Building bridges across disciplines



by Ann Haver-Allen

The mission statement of the School of Engineering and Applied Science (SEAS) identifies establishing a closer integration of SEAS with liberal arts programs at Princeton as a primary objective.

Changes in the Princeton curriculum, which require more science and quantitative courses for A.B. students, acknowledge that any superior liberal arts education must include a solid background in science and technology.

SEAS faculty members are challenged to develop courses targeted at providing an introduction to engineering and technology to humanities and social science students. Many faculty members have accepted that challenge.

"With technology playing a growing role in both professional and public policy decisions, we must ensure that all Princeton alumni are prepared to actively participate in decision-making processes," said James Wei, dean of the School of Engineering and Applied Science.

"New courses will help A.B. students better understand the importance and relevance of technology in their lives and seek to equip these students to prosper in an increasingly technological world," he said.

About 40 percent of liberal arts majors take one or more courses in the engineering school. Dean Wei wants to see that percentage increase.

"We need to find courses that the liberal arts students will find useful to their own careers and to their own understanding," he added. "This effort is central to our mission to educate new leaders in a global and technological society."

Six courses developed with that objective in mind are spotlighted on the following seven pages.



Wireless Revolution

An ancient communications idea catches fire

by Ann Haver-Allen

If giving advice today, Horace Greeley might say, "go wireless, young man, go wireless." Wireless communication is an ancient concept--Native Americans used smoke signals long before the first radio signals were broadcast. But wireless communications, as the term is used today, is actually somewhat of a misnomer.

Vincent Poor, professor of electrical engineering, teaches The Wireless Revolution. Photo by Frank Wojciechowski

Although it refers to communication by radio, and therefore, by wireless, a significant wire line infrastructure is required to make wireless work. Extensive wire line networks throughout the world make wireless communications possible. However, a key feature of wireless technology is that it affords mobility in communications.

Telecommunications and computer technology have grown at explosive rates over the last 20 years. Add to that the fact that during the past five years Internet use has skyrocketed. Wireless technology is key to the continued explosive growth of these technologies.

The statistics are daunting. The PC industry sells about 100 million PCs a year; the cell phone industry sells about 400 million phones a year. Industry experts expect sales of cell phones to top one billion in five years.

Every 2.25 seconds a new subscriber signs up for cellular service in the United States. Current estimates of the potential of wireless data industry range as high as $37.5 billion in revenues for the year 2002 for Internet applications alone. All this growth, and five out of six people in the world have never used a phone.

So what does this mean, and what implications will this have for industry, government, and society? Professor of Electrical Engineering H. Vincent Poor *77 designed ELE 391: The Wireless Revolution: Telecommunications for the 21st Century to explore some of those issues.

"I actually got the idea for this course from my interactions with students in Professor Ed Zschau's course ELE491: High-Tech Entrepreneurship," Professor Poor said. "Students in this course frequently come to me for information on my research in wireless communications in connection with various assignments in which they are asked to identify promising technologies for commercial development. These students come from all across campus, and in talking with them I realized that there was widespread general interest in this subject. I decided to put together a course tailored to a general audience of both engineers and nonengineers, my hope being to give students an understanding of the scope and importance of the field."

ELE 391 is an interdisciplinary course addressing technological, regulatory, economic, and social issues arising in the rapidly developing field of wireless communications. The course is intended to introduce students to a major technological trend that will be a significant force in worldwide commercial and social development throughout this century.

"I hope the students will understand several things," Professor Poor said. "First, with regard to wireless communications in particular, I want the students to realize that they are living in the midst of a major technological revolution, somewhat similar to the first wireless revolution of the Marconi era. The history of telecommunications is that the telegraph, telephone, and entertainment media have all gone from geographically bound delivery systems to wireless systems, with the advent of wireless telegraphy, radio, television, and mobile telephony.

Now this is happening with the most significant telecommunications medium of our time -- namely, the Internet." He added that wireless communications has many dimensions -- technical, economic, social, and political.

"I hope my students will gain an appreciation of all of these factors," he said. "A second motivation is to induce students to think about all technologies in the greater context of their effects on society, and vice versa. In this context, wireless communications serves as a paradigm for technology in general.

"For engineering students, thinking this way means realizing that technology development is highly dependent on social and economic factors, and for students in other disciplines it means realizing that technology is a major factor in shaping societies and in the success or failure of economies."

