Philip W. Anderson - Nobel Laureate in Physics at 96 - The New York Times March 30
"Much of Dr. Anderson’s most influential work concentrated on randomly structured, or “disordered,” materials that lack the regular crystalline composition of most matter.
He was particularly interested in the behavior of electrons within these disordered materials, which include certain kinds of semiconductors. In 1958, he published a paper in which he showed how electrons in disordered materials can either move freely or become fixed in a specific position, as if stuck in glue, depending on the degree of disorder. His finding of how electrons behave when trapped, or localized, became known as Anderson localization, and was subsequently extended to the properties of light and sound waves."
"In 1972, Dr. Anderson stirred up the physics world with an article in the journal Science called "More is Different," which became part of a spirited debate about the widely accepted concept of reductionism in science. Reductionism maintains that everything can be reduced to a few fundamental laws describing the particles that are the basic constituents of matter."
Here is that paper.
More Is Different: Broken symmetry and the hierarchical structure of science - Science August 1972
At least one of his books is in my house someplace. Too many boxes.