Space Refractors

Jack McVicker




The Invention of Space Telescopes and Refractors


I. Introduction

In 1609, an Italian mathematics professor named Galileo Galilei looked through a strange new device at the stars. Suddenly, the night sky that seems so familiar, revealed itself as uncharted territory. To the naked eye the moon looks like a gray-white sphere, but with Galileo's new instrument saw shadows and bright spots. With his new instrument Galileo could depict mountains and valleys on the moon.


II. History



Once Galileo started gazing at the stars through his instrument he changed his view on the planets. What he once thought were just little spheres in space, had now become miniature globes through the eyes of his invention. While discovering his deeper appreciation for the planets he found that they too have moons that accompany them. Galileo quickly published his discoveries in a bulletin he called "Message from the Stars." When his discoveries were read they were met with much excitement and wonder. Galileo originally named his device a "teliscopio," which means "to see at a distance," in Greek.


Galileo's refracting telescope used two lenses to concentrate the light on celestial objects. This delivered more light to the human eye than it could gather on its own. The light would be refracted through a spherical lens, forming an image. Galileo's original refractors had a spherical shape for primary lenses that made images blurry. The telescope had a double lens design also, and it was extremely simple. It was a tube that had two lenses; the primary lens curved outward, and the concave eyepiece of the lens was closer to the eye and it curved inwards. The inspiration for Galileo's telescope was the newly invented spyglass. The spyglass was an instrument used by the military to peer in on enemy camps.

III. Advances in Technology




The next leap in technology for refracting telescopes happened because of a man who never actually built one. Johannes Kepler, a German-born astronomer that studied in the field of optics, was the first man that figured out how glass lens' can focus light. He suggested changed such as the widening of the lens to give a more broad view. He also suggested removing the concave eyepiece with a convex lens. These changed gave the refractors a much larger area to view. After time people stopped using Galileo's design and adopted Kepler's two-convex lens design.

IV. Impact

Space telescopes and refracting telescopes enables us to achieve excellence in astronomical studies. Whether you are just doing recreational star gazing with buddies, or being paid to gaze at the stars, none of this would be possible without Galileo. He brought opportunity to the world, and everyone including himself utilized that opportunity. The impact Galileo and his telescopes have had on the history of our world cannot be put into words.

V. Resources

Bahcall, John. "Space Telescope Science Institue." Space Telescope Science Institute. 1 May 2000. http://www.stsci.edu/portal/.

Cain, Fraser. "Refractor Telescope." Universe Today. 1 Jan. 1999. Web. 15 Oct. 2010.
http://universetoday.com/15968/refractor-telescope/.

NASA, Researchers. "Telescopes: Galileo's Refractor." Amazing Space. 1 July 2001. Web. 15 Oct. 2010.
http://amazing-space.stsci.edu/resoures/exploration/groundup/lesson/scopes/galileo/index.php.

NASA, Researchers. "Telescope from the Ground Up" Amazing Space. 1 July 2001. Web. 15 Oct. 2010.
http://amazing-space.stsci.edu/resources/exploration/groundup/.