Nicholaus Copernicus - so what has he got to do with gravity and space capsules?

Well - he was one of the first people to say Aristotle was wrong about the Earth being at the centre of everything.

Copernicus was born in 1473 and he decided it would be much easier to work out the positions of the planets if the Sun was at the centre of the universe.

He based his ideas on a lot of naked eye astronomy. He used to look at the stars from a turret in the grounds of the cathedral where he was canon in Frauenburg, Germany.

He wrote a book called De Revolutionibus - in this book he came up with the idea that the Earth turns around once on its axis daily and that it takes a year for the Earth to go around the Sun!

That was quite amazing to say in those days.

Copernicus had his book published on or near his death but the church wrote a forward to the book saying that it was all theory...

Having new ideas about the universe didn't go down too well with the church in those days. If you came out and said it Copernicus's theory was true you might be burned at the stake by the Spanish Inquisition like the unfortunate Italian astronomer Giordano Bruno.

By the way did you know there's a crater on the far side of the moon named after Copernicus - click here to see it.