bluuebunny/crossref_metadata_2025 huggingface dataset:
The Population Game: A Socially Significant Laboratory Activity
Authors: Hobson Art
Published: April 2003

A game-like activity using dice-like cubes can bring population growth home to all students, scientists, and nonscientists alike, while demonstrating many aspects of probability and uncertainty that are too often ignored in the physics curriculum. The activity can proceed at a variety of levels of sophistication and complication, from a simple demonstration of exponential growth through an elaborate modeling of life expectancy, advanced versus primitive societies, family planning, birth rate, and population momentum. Variations can demonstrate radioactive decay, resource depletion, and the approach of a thermodynamic system to statistical equilibrium.
“Sweetening” Technical Physics with Hershey's Kisses
Authors: Stone Chuck
Published: April 2003

This paper describes an activity in which students measure the mass of each candy in one full bag of Hershey's Kisses and then use a simple spreadsheet program to construct a histogram showing the number of candies as a function of mass. Student measurements indicate that one single bag of 80 Kisses yields enough data to produce a noticeable variation in the candy's mass distribution. The bimodal character of this distribution provides a useful discussion topic. This activity can be performed as a classroom project, a laboratory exercise, or an interactive lecture demonstration. In all these formats, students have the opportunity to collect, organize, process, and analyze real data. In addition to strengthening graphical analysis skills, this activity introduces students to fundamentals of statistics, manufacturing processes in the industrial workplace, and process control techniques.
Collecting and Recording Bicycle Speed Data by CBL
Authors: Wehrbein William M.
Published: April 2003

Modern bicycle computers (actually electronic bicycle speedometers) display the current speed of the bicycle, but don't record the data so that a history of the motion can be investigated later. Euler et al.1 devised a method using an ordinary cassette audiotape recorder to store up to two hours of speed data. This paper describes another method employing the LabPro6 interface that was used to capture a record of the speed of a bicycle coasting to a stop.
Faster than exponential
Authors: Bartlett Albert A. , Kruglak Haym
Published: April 2003

Exponential growth (a fixed fractional increase per unit time) yields a straight line when plotted on a semi-logarithmic graph. This kind of graphic representation provides students with interesting insights into historic and current events that affect us all.
Physics and pharmacy: More than “Ph”
Authors: McCall Richard P.
Published: April 2003

Students in physics sections dominated by one academic major prefer examples that are relevant to their course of study. Topics for pharmacy majors (and other health sciences) include references to the human body. An example illustrating fluid dynamics is presented.
Modulated coil
Authors: Rathjen Don
Published: April 2003

A simple electromagnet is plugged into the headphone jack of a radio, and then placed near the head of a tape player which has been turned on, but with no tape. The radio is heard through the tape player’s speakers.
Physics Olympics
Authors: Bouffard Karen
Published: April 2003

Now, through the forum of a regular column in The Physics Teacher, we have the opportunity to present some of our best Olympics challenges to all our colleagues. We welcome your contributions.
Golf is a mysterious sport
Authors: Edge Ron
Published: April 2003

Recently I came across a little diagram that aims to sell a new golf club—an “iron.” Read the description and examine the diagram, and then think, “Is this correct?”
Newton’s second law for multi-particle systems
Authors: Greene Ronald L.
Published: April 2003

Newton’s second law is commonly misapplied to systems of multiple particles, as was done in a recent note in The Physics Teacher. This note revisits the problem of a rope sliding in an L-shape tube.
Specific gravity with electronic balances
Authors: Willems Paul L.
Published: April 2003

When performing a demonstration showing Archimedes’ principle, or conducting a laboratory exercise on density or specific gravity, an electronic balance can be a more difficult instrument to use than the older, mechanical balances.
Space race: A game of physics adventure
Authors: Vinson Michael
Published: April 2003

A simple game is presented to illustrate the application of Newton’s laws of motion. This game has been used for several years in teaching introductory physics at Shippensburg University.
Comparison of the four fundamental interactions of physics
Authors: O’Connell James
Published: April 2003

Expressions for the potential energies between two protons are given for the gravitational, electromagnetic, strong, and weak forces.
Physics on rollerblades
Authors: Etkina Eugenia
Published: April 2003

This paper describes how to connect the concepts of kinematics and dynamics with everyday life experience by using rollerblades in teaching mechanics. We describe seven experiments that were performed by the author while teaching general physics and science courses at Rutgers University.
How long can we breathe?
Authors: Larrabee David A.
Published: April 2003

I use to dread the introductory lecture on measurement that I gave to all my general-education physics classes (nonscience majors). Now this lecture is one of the highlights of the course. My solution is to ask the class to estimate the length of time it would take for the occupants of the classroom to use up “all the available air.”
Roget’s spiral. Nineteenth Century textbook illustrations—LVIII
Authors: Greenslade Thomas B.
Published: April 2003

Parallel wires, carrying currents in the same direction, attract each other. The student who understands this message on the theoretical level knows the Biot-Savart law and a couple of manifestations of the right-hand rule. On the other hand, Roget’s spiral provides direct evidence of the direction of the interaction between the two wires.
Demonstration of the parallel-axis theorem
Authors: Denardo Bruce
Published: April 2003

