Physics in Motion

Cyberschools Column

First Published in The Herald, October 1999



Lists of famous physicists will always include Einstein, Newton and Rutherford but for students studying physics at school today, a new list is becoming extremely influential: Hwang, Fendt, Kiselev, Pfaff, Wirt and Henderson.

These are the people using the visual and interactive nature of the Web to make physics easier to understand. They have created applets (little applications) and multimedia Web sites which show physics in motion and allow students to, for example, replay collisions with no collateral damage. On the Web, their demonstrations are successful every time.

Dr Hwang operates the Virtual Physics Laboratory from the department of physics at the National University in Taipei, Taiwan. His site contains over fifty such applets which allow students to interact with the theory and these are now being used by schools around the world.

One of those available, for example, lets students explore Kepler's laws. The page explains Kepler's ideas and because it shows rather than tells, it also illustrates the key part which applets are set to play in physics education.

Applets are provided which demonstrate mechanics, dynamics, waves, thermodynamics, electromagnetic fields, optics and light and Dr Hwang even offers teachers the opportunity to submit requests for short interactive demonstrations which he will then try to create.

Walter Fendt's materials are also reproduced around the world. His own Web site, Java Applets on Physics, provides resources on, for example, electrodynamics, the theory of relativity and nuclear physics. One of the wide range of applets illustrates the refraction of light. A ray of light is incidenting from the top left of the illustration to the boundary surface of two media. Students can select and change the substances and vary the incidenting ray of light. By using the application, they can also see the angles of reflection and refraction change as they do so.

Diffraction is a phenomenon which involves the bending of waves around obstacles and Sergey Kiselev and Tanya Yanovsky-Kiselev have designed an applet which shows the simplest case of diffraction, single slit diffraction. Students can change the colour of the light and the width of the slit simply by dragging the mouse of their computer. The Kiselev Web site, Interactive Physics & Math with Java, has more than twenty applets suitable for use in physics courses.

By creating java applets, Hwang, Fendt and the Kiselevs illustrate and demonstrate and insist that students get involved. What of Pfaff, Wirt and Henderson? Their aim is also to make resources more interactive but they've chosen to use Shockwave, a Web browser plug-in, rather than to create java applets.

Shockwave is an additional facility for viewing multi-media resources. It's free and it can be obtained on the Internet from the makers, Macromedia.

At Visualize Science, Roman Pfaff explains that from the moment he saw Shockwave he thought it was crucial for scientists to use it. He has set about creating a site which lets both students and teachers "interact with material on the Web, rather than just reading text". The list of Shockwave demonstrations now available on his site is extensive and includes resources which, for example, let students alter the initial velocity, mass, and angle of a frictionless inclined plane or consider why a train whistle sounds differently as it passes by, or carry out basics such as vector addition. New resources are added regularly and many schools are already finding them useful additions to their course materials.

Ithaca High School is one such school which has incorporated several of Pfaff's resources into its own Web site. Ithaca High's Physics Zone, run by Steve Wirt, is a very good example of how a school can use the Web in the teaching of physics.

The site contains three main areas - physics lessons, physics reviews and physics links - as well as course overviews.

The "Physics Lessons" area contains Shockwave resources such as those created by Roman Pfaff as well as many created by Steve Wirt himself. In the lessons on momentum, for example, one resource addresses the different types of collisions and the characteristics of each. It examines which type of collision transfers the greatest amount of force. It's only one of many.

The range of the resources goes right across the physics syllabus and the course outlines show how the topics are organised.

The "Physics Review" section includes hundreds of problems from past New York State Regents Exams in Physics. It provides the problems and answers, as well as an explanation about what the question was really asking. There are also free response questions and solutions.

Ithaca's "Physics Links" is a good place to start to find direct links to good physics sites and one of those links will take you straight to the Web site of Glenbrook South High School, where Tom Henderson and the Physics Department have created an extensive online tutorial.

The "Physics Classroom" is essentially follow-up materials for those having difficulty understanding the course or catch-up materials for those who have been absent. For schools, it's an ideal way to use the Web.

There's a "Shockwave Studio" which enables students to, for example, practise their skill at interpreting graphs or at constructing free-body diagrams for a given physical situation. There is also an extensive number of homework problems, providing six examples in each of twelve units. Teachers will appreciate that the problems provide the back-up of a help option and can be marked by the students. As with Ithaca, the "Review" section houses a range of tests, as well as explanations and answers.

Hwang, Fendt, the Kiselevs and Pfaff help students to visualise physics while Wirt and Henderson use the Web to teach the theory. It's a new list of famous physicists, famous for making physics easier to understand.