4-2 Buying a Telescope

The earliest known working telescopes appeared in 1608 in the Netherlands and are credited to Hans Lippershey. The design of these early refracting telescopes consisted of a convex objective lens and a concave eyepiece. Galileo used this design the following year. In 1611, Johannes Kepler described how a telescope could be made with a convex objective lens and a convex eyepiece lens, and by 1655, astronomers such as Christiaan Huygens were building powerful but unwieldy Keplerian telescopes with compound eyepieces.

Isaac Newton is credited with building the first "practical" reflector in 1668 with a design that incorporated a small flat diagonal mirror to reflect the light to an eyepiece mounted on the side of the telescope.

Summarize a new science technology. Complete Exercise 2.