The parallel-axis theorem implies that the period of a physical pendulum is the same for all locations of the axis equidistant from the center of mass. This can be demonstrated for the simple geometry of a rectangular plate with a concentric hole, where a knife edge supports the plate at different points along the rim of the hole.
Reprise (critical thinking and similar nostrums)
Authors: Swartz Clifford E.
Published: April 2003

Over the holiday, it occurred to me to list the great curriculum reforms of the last few years. One of our faithful readers had questioned my earlier assertion that every such reform had it predecessor. How about Critical Thinking, Hands-On Learning, standards, Constructivism, and Peer Group Instruction?
Quantitative demonstration of Lenz’s law
Authors: Ochoa O. Romulo , Kolp Frank , Handler Joel T.
Published: April 2003

We present a simple apparatus for demonstrating Lenz’s law in which we obtain data of distance fallen by a magnet as a function of time. A computer mouse serves as an interface between the apparatus and the computer to provide real-time data.
Dielectric breakdown of air as order-of-magnitude physics
Authors: Doty Steven D. , Doty Sandra L.
Published: April 2003

To assist student understanding, appreciation, and interest in the electricity and magnetism portion of introductory physics, we discuss the use of order-of-magnitude estimation of everyday phenomena, and apply it to the dielectric of breakdown of air.
Why shake your fever thermometer?—and more
Authors: Crane H. Richard
Published: April 2003

When taking your temperature, the physics of the thermometer is not high in your thoughts. But on a happier day it gets intriguing, and one question leads to another. Why is it the only thermometer that has to be shaken down before use? Why is it so hard to see the top end of the mercury column and get a reading?
Mars global surveyor aerobraking. A collaborative team approach in the physics classroom
Authors: Murphy Kenneth L. , Patterson Evelyn T.
Published: April 2003

Mars Global Surveyor arrived at Mars on 11 September 1997. For approximately the first four months the spacecraft undergoes “aerobraking.” Aerobraking consists of dipping into Mars’ atmosphere to lower the spacecraft’s orbit. This article presents the aerobraking process as a classroom activity.
The glorious glory
Authors: Pascuzzi Edward
Published: April 2003

Among the numerous optical phenomena visible in nature, one encounters the glory, a circular rainbow-like ring surrounding an observer’s antisolar point whose origin lies in the reflection, refraction, and interference of light.
True lines
Authors: Mersereau Arthur , Metz James
Published: April 2003

When computers and graphic calculators determine a regression line for a data set they do not consider that the initial data point may be more certain than other points. In this paper we find a line of best fit through a known point (0,b).
The joy of teaching the physics laboratory—Guest editorial
Authors: O’Kuma Thomas L.
Published: April 2003

One of the most rewarding aspects of teaching introductory physics has been the opportunity to teach the laboratory. The laboratory portion of my courses has given me a chance to interact closely with students, to better gauge their understanding of a specific physical principle, and to help develop ways for students to understand that principle. Because of this feedback, my laboratory instruction has evolved considerably over the years.
Boyle saves a spill
Authors: O’Connell James
Published: April 2003

When a full glass of water covered with a 3- by 5-in file card is turned upside down, atmospheric pressure prevents the water from spilling out.
The sun-protection factors of wet and dry T-shirts
Authors: Bartels Richard , Loxsom Fred
Published: April 2003

The sunburn protection factors (SPF) of dry and wet samples of two white T-shirt materials were experimentally determined by measuring the spectral transmission of solar radiation through the materials. The dry and wet SPF’s were, respectively: 15 and 5 for 100% cotton, and 19 and 17 for 35% cotton/65% polyester.
Three everyday examples of quantization
Authors: Thompson David
Published: April 2003

The aim of this note is to give three examples of quantization (although not of energy) that the students are familiar with: sitting on a flight of stairs, money, and mass.
The real image
Authors: Strahm Black Heidi
Published: April 2003

Have you had trouble showing a real image to your students? Don’t want to spend $40 on a Mirror Mirage? Try this low-cost replacement.
A microcomputer-based phase-change experiment
Authors: Hart Francis X.
Published: April 2003

Computers are useful for making measurements that are so lengthy as to be tedious if made by unaided investigators. The laboratory exercise presented readily acquaints students with this use of a computer.
Ultrasonic interferometers
Authors: Greenslade Thomas B. , Mason Joshua A.
Published: April 2003

The wavelength of ultrasonic waves is obtained with interferometers, in which the path length difference from two sources to the receiver is varied. Nine different interferometers are described, all using 40-kHz ultrasonic transducers and inexpensive reflectors.
A student project on wind chimes. Tuning in to standing waves
Authors: Baxter G. William , Hagenbuch Keith M.
Published: April 2003

We offered our students an opportunity to earn bonus points by demonstrating their knowledge of standing waves. The project we developed involves constructing a set of wind chimes in which each hanging rod produces a clear tone, and the combination of rods generates a chord.
Specific heats–direct, quick, and simple
Authors: Terry Colin
Published: April 2003

This trick of the trade uses a simple and direct method to measure the specific heat capacity of, say, a metal.
Feeling the physics of linear motion
Authors: Bracikowski Christopher , Bowman Doug , Brown Karen , Madara Russ
Published: April 2003

