Ptolemy was a 2nd century Greek mathematician, geographer, and astronomer (lived from 100 to 170).
Nicolaus Copernicus lived from 1473-1543. He published his heliocentric theory at the very end of his life (in 1543), knowing how dangerously controversial it would be.
So, from mid 16th century (1543) back to mid 2nd century (Ptolemy's time), that would be 14 centuries between the two.
