobel physics prize with Bloch. Photographed in 1953.