In this article we will describe some large-scale macro-experiments in which the student is actually part of the experimental apparatus itself. This allows the student to actually feel physical phenomena for him/herself. This sensory experience helps students develop an intuitive understanding of physical phenomena, and it’s great fun!
Back to the physics: Integration by Gauss
Authors: Sullivan Jerry
Published: April 2003

A major hangup in solving physics problems often occurs when evaluating integrals. About 200 years ago, the great Gauss gave us an easy-to-compute and accurate method for doing integrals. I give four examples, both familiar and not so familiar, that show the power of his method.
Historical trends in physics bachelor degree output
Authors: Ehrlich Robert
Published: April 2003

This article examines long-term historical trends in physics B.S. production, and possible factors responsible for those trends. The factors considered include: a changing profile of college entrants, the increasing lure of engineering, differential grade inflation, old-fashioned pedagogy, and poor teaching. Finally, the article considers whether it matters to society whether physics major enrollments continue to decline.
TI-TIMER: A solution to Stopwatch frustration
Authors: Koser Eric J.
Published: April 2003

TI-TIMER is a menu-driven timing program designed to run on a TI-85 calculator. It can be calibrated, records multiple time trials, and displays both a list of these trials and an average time value. The note includes information on obtaining this program.
Rotating wheels as seen on television
Authors: Ho Anthony M.-H. , Contardi LeeAnne H. , Dion Peter W. , Griffioen Erik
Published: April 2003

We use the stroboscopic effect to explain how a moving object seen on television can appear to be moving in an opposite direction and/or at velocities different from its true velocities.
Vector toy
Authors: Strahm Black Heidi
Published: April 2003

Walking Toys are a fun way to explore the workings of vectors. Students and teachers alike marvel at the way the toy “knows” to stop before walking off the edge of a table.
Egg drop solution
Authors: Li Danong
Published: April 2003

A physics principle was used to solve the problem in a game: how to protect eggs from being broken when dropped from a high building.
Early science books and their women translators
Authors: Badilescu Simona
Published: April 2003

By the late eighteenth century, women wrote books popularizing the major scientific advances of the times. From even an earlier stage, women translated popular science books, many written especially for the “use of the Ladies.” From Aphra Behn’s translation of Fontenelle’s famous Entretiens sur la Pluralité des Mondes in 1686 to Mary Somerville's 1831 lucid exposition in English of Laplace's well-known book, The Mechanism of the Heavens, translation moved gradually toward professional scientific exposition. Who were these women and what sparked their interest in science? How had they acquired the knowledge necessary to translate science books? The aim of this article is to shed some light on a little known area of women's activities—the translation of science books—and to show their contribution to the diffusion of the scientific knowledge.
What breaks the shadow of the tube?
Authors: Ferraro Pietro
Published: April 2003

When an object is partially immersed and inclined in the water, the shadow of the object seen on the bottom of the container appears to be broken in two distinct parts or blown up in correspondence of the immersion line. The effect is very simple to show and observations and discussions could be developed in the classroom about surface tensions, wettability, and optics.
Trinity sure—III
Authors: Swartz Clifford E.
Published: April 2003

The November editorial worried Newton’s second law and proposed methods of defining mass and of setting up a force scale. Experiment (not definition) shows that forces can be represented by vectors. Experiments also show that inertial mass and gravitational mass are equal, and in Einstein’s view, identical.
A human hamster wheel?
Authors: Dunn Jason W.
Published: April 2003

Newton’s third law force pairs are sometimes difficult for students to identify, especially when one of the forces produces no discernable acceleration. In the context of a Fermi problem, the third law pairs involved in walking is investigated, paying specific attention to whether the force on the Earth by the walker can impact the Earth’s rotational motion.
Demonstrating normal forces with kitchen scales
Authors: Stavrinidis Vassilis
Published: April 2003

A way to demonstrate normal forces using a precision laboratory electronic balance has been reported in this magazine. I propose a simpler and less expensive way of demonstrating normal forces.
“Crying” electrostatics
Authors: Amann George
Published: April 2003

Japanese physics teachers have developed a novel electrostatics demonstration that uses and “electrophrus,” a neon light, and an amplifier to make changes in potential audible. This paper provides instructions for construction of a simple apparatus, and an explanation of how the audible effects are obtained.
Bernoulli's Challenge
Authors: Bouffard Karen
Published: April 2003

This month’s Olympic activity was brought to the Eastern Massachusetts Physics Olympics group by Ron DeFronzo of Pawtucket, Rhode Island. Using a hair dryer, contestants must maneuver a Ping-Pong ball into a three-dimensional “bullseye” target.
Pressure measurements: A diagrammatic comparison
Authors: Peckham Gavin D. , Sutherland Lee
Published: April 2003

This short article presents a diagram that may help students understand the relationships between various ways in which pressure is commonly measured.
Particle-model derivation of pVγ
Authors: Akridge Russell
Published: April 2003

The adiabatic compression formula pVγ=constant for an ideal gas is derived from simple gas particle collision concepts similat to those used in deriving the ideal gas equation of state.
Thermal patterns in the snow: Structure of a roof
Authors: Bartlett Albert A.
Published: April 2003

