Brown CS News

“Everything has to have a life cycle,” says An Wang Professor of Computer Science Franco P. Preparata, speaking at his farewell address on December 5, 2013. “This is the first official step of my walk into the sunset.”

Preparata’s career spans more than a half-century, including twenty-three years with Brown University alone. It includes the publication of three books that have been translated into five languages; more than two hundred papers; numerous pioneering contributions to coding theory, computational geometry, design and analysis of algorithms, parallel computing, very-large-scale integration (VLSI) computation, and computational biology, including personal responsibility for the genesis of that last field at Brown.

Interviewed after the event, Franco notes with pride that he also co-created a monthly seminar that bridged the humanities and the sciences at Brown, featuring some of the most visible people on campus for an entire decade. On the night of his address, this love of interdisciplinary work, his many achievements in the field, and his passion for social change were all evident.

Department Chair Roberto Tamassia spoke first, expressing thanks to Preparata as a mentor (Tamassia was one of his PhD students) and colleague: “We are hugely grateful to Franco for his research and his educational leadership...we have greatly benefited from his strategic vision and academic wisdom.” Franco, he explains, “sets such a high bar in multiple ways. Not only in his incredible research productivity, but as an amazing individual in many other dimensions...I am thankful to Franco for being a role model for me.”

Preparata began by offering gratitude for the “hospitable home in which I have dealt with very congenial colleagues” for so many years. His remarks that follow trace the “extraordinary journey” that the field has experienced, highlighting technological and sociological issues through lenses that include memory, culture, and art. Franco frames his discussion as a narrative of the evolution of computer hardware: “The development of computer science was punctuated at all times, in my view, by the development of the corresponding physical support.”

Preparata’s experience with hardware began in the 1950’s with his work on one of the first floating-point machines, the Mercury computer of Ferranti, Ltd. Its circuits consisted of thousands of vacuum tubes, Franco explains, “and the probability that things could go wrong was very high. Mean time between failures was measured in terms of hours...How rudimentary, and yet how exciting it was, the computer at that time! It caught the public imagination and was popularly referred to as an ‘electronic brain’.”

The era that followed, he maintains, was that of “differentiation” from computer science’s two progenitors, electrical engineering and mathematics. Transistors emerged, providing much greater reliability. Higher-level languages and compilers freed programmers from writing in machine language, allowing algorithmic portability.  “I remember the excitement,” Franco recalls, when a distinct Department of Computer Science emerged at University of Illinois, where the ILLIACs had been conceived.

Next was the advent of the semiconductor and the integrated circuit, merging together vast assemblies of transistors and resistors, and giving birth to Moore’s Law. Here Preparata pauses for a moment, returning to the theme of memory: “In our field, when a technology becomes superseded, there is no remnant, not even a memory of it.”

The next twenty years, he explains, “could be described as the careful construction of the scientific profile of the field.” Highlighting the concept of algorithm complexity and the “pivotal milestone” offered by the work of Stephen Cook, he maintains that Computer Science “came of age in the seventies, emancipated from its tutors, assuming the profile of a mature science.”

Franco provides an interesting perspective on the era of the personal computer, in which very large-scale integration was coming onto the scene. Often remembered purely in terms of its potential, the 1980’s also held considerable challenges for computer scientists. “Parallel computation at that time,” he explains, “was funded by the federal government. When the Cold War came to an end, the funds dried up. There was an inflection of the community...it was a very somber moment.”

The current age, Preparata says, is characterized by a cultural divide: “Anything that has a societal aspect is affected by the Internet, by this new technology. Computer science, while continuing to build its own structure, has become an enabler for any discipline...The question now: is it all good?” A desire for speed, for example, can become a threat to the intellectual quality of scientific results. The tremendous facility of e-mail, Franco believes, is available to us only after sacrificing a substantial amount of privacy.

These problems, he maintains, require action: “Income inequality  is an incredible societal problem, and solutions don’t exist or are ineffective...Computer science is playing a central role in society today. I have no answers, but I’m exhorting my colleagues to consider themselves as actors in society, not just providers of tools and services...Take an active role!”

At the end of his remarks, Franco returns to the happiness he found in hard work and collaboration: “I remember the satisfaction  at the long hours in the classroom, the long hours with my students, and the honest and respectful debate with congenial and like-minded colleagues.” He also mentions a cultural contribution to Brown CS, explaining that he “instigated” the artwork hanging in the CIT to this day.

“See it,” he requests, “and remember that I was at some time a member of this department.”

After a few questions, the address is over, the exhortation to remember still hanging in the air. It’s all the more poignant in light of his earlier words: “In our field, when a technology becomes superseded, there is no remnant, not even a memory of it.”

In just a few months, at the start of the semester, a new cohort  of students will arrive ready to act, to address the challenges that Franco outlined. They’ll sit in atrium sunlight; they’ll gather at tables and in classrooms. They’ll see the artwork. If they don’t yet know who Franco Preparata is, their professors will tell them.