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

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

What does the heliocentric model mean?

what does the geocentric model state?

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

Who thought of the Geocentric model?

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

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

Why can we see objects like stars?

Why can we see planets in our Solar System?

What do telescopes do?

What are converging lenses used for?

what is a converging lense?

Describe the focal point.

NOTE :

What is a refracting telescope made up of?

What happens in a refracting telescope?

What is the incident ray?

What does a reflecting telescope use?

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

Which EM wave has the highest frequency?

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

Which EM wave has the biggest wavelength?

What did Herschel discover in 1800?
How?

Who discovered Ultraviolet radiation, when?

How did Ritter discover UV radiation?

What are the dangers of Microwaves?

What are dangerous about infrared radiation?

What are the dangers of Ultraviolet radiation?

What are the dangers with gamma/x-rays?