Of the 183 undergraduates who enrolled in ELE 391, 63 percent were A.B. students, representing majors such as economics, politics, religion, art, art history, psychology, philosophy, and history.



Space stations

From the pages of literature to reality

by Ann Haver-Allen

On Election Day 2000, Jerry Grey welcomed students to MAE 399: Space Science and Technology by stating that he hoped everyone not in attendance was out voting.

Space Science and Technology was designed to provide humanities students with an understanding of space science and technology and its implications to society at large. Space stations were the topic for this election day.

"Space stations are a really old concept," Professor Grey said. "The first sign of a real space station in literature appeared in 1869 when Edward Everett Hale wrote a story in the Atlantic Monthly called "Brick Moon." But the space station really came to life with Hermann Oberth, who wrote a book while in his twenties about a space station. In this book, he kind of projected everything we know about space stations today. This was 75 years ago. Long before we had space flight."

Pictured above is a computer-generated illustration of the TransHab Module design installed on the International Space Station. NASA image

Douglas Aircraft designed the first actual space station. Douglas is today part of the Boeing Co. The London Daily Mail held a contest to design "a home in space," and Douglas produced a 17-foot, 4-person station that was actually the progenitor of today's space station.

Skylab, launched by the United States in 1973, was the first real space station. It was successful beyond expectations.

"Crews were able to conduct long-term microgravity experiments and long-term research on antigravity effects," Professor Grey said. "The foundations of microgravity science was created in the Skylab space station. All the physical and chemical studies that we are now doing in great detail, all the biological and biomedical studies, these all began on Skylab."

Professor Grey said scientists also learned more about the sun than had ever been known before in human history.

"We were able to study the sun in so much greater detail than ever before," he said. "Previous studies of the sun had all been done by unmanned space craft and sounding rockets. So these studies were phenomenal. They laid the basis for much of the solar physics that we work on today."

The space station creates a microgravity environment--gravity terms are subtracted terms from all equations. When gravity is absent, things behave differently, and you can study what's going on in a much more detailed way.

"Gravity tends to mask a lot of things," Professor Grey said. "For example, in liquid mixtures, gravity causes heavier liquids to settle and lighter liquids to go to the top. When you take gravity away, sedimentation and convection disappear. Therefore, you can study much more delicate forces, things we could never study before because they were masked by the forces of gravity."

Microgravity research offers the first major change in physical, chemical, and biological environments that has occurred since people were first placed on Earth. The space station, therefore, is extremely important.

Professor Grey said the primary purpose of a space station is to teach us how to operate in space so that humans will be able to venture confidently out beyond Earth's orbit, to Mars and beyond.

"A space station is to human space exploration and development what a wind tunnel is to aircraft development," he said. "We have learned from past experience with the Russian Mir and with several recoveries of errant satellites that there is no viable alternative to in-space experience. Ground simulations are a good aid to help guide actual space experiments, but are not adequate in themselves."

Professor Grey is director of the Aerospace and Science Policy for the American Institute of Aeronautics and Astronautics, editor-at-large for Aerospace America, a member of the Science Counsel of the NASA Institute for Advanced Concepts, and consultant to a number of government and commercial organizations.

He was previously on the faculty in the Department of Mechanical and Aerospace Engineering for 17 years, where he taught courses in fluid dynamics, jet and rocket propulsion, and nuclear power plants.

In the fall semester there were 169 students registered for MAE 399. Of these, one was an MAE student, five were from other engineering disciplines, 22 were science majors, and 141 majored in the humanities.



Computer savvy

Course introduces technology to nonprogrammers

by Ann Haver-Allen

Brian Kernighan *69, professor in the Department of Computer Science, said that when he first began using computers more than 30 years ago the programming was difficult and the machines were harder to use than they should have been. Although much has changed in the ensuing three decades, programming is still difficult and machines are still too hard to use, he said.

But computers are part of our everyday life and Professor Kernighan designed COS 109: Computers in Our World to introduce humanities and social science students to how computing works and how it affects the world in which we live.

"It's for people who don't expect to be doing computing in any technical field but want to know what it's all about," Professor Kernighan said. "Even though most people won't be directly involved with programming, everyone is affected by computers, so an educated person should have a good understanding of how computer hardware, software, and networks operate."

