How Telescopes Work
Allison Hutton
History
foundation for invention of the telescope was developed between 1350 and 1450
in 1570 the first actually instrument composed of lenses and mirrors was constructed by Leonardo and Thomas Digges
the telescope was officially released to the public in the Netherlands in 1608
Galileo was first to take advantage of the telescope to make discoveries in space such as sunspots, Jupiter’s moons, and the phases of Venus
Major Uses
mainly used to study astronomy
use ranges from actively attempting to make new discoveries to recreationally star gazing
can view moon, planets, stars, comets, meteor showers, galaxies, nebulae, etc.
Two Types of Telescopes
Refracting Telescopes
lens used in refracting telescopes was designed by Hans Lippershey in the Netherlands in 1608
Lippershey created the first telescope by putting his lenses in front of each other in a tube
Galileo used a refracting telescope in during his space study in 1609
How Refracting Telescopes Work
convex lens bends light inward
convex lens is thick toward the center of the class in order to bend the light more around the circumference of the lens
the light is focused and an image is created at the focal point
a concave lens is placed near the eyepiece of the telescope in order to magnify the image, thus making it appear closer to the viewer
Reflecting Telescopes
James Gregory developed the theory and design in Scotland in 1663
Isaac Newton put this plan into action and created the first model in 1688
How Refracting Telescopes Work
use concave mirrors instead of convex lenses
center of mirror is thinner than the edges
light hits the mirror and reflects back and collects light to form an image at the focal point
Refracting vs. Reflecting Telescopes
Refracting Telescope Reflecting Telescope
Disadvantage: telescopes must be large in size in order for the viewer to see the image at the focal point
Advantages: able to see dark or dim objects, powerful, capable of viewing far distances, clearer images
Advantages: lenses are more durable than mirrors
Disadvantages: produces unclear images sometimes, size of lens affects power so usually are less powerful
Relation to Physics 001
related to three major topics: reflection, refraction, and optics
chapter 28 in Conceptual Physics
from 4/9/12 - 4/13/12 we discussed how light behaves when shone through lenses or on mirrors which is directly related to telescopes
the ray diagrams taught in class come in handy to accurately illustrate the physics behind the telescope
Insight
I have used a telescope many times, but never stopped to think how it actually works, and this project allowed me to learn all about the physics behind the telescope
knew that there were reflecting and refracting telescopes, but now I actually understand the difference
learned that there are combination telescopes that involve both lenses and mirrors and these are usually the most effective but require the most effort and are typically constructed for a specific purpose
Bibliography
http://galileo.rice.edu/sci/instruments/telescope.html
http://library.thinkquest.org/J0112188/refracting_and_reflecting_telescopes.htm
http://abyss.uoregon.edu/~js/glossary/reflecting_telescope.html