What is common and how are the systems of the world of Aristotle and Ptolemy different?

The common in the systems of the world of Aristotle and Ptolemy is geocentrism: in the center is the Earth, all the planets and the Sun revolve around it, there is a sphere of fixed stars. Difference: in the system of the world of Aristotle, all bodies move along concentric circles, in the system of the world of Ptolemy – along the epicycles, and the epicycle moves along the deferent.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.