Spring 2003



Previous Newsletters

Current Issue

Contact the Editor

University of Maryland

Traveling Physics Demonstration Programs

In the fall of 1972, after six years as an assistant professor of Physics, working on the new cyclotron and teaching large lecture classes in physics at the University of Maryland, I was offered the position of Director of the Physics Lecture-Demonstration Facility. Also that fall I purchased my new 1972 Pinto station wagon. In the fall of 1973, the second of my two sons joined their older brother in elementary school. Very shortly thereafter, one of their teachers asked if any of the parents could come to school to talk about their job. I packed up a bunch of demonstrations in the Pinto and trundled off to the school, initiating the University of Maryland physics demonstration road shows.

It seemed that word of these programs passed among local teachers only slightly slower than the speed of light, and soon I was being asked to present programs at more schools than I could possibly accommodate while actually doing my real job. This arrangement continued until 1989, when the Pinto sputtered for the final time, leaving me without adequate transportation for the equipment. When we pointed this out to the University, the Dean of the College of Mathematical and Physical Science and the Office of School/University Programs put up about $15,000 to purchase and outfit a new Physics is Phun van. Our van has served well for the ensuing 13-plus years.

Our new Lecture-Demonstration logo with appropriate lettering was installed professionally, and the manufacturer installed a standard wheelchair lift, accessed through the sliding door at the right side of the van. Most of the demonstrations are carried in two 21/2 foot by 31/2 foot rolling mail baskets that can be loaded into the van using the lift; anything too large for the baskets can be loaded through the side or rear doors onto the floor of the van beside the baskets. This van arrangement allows us access to any schoolroom that is handicapped accessible, which includes virtually every conceivable location in the years after 1989.

In the fall of 1991, in coordination with the Acoustical Society of America meeting in Baltimore, we obtained an Eisenhower grant from the State of Maryland to offer workshops on sound for about thirty middle school science teachers. The workshop consisted of five four-hour Saturday morning sessions to study acoustics concepts, perform related demonstration experiments, and collect equipment that the teacher would keep for use with his or her students. Workshop time was used to train the teachers in use of their new equipment. Inservice credit was available for interested teachers. One of the extended workshop activities was for me to present a physics demonstration program on sound at each participating teacher's school. The next year we obtained a similar Eisenhower grant to present workshops on light to another group of thirty middle school science teachers.

We used this experience to obtain a National Science Foundation grant for the period 1993 to 1995 to repeat our workshops on sound and on light, and to offer additional workshops on Newton's laws and electricity and magnetism (topics generally included in the middle school curriculum in this area). These workshops significantly expanded our number of road trips. Lamentably, the NSF apparently changed their philosophy about such teacher activities and we were unable to continue our workshops.

However, the more recent NSF policy is to support longer-term relationships with individual schools, and the UM Physics Department has become very active in such arrangements during the past several years. The Materials Research Science and Engineering Center (MRSEC) has administered a large number of outreach programs ( in coordination with their NSF grants. Activities include presenting demonstration programs to students at their schools, teacher training workshops, sponsoring science fairs and providing judges, and bringing groups of students to the University for physics activities and the local Physics is Phun programs (

I have also presented demonstration programs regularly for middle schools in several southern Maryland counties in which the student population has been recognized by the state as being under-represented in college attendance. This is part of an ongoing contract coordinated by the University of Maryland Office of School/University Programs (

Most of our school visits originate from unsolicited requests for demonstration programs, generally by representatives of elementary or middle schools. Usually they want some sort of physics demonstration program that will inspire interest in physics (or perhaps science, or perhaps just school), or that can be used as an example of what students might experience later in their academic careers. In this situation I usually refer them to our traveling program web site ( and suggest one of the standard programs: Sound and Light, Newton's Laws, or the Physics IQ Test. If the purpose of their program is to reinforce material in other topics, a special program is developed for that occasion.

