These simple demonstrations are a great way to illustrate the path of light as it reflects off of mirrors and how this is used in telescopes, especially if you have ever been asked why the Moon appears "flipped" or "upside down" in your eyepiece. All you need are a few sticks, some flexible foam, and a spoon. 

Check out the video below to see  this quick and simple demonstration in action. There is another discussion of how mirrors work in reflecting telescopes as part of the "How Do Telescopes Work?" video here.

Uploaded: October 2008