PhysLab.net – Help and FAQ

Why don't the simulations play in my browser?
Make sure that you have Java enabled in your browser. For Internet Explorer on Windows go to "Internet Options", click the Security Tab, and make sure that "Java permissions" are enabled. You also should enable "scripting of Java applets".
In addition, you may need to get Java software if you don't have Java, or have an old version.
How can I show the simulations to my class?
You can copy the applet onto your local computer hard disk. See the sections below on Displaying Simulations Off-line and Changing Size of Display.
Clicking the buttons doesn't do anything.
For the buttons outside of the Java applet, make sure that "scripting of Java applets" is enabled in your browser security preferences.
The math symbols don't appear.
These symbols: − θ π ω √ ∫ ∑ ⁄
should look like this:
If the symbols don't appear, try changing the serif font or default font in your browser, by looking in tools or preferences. Some fonts don't have all these special symbols. In some cases, choosing a different size of font may also help. There may be other browser settings needed to enable these HTML 4.0 character entity references. More info on how to configure your browser and fonts is at Alan Wood's Unicode Site.
How do you display math on the web?
Displaying math on web pages with HTML is challenging. There are many approaches. I have some notes on how to display math on the web that you can look at for ideas.
Is source code available for the simulations?
Yes! Just scroll down on this page for information about getting source code.

Free Source Code

The Java source code for the PhysLab.net applet is available at physlab.net/source/. You should be able to download individual files there by right-clicking on a file.

The source code is covered by the GNU General Public License. Using the GNU GPL ensures that all subsequent improved versions will be free software. Here free means freedom rather than "no cost".

I would like to hear from anyone downloading, using, or improving the source code. Send me a note about what your interests are with the code. I would also appreciate if you could provide a link to physlab.net if you use the source code on your website or at your school.