Do things exist even if we cannot see them? Yes! But how can this be possible? Our eyes can only see objects which are up till some distance. Sometimes if the object is too far our eyes are unable to see it. So how do we know what is happening at a far distance?
We use a device called Telescope. Earliest versions of telescope used mirrors which gathered the visible light from the far objects. The newer versions of telescopes collect invisible light ( light that our eye cannot see) such as radio waves and x-rays.
The bigger the telescope the farther it can see. Telescopes are very important as without we would not be able to discover the universe beyond us.
Why a Telescope named so? Because Tele (in Greek )means far and Skope (in Greek) means seeing.