A few years after his work with Dr. Bardeen, Dr. Pines collaborated with two other physicists, Aage Niels Bohr and Ben Roy Mottelson, on a paper describing excitations in nuclei. That work led to Dr. Bohr and Dr. Mottelson’s winning the 1975 Nobel in physics, shared with another physicist, Leo James Rainwater, who had independently come up with similar ideas.
A recurring theme in Dr. Pines’s nearly 70 years of research was the notion of “emergence.”
For many physicists, the aim is to discover the smallest basic building blocks of the universe and write down the simplest equations that describe the fundamental forces of nature.
In an article published in 2000, Dr. Pines and Dr. Laughlin argued that this pursuit was “the science of the past.” They maintained that many crucial phenomena in nature arise as the collective behavior of a large number particles, and that these phenomena could not be readily understood by extrapolating from the properties of a single particle.
“The central task of theoretical physics in our time,” they wrote, “is no longer to write down the ultimate equations but rather to catalog and understand emergent behavior in its many guises, including potentially life itself.”
David Pines was born on June 8, 1924, in Kansas City, Mo., to Sidney and Edith Adelman Pines. In 1938, his family moved to Dallas, where his father started a company that installed heating and air-conditioning systems. He graduated from high school two weeks before his 16th birthday as class valedictorian. He attended Black Mountain College near Asheville, N.C., for one year before transferring to the University of California, Berkeley.
He graduated from Berkeley in 1944 with a bachelor’s degree in physics and started taking graduate classes. After being drafted into the Navy and serving for two years, he resumed his physics studies, first at Berkeley and then at Princeton, where he finished his doctoral degree in 1950.
With his thesis adviser, the renowned theoretical physicist David J. Bohm, Dr. Pines developed a technique, known as random phase approximation, to describe the behavior of electrons in a dense gas. That led to the notion of the plasmon, where vibrations in the gas could behave like particles.