Jack Steinberger, a Nobel Prize–winning scientist with a distinguished career in experimental physics, died December 12. He was 99.
Steinberger was most famous for his co-discovery of a new type of ghostlike particle called the muon neutrino—a breakthrough that earned him, Leon Lederman, and Melvin Schwartz the Nobel Prize in Physics in 1988. Steinberger studied the basic particles that make up the universe, and the elemental forces that govern their interactions, over a long scientific career that was jump-started by Enrico Fermi at the University of Chicago.
Landmark experiment: After earning his Ph.D. from the University of Chicago in 1948, Steinberger moved to Columbia University, where at nearby Brookhaven National Laboratory in the early 1960s he would undertake a landmark experiment to produce neutrinos—the “ghost” particles that zip through us undetected all the time but had been difficult to study.
In the stream of particles that Steinberger, Lederman, and Schwartz produced, it became clear that there was not just one kind of neutrino. In addition to the expected particle, there was also one that was named the muon neutrino. The breakthrough also pointed the way toward new techniques to study the “weak force,” one of the four basic forces of nature, which is regarded as a fundamental pillar of the understanding of the basic particles that still stands today.