Question of the Day: How do magnifying glasses work?

Brought to you by Katie Grace.

Wikipedia article
A magnifying glass works by creating a magnified virtual image of an object behind the lens. The distance between the lens and the object must be shorter than the focal length of the lens for this to occur. Otherwise, the image appears smaller and inverted, and can be used to project images onto surfaces.

Science, Optics, and You- Click on the link for a Java tutorial.
A magnifying glass is a bi-convex lens. It is convex on both sides, meaning that the glass is curved outward to form a dome. Things look bigger looking through convex lenses. Below, you can see how a magnifying glass works to project an enlarged image on the retina of the eye.

Kitchen Science Experiments
Create images on the wall with a magnifying glass.

Magnify It!
An experiment for the K-2 set.

Safety Rules for Using Magnifiers
Apparently it's easier to set things on fire than I thought!

My children often ask me questions that I don't know the answer to (or don't know how to explain!), and I tell them we'll look it up later. More often than not, we forget and later never comes. Lately, I've been adding their questions to my never-ending "to do" list. I thought it might make good blogbait.