A dramatic thermal pattern on the south-facing roof of our university’s Fine Arts building is shown in analyzed. From the patterns in the snow on the roof, it is possible to draw a number of tentative conclusions about the makeup and structure of the roof.
Pencils solution to an egg-citing problem
Authors: Lan Boon Leong , Ooi Gary , Keh Chooi Yiang
Published: April 2003

Here is an egg-citing contest that will make physics interesting and fun while allowing students to practice creative problem solving. Have each student drop a raw egg from an upper level of a building. The egg that falls fastest to the ground without breaking wins the contest.
How to avoid Niagara Falls
Authors: Blanck Harvey F.
Published: April 2003

Determination of an optimum strategy for crossing a river in a boat to minimize downstream drift generates several simple equations. If the speed of the boat, b, is less than that of the river, r, the equation relating the angle, θ, between the boat heading and the upstream shoreline is cosθ=b/r.
Bad timing in swimming races: A physicist to the rescue
Authors: Crane H. Richard
Published: April 2003

During official swimming competitions in the “bad old days,” there were judges, armed only with their vision, to determine the sequence of arrival, and there were timers, armed with mechanical stopwatches, to get the times. At the University of Michigan, back in 1953, Bill Parkinson of the physics department, himself a swimmer, started work developing an electronic timing system to eliminate the human judgment and to have the accuracy of which electronics is capable.
Class simulation of thermal energy and heat
Authors: Jadrich James , Haan Stanley L.
Published: April 2003

The concepts and the measured quantities associated with thermal energy, heat, temperature, and phase changes are made transparent to introductory physics students through participation in a whole class simulation.
What can we learn from recent changes in physics bachelor degree output?
Authors: Ehrlich Robert
Published: April 2003

We have examined the numbers of bachelor degrees awarded during the last seven years at each of the approximately 750 physics programs in the U.S. Seven programs were found to have statistically significant gains and 28 programs were found to have statistically significant losses. Department chairs were contacted at all the “big gainers” and a sample of the “big losers,” in order to learn what factors were responsible for the changes in degree output that they experienced. Several common factors appear to be responsible for the big gains, which should be replicable elsewhere.
Magnetic cards for teaching electronics
Authors: Hapka Alison
Published: April 2003

I describe the use of business-card sized magnets for teaching electronics as a demonstration tool or by groups of students during an activity. Suggestions for creating magnets that can be used for other topics are also suggested.
Problem-solving challenges
Authors: Schardl Nicholas
Published: April 2003

The writer’s students are assigned, from time to time, complex problem-solving challenges which serve to reinforce learning by interrelating topics. These challenges involve freefal and projectile motion. Students work in groups to produce solution models for the challenges.
Examination questions based on historical apparatus
Authors: Greenslade Thomas B.
Published: April 2003

In my sophomore-level electricity and magnetism course, I have been using questions based on historical apparatus. This note presents three examples.
Confusing color concepts clarified
Authors: Woolf Lawrence D.
Published: April 2003

Primary colors, complementary colors, and the color wheel taught in art classes differ from that taught in physics classes. The reason for these differences and some hands-on experiments that clarify these color concepts are described.
On the run: Unexpected outcomes of random events
Authors: Silverman Mark P. , Strange Wayne , Silverman Chris R. , Lipscombe Trevor C.
Published: April 2003

When purportedly random processes give rise to surprisingly nonrandom outcomes, how can one tell whether the process are truly random? One way exploits the relatively little-known method of runs. We discuss the perplexing probability problem that brought this procedure to our attention, and our experimental tests of random processes produced by (a) numerical algorithm, (b) coin selection, and (c) nuclear decay.
Standing microwaves on the overhead projector
Authors: Greenslade Thomas B.
Published: April 2003

Standing waves are produced by putting a metallic reflector in front of a microwave generator, and the nodes and antinodes detected with a microwave diode. The system is placed on an overhead projector so that data can be taken for class analysis.
Einstein and baseball
Authors: Pesic Peter
Published: April 2003

Although Albert Einstein disliked games, he used the game of dice to illustrate his criticisms of quantum theory. If, however, he had considered basebal, he would have confronted a game whose unpredictable plays rise in wavelike rhythms analogous to quantum physics.
Including students in the search for extraterrestrial intelligence
Authors: Slater Timothy F.
Published: April 2003

As anyone who teaches astronomy to large classes of nonscience majors knows, the most difficult part is finding an assignment that encourages students to participate in, rather than just learn about, science. Now, teachers have a new opportunity to involve students in “real” science. All the student needs is access to a computer and the Internet. The project is know as SETI@home.
Easy projectile-motion demonstrations
Authors: DePino Andrew
Published: April 2003

This note describes three demonstrations that can be used to introduce projectile motion. They are simple to conduct, are fun for the students, and require their participation at all stages. There is no lack of student volunteers for these demonstrations.
Lenz’s law in the kitchen
Authors: Dindorf Wojciech
Published: April 2003

A steel blade—a rather vital part of a mixer—has fallen behind a cupboard in my kitchen. The cupboard is heavy and quite permanently mounted between stove and fridge. Hopeless situation! Unless—you are an experimental physicist. This straightforward demonstration helps in appreciating the connection between Lenz’s law and the law of conservation of energy.
Fiestaware™ radiography
Authors: Peplow Douglas E.
Published: April 2003

