Copernicus and Galileo

At first people believed that the Earth was at the centre of the Universe. This was known as the 'Geocentric' model of the Universe. Astronomers like Copernicus decided the only thing that actually made sense, when observing the night sky, was if the Sun was at the centre of the Universe. This was known as the 'heliocentric' model.

And okay, the sun isn't at the centre of the Universe, but it is at the centre of the solar system - so it's closer to being write than the previous model.

This first video mentions Copernicus and Galileo:

 

 

Galileo Galilei - a brief biography of the father of modern science. He wasn't just an astronomer.