Engineering as Liberal art


Dividing lines between disciplines diminish

It is becoming as important for liberal arts students to be technologically capable and computer savvy as it is for engineers to be knowledgeable of economics and politics.

A well-rounded education increasingly must embrace both technical and liberal arts components. The divisions between disciplines continue to blur as the world becomes smaller and smaller.

The School of Engineering and Applied Science (SEAS) has historically required all B.S.E. students to take humanities courses to ensure a well-rounded education. The SEAS is now increasing its effort to introduce liberal arts students to the basics of engineering. Faculty members are offering many courses--and creating others--to reach out to liberal arts students.

"One of the central themes of the School of Engineering here at Princeton is what we have come to say in the simple phrase 'engineering as liberal art,'" said Richard Golden *54, associate dean of operations and research. "We see engineering at Princeton as not being trade training, but part of the liberal education of all young men and women."

A sampling of the innovative and creative courses being offered--and being planned--is presented on the following pages.

Course studies bicycle, other human-powered vehicles

Which machine is more efficient: a human or an internal combustion engine? The answer may surprise you. Mechanical efficiencies of participants in a cycling marathon are estimated between 17 and 20 percent. For a typical car, efficiencies are on the order of 15 to 20 percent.

Measuring efficiency In the class Human Powered Vehicles, students will use a bicycle ergometer to measure the work done by a cyclist in an upright position under different load conditions Photo by Denise Applewhite

Of course, many variables are included in the human equation, such as age, gender, and general physical condition. The power output capability for adult men is about 20 percent greater than that of adult women. The peak capability of both genders occurs between 20 and 35 years of age.

If this information intrigues you, a new course in the Mechanical and Aerospace Engineering Department to be offered this fall may be just the course for you.

Human Powered Vehicles, developed by Professor Barrie Royce, will explore the human being as a power source and look at ways in which this limited resource can be applied to land, water, and air vehicles.

The course is designed to introduce first-year students to quantitative and experimental exploration of this engineering topic. Some of the engineering concepts needed to design and understand the functioning of human-powered vehicles will be examined. The laboratory satisfies the University's science and technology distribution requirement.

"The vehicles will be treated as engineering systems, and their historical development, energy paths, structural and materials options, and infrastructural needs will be discussed," Professor Royce said. "In the laboratory, students will study these topics experimentally to quantitatively evaluate postulates about the importance of competing design options."

The laboratory experience will culminate in a student-designed, open-ended, independent work experiment carried out over a two- to three-week period.

Students will discover, for instance, that very little work is lost in the mechanical components of the bicycle. At 7 m/s, 86 percent of the energy expended by a cyclist is used to overcome the air resistance. For a skater at the same speed, the same air resistance only accounts for about 57 percent of the total energy used--the additional energy being needed because skating is less efficient.

"A bicycle should not be thought of as a stand-alone device, but as part of a system--the machine and the rider," Professor Royce said. "The performance of the rider as a power source is an essential constituent of the engineering design of the bicycle and influences decisions about weight, structural materials, tire design, and aerodynamics."

In the laboratory, students will measure their performance efficiencies by using various instruments. A bicycle ergometer will measure the work done by a cyclist in an upright position under different load conditions. A prone bicycle ergometer will be used to evaluate the merits of this cycling position. A rowing ergometer will be used to evaluate leg plus arm and back work output, which will then be compared to the cycling data.

In addition to the bicycle, students will study boats, hot-air balloons, and airplanes that are human-powered.

"All human-powered vehicles have to contend with the relatively low-power output capability of people," Professor Royce said. "Everyone can relate to the bicycle, but I want to show that boats and airplanes also can be powered by humans and put all this into a social and historical context."

The historical development of machines is tracked along with the engineering advances made. For example, natural waterways initially provided transportation routes, but the construction of canals to augment them started early in recorded history. The peak of canal transportation in the United States occurred at the time the railroad was being developed. The greater speed and flexibility of the railroad has largely replaced the canal as an inland transportation mode. The Interstate Highway system and road transport is now undermining the railroad system.

