Biruni's Planetary Theory

The aim of this thesis is to explain the planetary theory of Abu'r-Rayhan Muhammad bin Ahmed al-Biruni, one of the most important mathematics and astronomy scholars of the 11th century Islamic World. For this purpose, the relevant sections in Bîrûnî's work Kânûnü'l Mesûdî fi'l İlmü'l Hey'e ve'l Nücûm were translated and interpreted into Turkish by creating the Arabic edition critical text. In addition to this work, the Turkish translation of the sections in which he explains the basic astronomy concepts in his book Tefhîm li'l Evâili'l fi's Sınâti'l Tencîm, which explains astronomy subjects as an introduction, has also been added. Since Biruni based his theory of planets on Ptolemaic system, the principles of Ptolemaic astronomy are explained in the introduction part of the thesis. Because of doing this, Ptolemy's theories in el-Mecistî and Kitâbü'l İktisâs/Kitâbül Menşûrat (Planetary Hypotheses) were explained. In the commentary section of the translated texts mentioned above, the subjects on which Biruni agreed and disagreed with Ptolemy were stated and his comments and innovations were emphasized. In this study, Biruni's contributions to the criticism of Ptolemaic planetary theory in the 11th century was also questioned. The critical text at the end of the thesis is prepared using the manuscripts of Veliyüddin Efendi 2277, Berlin 1613, London 1997, Kandilli 364 and the printed text of Hyderabad (1954-1955) among the manuscripts available.