Brian Kernigan, professor of computer science, teaches Computers in Our World. Photo by Frank Wojciechowski

Class topics were motivated by current issues and events and included discussions on how computers work, what programming is and why it's hard; how the Internet and the Web operate; usability, reliability, security, and privacy issues.

"Napster was a great case study this year: everyone uses it, and it is based on everything we talked about in the class," Professor Kernighan said. "On the technical side, that includes hardware, software, networking, analog and digital representation of information, how music is compressed, and the like. And on the "societal" front, who owns the music that Napster makes accessible? How do property rights work, and can they be enforced in the face of new technology? How might Napster reliably identify copyrighted songs?"

This introductory course required no prerequisites, no math background, and no prior experience with computers.

"It's important to be informed about issues like usability, reliability, security, privacy, and some of the inherent limitations of computers," Professor Kernighan said.

Students were required to construct their own home pages and to add to them throughout the semester using practical applications, including graphics and digital sound. An additional component of the course was a" gentle introduction to programming" in Visual Basic.

Forty-five students--all A.B.'s--took the course.

"My survey at the beginning indicated that the potential majors of students matched the campus as a whole: economics, history, politics, and English were most frequently cited," Professor Kernighan said. "The class was about two thirds women, and (perhaps because it was announced late) about two thirds freshmen."

Professor Kernighan said that teaching this class is "amazing fun. I really enjoy it, and the class is small enough that there's a chance to get to know everyone."

Professor Kernighan joined the Princeton faculty last fall after more than 30 years with Bell Laboratories. He previously taught computer science courses at Stevens Institute of Technology and Harvard University and was a visiting professor here in 1999-2000.

Detectives of deterioration

These sleuths work to spot and diagnose causes of erosion in stone buildings and monuments

by Steve Schultz

George Scherer, professor of civil and environmental engineering, does not see the Princeton campus as others do. Among the meticulously maintained buildings and the treasured stone carvings, Professor Scherer's eyes seek out the problems, the flaking stone here, the eroded inscription there.

"This is a lovely example of salt deterioration," he said as he led a group of undergraduates past Firestone Library during a tour of campus.

His enthusiasm for spotting and diagnosing problems is infectious, and is at the heart of a new teaching and research program he is developing. After spending most of his career as a materials scientist at Dupont and Corning research labs, Professor Scherer came to Princeton in 1996 and turned his expertise to the conservation of art, with a specialty in stone buildings and monuments.

George Scherer, professor of civil and environmental engineering, supervises a lab experiment. Photo by Denise Applewhite

His research program already is producing insights into the ways stones deteriorate as well as into materials that soak into stones to prevent and repair some types of damage. One such material developed by Professor Scherer may soon be tested on crumbling walls around the ancient Greek city of Rhodes.

Professor Scherer has introduced a new course on conservation of art. Although it is a lab-based course in materials science, the class is geared toward nonscience majors. The fall course was popular, with all 36 slots filled. All but one student (a computer science major) were A.B.'s

For both his teaching and research, the Princeton campus, with its rich variety of stonework, is the perfect laboratory. Professor Scherer works closely with staff in the facilities department to develop strategies for protecting and repairing buildings.

His campus tour was a lab session of his art conservation class, and an opportunity for him to introduce his students to some of the subtle and not-so-subtle ways that seemingly impervious stone can succumb to the elements.

Stopping to look at a monument between the Chapel and McCosh Hall, Professor Scherer pointed out that frost and acid rain had worn nearly all the inscriptions from the 80-year-old obelisk. In the courtyard between the Pyne Hall archways, he noted a single carved medallion that was almost completely obliterated while those next to it were unharmed, the result, he believes, of the peculiar way rainwater runs down that wall.

Students in George Scherer's lab test the ability of different stones to absorb water. Photo by Denise Applewhite

His conclusion was not just idle speculation. "I stood here in the rain one day and watched where the water was running," he said, "which is something you do quite a bit in this business."

Each stop on his tour was its own small mystery, with Professor Scherer nudging the students to make deductions about the evidence before them, like Sherlock Holmes to a class of Dr. Watsons.

Professor Scherer's emphasis on sleuthing out true causes and effects of damage is central to his research and his teaching.

"If you want to make a proper repair, first you need a good diagnosis," he told the class. "Just as in medicine, you need to diagnose the problem before you treat it."

