Telescopes Introduction: In this lab, you will investigate the properties of lenses and build a simple telescope. The telescope you will build is similar in design to the telescopes used in the time of Galileo and Kepler. Telescopes have two main functions: to gather more light and bring it to the observer's eye and to magnify distant objects. The telescope you build will have a magnification of 25 times, which is comparable to Galileo's best telescope and to commercial binoculars today. This magnification is useful for observing the Lunar surface and the moons of Jupiter. Background material: When light travels through space, or inside something transparent like air or glass, it travels in a straight line. If light reflects off an object, such as a mirror, it will change direction at the surface. If light moves from one medium to another, such as from air to glass, it can change direction again at the surface. However, once it has changed direction, it will continue along a straight line. We call the straight paths of light "light rays