"The emphasis will be on a hands-on cooperative learning experience where a number of open-ended problems will be posed," Professor Royce said. "It is an issue of discovering answers to questions that you have proposed yourself."

Teaching computer science

using the precept format

Gustav Mahler's (1869-1911) first symphony was softly playing in the background as students began to take their seats in preparation for the morning's class. But this wasn't an art class, and it wasn't a music class. It was Computer Science 111: Computers and Computing, taught by Professor Douglas Clark.

The class cannot accurately be called a lecture; instead, it is more like a large seminar or precept. Professor Clark believes that students learn best by engaging the material directly in discussion with other students and himself. Students are expected to contribute to the process of discussion by making connections with other students' remarks, raising overlooked issues, asking questions, and making summaries.

"My course uses a discussion, not lecture, format," Professor Clark said.

"Did you notice how many students spoke? It was almost all of them. This aspect of my course is what makes it different from many science and engineering courses."

Professor Douglas Clark leads students from CS 111 in discussion. Photo by Denise Applewhite

CS 111 is intended for students from the humanities and social sciences who want a one-course introduction to computers and have little or no computer experience. The course, which has no math or programming prerequisites, is a broad introduction to computer science, including topics from hardware design, algorithms, data structures, and theory.

This particular morning students were learning the differences between sequential and binary searches. Motivated by a Dilbert cartoon, Professor Clark proposes that a certain company has grown enormously and a searchable "reverse" phone directory is needed.

The company wants the directory to list both names and extensions for employees. The information has to be available rapidly to identify incoming callers. How can such a problem be solved?

He coaxes the class into tackling the problem by first putting the challenge into words, which they do: When you need to find a number in a sorted list, it makes sense to start looking in the middle and cut the list in half each time you look at it, or probe it.

That observation leads to the creation of an algorithm, developed and refined by the class, designed to locate a phone number on demand. The resulting algorithm is a series of commands that tells the computer what to do. This is computer programming at its most basic level. The alternative method, a sequential search, has limitations, the class discovered. A binary search, which uses the cut-in-half trick, is much more efficient.

To illustrate, Professor Clark asks how big the list could be if you searched it using, on average, no more than 30 probes. The answer: the list could contain 60 elements if a sequential search is used, or about a billion elements if a binary search is used.

"The sequential/binary business is a very simple and powerful example of a branch of computer science called analysis of algorithms," Professor Clark said. "For some problems there may exist several different algorithms, and by analyzing how efficient they are we can figure out which one is best. The example we did in class is nearly trivial compared with the analyses that actual algorithmic researchers do, but it gives students a feeling for this important strand of work in computer science. Later in the course they will have the harder challenge of analyzing different sorting algorithms."

Students enrolled in the course represent a cross-section of Princeton's student body. Shawneequa Callier '00 is a politics major; Peter Helm '01 is a history major; Patrick Hong '99 is an economics major; Tanya Tivorsak '01 is an ecology and evolutionary biology major; and Tee White '99 is an anthropology major.

"Understanding computers has become a valuable skill for work, study, and leisure to the extent that neglecting computer literacy could be detrimental to one's overall development," Patrick said. "Computer literacy begins with a thorough grasp of general concepts covered in COS 111 that help lay the foundation for a better understanding of the actual machines and the way in which they function."

Patrick said he had not anticipated that he would "enjoy" the class, but that the content and the methodology of the course have combined to make it "one of the most enjoyable courses."

Shawneequa said she took CS 111 to become more well-rounded academically. She said her favorite part of the course is the labs.

"I love web page design, and I wanted to learn the basics," she said. "The professor is great, and he really tries to make things interesting." Shawneequa added that while basic computer knowledge is essential, she believes that the "more you know, the further you'll go."

Professor Clark said it is important to offer classes such as this to encourage students studying the humanities and social sciences to broaden their education.

"Just as the SEAS requires that engineering students encounter some Shakespeare or philosophy or music while they're at Princeton, we wish to give nonengineers opportunities to explore important areas outside their major interest," he said. "Certainly computer science is one such area."

