August 30, 1912–March 7, 1997
BY ROBERT V. POUND
EDWARD MILLS PURCELL, Nobel laureate for physics in 1952, died on March 7, 1997, of respiratory failure at his home in Cambridge, Massachusetts. He had tried valiantly to regain his strength after suffering leg fractures in a fall in 1996, but recurring bacterial lung infections requiring extended hospitalizations repeatedly set back his recovery.
Two of the best known of Purcell's many outstanding scientific achievements are his 1945 discovery with colleagues Henry C. Torrey and Robert V. Pound of nuclear magnetic resonant absorption (NMR), and in 1951 his successful detection with Harold I. Ewen of the emission of radiation at 1421 MHz by atomic hydrogen in the interstellar medium. Each of these fundamental discoveries has led to an extraordinary range of developments. NMR, for example, initially conceived as a way to reveal properties of atomic nuclei, has become a major tool for research in material sciences, chemistry, and even medicine, where magnetic resonance imaging (MRI) is now an indispensable tool. Radio spectroscopy of atoms and molecules in space, following from the detection of the hyperfine transition in hydrogen as the first example, has become a major part of the ever-expanding field of radio astronomy.