What is a refracting telescope made up of?

What are the dangers with gamma/x-rays?

What are the dangers of Ultraviolet radiation?

What are dangerous about infrared radiation?

What are the dangers of Microwaves?

How did Ritter discover UV radiation?

Who discovered Ultraviolet radiation, when?

What did Herschel discover in 1800?
How?

Which EM wave has the biggest wavelength?

Which EM wave has the smallest frequency and is the most dangerous?

Which EM wave has the highest frequency?

What are the seven types of electromagnetic (EM) waves?
-start from the shortest wavelength-

What does a reflecting telescope use?

What is the incident ray?

What happens in a refracting telescope?

What did the ancient Greeks think about how the universe was situated?

NOTE :

Describe the focal point.

what is a converging lense?

What are converging lenses used for?

What do telescopes do?

Why can we see planets in our Solar System?

Why can we see objects like stars?

Apart from telescopes, what else can tell us a lot about the universe?

The invention of the telescope helped lead to the discovery of which planet?

Who thought of the Geocentric model?

Who proved that the heliocentric model is the correct model for today? How did he do this?

what does the geocentric model state?

What does the heliocentric model mean?

What are the two models called for how the planets and sun and the earth move