Building blocks

Understanding basics of environmental problems

The environment is one of those topics on which everyone has an opinion. As people become more aware of the environmental damage caused by modern industrial society, the debates heat up. Discussions are frequently emotional, with a noticeable absence of scientific data and quantitative reasoning.

Richard Golden *54, associate dean of operations and research for the SEAS, is trying to change that. He is teaching FRS 114: Sustainable Development and the Environment. The course objective is to help students build a basic understanding of the science, technology, and economics of

Richard Golden How it works Some 30 percent of incoming solar energy is reflected (left) in the atmosphere; the remaining 70 percent is absorbed. The absorbed energy is reemitted at infrared wavelengths by the atmosphere (which is also heated by updrafts and cloud formation) and by the surface. Because most of the surface radiation is trapped as greenhouse gases and returned to the earth, the surface is currently about 33 degrees Celsius warmer than it would be without the trapping.

environmental problems so that they can think and act in a more informed and quantitative way.

"We broadly cover energy and its sources, its uses, and the environmental impact that the various sources of energy have on the environment," Dean Golden said. "We discuss the ozone layer problem, pesticides, and artificial fertilizers. We also consider the environmental economics, and how economic instruments instead of legislation may be used to control environmental damage."

Global climate change was the seminar topic on a recent cold, snowy afternoon in March. Global warming, or the greenhouse effect, is a phenomenon attributed partly to the increasing levels of carbon dioxide being pumped into the atmosphere when fossil fuels are consumed.

It works like this: Light reaches the earth's surface, warms it, and the earth radiates infrared rays back into the atmosphere. But the infrared rays are trapped by the carbon dioxide and other "greenhouse gases." A portion of the radiated heat is emitted back to the Earth, causing it to be warmer than it would if the heat radiated freely back into space (see illustration).

The Conservation Law Foundation, headed by Douglas I. Foy '69, labels automobiles as the biggest environmental offenders, accounting for one third of the world's air pollution. The United States represents 5 percent of the world's population, but it owns one third of the world's cars. One half of all the driving in the world is done in America. And the situation is worsening.

Automobile manufacturers have found a new cash cow, and it's called the Sports Utility Vehicle, or SUV. These vehicles are exempt from emissions regulations that pertain to cars because they are not classified as cars. Skirting the environmental laws has been a profitable venture for the automobile manufacturers, which make their highest profit margin on SUVs.

These issues were discussed and debated by the class as they sought ways to address the problem. Public education is an important component; the public needs to know that using alternative energy sources is better for the public good. Translating the effects of pollution into economic terms is another key point. People need to see in dollars and cents how pollution is hurting society.

"Any efforts to switch from fossil fuels have to start with industry," one student said. "It has to become more profitable for industry to produce alternative energies. You have to start at the top. You can't start at the bottom with grass-roots movements."

The class proposed using the economic power that the United States wields as a public relations tool. Power appeals to people. Tell people that being the first to adopt alternative fuels will make the country even stronger economically. Those who take the lead always benefit the most financially.

Dean Golden told the class that that argument is similar to the "national pride" argument used by President John F. Kennedy to enter into the space race with Russia.

"He went on TV and said we need to beef up the space program because we have to beat the Russians," Dean Golden said. "He gave no economic reasoning--he just proposed beating the Russians."

But what country could be the competitor this time? All agreed that nothing is on par with Russia and the space race.

As the discussion grew to a close, the class reached the consensus that scientists must take more of a leadership role and clearly define global warming and fossil fuel depletion as real problems that must be addressed sooner rather than later. The class then moved on to discuss another serious environmental problem: the ozone hole.