A fun and exciting way to demonstrate the ionizing properties of radiation is to create radiographs. This note describes the procedures for performing a classroom demonstration or student laboratory to investigate the ability of ionizing radiation to expose ordinary camera film.
Physics: Principles and Problems
Authors: Zitzewitz Paul W. ,   Physics Textbook Review Committee
Published: April 2003

This 1999 textbook by Paul Zitzewitz is one of seven textbooks reviewed in this issue of The Physics Teacher.
PSSC (Physical Science Study Committee) Physics
Authors: Haber-Shaim Uri , Dodge John H. , Gardner Robert , Shore Edward A. ,   Physics Textbook Review Committee
Published: April 2003

This seventh edition of the PSSC textbook is one of seven textbooks reviewed in this issue of The Physics Teacher.
Demise of a shibboleth
Authors: Swartz Clifford E.
Published: April 2003

I was startled the other day to receive a manuscript describing a new teaching method that is being carried out in a “constructivist atmosphere.” It suddenly occurred to me that I had not heard anything about constructivism for a long time. I always had trouble with that word. When it was becoming popular, I couldn’t figure out what the methodology was or why it was unique.
Wind car
Authors: Salzsieder John C.
Published: April 2003

A pinewood “derby” car like those used by the Boy Scouts is modified to demonstrate the addition of the force vectors that are important in sailing.
The five-legged table
Authors: Binder Philippe M. , Sinisterra Paola , Esguerra Felipe
Published: April 2003

A small model of a table with five easy-to-cut legs can stimulate discussions about statics and stability.
Yale Physics Olympics, 1998
Authors: Bouffard Karen
Published: April 2003

We report on how Yale University’s Physics Department organized a day-long event for approximately 100 high school students, mostly seniors. The underlying theme was simple: Physics is Fun.
Exercise your physics when flying
Authors: Baffa Oswaldo
Published: April 2003

Recently, while flying, I found it difficult to sleep and started to pay attention to the television screens in the airplane. There were two types of TV to watch—a large cathode raye tube (CRT)monitor and smaller liquid crystal display (LCD) for passengers sitting near the bulkhead. In one of my glances at the large monitors I noticed that the colors were changing. I looked at the LCD monitors and the colors were fine. What could be happening?
Using role-playing exercises to teach astronomy
Authors: Francis Paul J.
Published: April 2003

I’d like to share a rather cavalier, but enormously enjoyable technique I’ve been using to teach introductory astronomy classes for nonscience majors. Rather than preparing a conventional lecture on some area of astronomy, I divide my class into groups that compete among themselves to be the first to understand a given aspect of astronomy, using clues that I supply.
Metric units and postage stamps
Authors: Hillger Donald W.
Published: April 2003

The metric system has evolved from the French (“metre”) units of 1790 to be officially recognized by the Eleventh General Conference on Weights and Measures as the International System of Units (SI) in 1960. This note brings together brief biographical notes of the scientists for whom many SI units are named, along with reproductions of postage stamps from around the world that have been issued to honor these men.
Conjugate relationships in basic electricity
Authors: Fisher Kurt
Published: April 2003

A listing of conjugate terms, along with commonly expressed theorems utilizing these terms, is presented. These “reciprocity relations,” which underlie the subject of electricity, are showcased to emphasize to students the distinctions between the fundamental electrical parameters. Reasons for the difficulty students have with electricity are also briefly discussed.
Modeling forces on the human body
Authors: Pagonis Vasilis , Drake Russel , Morgan Michael , Peters Todd , Riddle Chris , Rollins Karen
Published: April 2003

Several simulations involving the human body, using the simulation software Interactive Physics™, are used to analyze the forces during both static situations and dynamic collisions. The connection of the simulations with the biological sciences and with sports activities should make them appealing to both high school and college-level physics students.
Experiment problems for electricity and magnetism
Authors: Van Heuvelen Alan , Allen Leith , Mihas Pavlos
Published: April 2003

We describe problems for electricity and magnetism that are presented in the form of experiments—called experiment problems. The problems can be used in lectures or in laboratories in introductory high school and college physics courses that emphasize quantitative problem solving.
Extending the analysis of one-dimensional motion
Authors: Canderle Luis H.
Published: April 2003

Some authors propose an experimental setup to develop an understanding of the concepts of velocity and acceleration by using balls rolling in tracks with or without slope and analyzing the different situations by considering the motion as one-dimensional. However, it is possible, in the next level of sophistication, to use the same experimental setup to extend the analysis to more than one dimension. This teaching increases meaningful learning and reasoning ability because the motion curves of both x and y are presented simultaneously.
The wall of death: Newtons, nerves, and nausea
Authors: Charoenkul Niran , Wheeler David , Dejasvanong Chanwit
Published: April 2003

What really happens on the “Wall of Death”? We ride it (by motorcycle and car) and find out … and put the resulting video on a website!
Using an internet message board in teaching
Authors: Sullivan Peter
Published: April 2003

The use of an Internet-accessible web-based message board system for engaging students in rich out-of-class discussions is described. Examples of the message board webpages are included.
Animations in spreadsheets
Authors: Aubrecht Gordon J. , Bolland T. Kenneth , Ziegler Michael G.
Published: April 2003

