What did ancient Greeks thought was at the centre of the universe?

In the 1600's what model began to replace the geocentric model

What was one of the most convincing pieces of evidence for the heliocentric model?

What where Galileo's observations of Jupiter?

What did Galileo's observation of the moons show?

What does the current model of the solar system say?

How has technology improved our ideas about about the solar system.

How has scientists found out most of the things it knows about the universe?

How did early astronomers observe the universe?

What do telescopes do?

What do photographs of the universe taken by telescopes do?

What is wavelength

What is frequency on a wave?

What is frequency measured in?

What is amplitude?

What is speed?

What do waves transfer and what do they not?

What is the formula that links speed, frequency and wavelenght

What unit is speed measured in?

What is wavelength measured in?

What formula links wave speed, distance and time?

What are the properties of a Transverse wave?

What are the features of a Longitudinal wave?

What is reflection?

What is refraction?

What is a real image?

What is a virtual image

What are converging or convex lenses use for?

What is the focal point?

What is the axis of a lens?

Where are the focal points of a lens?

How do you draw a ray diagram for an image through a converging lens?

What is focal length?

How can you work out focal length?