Copernicus

Copernicus was one of a number of people who were trying to solve the problem of why astrology charts kept coming out wrong.

Basically, this was because the old system of predicting where planets were kept breaking down, because it had the Earth in the middle.

Copernicus realised that if you put the sun in the middle, then you could predict where, say, Venus would be with much greater accuracy.

And thats useful, becuase it meant you could publish a much better set of astrological charts - one that didnt keep having planets in the wrong positions.