Leo P. Kadanoff, a leading theoretical physicist best known for developing the concepts of "scale invariance" and "universality" as they apply to phase transitions, died Oct. 26 in Chicago. He was 78.
Kadanoff, a professor at the University of Chicago from 1978 until his retirement in 2003, won the Buckley Prize of the American Physical Society in 1977, the Wolf Foundation Prize in 1980, the 1989 Boltzmann Medal of the International Union of Pure and Applied Physics, and the 1999 National Medal of Science.
From the Boston Globe obituary:"Phase transitions, such as those between steam and water and between water and ice, in which a single substance takes many forms, have intrigued scientists for centuries. Some have been well explained, but creating detailed explanations for some of the more complex transitions continued to challenge physicists until the last half of the 20th century.
"Throughout the world of modern physics, Dr. Kadanoff was lauded as one of the foremost in delineating how even the most subtle and complex phase transitions occur. He was also credited with showing how the large-scale changes that are easily observable stem from microscopic changes beyond the reach of the senses."