Adventures of Raghu - Through the eyes of a telescope

"Rasiya, just look at all the stars up there! Sometimes I wish I could just touch them, go closer, feel and see them more closely." said Raghu as he lay under the Banyan tree in his garden looking up into the night sky. Rasiya was lazily coiled on the banyan tree branches listening to Raghu and half falling asleep. "Hmmm" muttered Rasiya.

"Hey Rasiya! Get up!!! Let's make a telescope! I remember my teacher talking about it in class last month. At the time it sounded so boring, but today when I look up at the night sky, I really want to make it. Come on! Get up Rasiya!" cried out Raghu. "Oh no, not right now Raghu. Its almost 8pm and all I want to do is sleep." But Raghu had already ran indoors to collect the items that were needed to make his simple little telescope. "That boy! Did anyone teach him to listen!"mumbled Rasiya as he started shaking his body awake.

10 minutes turned to 30 minutes as Raghu came running back outside. "Look what I brought Rasiya! Paper towel rolls, A thick sheet of paper, tape and the two lenses our teacher gave to us at school. They're both double convex lenses. One is 150mm and another is 500mm. Let's get to work!"

Raghu began by rolling up the sheet of paper the long way, to form a tube that was about the diameter of the lens with the shortest focal length. "This will be the eyepiece Rasiya! Can you tape the edges of the eyepiece lens to one end of the paper tube Rasiya?" Rasiya was at it immediately. He was waiting to complete this project as soon as possible!

Raghu then began to tape the second lens with a larger focal length to the end of the paper towel tube. He then inserted the empty end of the paper tube into the paper towel tube. "Rasiya, its ready!!!" shouted Raghu in excitement. "Really!" said a surprised Rasiya. He couldn't believe it could really be that simple.

"Look through the lens with the shorter focal length and point the other end of the telescope at a distant object. Slide the two tubes in and out until the object comes into focus. You will see the image upside down and magnified. If you have trouble focusing the telescope, you may need to lengthen the tube. That's what our teacher had said at the end of the session." Rasiya looked through this simple telescope up to the sky. He pointed it towards the moon. It definitely looked magnified, he had never seen it like this before. "Wow! It actually works Raghu!" shouted a now some what enthusiastic Rasiya. "Ofcourse it does Rasiya! We'll make another longer one tomorrow." Raghu called back.