Recently, Ole Haglund mentioned in this journal that it was possible to incorporate animations into spreadsheets. We would like to describe what might be an easier way to incorporate animations into spreadsheets using Excel™ software.
Telepresent teaching
Authors: Windelborn Augden
Published: April 2003

A new physics tool is quietly developing on the Internet. The tool is telepresence and its application to physics and teaching is filled with promise. What is telepresence? The name appears to be a contradiction—present at a distance. Currently, telepresence allows a computer user to effectively be present at some other location through the use of remote cameras, sensors, and controls. This means that a user at location A can see, hear, talk to, and control operations at location B. Effectively, telepresence is similar to a “picture phone” with the addition that user A can control and acquire data from instruments at location B. The involvement of the physics com!!munity in the development of the World Wide Web is well known. Telepresence will evolve over the next few years into a much more sophisticated tool and again physics (and physics teaching) can play a leading role.
A different kind of physics competition—The IYPT
Authors: Haskell Hugh , Britton Charles , Edge Ronald
Published: April 2003

Tired of having your students just solve the same old problems? Would you like to have them get a feel for how science is really done and reported? Then look into the International Young Physicist’s Tournament (IYPT), an event with a difference. The IYPT was founded by physicists at Moscow State University in 1979 as a local event for high school students. It became international in 1987, meeting in various European cities.
Finding the equation for a vibrating car antenna
Authors: Newburgh Ronald , Newburgh G. Alexander
Published: April 2003

There is much pedagogic value to relating everyday observations to complicated equations. As a teacher traces such a relationship and demonstrates how to construct the governing equation, students see how physics is done. Surprisingly, even an ordinary automobile antenna can provide such a lesson.
Getting a charge from coffee
Authors: Cheyne Stanley A.
Published: April 2003

Is it best to store your coffee beans in the freezer or at room temperature? You can ask java connoisseurs at any level and receive difference answers. This note will not directly answer that all-important question, but discusses one of the consequences of choice that I discovered as I pondered the query.
The physics of soaring
Authors: Ford Kenneth W.
Published: April 2003

A glider flying at constant velocity, whether through still air, rising air, or sinking air, provides a nice example of a vehicle acted upon by forces that add to zero. A glider’s performance characteristics are displayed in a single “polar” graph that lends itself to simple graphical analysis to reveal how fast a glider pilot should fly under various conditions.
Don’t run naked and shout “Eureka!” yet
Authors: Lan Boon Leong
Published: April 2003

The source of error of an incorrect solution given by authors of current popular introductory physics textbooks to a standard fluid static example—problem involving Archimedes’ Principle is identified and the correct solution is given.
Modern physics — Guest editorial
Authors: Howes Ruth
Published: April 2003

What an exciting time to be a physicist! You only have to attend the plenaries at an AAPT meeting to realize just how many mysteries there still are. Will string theory actually prove to be a Theory of Everything? Can we use physics to understand, predict, and perhaps eventually mitigate damaging hurricanes? Is the warming trend of the Earth due to man-made changes in the atmosphere? Have we found the nuclear “island of stability” with elements 114, 116, and 118? For that matter, why is ice slippery?
Measuring the speed of sound in a solid
Authors: Key Tony , Smidrovskis Robert , From Milton
Published: April 2003

The speed of sound in a solid is measured using an oscilloscope, a square-wave oscillator and a piezo-electric pick-up. A study of the relationship between the distance traveled and the time of arrival of the sound pulse allows a graphical determination of the speed of the pulse in the lucite rod.
More on projectile motion
Authors: Molina M. I.
Published: April 2003

We consider a classical projectile launched in a constant gravitational field and focus on the relative error in several projectile observables against an error in the initial angle. We found that, while the relative error in maximum height or flight time is monotonically decreasing with initial angle, the relative error in the range of the projectile displays a minimum which is located (at small aiming errors) in the vicinity of 45 degrees and is the same for two complementary initial angles.
Background and professional qualifications of high-school physics teachers
Authors: Neuschatz Michael , McFarling Mark
Published: April 2003

There has been much concern recently about high school physics teachers’ qualifications. This article discusses the results of AIP’s survey of high school physics, highlighting findings indicating that some of those fears may be overstated, while others seem well warranted.
The minilab as a tool in physics instruction
Authors: Etkina Eugenia , Horton George K.
Published: April 2003

This paper describes a method that helps students master concepts by hands-on experimentation — the concept-centered minilab — and lists possible minilabs for use in introductory physics courses. We have used minilabs successfully at Rutgers for 15 years. They are inexpensive and inherently student-active.
Herschel’s interference demonstration
Authors: Perkalskis Benjamin S. , Freeman J. Reuben
Published: April 2003

Early in the nineteenth century, W. Herschel introduced a striking demonstration of interference arising from many coherent rays. Today’s students can reproduce this demonstration and attain beautiful multiple-beam interference patterns.
A consistent sign convention for work
Authors: Ingham William H.
Published: April 2003

Since the development of thermodynamics by Carnot, Clausius, and others, physicists and chemists have made different use of the basic principles, and this has been reflected in the differing conventions in writing the First Law. Physicists usually have written the First Law as ΔU=Q−W, using W to denote work done by a system on its surroundings. Chemists have typically used W to denote work done on a system by its surroundings, so they have written the First Law as ΔU= Q+W.
Instability of oscillations in an electrostatic potential
Authors: Huang Ding-wei , Huang Wei-neng , Tseng Hsiang-chi
Published: April 2003