Although I have set up a few "standard" demonstration programs that I suggest for most inquiries, the nature of our traveling programs over the past 30 years have been quite varied. Many teacher workshops have been given, ranging from one-hour presentations on specific topics to full eight-hour detailed discussions of demonstrations, how they are constructed and how we use them. These workshops have been presented to groups ranging from elementary through high school. Demonstration presentations have been made at professional meetings such as the American Association of Physics Teachers or its regional subsidiaries, and the National Association of Science Teachers or its state or local subsidiaries. These programs have been adapted for levels from pre-kindergarten classes through senior citizen groups. I have presented some set of demonstrations from The Physics IQ Test as the keynote program for science fair and science week events.

One important philosophical issue regarding the presentation of these programs regards use of hands-on activities as opposed to more of a lecture type format. My personal bias has been in favor of the lecture format, leaving the more hands-on laboratory activities to the teachers. Although I do not usually work in the detailed hands-on mode, I try to include in my programs lots of opportunity where the students are guided in observing specific phenomena illustrated by the demonstrations, and ask them to respond to questions about their observations. As much as possible, I select students to help with the experiments, creating more interest in the demonstrations and their outcomes. I believe that demonstrations are inherently of very great interest to young students, and that as such demonstrations can be a very compelling centerpiece to virtually any program covering classical physics. Hands-on laboratory experiences form an integral part of scientific development for young students. However, I believe that my part in the educational process should be to inspire their interest, show them things that in my absence they would almost certainly not experience, and provide some information to them that is beyond what they might get in their standard classroom/laboratory experience. Even at the lowest level, I prefer to discuss the demonstrations performed in terms of the laws of physics illustrated rather than as a magic show or a show-and-tell experience. As it turns out, some of the content of these programs is not even familiar to the teachers!

Perhaps my favorite program is that on sound and light. The topics of sound and light provide material for discussion that is directly related to the most important human experiences in communication and observation. Examples of this might include demonstrations of curved mirrors. Almost all of the students are aware of the use of convex mirrors in stores, and many are aware of their use as the right-hand rear view mirror of cars. On the other hand, very few are specifically aware that the convex nature of the mirror is what creates this type of image. Almost none are aware of the compromises in the PHYSICS that lead to the specific shape of the rear view mirror, and the warning "OBJECTS IN THIS MIRROR ARE CLOSER THAN THEY APPEAR." Most students are not aware of the numerous uses of concave mirrors, such as reflecting telescopes, microwave dishes, and parabolic microphones for football game sound production. Although virtually all students (and teachers) have used vanity mirrors, most of them are unaware that the reason they create enlarged images is because they are concave and the object (your face) is close. Such examples as this can be included very efficiently in the lecture demonstration format, and "homework" assignments can even be made for them to look at images of near and far objects in their vanity mirrors. Their learning experience might even include how to describe the images produced by these two types of mirrors. Use of a SLINKY spring to illustrate transverse (light) and longitudinal (sound) waves can be accompanied by detailed observation of the differences between the two types of wave. We can do a polarization experiment using a rope and cookie cooler racks, then repeat the experiment using light and crossed Polaroid sheets. An appropriately selected oscillator and loudspeaker combination can be used to demonstrate the range of audible frequencies and introduce use of metric prefixes in words like "kilohertz." Infrasound and ultrasound can then easily be discussed, with numerous applications, such as the students' own sonograms. The idea of audible spectrum can then be extended to the correlation between frequency and color in the prism spectrum of white light, the same colors that occur in the rainbow or in refraction by diamonds. Infrared can be described as an example of heat radiation (one of the three forms of heat transfer that they have studied). Ultraviolet can be mentioned and the associated importance of the ozone layer in our atmosphere. For the more scientific audiences I like to discuss the history of the bell in vacuum experiment, for which the vacuum pump was invented!

My experience has been that demonstrations related to the students' experiences maintain the most interest by the students and therefore provide the best opportunity for a positive learning experience, longer retention and the greatest likelihood of interesting these young students in science. As demonstration and laboratory experts with an enormous amount of interesting equipment readily available, we are uniquely positioned to take advantage of these opportunities.

For more information, contact:

Richard E. Berg, Director
Lecture-Demonstration Facility
Department of Physics
University of Maryland
College Park, MD 20742