A movement catches on

No forum on the topic of teaching technical issues to liberal arts students can be complete without including David P. Billington '50, the Gordon Y.S. Wu Professor of Engineering in the Civil Engineering and Operations Research Department. Professor Billington, a pioneer of this teaching movement,

Building bridges to liberal arts Professor David Billington, right, is a pioneer of the movement to span the gap between engineering and liberal arts. Photo by Richard Frank

created two courses that span the gap between engineering and liberal arts. The first course, CIV 102: Engineering in the Modern World, is taught in an historic time line beginning with the steamboat, moving to textile mills, railroads, the electrical industry, oil industry, automobile industry, and aircraft industry. Michael Littman, professor in the Mechanical and Aerospace Engineering Department, has joined forces with Professor Billington to strengthen the course by introducing new multimedia resources via the Internet. "This course talks about the scientific, social, and symbolic aspects of engineering as it relates to technological innovations," Professor Littman said. "In this course, we try to define engineering. It's tough. It's kind of like trying to define art. We use the definition that art is that which you put in an art museum. So engineering is defined through it's objects and systems." Engineering objects are scrutinized from three different perspectives. The scientific level is first. How does it work, and what are the engineering principals involved? The social context is next. What are the political ramifications of the object? Lastly, the object is viewed from an artistic point of view. How does it contribute to or change society? "All too often mathematics, science, and technology are treated as worlds unto themselves," Professor Billington said. "Instruction is typically by abstract example on a blackboard or computer screen. There is no sense imparted of the social and aesthetic consequences of an equation, or of the individuals who struggled against great difficulties to transform that equation into a steamboat, an automobile, an airplane, or a computer." Professor Billington's second course is CIV 262: Structures and the Urban Environment. This course addresses the technology, art, and social factors involved in the planning, design, and construction of the large-scale buildings and bridges essential to the public life of modern cities. An historical perspective provides a basis for criticism of contemporary public works related to transportation, water supply, and public buildings. "We are not trapped between two cultures, the culture of science and engineering on the one hand and the culture of the social sciences and humanities on the other," Professor Billington said. "We can connect the two cultures by teaching the great works of technology in the same way that art historians teach the great works in the history of art."

Engineering contributions

Without engineers, life would be dry

You might think that James Wei, dean of the School of Engineering and Applied Science, would be a fish out of water on the liberal arts side of campus. But you would be wrong. Dean Wei is equally comfortable on either side of campus and he is doing his best to try and eliminate that perceived dividing line between engineering and the humanities.

Roman engineering art In this photo illustration, Dean James Wei stands in front of the Pont du Gard in Nimes, France. The Pont du Gard is one of the most impressive monuments to Roman engineering that still survives today. Photo illustration by Denise Applewhite

Dean Wei, who studied fine arts at Harvard University while earning his master's degree and Sc.D. in chemical engineering from Massachusetts Institute of Technology, is teaching FRS 156: Great Inventions That Changed the World.

"This course examines a number of great inventions in 20th-century chemical technology," Dean Wei said. "We study problems of society that range from making water safe to drink to making piano keys without elephants."

All topics are discussed in terms of the inventors, the engineering methods and reasoning they employed, and the methods used to collect and analyze the data that led to the new invention. Each session is concluded with a discussion on how these inventions have impacted the world and changed the lives of millions of people.

"In some sense, if an invention doesn't change the world, then it's not really a great invention," Dean Wei told his students, as he introduced them to hydrology.

"Hydrologics is the first branch of engineering to develop," he said. Water is an essential commodity for survival, and man began thousands of years ago trying to control water flow.

The ancient Romans mastered hydrology by building aqueducts. The Pont du Gard, which brought water to the city of Nimes, France, from a spring more than 50-kilometers away, is the impressive monument to Roman engineering that still survives today.

The Pont du Gard used simple gravitational flow to deliver its water and was engineered with a very gradual drop--the difference in height over the entire length is only 17 meters. While most of the aqueduct was actually subterranean, it bridges the river Gard about 21 kilometers northeast of Nimes.

But getting water to a city is not good enough. It needs to be clean water. Dirty water carries many deadly bacteria, including typhoid, cholera, and dysentery. Dean Wei told his class that Prince Albert, husband of Queen Victoria, died in 1861 of typhoid he contracted by drinking the water in Windsor Castle.

In 1833 Ralph Waldo Emerson wrote that cholera killed 5 to 15 percent of the U.S. population. It wasn't until 1940 that water filtration, chlorination, and sewage treatment had stopped most of the aquatic killers in this country.