Unfortunately, he noted, there is too little of this kind of analysis in the conservation business. His research program is unique in that he is focused on studying the underlying principles of stone conservation, rather than developing immediate solutions to pressing problems.

Traditional funders of science, such as the National Science Foundation, have almost no grant opportunities for basic research in art conservation, Professor Scherer said. As a result, conservation scientists often have to use ideas and techniques handed down over generations, rather than developing solutions based on rigorous analysis. And any time or money that might be spent on basic research is often pressed into service to solve immediate problems.

"There's a lot of Band-Aid work in this field," agreed George Wheeler, a research chemist at the Metropolitan Museum of Art. "George's research is really quite high level and cutting-edge. He is taking a fresh look at some fundamental problems we've had for a long time."

Professor Scherer credits Dr. Wheeler with sparking his interest in the field 15 years ago when the two met at a scientific conference. Professor Scherer was studying inorganic gels that have a wide variety of potential applications from optoelectronics to transparent thermal insulation.

Dr. Wheeler was interested in the same materials for a use Professor Scherer had never heard of--protecting porous stones from damage by salt crystals. After keeping up an association over the years, Professor Scherer has now used similar materials to develop the protective products that he hopes to test in Greece.

Saltwater damages stone when it seeps into the pores, then dries and leaves crystals, Professor Scherer said. As the crystals grow, they develop an electrostatic repulsion with the stone around them, and this repulsion exerts pressure that can break the stone. The material Professor Scherer developed coats the insides of the pores and makes it compatible with salt, so the crystals fill up the space and stop growing.

Using samples of limestone, Professor Scherer and students in his lab compared the effects of salt on treated and untreated stones. After six cycles of soaking and drying, the untreated stone was badly damaged, but the treated one was mostly unharmed.

Another material, which Professor Scherer is testing on samples sent to him by Greek conservationists who are working on the ancient wall of Rhodes, would strengthen already damaged stone.

The Greek conservators are "very interested in having some of our materials to paint on the wall," Professor Scherer said. "We're just very conservative. We want to make sure we've done it right."

One challenge, he said, is to make sure that the proposed solution does not do more harm than good. "You always worry about doing something subtle, but pathological, that may show up 10 years down the road," he said. One way to avoid such problems would be to simulate the repair and subsequent aging process in the laboratory. But there are no clear methods for accelerating 10 or 100 years of aging.

Such questions underscore the need for basic research in the field, he said. Professor Scherer credits Princeton with giving him the freedom to pursue such work, and is looking for creative ways to fund it. He has hired one postdoctoral scholar, Robert Flatt, who developed an expertise in ancient mortars at the Ecole Polytechnique of Lausanne, Switzerland. The rest of his research help comes from undergraduates, who have helped test and develop the new materials for senior theses and summer work projects.

So far that arrangement has worked well, because the students have been enthusiastic about experimenting with real stones from antiquity. In one project last semester, students from his class helped conservators at the University Art Museum to catalog ancient Egyptian stones that recently began to deteriorate rapidly and lose their hieroglyphics. Professor Scherer, meanwhile, will try to decipher the cause of the damage.

This interplay between research and teaching opportunities is ideal, Professor Scherer said. "These are beautiful problems in materials science, and it seems to me to be a perfect vehicle for teaching undergraduates about the field."


The engineering of cities

Students learn what makes cities work

by Ann Haver-Allen

On a blustery afternoon last October, 14 students piled into a van for a field trip to the Stony Brook Regional Sewerage Authority. No one complained about the weather; in fact, everyone commented that at least it wasn't raining like it had on previous outings. Everyone did make a fuss about the smell, however, as Stony Brook engineer John Kantorek led the group through the facility.

Professor Sigurd Wagner in the mechanical room of Princeton University's DeNunzio swimming pool. Photo by Frank Wojciechowski

This field trip was part of FRS 111: How Cities Work. Developed by Sigurd Wag-ner, professor in the Department of Electrical Engineering, this freshman seminar introduced students to the infrastructure that makes cities work.

"I want to use for instruction the vast infrastructure of the campus and the knowledge of its managers," Professor Wagner said. "I want to open freshmen's eyes to the breadth of the infrastructure of a city and the expertise that is needed to run it."

Throughout the course, students examined how cities supply water, electricity, heat, information, and security for its inhabitants. Each lesson centered on one city service. Princeton University was used as the model city. Students studied the underlying scientific and engineering principles at work and then visited each facility for a firsthand view of its operations.

