Web-Based Interactive Physics Problems

A CD to accompany the book Physlets: Teaching with Interactive Curricular Material

by Wolfgang Christian and Mario Belloni.


Physlets  require a Java 1.1 enabled browser that supports JavaScript to applet communication.  Unfortunately, not all browsers support both this communication and the Java 1.1 virtual machine. Only recent versions of Microsoft Internet Explorer  and Netscape support scripting of  Java 1.1 applets.  All Physlets have been tested on Netscape Navigator 4.7 and Internet Explorer 5.0 on Windows NT.  Please consult your browser documentation for additional information.

Macintosh Support

Although both Java 1.1 and JavaScript are currently implemented on all major platforms, the ability of JavaScript to communicate with a Java applet is still problematic on Apple computers. Physlets will run in interactive mode, that is, without script, using the latest Apple Java Virtual Machine. However, Microsoft Internet Explorer 5.0 for the Mac still does not support JavaScript to Java communication. We believe that this problem will shortly be solved. Both Netscape and iCab, a new browser being developed in Europe, have announced plans to support the necessary features in their next release. In fact, older Physlets written using Java 1.0 can be scripted on the Mac using Netscape Navigator version 4.5. Unfortunately, this browser has a rather ancient Java 1.0 Virtual Machine and that will not support our recent Physlets.

In the interim, it is possible to run Physlets on all operating systems, including Apple Macintosh, using the Sun Microsystems HotJava browser. This browser is actually a Java application that runs inside the local Java VM. In other words, the Java VM is an operating system within your operating system. In order to use HotJava, you must first install a stand alone Java VM onto your computer. Then download HotJava and start this application. You will see a browser interface that is very similar to a browser that was written specifically for the operating system that you are using. There is almost no performance penalty using this approach since Physlets are written in Java and the HotJava browser is an optimized Java application.