While most people living in the United States take clean water for granted, water in third world countries is still not safe. Human wastes without sewage treatment kills more people than nuclear wastes, Dean Wei said.

He challenged the class to pretend they were on a Peace Corps mission to design and build a clean drinking water system. How would they propose providing clean water to a village, and how would they build the system?

If they chose to clean water the natural way by using a settling pond, how would they determine how wide and how shallow it should be? If they chose to filter the water through sand, how would they determine the size of the sand grain and how to get the water to flow through it? If they chose to sterilize the water with chlorine, from where would they get the chlorine and how much would be needed?

"We emphasize quantitative reasoning," Dean Wei said. "How do we acquire and analyze data? How do we suggest possible solutions? And how do we use construction and testing to confirm our solutions?"

Optimization by any other name

Engineering professor translates secrets of decision making for 'petrified masses'

David Bernstein, assistant professor in the Civil Engineering and Operations Research Department, teaches an introductory course in statistics and operations research. But that's not what the course is called. The course, CIV 105, is called The Science and Technolo gy of Decision Making.

Decisions, decisions, decisions What to pack may be among the most difficult decisions in life. David Bernstein's CIV 105 class can help you narrow the options and pack efficiently for any upcoming adventure. Photo illustration by Denise Applewhite

"You make decisions every day," Professor Bernstein said. "In addition, other people are constantly making decisions that have an impact on you. In this course we consider both how these decisions are made and how they should be made. In particular, we focus on the use of computing and information technology in the decision-making process."

Professor Bernstein said CIV 105 is designed to teach quantitative reasoning courses to "the petrified masses." Topics covered include convex optimization, optimization problems when the decision variables are integers, optimization problems on a network, equilibrium problems, fixed point theory, probability theory, and stochastic processes.

Lecture topics as listed in the syllabus sound nonthreatening to students who are unreasonably scared of quantitative reasoning courses, Professor Bernstein said. For example, complexity theory becomes: How to pack a suitcase. The introductory paragraph reads:

You're packing for a trip, you don't want your backpack to be too heavy, there's no point in packing the peanut butter if you can't also pack the jelly...What should you do?

"We talk about how this relates to the problems that Federal Express has to solve every day about which packages to put on which planes," Professor Bernstein said.

Other topics include: Why is there a Burger King™next to every McDonalds™? and Why is Yogi so smart? A consistently favorite topic is: Why are there too few green M&Ms®?

"I am convinced that there are too few green M&Ms® in a bag," Professor Bernstein said. "They don't put the right number of greens in the bag. There at 54 M&Ms®; there are six colors. There should be nine greens. There aren't."

But he doesn't expect the class to just take his word for it. Everyone receives a bag of M&Ms®. They open their bags and separate the M&Ms® by color. The collective data is posted on the web, so that when the class does hypothesis testing, they use the actual data they collected in class.

"The examples we consider are taken from everyday life," he said. "We then consider the broader implications of these examples."

CIV 105, which satisfies the University's quantitative reasoning requirement, is offered in the fall. Each year about 60 students "stick it out to the bitter end."

They include art majors, architecture majors, and English majors. And, he added, there are always a few engineering students who take the class thinking it'll be an easy ride.

"This year the top grade on the final was a young woman who was majoring in the English Department," Professor Bernstein said. "All semester I had several engineering and astrophysics students who acted so cocky. In the end, this young woman showed them all. I couldn't have been more pleased."

The Science and Technology of Decision-Making can be found on the web at: http://www.princeton.edu/~civ105/.

Some engineering treats are tastier than others

Chemical Engineering Professor T. Kyle Vanderlick said the essence of engineering can be served up in two words: ice cream. She is developing a new course that uses ice cream as the story line to introduce students to the basic foundations of engineering analysis.

