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Nothing is known about where Ptolemy was born or lived during his life. But he is known for his study of the heavens and for his maps. He was one of the first to try and make a complete description of the stars and planets. His model assumed that the earth was in the center of the universe, and the other planets and stars orbited around it.  

Nothing is known about where Ptolemy was born or lived during his life. But he is known for his study of the heavens and for his maps. He was one of the first to try and make a complete description of the stars and planets. His model assumed that the earth was in the center of the universe, and the other planets and stars orbited around it.  

This theory was popular for nearly 1500 years. It accurately predicted the motion of the planets better than any alternative. It was eventually replaced by [[heliocentric theory]].

This theory was popular for nearly 1500 years. It accurately predicted the motion of the planets better than any alternative. It was eventually replaced by [[Heliocentric|heliocentric theory]].