How to make a simple Telescope

You need:

• Two magnifying glasses
• Two cardboard tubes of different diameters
• Sticky tape

What to do:

1. Slide one tube into the other. Fix a magnifying glass at one end with sticky tape.
2. Look at the moon through the tubes, with your eye against the taped magnifying glass and holding the second glass at the other end. Make the tube longer and shorter and move the second glass until you get a clear image.

What happens?

Through the taped magnifying glass, you can obtain a closer image of the moon , but upside down.

Reason:

This is because the lens at the end make the rays of light from the moon converge and create the image inside the tube. The lens nearest to the eye enlarges this image and makes the moon appear closer. Refractor telescopes work in the same way, but these are much larger in order to show images which are not upside down.