John King, physics professor emeritus, dies at 88

Experimental physicist remembered for passion in education, inventions, and science

Professor emeritus John G. King ’50, PhD ‘53, an experimental physicist, transformative physics educator, and leader of the MIT Molecular Beams Laboratory in the Research Laboratory for Electronics for 42 years, died on June 15 at his summer house in Wellfleet, Mass. A longtime resident of Cambridge, King was 88. The cause of death was congestive heart and renal failure.

“John was an inspiring teacher and experimentalist. His educational passion was creating hands-on experiments built from ordinary parts you can find at any hardware store, what he lovingly called ‘mulch,’” said MIT senior lecturer in physics, and former King student, Peter Dourmashkin ’76. “He was MITx before MITx.”

King was born in London and educated in France, Switzerland, and the United States. He came to MIT as an undergraduate in 1943 and completed his undergraduate studies in physics following war service for the U.S. Army, U.S. Navy, and the Harvard Underwater Sound Lab. He joined the MIT physics faculty in 1953. King was named the Francis L. Friedman Professor of Physics in 1974 and retired from MIT in 1996.

King was renowned for his null experiments — those designed to test fundamental principles. He helped develop the atomic clock and invented the molecular microscope. King’s best-known experiment, still found on the first page of most electricity and magnetism textbooks, is the measurement of the charge magnitude equality of the electron and the proton, and the neutrality of the neutron to a 10-20 of an electron charge. King also conceived an imaginative experiment, prompted by cosmological ideas, to set a hard limit on the possibility that matter, over cosmological time, begets new matter, a version of what was once called the steady state cosmology.

Building atomic and molecular beam research

Professor of physics emeritus Rainer Weiss ’55 was a colleague of King throughout his student and faculty years at MIT and considers him to be “one of the most creative and imaginative experimental physicists of his generation.” Both physicists were students of Jerrold Zacharias, who began the Molecular Beam Laboratory at MIT shortly after World War II.

Molecular beam experiments measure the properties of individual atoms in a vacuum unperturbed by interactions with other molecules. The technique provides precise and universally reproducible values for the energy levels and other parameters of these quantized systems. King began his work in molecular beams by pioneering new methods to measure the charge and current distributions in the nuclei of the halogens. He discovered the magnetic octupole moment of the common isotope of iodine.

During his years as director and principal investigator of the Molecular Beam Laboratory, King transformed the research conducted there. It branched into molecular beam techniques applied to collective body physics, cosmology, and biophysics. More than 100 undergraduate and 25 doctoral students obtained their degrees working on these topics during King’s tenure at the laboratory.

Reinventing physics education

Dissatisfied with the lab exercises used in mid-century physics pedagogy, King worked tirelessly on innovative methods that stressed hands-on learning and independent thinking. In 1966, he initiated the Project Lab, in which students developed their own open-ended research projects. His belief that anyone could “find something interesting to study about any mundane effect” reflects the independent spirit of King’s own early and eclectic science education. He told his students that “the best way to understand your apparatus is to build it.”

As an adviser, King quickly became a project participant. Charles H. Holbrow, professor of physics emeritus at Colgate University and currently a lecturer at MIT, recalled that King had “the wonderful gift of seeing physics in everyday phenomena and turning these into research projects.” Some 2,000 MIT undergraduates experienced Project Lab.

With other educators in the late 1950s and ‘60s, King worked on the revitalization of high school physics, following the startling realization on the part of Zacharias that “while students had taken physics, they didn’t understand anything.” When the 1957 launching of Sputnik spurred a nation-wide alarm and allocation of money to improve science teaching, King became deeply involved. In cooperation with the influential Physical Science Study Committee (PSSC), he produced — and acted in —eight physics movies, including “Times and Clocks,” “Interference with Photons,” “Size of Atoms from an Atomic Beam Experiment,” and “Velocity of Atoms.”

A life of invention

Family, friends, and colleagues paint a portrait of an energetic, curious, and engaging man who applied these characteristics equally to his intellectual, professional, and personal lives. King’s wife, Jane Williams, recalls him as “interesting, imaginative, ingenious and lots of fun.” In addition to his enthusiasm for physics and the value of science as the basis for understanding the world around us, she says, he was throughout his life “passionate about classical music, poetry, and any kind of dictionary. Since his early years were spent in France, he cared about things French, including French wines.”

King’s French stepfather introduced him to the tinkering that informed much of his approach to science, especially science teaching. As a high school student at Phillips Exeter Academy, he had his own laboratory. In life, as in science, he remained a relentless tinkerer, once rebuilding a bus, complete with bunks, to transport his large family to the farm in Woolwich, Maine, where he and his first wife, Elizabeth, lived for many years. She and several of their eight children still live in or around Woolwich.

King was the recipient of many honors and awards for contributions to physics and physics education. These include the Alfred P. Sloan Award (1956), the AAPT Robert Millikan Medal (1965), the E. Harris Harbison Award (1971), and the Oersted Medal (2000), the most prestigious award of the American Association of Physics Teachers.

A memorial service will take place at MIT in October.

Reprinted with permission of MIT News.