What Ptolemy theory did Gersonides disprove?

Shortly before Copernicus died he figured that not the earth was centerof things but the sun was. This theory is stilled used today.

Copernicus did not disprove anything. He advanced a simpler theory which turned out to be more correct.

Ptolemy's theory was that the earth was the center of the universe, around which all things - including the sun - revolved.

i think he was tring to figure out how the universe was shaped. he probably thought the earth was in the middle of everything because we could see the sun and the moon from earth, but the other...

Ptolemy's theory accounted mathematically for the movement of the planets, sun, and moon relative to fixed stars. Ptolemy thought it was that the earth is the center of the universe, which is wrong...