Field trip Chemical Engineering Professor T. Kyle Vanderlick is on a fact-finding mission at Thomas Sweets in downtown Princeton as she prepares to teach The Engineering of Ice Cream. Photo by Denise Applewhite

"A lot of real engineering goes into making ice cream," Professor Vanderlick said. "It's an emulsion and a foam, with parts crystalline as well as glassy. This is actually what engineering is all about: making products for society in quantities and qualities sufficient for society's needs."

The course, The Engineering of Ice Cream, will be on the menu next spring. Initially planned as a Freshman Seminar, she hopes to expand the course to include a laboratory component to satisfy the University's science and technology distribution requirement.

"This course will expose students to the rudiments of quantitative thinking, beginning with mass balances--for producing different formulations--and ending with an economic analysis for starting a new company," Professor Vanderlick said.

In between, students will be introduced to conversions, processing and design, phase behavior and thermodynamics, kinetics of phase transitions, transport phenomena, interfacial science, and molecular structure and function.

In the lesson on conversions, students will learn that ice cream is about half air by volume. Volume (and density) is the measure used in the processing and packaging of ice cream. This is accomplished through so-called overrun calculations, which reflect the amount of air in the product. Figuring various plant and packaging overruns requires understanding the units of, and conversions between, fundamental material properties.

The transport phenomena unit focuses on heat transfer, which is, of course, central to the processing of ice cream. Also to be discussed are the flow properties of ice cream, which will introduce students to the meaning of viscosity and science of rheology.

"I want to accomplish two things with the course," Professor Vanderlick said. "First, I hope to draw students into engineering who may be thinking about it. Second, I hope this course will help demonstrate the scope and breadth of what chemical engineers do."

Because everyone can relate to ice cream, it is the ideal platform for introducing many of the basic concepts of engineering, she said, adding that the topic is sufficiently interesting that it should also appeal to a nontechnical audience "in a way that won't scare them, but will show them the power of quantitative thinking."

In the end, Professor Vanderlick said, the most important mission is to illustrate the essence of engineering: making products available to society in sufficient quantity, quality, and affordability through effective product and process design.

"Every student who comes to Princeton has the intellectual capability to do the quantitative calculations that are needed in the course," she said. "It's just that quantitative thinking scares students, and they don't have to be scared. Hopefully, I can enlighten them and show them the power of quantitative thinking and encourage them to be more quantitative and technical in their own thinking. It should help them appreciate what scientists and engineers do."

Studying social outcome of engineering activities

Zellman Warhaft, a 250th Anniversary Visiting Professor for Distinguished Teaching, believes that engineering is the most social of activities. There is no such thing as an engineer who is doing something that has no application to society, he said. "It follows then, that engineers should be inter ested in the social consequences of their works and do their work accordingly," said

Photo illustration by Denise Applewhite Big polluters This photo illustration shows Visiting Professor Zellman Warhaft behind a Sports Utility Vehicle. SUVs are major contributors to air pollution. (See related story on page 13.) Photo illustration by Denise Applewhite