A popular exercise appearing in many undergraduate textbooks of introductory physics courses is re-examined. We analyze in detail the motion of a charged particle started from rest near the center of a charged ring. When the initial position of the particle is exactly along the central axis, simple harmonic motion is expected. With small deviations away from the axis, the oscillations sustain only a few cycles. We suggest that the instability of oscillations in electrostatic potentials can be demonstrated by this exercise.
Interactive worksheets in large introductory physics courses
Authors: Leslie-Pelecky Diandra L.
Published: April 2003

This paper analyzes in-class worksheets as an active-learning technique in a large introductory physics class. Instructor and student evaluations of the worksheets are discussed, and suggestions for teachers interested in writing their own worksheets are made.
Magnetic therapy in physics?
Authors: Welsh Gail S.
Published: April 2003

A critical thinking activity focused on students’ understanding of magnets is described. The activity includes a short written paper about the validity of advertisements for alternative medical therapy devices based on magnets. It includes also self assessment through peer interaction.
Resistance of wheels rolling over obstacles
Authors: Hauger Joseph A.
Published: April 2003

An experiment investigating the force required for a wheel to roll over an obstacle is discussed. The experiment introduces students to an interesting application of the requirements for static equilibrium of a rigid object.
Exploration center for large introductory physics courses
Authors: Singh Chandralekha
Published: April 2003

We have designed a Physics Exploration Center (PEC) to supplement traditional lecture-oriented teaching in large introductory physics courses. The central objective of PEC is to provide students with an opportunity for hands-on, lecture demonstration-based homework problems. It is a cost-effective supplement to lectures since PEC equipment can be borrowed from existing lecture demonstration equipment.
Grading the teacher
Authors: Swartz Clifford E.
Published: April 2003

Several fads ago there was a movement to grade teachers in terms of their competency — competency-based testing. Everyone knows that there are good teachers and there are bad teachers. The trouble is, it’s hard to define the categories. It’s like the Supreme Court justice who couldn’t define pornography, but knew it when he saw it. In New York State, prospective teachers must take tests in both pedagogy and subject material. That seems reasonable. There ought to be some minimum standards, so I thought that I would try my hand at setting up such requirements.
A simulation of optical polarization
Authors: Stevens Richard E.
Published: April 2003

A wire that can vibrate in two dimensions serves as an excellent demonstration of optical polarization. A description of a simple setup is presented that can be used either as a lecture demonstration or as a laboratory activity to help students develop a better grasp of the relationship between linear and circular polarization.
A conical spring—Which end up?
Authors: Greene Nathaniel R. , Dunn Ryan J.
Published: April 2003

A helical spring commonly used in undergraduate simple harmonic motion labs is composed of two diameters of windings joined by a truncated conical section. A hanging spring-mass system will oscillate with slightly different frequencies depending on whether the spring is hung from its large end or from its small end. We examine the effective mass of such a spring, comparing measurements with a theoretical calculation that uses an energy approach.
The great thermometer challenge
Authors: Wheeler David , Mazur Eric
Published: April 2003

Students assume instruments always produce accurate results. We describe a surprisingly exciting exercise which confronts that belief in a dynamic and memorable manner using just a simple thermometer.
Inner solar system concepts
Authors: Slater Tim
Published: April 2003

After many discussions with colleagues, I realized that I was presenting facts and concepts in a disjointed way. Now I teach the inner solar system to nonscience majors by using a system of overarching concepts instead of talking about Mercury, Venus, Earth, and Mars one after the other. Hopefully, these concepts will transfer directly to the newly discovered extra-solar planetary systems.
A simple barometer
Authors: Reddingius E. R.
Published: April 2003

An improved sympiesometer with temperature compensation, which can be made easily using cheap materials, is described.
Physics Olympics celebrates silver anniversary
Authors: Riban David M.
Published: April 2003

The Physics Olympics series of competitions for secondary students was begun in Pennsylvania in 1975. Reported in the next year’s The Physics Teacher, it spread worldwide. This spring it celebrates its silver anniversary at the author’s new home institution.
The precessing top
Authors: Bolina Oscar
Published: April 2003

When a symmetric top is set spinning with angular velocity ωc about its own axis, it traces out a circle about a vertical direction with angular velocity ωz.
Symmetry in electromagnetism—A new magnetic needle
Authors: Gibson F. M. , MacInnes Iain
Published: April 2003

Students frequently are introduced to Oersted’s experiment by deflecting a plotting compass beneath a straight current-carrying conductor. Thereafter, electromagnets, electric bells, relays, and motors are explored. When attention is turned to electromagnetic induction, the usual setup involves thrusting a straight wire between the jaws of a powerful horseshoe magnet. To help underline the symmetry involved, we have developed a stronger magnetic needle and outline here how we use it in our classes.
Ultrahigh-Density Nanowire Lattices and Circuits
Authors: Melosh Nicholas A. , Boukai Akram , Diana Frederic , Gerardot Brian , Badolato Antonio , Petroff Pierre M. , Heath James R.
Published: April 2003

