Muhammad al-Baghdadi, a Syrian professor and university professor specializing in theoretical physics, the author of the first large Arab encyclopedia of physics, and one of the most prominent scientific figures of our time. Among the most prominent of his positions is his constant call to teach scientific subjects in Arabic and his opposition to teaching in French in Arab countries, in addition to enriching the Arabic library with his physical encyclopedia “The Foundations of Contemporary Physics.” Professor Muhammad Al-Baghdadi was born in 1930 in Syria in the city of Damascus. He joined the Faculty of Law at Damascus University. After completing his studies in law, he was sent on a scholarship to France, where he studied mathematics and obtained a doctorate in it. Mathematics encouraged him to study physics, especially theoretical physics. He worked temporarily as an expert with UNESCO in mathematics and physics curricula, before settling in the Kingdom of Morocco to establish the first theoretical physics laboratory at the Faculty of Science at Mohammed V University in Rabat. Al-Baghdadi is also one of the founders of the Arabic department, which taught scientific subjects in Arabic at the Higher School of Teachers. Professor Al-Baghdadi has many books and translations in Arabic, English, French and German, most of which are in theoretical physics and the history of science, and the name of the professor has always been brilliant in the field of scientific research and has many works and contributions in this field. Muhammad Al-Baghdadi died on March 18, 2020 in Morocco, leaving his physical encyclopedia, benefiting from his experiences in the field of teaching and scientific research. history and civilization, and that it is capable of accommodating various sciences and their terminology at all levels.