"More stars in the north are seen not to set, while in the south certain stars are no longer seen to rise"

Nicolaus Copernicus' quote is referring to the fact that the stars in the northern hemisphere appear to remain in the very same place in the night sky, while stars in the southern hemisphere appear to relocate the night sky. This is because of the reality that the Earth is turning on its axis, triggering the stars in the northern hemisphere to appear fixed, while the stars in the southern hemisphere appear to move. This phenomenon is called the "evident movement of the stars". Copernicus' quote is a suggestion that the stars in the night sky are not actually moving, however rather it is the Earth that is rotating and triggering the stars to appear to move. This was an innovative concept at the time, as it was previously thought that the Earth was fixed and the stars moved it. Copernicus' quote is a reminder of the value of his discoveries and the effect they had on our understanding of deep space.