When you entered "No Escape: The Truth about Black Holes," it opened in a separate window. To exit the lesson at any time, simply close this window.

A navigation icon appears at the top of each page. Use the arrow buttons to go through the site like this:

If the navigation icon appears without the right arrow, like it does on this page, you can only return to the previous page and the main menu. To begin exploring the realm of black holes, go back to the main menu.

[Please note that in order to properly use all aspects of this lesson, you must be using Netscape 3.0 or higher or Internet Explorer 4.0 or higher, and your monitor must be running in at least 800x600 resolution. If you are a student and are unsure what these terms mean, ask your teacher for help.]