Ibn al-Haytham writes, between approximately 1025 and 1028 (academic sources disagree on the exact range; some studies place parts of the work as late as 1038), the Al-Shukūk ʿalā Baṭlamyūs ("Doubts Concerning Ptolemy"), a systematic critique of three works by Ptolemy — the Almagest, the Planetary Hypotheses, and the Optics — pointing out internal contradictions and contradictions between them. His central objection is that the Ptolemaic equant, an auxiliary mathematical point that forces an apparently uniform motion without it being physically so, violates the principle that celestial motions must be real uniform circles, not abstract geometric constructions. Ibn al-Haytham proposes no complete mathematical alternative, but inaugurates the "Shukūk tradition" of astronomical criticism that drives later generations — including the Maragha school of Al-Tusi — to seek a geometric solution eliminating the equant without sacrificing uniform circular motion.