Fifth Grade
Worksheets
How Do Telescopes Work?
When people look at things that are far away, they use telescopes. Telescopes were first invented in the early 1600s. The first telescopes were long tubes with glass lenses inside.
Here's why telescopes make things look bigger. Light moves in straight lines. When it passes through a different medium - like when light passing through air moves through water or glass - it slows down or speeds up a little. The path of the light bends. Lenses are curved pieces of glass. Lenses can focus the light and make things look bigger (telescope) or smaller (microscope).
A telescope does three things. First, a telescope collects light. The more light it catches, the brighter the light is, and the better a person can see. It works sort of like a funnel. Light goes into the large opening and is funneled into a smaller opening. A telescope's size is measured by the size of its main light-collecting lens or mirror.
