In Part Three of #100Years100Facts, we examine the mentor-student connections that link one generation to another at Princeton Engineering.

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Which Princeton alumnus is known as a founder of the internet?

The internet is full of wisecracks about who created it, but the title “father of the internet” goes most commonly to two men who created the principles and technical protocols that allowed information to be transmitted in packets and routed effectively through a decentralized network. One of them was a doctoral student at Princeton who graduated in 1964. Who is this internet pioneer, and who was the longtime electrical engineering professor who served as his mentor?

Robert Kahn *64, born in Brooklyn, New York, is recognized for his work with Vinton Cerf in creating the Internet’s basic protocols, TCP/IP. As an engineering consultant in Cambridge, Massachusetts, he worked on ARPANET, sponsored by the Defense Advanced Research Projects Agency. It was there, in the early 1970s, that he formulated the concept of open-architecture networking upon which the Internet was built, allowing for easy interconnection and communication. While an electrical engineering student at Princeton, he learned from John B. Thomas, who spent 35 years on the faculty and who was a pioneer in the field of information theory. In a 2006 oral history project, Kahn said he appreciated Thomas’s ability to guide while giving students room to work independently: “He would say, ‘Okay, tell me about your progress. … And what problems did you encounter? What’s your approach to solving them? How are you going to deal with this thing that you’re not sure how to deal with?’” Two Princeton Engineering deans also called Thomas a mentor: H. Vincent Poor *77, a leader in wireless networks and energy systems; and Hisashi Kobayashi, who played a seminal role in advancing the storage of digital information. Today, Princeton Engineering faculty, at the forefront of their fields, are mentoring the next generation of leaders in industry, academia and government. They are committed to nurturing talented individuals with a wide diversity of backgrounds and experiences.


“Mentoring is not something I do instead of research, it is something I do because of my research.” - William Massey.

One day a few years back, William Massey spotted Nicholas André G. Johnson ‘20, then an operations research and financial engineering sophomore, giving a poster presentation at a campus conference. Johnson, who went on to become the first Black valedictorian in Princeton history, said that Massey noticed he was one of a small number of Black researchers presenting at this conference. Massey, Johnson said, “really took an interest, to stop, see my presentation, and get to know me beyond my research, what I was presenting. That really sparked a mentorship relationship that’s been invaluable during my years at Princeton.”

Massey encouraged Johnson to attend the Blackwell-Tapia Conference, which recognizes and showcases mathematical excellence by minority researchers. Mentorship is an important aspect of the Princeton Engineering experience, as students learn from leaders in their fields about not just what it takes to do the job, but how to persevere and flourish as whole individuals.

This photo is from that 2018 conference which Johnson attended, along with a number of current and former Princeton students. Johnson, who is now a graduate student at MIT, is at left in the picture, where he was joined by, from left to right: Emmanuel Ekwedike *20; Jamol J. Pender *13, who is currently an assistant professor at Cornell; William Massey ‘77, the Edwin S. Wilsey Professor of Operations Research and Financial Engineering; Ludovic Tangpi, an ORFE assistant professor; and Robert Hampshire *07, an associate professor at the University of Michigan who recently joined the U.S. Department of Transportation.. Massey is the first Black Princeton undergraduate alumnus to become a full professor at Princeton. He supervised the theses of Hampshire, Pender and Ekwedike. “Mentoring is not something I do instead of research, it is something I do because of my research,” Massey said.


Who was the first Black student to earn a doctorate from Princeton Engineering?

It was Wesley Harris, who received his doctorate in aerospace and mechanical sciences from Princeton in 1968. He is now the Charles Stark Draper Professor of Aeronautics at the Massachusetts Institute of Technology.

His work has included associate administrator for aeronautics at NASA headquarters from 1993-95. In a 2016 visit to Princeton to celebrate the legacy of Martin Luther King Jr., he said: “Dr. King transformed the ‘Negro’ to the ‘Black’ man and woman,” Harris said. “Fear was replaced by newly self-made courage. Respect for self was followed by heightened self-confidence that Black Americans could, if allowed, add unqualified value to the country.”

The Wesley L. Harris Scientific Society was established at Princeton Engineering in 2006 to encourage students from communities that are underrepresented in the sciences to pursue research careers. His advising philosophy statement at MIT reads: “I ask graduate students performing research in my teams to engage in a partnership with me where the opportunity space for success goes beyond technicalities of research to include the whole persons of the partnership. If my students are challenged, I am also challenged; if I am challenged, my students are likewise challenged. It is a partnership based on mutual respect and trust that resolves the challenges.”


“Academically, he was no-compromise in terms of quality and excellence. I try and instill that into my students.” - Edgar Choueiri, speaking about Robert Jahn.

Edgar Choueiri’s Electric Propulsion and Plasma Dynamics Laboratory (EPPDyL) -- yes, rocket science -- carries on the groundbreaking work of his adviser, the late Robert Jahn, fourth dean of the School of Engineering and Applied Science. The lab is the oldest continuously funded lab at Princeton, founded in 1962 by Jahn and expanded and headed by Choueiri since 1993.

During the space race, Jahn and his lab laid critical groundwork for spacecraft propelled by electrically charged particles, instead of conventional rockets that burn chemical fuels. Today these engines are enjoying widespread use in spacecraft propulsion, including in positioning satellites and interplanetary spacecraft. Those whom Jahn mentored attribute his success to openness to exploration, rigorous thought, and a focus on the fundamental underpinnings of questions rather than specific implementation solutions.

