Discontent and frustration with the Ptolemaic system, loosing faith in ancient philosophers, practical need for a better calendar, a new scientific attitude preferring qualitative neatness and simplicity, rebellion against the oppression of church, yes, all of these psychological and social factors created a militant intelligentsia and a scientific elite that was ready to put the sun in the center. Putting the sun in the center was similar to raise the flag of revolution. It was the first concrete monument that could express all of the feelings and information accumulated throughout the centuries.