Melvin Schwartz | Biography

Melvin Schwartz's research and experimentation in the weak force of the four fundamental forces of nature resulted in the proof of the existence of the neutrino, a particle of zero-rest mass, and the Nobel Prize-winning discovery and definition of the two existing types of neutrinos, the electron neutrino, and the muon neutrino.

Schwartz was born in New York City on November 2, 1932, to Harry and Hannah Shulman Schwartz. He entered the world-famous Bronx High School of Science in 1944, at the age of twelve, and graduated five years later. By that time, he had made up his mind to become a theoretical physicist. That decision having been made, his choice for a college education was easy. At the time New York City's own Columbia University had, as Schwartz later characterized it, a physics department that was "unmatched by any in the world."

Schwartz earned his bachelor's degree in mathematics and physics in 1953. That year, Schwartz was married to Marilyn Fenster, with whom he later had two daughters and a son. He began his doctoral studies under the direction of Jack Steinberger. It was from Steinberger that Schwartz gained his special interest in particle physics, an interest that was to dominate much of his research over the next four decades.

Schwartz was awarded his Ph.D. in physics in 1959 and then joined the faculty at Columbia. Within a year, an event was to take place that would dramatically alter Schwartz's future. During an afternoon coffee hour in November 1959, at Columbia's Pupin Laboratory, a group of physicists discussed the problems of studying the weak force, one of the four fundamental forces of nature (the others being gravitation, electromagnetism and the strong force). Tsung-Dao Lee, a theoretical physicist, challenged his colleagues to find a way to obtain additional empirical evidence on the weak force. In less than twenty-four hours Schwartz had the answer. "It was incredibly simple," he decided. "All you had to do was use neutrinos."

Neutrinos turned out to be the perfect tool with which to study the weak force. Because these tiny particles are uncharged and have very small mass, they are essentially unaffected by electromagnetic or strong forces. When a beam of neutrinos passes through matter, the only interactions it undergoes are those involving the weak force.

To work out the details of the neutrino/weak force experiment, Schwartz met with his former doctoral advisor, Steinberger, and Columbia colleague Leon Max Lederman. The three devised a method for generating an intense beam of neutrinos using the Brookhaven National Laboratory's new 30 billion-electron-volt alternating gradient synchrotron (AGS). Proton beams from the AGS would be directed at a target of beryllium metal. The collision between beam and target would tear apart beryllium atoms and release an avalanche of subatomic particles, neutrinos among them. The neutrinos thus produced would then be directed through a block of steel where at least some would interact with atoms by means of the weak force.

One issue involved in the experiment was the nature of the neutrinos to be used, as relatively little was known about these particles. When the neutrino was discovered, physicists assumed that it existed in only one form, the form now known as the electron neutrino. For various theoretical reasons, however, Columbia theoretical physicist Gerald Feinberg posed the possibility in 1958 that a second neutrino, associated with mu mesons (muons), which are particles of a different weight, might also exist. The Schwartz-Steinberger-Lederman experiment was designed to determine also the validity of Feinberg's hypothesis.

By September 1961, the experiment was under way. Eight months later, an estimated 10¹⁴ neutrinos had been produced, of which fifty-one interactions with matter were observed. In every one of these cases, the interaction was such that it confirmed the existence of a muon neutrino distinct from the electron neutrino. Feinberg's hypothesis had been confirmed. The 1988 Nobel Prize awarded to Schwartz, Steinberger, and Lederman recognized not only the discovery of the muon neutrino, but also the development of a technique that, the Nobel committee said, promised to provide "entirely new opportunities for research into the innermost structure and dynamics of matter."

Schwartz resigned his post at Columbia in 1966 in order to take a position as professor of physics at Stanford University, where the new 2-mile long linear accelerator was available for his research. Meanwhile, he published the now-classic textbook Principles of Electrodynamics in 1972. He remained at Stanford until 1979 when he decided to establish his own software development business, Digital Pathways, Inc. After dividing his time between Stanford and Digital for four years, he resigned the former post and became a full-time business man.

In 1991 Schwartz returned to the academic world by accepting the posts of physics professor back at Columbia and associate director of high energy and nuclear physics at the Brookhaven National Laboratory. He left the latter position in 1994. Also that year, Columbia named Schwartz as its I. I. Rabi professor of physics. Schwartz is a member of the National Academy of Sciences and is a fellow of the American Physical Society, which awarded him the Hughes Prize in 1964.

Schwartz remains a professor in the Physics Department of Columbia University, and is also the chairman of the Weizmann Institute of Science's Feinberg Graduate School. Some of his later research has centered on Brookhaven's Relativistic Heavy Ion Collider, a new facility where scientists hope to produce highly energetic collisions between relativistic heavy nuclei, possibly leading to a totally new state of matter called quark-gluon plasma.