Most of the non-magical things of astronomy were made by Muggles (I know crazy right) 😂

TELESCOPES

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  A telescope is an object that magnifies an object in the distance and makes it look closer/brighter (depending on the type of telescope)

  
  


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  Astronomers have discovered hundreds of celestial bodies using the telescope.

  
  


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  Edwin Hubble (the creator of the Hubble telescope) concluded that the universe was expanding.

  
  


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  Edwin Hubble created the astronomical branch called cosmology

  
  


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  Early telescopes had two lenses on opposite sides of a long tube

  
  


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  The far end of the tube has a light-gathering lens, formally called the objective lens

  
  


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  The objective lens is convex (thicker in the middle than the edges)

  
  


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  To make objects look clear to the eye, through the telescope, there is another lens on the telescope, which is called the eyepiece

  
  


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  Early telescopes had an eyepiece that was concave (opposite of convex), and people called it a negative lens

  
  


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  The first Muggle telescope (made by Hans Lippershey in 1608) had this design

  
  


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  Mr. Lippershey’s telescope made objects look three times as big than they did to your naked eye (without a telescope)

  
  


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  In 1610, Galileo Galilei improved Lippershey’s initial telescope design by making the objective lens less curvy, making the magnifying power much higher.

  
  


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  Galileo discovered that Venus had phases (just like our moon) 

  
  


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  Galilean telescopes had a problem: they had a VERY narrow field of view, meaning that you could only see a very small part of whatever you were looking at with it.

  
  


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  A man named Johannes Kelper discovered that if the eyepiece were also positive, you would be able to see much more of the sky.

  
  


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  After doing this, everything looked upside down (this didn't matter to astronomers because they would still be able to see the same things). This is called an astronomical telescope.

  
  


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  Navigators and pirates use terrestrial telescopes so that they can see right-side up.

  
  


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  In newer telescope models, there are two tubes instead of one and a way to focus to see clearer.

  
  


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  Some telescopes only use lenses, which are called refracting telescopes.

  
  


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   Refracting telescopes have a problem, though, the objects seen at the edge of the field of view appear to have little fringes of color. This is because of the way light bends along the edges of the glass. 

  
  


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  In 1688, Isaac Newton solved this problem by using mirrors instead of glass lenses.

  
  


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  He called this telescope the refracting telescope, and telescopes with his design are called Newtonian telescopes.

  
  


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  The amount in which a telescope can magnify distant objects is called the telescope’s power. 

  
  


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  The weaker the objective lens or mirror is and the stronger the eyepiece is, the more powerful the telescope will be.  

  
  


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  Astronomers also want to be able to see things that are too dim to be seen with their naked eye, and the bigger the objective lens or mirror is, the more light it will gather.  

  
  


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  The amount of light a telescope gathers depends on its area, and not its diameter.

  
  

An advantage of making the objective lens or mirror bigger is that it improves the resolution of the telescope (how close together two points of light can appear to be and still be seen as two distinct points instead of one).