We describe a general method for producing ultrahigh-density arrays of aligned metal and semiconductor nanowires and nanowire circuits. The technique is based on translating thin film growth thickness control into planar wire arrays. Nanowires were fabricated with diameters and pitches (center-to-center distances) as small as 8 nanometers and 16 nanometers, respectively. The nanowires have high aspect ratios (up to 10
6
), and the process can be carried out multiple times to produce simple circuits of crossed nanowires with a nanowire junction density in excess of 10
11
per square centimeter. The nanowires can also be used in nanomechanical devices; a high-frequency nanomechanical resonator is demonstrated.
Cloning and Heterologous Expression of a β-
d
-Mannosidase (EC 3.2.1.25)-Encoding Gene from
Thermobifida fusca
TM51
Authors: Béki Emese , Nagy István , Vanderleyden Jos , Jäger Szilvia , Kiss László , Fülöp László , Hornok László , Kukolya József
Published: April 2003

Thermobifida fusca
TM51, a thermophilic actinomycete isolated from composted horse manure, was found to produce a number of lignocellulose-degrading hydrolases, including endoglucanases, exoglucanases, endoxylanases, β-xylosidases, endomannanases, and β-mannosidases, when grown on cellulose or hemicellulose as carbon sources. β-Mannosidases (EC 3.2.1.25), although contributing to the hydrolysis of hemicellulose fractions, such as galacto-mannans, constitute a lesser-known group of the lytic enzyme systems due to their low representation in the proteins secreted by hemicellulolytic microorganisms. An expression library of
T. fusca
, prepared in
Streptomyces lividans
TK24, was screened for β-mannosidase activity to clone genes coding for mannosidases. One positive clone was identified, and a β-mannosidase-encoding gene (
manB
) was isolated. Sequence analysis of the deduced amino acid sequence of the putative ManB protein revealed substantial similarity to known mannosidases in family 2 of the glycosyl hydrolase enzymes. The calculated molecular mass of the predicted protein was 94 kDa, with an estimated pI of 4.87.
S. lividans
was used as heterologous expression host for the putative β-mannosidase gene of
T. fusca
. The purified gene product obtained from the culture filtrate of
S. lividans
was then subjected to more-detailed biochemical analysis. Temperature and pH optima of the recombinant enzyme were 53°C and 7.17, respectively. Substrate specificity tests revealed that the enzyme exerts only β-
d
-mannosidase activity. Its kinetic parameters, determined on
para
-nitrophenyl β-
d
-mannopyranoside (
p
NP-βM) substrate were as follows:

K
m

= 180 μM and
V
max
= 5.96 μmol min
−1
mg
−1
; the inhibition constant for mannose was

K
i

= 5.5 mM. Glucono-lacton had no effect on the enzyme activity. A moderate
trans
-glycosidase activity was also observed when the enzyme was incubated in the presence of
p
NP-αM and
p
NP-βM; under these conditions mannosyl groups were transferred by the enzyme from
p
NP-βM to
p
NP-αM resulting in the synthesis of small amounts (1 to 2%) of disaccharides.
5-Keto-
d
-Gluconate Production Is Catalyzed by a Quinoprotein Glycerol Dehydrogenase, Major Polyol Dehydrogenase, in
Gluconobacter
Species
Authors: Matsushita Kazunobu , Fujii Yoshikazu , Ano Yoshitaka , Toyama Hirohide , Shinjoh Masako , Tomiyama Noribumi , Miyazaki Taro , Sugisawa Teruhide , Hoshino Tatsuo , Adachi Osao
Published: April 2003

Acetic acid bacteria, especially
Gluconobacter
species, have been known to catalyze the extensive oxidation of sugar alcohols (polyols) such as
d
-mannitol, glycerol,
d
-sorbitol, and so on.
Gluconobacter
species also oxidize sugars and sugar acids and uniquely accumulate two different keto-
d
-gluconates, 2-keto-
d
-gluconate and 5-keto-
d
-gluconate, in the culture medium by the oxidation of
d
-gluconate. However, there are still many controversies regarding their enzyme systems, especially on
d
-sorbitol and also
d
-gluconate oxidations. Recently, pyrroloquinoline quinone-dependent quinoprotein
d
-arabitol dehydrogenase and
d
-sorbitol dehydrogenase have been purified from
G. suboxydans
, both of which have similar and broad substrate specificity towards several different polyols. In this study, both quinoproteins were shown to be identical based on their immuno-cross-reactivity and also on gene disruption and were suggested to be the same as the previously isolated glycerol dehydrogenase (EC 1.1.99.22). Thus, glycerol dehydrogenase is the major polyol dehydrogenase involved in the oxidation of almost all sugar alcohols in
Gluconobacter
sp. In addition, the so-called quinoprotein glycerol dehydrogenase was also uniquely shown to oxidize
d
-gluconate, which was completely different from flavoprotein
d
-gluconate dehydrogenase (EC 1.1.99.3), which is involved in the production of 2-keto-
d
-gluconate. The gene disruption experiment and the reconstitution system of the purified enzyme in this study clearly showed that the production of 5-keto-
d
-gluconate in
G. suboxydans
is solely dependent on the quinoprotein glycerol dehydrogenase.