John Robert Schrieffer was an American physicist known for his significant contributions to the field of superconductivity. He was born on May 30, 1931, and is best recognized for co-developing the BCS theory, which explains how certain materials can conduct electricity without resistance at low temperatures. This groundbreaking work earned him the Nobel Prize in Physics in 1972, shared with John Bardeen and Leon Cooper. Schrieffer's academic career included teaching positions at various prestigious institutions, including the University of California, Santa Barbara. He was also involved in research related to quantum mechanics and condensed matter physics. His legacy continues to influence the study of superconductors and their applications in technology.