MIT Professor Emeritus Richard “Dick” Thornton SM ’54, ScD ’57 passed away on May 16. He was 93.
An innovator, entrepreneur, adventurer, and outdoor enthusiast, Thornton’s influence upon all the communities he touched was profound. He was well known for his leading work on maglev technology and other electronics innovations, as well as his key contributions to electronics education.
Born Sept. 24, 1929 in Scarsdale, New York, Thornton earned his undergraduate degree from Princeton University in electrical engineering, and his master's degree and PhD from MIT before taking a position within the former Department of Electrical Engineering (now the Department of Electrical Engineering and Computer Science, or EECS), where he would stay for the remainder of his academic career. During his 40-plus year tenure at EECS, Thornton mentored and inspired countless individuals, consistently advocating for bold and fearless exploration in all areas of life.
An inventive tinkerer who once burned down his own garage while repairing his home’s solar water heating system, Thornton “was much more at home in the laboratory than in the classroom,” according to his then-student John Kassakian, now an MIT emeritus professor of electrical engineering. “During the ’62-’63 school year he created a lab course where students designed and built an oscilloscope … He also invented what we students called the ‘Dickie Board,’ a plastic board with an array of hollow pins that allowed one to build a circuit using toothpicks to fasten and connect the component leads in the pins.”
Thornton’s gift for improvisation belied a stringent sense of academic and intellectual rigor. “My single most important and memorable moment with Dick was in the context of an EE lab that he taught and I took as a sophomore,” remembers Chuck Counselman, now an MIT emeritus professor of planetary science. “He wrote in my laboratory notebook, ‘Stop being a ham.’ He was referring to my hobby, since childhood, of amateur ham radio. As a ‘ham’ I had designed and built electronic circuits by qualitative thinking and trial-and-error, a.k.a. ‘cut-and-try.’ I did not analyze circuits theoretically and quantitatively, by means of linear algebra, differential equations, and Fourier transforms. [In other words], I had not yet learned to think analytically. Dick’s four-word comment changed the course of my life as an engineer and a scientist.”
Counselman’s experience of having his life’s course affected by Thornton is one shared by hundreds of MIT students. Over the years, Thornton supervised over 100 bachelor's-level theses, 60 master's- and engineer's-level theses, and was a supervisor or reader for over two dozen doctoral theses. “He was one of relatively few faculty to teach our entire common undergraduate core at the time,” says Steve Leeb, now the Emanuel E. Landsman (1958) Professor of EECS. “He was beyond generous with his time, insight, and resources, and a critical mentor to graduate students and junior faculty far outside of his own group.”
One of Thornton’s SM thesis advisees, Jeff Lang, now Vitesse Professor of EE, remembers that “Dick was one of several faculty (Melcher, Haus, and Staelin, too) that got me interested in electromechanics, and E&M in general. He was a great advisor in the sense that he involved me not only in the technical part of my thesis, but the “business” side too, i.e., dealing with industrial sponsors before, during, and after our project.”
Thornton’s business sense was the product of extensive experience; during his time at MIT, he founded two separate companies. The first was Thornton Associates, which focused on improving methods of measuring and controlling water purity. Leeb explains: “Instruments that Dick Thornton designed and patented are now used by virtually all major semiconductor manufacturers to monitor the purity of water and to provide automatic control of fabrication operations. He designed and patented techniques and circuit topologies which have introduced fundamental, widely used techniques in power electronic drives for, among other applications, the increasingly important variable reluctance machine.”
The second company that Thornton founded, alongside some of his graduate students, was MagneMotion, later acquired by Rockwell Automation, which focused on the commercial application of linear synchronous motors in a variety of settings, including manufacturing lines, luggage handling, elevators (such as weapons elevators in U.S. military ships), biological sample handling (including for Covid-testing and blood-testing equipment), and amusement park rides (notably at Disney).
“His maglev work spanned a long duration up to his founding of MagneMotion, including seminal work in the early 1970s with Henry Kolm,” says Ford Foundation Professor of Engineering David Perreault, noting an article, “Electromagnetic Flight,” which Thornton and Kolm published in the Oct. 1, 1973 issue of Scientific American with the tempting subhead: “The future of high-speed ground transportation may well lie not with wheeled trains but with vehicles that ‘fly’ a foot or so above a guideway, lifted and propelled by electromagnetic forces.”
