How Telescopes Work

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"How Telescopes Work"
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Galileo in 1609, exhibited to the world the first telescope, although someone else had invented it; his name was Hans Lippershey, a Dutch eyeglass maker. With the Refractor Telescope as it was called, Galileo was able to come to a hypothesis, that the Earth revolved around the Sun. He was soon after imprisoned for heresy by Catholic authorities, of the Church, because it was against their teachings. It took the Catholic Church over 300 years to correct their error and reinstate Galileo, which they did in 1992. Improvements of the telescope continued and in 1668, Sir Isaac Newton invented the Reflector Telescope. Even recently with Global Positioning Systems, telescopes are becoming faster and sharper.

How does a telescope work? To begin with there are 3 types of telescope: The Refractor Telescope, which works on the light principle that, the wavelength of the light is changed as it goes through a different medium such as glass. The Reflector Telescope, which reflects and changes a lights direction through a different medium also glass. The third telescope is the Catadioptric Telescope which follows the same transmission of light wave principles. The Refractor and the Reflector Telescopes, are the two used primarily by the public, therefore we'll discuss how these work. The Catadiopric Telescope works along the same rules.

The Refractor Telescope, consist of a long tube with an objective lens placed in front; this objective lens gathers light waves, which are reflected from the intended object, focuses it through the focal point and onto the eyepiece located at the rear of the tube, which magnify and allow an image to be seen. The amount of magnification can be accomplished using an eyepiece, with different magnification strength.

The Reflector Telescope, has no lens at the front of the tube, and is bigger in diameter than the Refractor. At the back of the tube is a large concave objective mirror, which light waves from an object falls on, this then bounces onto a smaller flat mirror situated in the middle of the tube. The image is then reflected to the eyepiece on top of the telescope

Because light is so important in viewing objects to be seen, the greater the aperture or opening that allows light through the objective lens is very important. A telescope with a large aperture would give you a better image.

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