"This course was excellent," said Nicholas Hobson '04. "It was interesting, informative, and covered many aspects of how a city is organized. Since all the organizations we visited were related to the campus, they applied to the students' lives. This made us more interested in how the functions worked and their importance to us."

Beth Gordon '04 said the course was comprehensive and kept students interested.

"I learned new things regarding energy and waste treatment; the things that go into city planning that one would often overlook," Beth said. "These seemingly external influences are actually integral parts of the engineering and design of cities, towns, and all inhabited areas."

At Stony Brook students learned that 10 million gallons of sewage is processed daily. The facility cleans the wastewater using biological processes and organisms do most of the recycling work. Mr. Kantorek told the group that more than 99 percent of the waste is removed from the effluent.

In addition to visiting the Stony Brook sewer plant, the students also visited the Elizabethtown Water Company's plant, as well as Princeton University's DeNunzio swimming pool's mechanical room, the chilled water plant, the central control room for the campus HVAC systems, the cogeneration plant, and the main campus telephone switching system.

Professor Wagner said the course was a success, and he plans to offer it again in the fall. One student, he said, had a roommate who asked every Tuesday night to hear about the class' excursion of that afternoon.

"Although I am not an engineer and do not have a background in science and technology, this course gave me a very good understanding of the basic organizations involved in the working of a city," Nick said. "And I got to know a great bunch of freshmen during my first semester at Princeton."


Students learn that developing new drugs is a multidisciplinary process spanning years

by Ann Haver-Allen

ChE 420: Life Science Industries in the 21st Century: Chemistry, Physics, Infomatics, and Economics introduces students to the multidisciplinary team efforts needed to succeed in the life sciences industry today.

Stephen W. Drew, who has worked in the life sciences field for more than 34 years, taught the class that was created by the Department of Chemical Engineering.

"Engineering, and particularly the life science industries, are changing at an awesome pace," said Dr. Drew, who holds a Ph.D. in biochemical engineering from Massachusetts Institute of Technology. "The focus on molecular mechanisms in disease and in the design and synthesis of new medicines has greatly increased our ability to combat infection and metabolic disease. Tomorrow's medicine will be quite different than today's, and the thinking processes needed to generate it are evolving across disciplines in both academe and industry."

Stephen Drew teaches Life Science Industries in the 21st Century: Chemistry, Physics, Infomatics, and Economics. E-Quad Photo by Frank Wojciechowski

Dr. Drew said it was his goal to share some of those trends with the students at a time when they are forming their own plans for careers.

About half the students in ChE 420 were chemical engineering majors. The other half represented economics, chemistry, molecular biology, electrical engineering, and operations research and financial engineering. Two graduate students and one freshman rounded out the class roster.

Visiting lectures by industry professionals were an integral part of the course. Joye L. Bramble, senior director, project planning management at Merck & Co., explained the complex team structure that is needed in drug development.

"Compound development is a very complex process that takes an average of half a billion dollars to discover and develop one compound, and it takes an average of 12 to 15 years," Dr. Bramble said. "Image you are working in teams for 12 to 15 years to get a compound out the door." She added that the pharmaceutical industry was among the first to recognize the importance of teams and project management. It's vital to develop team skills.

Students were charged with creating virtual companies that evaluated and developed new products and services in the pharmaceutical, biotechnological, agricultural, or medical sectors. This course emphasized the team approach to research and leadership. Students were required to:

* Define terms from cellular and molecular biology, medicine, and engineering.

* Describe electrical, chemical, and mechanical signals that emanate from living cells and whole organisms.

* Describe interactions in metabolism that achieve complex tissue function.

* Describe information technology in the discovery and development of new drugs.

* Describe the processes of bringing a new product to the marketplace.

* Create a business plan to evaluate and develop products in the life sciences.

* Identify and discuss ethical issues in discovery, development, manufacturing, and marketing in the life science industries.

* Search the scientific and business literature; retrieve specific information.

* Ask probing questions about science and tech nology in the life science industries.

The semester culminated with the students forming teams to present their findings. Each team member assumed the role of a key player in the decision process.

"I enjoyed the course and hope that it met the students' needs," Dr. Drew said. "I certainly learned a great deal from my interaction with the students -- they are a marvelously talented group and represented their many disciplines quite well." He plans to offer the course again in spring 2002.