Professor Aniol
Astronomy 360, Term Paper
27 November 2014
Seeing Things Far Away as Though Nearby The main purpose of a telescope is to collect light. Telescopes are designed and built to gather specific kinds of information at different wavelengths in the electromagnetic spectrum, such as visible, infrared or millimeter wavelengths (Takunaga). The word “telescope” consists of the Greek roots “tele-“ meaning “far” and “-skopos” meaning “seeing”. The telescope is an optical instrument for making distant objects appear larger and nearer. Refracting telescopes consist of an objective lens set into one end of a tube and an adjustable eyepiece or a combination of lenses set into the other end of the tube and the enlarged object is viewed directly. A reflecting telescope has a concave mirror that gathers light from the object and focuses it into an adjustable eyepiece or combination of lenses through which the reflection of the object is enlarged .Compound lenses are used to avoid distortions such as spherical and chromatic aberrations. Most optical telescopes are reflecting telescopes because very large mirrors, which are necessary to maximize the amount of light received by the telescope, are easier to build than very large lenses (Definition).
It is true that the properties of convert and concave transparent objects were known in antiquity. Magnifying glasses became common in the 13th century for seeing. Glassmakers in Venice, Italy made small disks of glass, convex on both sides, that could be worn in frames. The DeMoss 2 earliest illustrations of spectacles date from about 1350 and soon became symbols of learning. Around 1450, the factors for the telescope existed but it is likely that lenses and mirrors of the appropriate strengths were not available until later (Galileo Project). Galileo Galilei
Cited: "About Mauna Kea Observatories." About Mauna Kea. University of Hawaii, n.d. Web. 27 Nov. 2014. <http://www.ifa.hawaii.edu/mko/about_maunakea.shtml>. "Definition of "Telescope"" Dictionary.com. Dictionary.com, n.d. Web. 27 Nov. 2014. <http://dictionary.reference.com/browse/telescope>. Helden, Albert Van. The Origins of the Telescope. Amsterdam: KNAW, 2010. Print. Takunaga, Dr. Alan T. "Telescopes." On Mauna Kea. University of Hawaii, July 1995. Web. 27 Nov. 2014. <http://www.ifa.hawaii.edu/info/bulletins/telescope.html>. "Telescope Types - Astronomy For Kids." Telescope Types - Astronomy For Kids. Kids Know It Network, n.d. Web. 27 Nov. 2014. <http://www.kidsastronomy.com/telescopesB.htm>. "The Galileo Project | Telescope." The Galileo Project |Telescope. Ed. Albert Van Helden and Elizabeth Burr. Rice University, n.d. Web. 27 Nov. 2014. <http://galileo.rice.edu/sci/instruments/telescope.html>. "Time Line: A History of Telescopes." Telescopes Timeline — National Geographic Magazine. National Geographic, 2014. Web. 27 Nov. 2014. <http://ngm.nationalgeographic.com/2009/07/telescopes/telescopes-interactive>. DeMoss 9 Wethington, Nicholos. "Who Invented the Telescope." Who Invented the Telescope. Universe Today, 1 Oct. 2009. Web. 03 Dec. 2014. <http://www.universetoday.com/41889/who-invented-the-telescope/>.