Refracting Telescopes

While we have no physical evidence, we have very strong documentation that refracting telescopes were used in England as early as the sixteenth century. The use of telescopes became widespread in the early seventeenth century in the Netherlands.

Hans Lippershey and Zacharias Janssen of the Netherlands claim the invention of the original telescope. This original scope had both concave and convex lenses so that the image would not be inverted. After the Netherlands started producing them, they were rapidly found all over Europe.

In 1609, Galileo was visiting Venice and claims to have solved the problems with the telescope by using a convex lens in one end and a concave in the other end. Thus, moving the two pieces of glass further away from each other. This led to better image viewing with less rainbow effects around the distant object. Galileo spent much of his time to perfecting the telescope after that. His first telescope magnified at a power of three diameters, and the best one he made magnified at a diameter of thirty-three diameters. These last telescopes were so great that in 1610, he discovered the satellites of Jupiter, the spots on the sun, and the hills and valleys on the moon.

These telescopes are common today. They are made out of a long tube of metal or wood. They have a glass lens at the front and back ends as well as an eyepiece at the back. The tube helps to keep moisture and dust away from the lenses for a better image. The two lenses help focus light and refract it to the back of the tube where the eyepiece magnifies it so that you can see it clearly.

Refracting scopes have a resolution high enough to see details in binary stars and planets. They are expensive and less useful for looking at other galaxies or nebulae. You can see a plethora of stars and other heavenly bodies with them though.