Choueri, whose lab today continues to pursue research at the forefront of electric propulsion, called Jahn a “fierce independent thinker” committed to pursuing big questions, and, as dean, an advocate for women in engineering. The lab’s students, including numerous master’s students and 51 doctoral recipients, form the backbone of today’s electric propulsion research around the world. This is the sixteenth of 100 facts to celebrate Princeton Engineering’s 100th anniversary!


Who was Sir Gordon Wu’s mentor?

It was rare in the 1950s for an engineering student to hail from Hong Kong. When Sir Gordon Y.S. Wu came to Princeton as a civil engineering student, he spent many hours learning from a longtime faculty member who would later be the department’s chairman, and who would be credited with growing the department. Wu, who would go on to help found a major construction firm, returned to Princeton years later to give a major gift and establish a professorship in his mentor’s name. Who was Wu’s mentor?

It was Norman Sollenberger, a civil engineering professor and former department chairman who died in 2009, was credited with being a fine teacher who deeply cared for his students. He was a mentor not just to many students, but younger faculty as well, who dubbed him an “educator’s educator” upon his retirement in 1980.

One of his students was Gordon Y.S. Wu, a young civil engineering student from Hong Kong who would go on to form a major construction firm in Asia. When Wu returned to Princeton in 1995 to announce his $100 million gift, the first person he asked to visit was Sollenberger. “I have always wanted to do all I could to assure that students in the future -- from the United States and around the world - will have the same kinds of opportunities I had to learn from faculty members who are leaders in their fields at a university that remains second to none in its commitment to teaching,” Wu said at the time. Among his many gifts to the University, Wu established the Norman J. Sollenberger Professorship, currently held by Sankaran Sundaresan of Chemical and Biological Engineering.


“Having a supportive and knowledgeable advisor means being able to make progress every week, which is the best motivation for any graduate student.” - Julie Kim

Julie Kim is a graduate student in civil and environmental engineering, in the lab of Catherine Peters. In the lab, Kim studies how to treat mining wastewater, which is rich in toxic chemicals. She performs some of her work under a plastic tent like the own shown, which has been filled with nitrogen to remove the oxygen.

Kim credits Peters with encouraging her to seek out, apply for, and participate in programs outside of Princeton, as well as opportunities to collaborate with those outside her research group. This helps build her professional skills, she said. The department is the oldest at Princeton Engineering, dating back to 1875 when its chair was Charles McMillan. Today, Peters is chair, and she follows in a long tradition of leaders who place an emphasis on teaching and mentorship. Scientific advancement, she says, is a team effort. As she says on her lab website: “Through locked arms we forge ahead, being inspired from each other as much as from the scientific discovery itself. Every single day, I am awed by the work of my students and collaborators.”


Which alumnus helped solve the Deepwater Horizon oil spill?

After the Deepwater Horizon rig exploded in 2010, engineers worked for 87 days to cap it. But it was unclear that the cap would hold. A 1977 Princeton civil engineering alumnus performed an important analysis for the U.S. Geological Survey to determine that the capped well was sound and safe from an “underground blowout.” Who was this civil engineer, and who was the Princeton civil engineering legend with whom he studied?

When the Deepwater Horizon oil rig exploded in 2010, Paul Hsieh ‘77 was called in to perform an important task. After 87 days, workers were able to cap the well, but they were unsure if the cap would hold. Hsieh, who worked for the U.S. Geological Survey until 2018, develops computer models to predict the follow of underground water and potential contaminants.

While at Princeton he had studied with George Pinder, a celebrated professor of civil engineering. (Pinder later went on to the University of Vermont, where he is a pioneer in the creation and use of computer models for solution of groundwater contamination problems). Hsieh measured the well’s pressure to determine the danger of an underground blowout, which would have been a disaster beyond control. But his computer models showed the well would hold -- and it did. For his work, Hsieh won the 2011 Federal Employee of the Year award from the Partnership for Public Service.

Today, Princeton Engineering students and faculty make important contributions to averting and containing the next environmental disasters, including designing giant umbrellas to shift into position as a storm-surge seawall; cleaning groundwater; determining carbon gas leaks from leaky wells; and finding a way to get to net-zero emissions by 2050.


“Mentorship is very important in our school. It is like a light tower in the sea giving you direction and light…” - Lei Wu, postdoc in the Register Lab.

Lei Wu is a postdoc in the lab of Richard Register, the Eugene Higgins Professor of Chemical and Biological Engineering. In that lab, Wu works on polyethylene plastics with degradable linkages, to help make it possible to build product packaging that degrades more easily. “I have learned so much from Rick,” Wu said, noting his mentor’s passion for science and strong sense of responsibility.

“Mentorship is very important in our school. It is like a light tower in the sea giving you direction and light… A mentor will give you an interesting area for study, and support you when facing difficulties.” Register was honored in 2018 with the school’s Distinguished Teacher Award. During the eight years he was chair of the department, he continued to teach courses, and undergraduates appreciated his responsiveness and availability for extra help. One grad student said of his teaching: “For any question we raise, he not only provides explanations, but also encourages us to read more and think further.”

Over the years and today, Princeton Engineers -- from undergraduates to postdocs -- have praised the faculty’s dedication to mentorship, enabling them to spend time learning from, and leaning on, their advisers, as well as becoming connected to a larger intellectual community at Princeton and beyond.