Certainly he was right to be careful.The Christian Church rejected his theory,saying it was against God's idea and people who supported it would be attacked.Yet Copernicus'theory is now the basis on which all our ideas of the universe are built.His theory replaced the Christian idea of gravity,which said things fell to earth because God cerated the earth as the centre of the universe.Copernicus showed this was obviously wrong.Now people can see that there is a direct link between his theory and the work of Isaac Newton,Albert Einstein and Stephen Hawking.