Not content merely to spark scientific readers’ imaginations, Thornton and Kolm went on to develop a scale version of the “magplane” they proposed, and to author multiple papers on linear motor propulsion. Thornton’s work on maglev made him an in-demand lecturer, with frequent invitations from the U.S. Department of Transportation, the National Maglev Initiative, Draper Laboratories, and Bechtel; as his career at MIT progressed, he led the development of critical innovations and techniques for making maglev systems practical, implementable, and safe — including crucial work on fault-tolerant power electronic drives; low-cost guideways for maglev; and the development of safe, economical techniques to shield passengers and bystanders from the strong magnetic fields involved in these transportation systems.
Additionally, Thornton was a significant contributor to the Semiconductor Electronics Education Committee (SEEC) book series, acting as lead author on three of the influential texts, collectively the first such series to address semiconductor devices and circuits. He also co-taught the first course in solid state electronics at MIT with co-authors Campbell Searle, Paul Gray, Richard Adler, and Arthur Smith. Kassakian, who worked with the co-authors during summer 1963, remembers that influential course: “The lectures were lively since all the faculty not lecturing were in the room criticizing, commenting, and correcting, as all the material had never been taught before.”
A great advocate for career flexibility, Thornton stressed the importance of staying curious and taking career risks. “Over my career, I observed that virtually all MIT faculty at some point had to make significant changes in their career,” he recalled in a 2022 interview with MIT’s Alumni Association. “It can be difficult for a faculty member to pivot because, ironically, if you’re an expert in the field, it’s easier to gain funding to be a better expert in that field. It’s much harder to transition.” To ease that transition for other MIT faculty members, Thornton established the Thornton Family Faculty Research Innovation Fund, a grant designed to encourage mid-career faculty members to explore new and exciting directions in their research, with an emphasis on novel and untested ideas.
In congruence with his risk-taking career persona, Thornton was personally an adventurous outdoors enthusiast whose hobbies included whitewater canoeing, electric car racing, skiing, hiking, and sailing (a sport he was first introduced to at the MIT Sailing Pavilion). He met his wife, Marian, when she signed on as an extra crew member for a two-week cruise along the coast of Maine. The two enjoyed not only cruising but racing, according to Kassakian: “I sailed with him several times, including the race around Nantucket where we came in last because the spinnaker wrapped itself around the forestry. Poor Marian spent 20 minutes at the top of the mast, swinging around in a bosun’s chair, trying to untangle it.”
On other occasions, Kassakian remembers the couple being more characteristically ahead of the crowd. “They were always in the lead [in our annual bike ride from MIT to Provincetown]. During one trip, after a 65-mile leg to spend the night at my place on the cape, we were missing some key ingredient for dinner. Dick said he had it at his home in Woods Hole, which was about 15 miles from my house. So he hopped back on his bike, rode to Woods Hole, got whatever it was, and returned so we could make dinner.”
James Kirtley, professor of electrical engineering (post-tenure), corroborated the couple’s remarkable speed: “Dick and Marian also met the LEES group on the Tour de Cape on bicycles, but were both much faster than the rest of us.” The couple remained married for 60 years, by all accounts decades filled with an enormous number of wilderness adventures, including canoeing through spring floods and regular hiking pilgrimages to the White Mountains, plus many peregrinations between Maine and New York by sail.
Thornton was predeceased by Marian, as well as by a sister, Julie Wagoner. He is survived by daughter Margo Webber and her husband Todd; son Dick and wife Toni; son Doug and wife Alison; seven grandchildren, including Alex Webber and wife Nicole, Kip Webber and wife Katie, Karen Thornton, Margo Thornton, Christopher Thornton, Arianna Thornton and Nicholas Thornton; great-grandson Riley Webber; sisters Mary Carr and Nina Asgeirsson; dearest friend and companion Kathleen Lang; and many nieces, nephews, extended family, and friends.
Of Thornton’s extraordinary and personal impact on his community, both at MIT and beyond, Steve Leeb summarizes, “He was consummately knowledgeable as an engineer, yet always humble and compassionate … a man of diamond clarity and sterling honesty, he defined the phrase ‘a gentleman and a scholar.’ He will be greatly missed.”
The author thanks Steve Leeb, John Kassakian, James Kirtley, David Perreault, George Verghese, Jeffrey Lang, Chuck Counselman, and other friends and colleagues of Richard Thornton for extensive contributions to this obituary.