Professor Warhaft, who is affiliated with the Mechanical and Aerospace Engineering Department. "In effect, what we do as engineers is to change the nature of society; surely we should be interested in the consequences and the effects." At Princeton, Professor Warhaft is teaching two courses. Last semester he taught MAE 223: The Engine and the Atmosphere: An Introduction to Thermal Fluid Engineering. This semester he is leading a graduate-level workshop called MAE 500: Social Issues in Engineering Education, which is a one-time, semester-long workshop for engineers at the advanced undergraduate and graduate levels. "Engineering is often taught in a piecemeal approach," he said. "Students learn various aspects of engineering, but they aren't integrated. A fragmented approach makes it difficult for the student to see the unity of the subject, let alone its connection to society." Hence, Professor Warhaft introduces thermal fluid engineering "as the interrelation among the various disciplines of thermodynamics, fluid mechanics, heat transfer, and combustion." He also emphasizes the relation of technology to social and environmental effects, using the automobile as an example. "The engineering tendency is to talk about aerodynamics and drag reduction with the focus on the unit (the car) itself, rather than the effect of thousands of such cars on the local or even global atmosphere." Yet, he pointed out, "Engineering students are ideally trained to learn about the greenhouse effect, with all their groundwork in thermodynamics and heat transfer." Five broad topics are being addressed in the graduate-level workshop: the socialization of the engineer, war and the engineer, calculation in engineering education, the engineer and the environment, and engineering knowledge. The workshop uses technical examples and examines a series of case studies, including the ballistic missile systems such as the Scud-Patriot encounters of the Gulf War. "War is not discussed in the engineering classrooms," Professor Warhaft said. "War is discussed in all other departments: history, classics, government, psychology, economics, and so forth. And it is discussed in context. Engineers are taught how a combustor works, how a guidance system works, and how a rocket works, but not how or what this does once it's put together and what implications to society it has. It means that engineers frequently lack the vocabulary necessary to talk to people in government and arms control." Professor Warhaft has been a faculty member of the Cornell's Sibley School of Mechanical and Aerospace Engineering since 1977. His textbook, An Introduction to Thermal-Fluid Engineering: The Engine and the Atmosphere (Cambridge University Press, 1997), grew out of his teaching at Cornell. His own professional interest is fluid dynamics, especially turbulence, which transports heat and moisture. "If you pour cream in your coffee, the cream will remain pretty much at the top--a demonstration of laminar, or layered, flow," he said in explanation. "But give it a few flicks with a spoon, and the coffee and cream mix--that's turbulent flow." Turbulence has its environmental pros and cons, he said. "Turbulence causes higher drag over surfaces, so cars and planes need more fuel, and there's resistance to flow in pipelines." Turbulence, however, can also dispel smog. "If the ground is hot, the air convects up like a bubbling kettle," he explained. "But if the ground is cool and the air is warm, nothing wants to move. The cool air doesn't rise, and the warm air is happy where it is. This is called a temperature inversion--there's no turbulence, and all the pollution stays in the air. "The pollution will ultimately affect us all," he said. "It is selfish to think that we are okay while the rest of the world is a mess. We use other countries to produce our products--China, Korea, etc. So surely we must share the responsibility."

This article is based on a story by Caroline Moseley that first appeared in the Feb. 15, 1999, Princeton Weekly Bulletin.

Multimedia: wave of tomorrow

Bede Liu, professor of electrical engineering, is working with Professors Wayne Wolf and Ruby Lee to develop a new course that will be offered next spring.

The stuff spy movies are made of Digital watermarking can be added to any presentation media as a guarantee of authenticity, quality, ownership, and source. In the top image, the words Princeton University and ©Copyright 1997 are edited into Alexander Hall and January 1998, circled in the middle image, resulting in the signature changes from bottom left to bottom right. Unauthorized changes can be easily detected and deleted or replaced.

Titled Multimedia and its Impact in the Next Millennium, the course will provide a technological dimension of multimedia that will help students better understand not only its potentials and limitations, but also its impact on social and political development and interpersonal relationships.

"Multimedia is important technology," Professor Liu said. "We have made lots of advances in multimedia. It touches the lives of all of us."

The course will introduce fundamental concepts to provide intellectual rigor.

"Hands-on experiments will bridge the gap between abstract concept and the real world and will help engage students in active learning," he said, adding that while the course will be "quite quantitative" it is being designed so that a high school background in physics and trigonometry, and a familiarity with computers should be adequate preparation.

The course will review how information is received via the human senses--analog and digital information sources and their conversion. Topics will include digital cameras, compact discs, digital video discs, medical imaging, electronic commerce, multimedia and learning, digital library, electronic games, and media and politics.

Underlying technologies will be introduced with hands-on experimentation for each topic. For example, in the digital camera module, the underlying technologies are image sensors, image compression, and color printing. Other questions of interest may include the future of the photographic industry.

Digital watermarking will be the underlying technology introduced in the digital library module. Digital watermarking is the ability to secretly embed messages into digital images (see illustration). Public policy and legal issues surrounding digital watermarking will be covered.

"In the future, we expect multimedia will have an even stronger impact on the way we work, learn, socialize, and do business," Professor Liu said. "The course will focus on how multimedia content is created, how such information is distributed and used, and the impact of multimedia."