The development of the exact sciences
In the 15th century Samarkand and Herat gathered scholars, poets and composers. Ulugh Beg was interested in mathematics and astronomy from youth and studied the works of Farghani, Khorezmi, Biruni, Ibn Sina and Greek scholars. In 1424–1429 he had an observatory built by the Obi-Rahmat canal near Samarkand; according to the book it was 31 metres high, and its main instrument was a huge sextant. Jamshid Kashani, Qadi-zada Rumi, Ali Qushchi and other scholars made observations there. As a result the positions of 1018 fixed stars were determined and the “Zij-i Jadid-i Guragani” (the new astronomical tables of Guragan) was compiled: it has a wide introduction and tables of stars. The tables are counted among the most accurate of their time; the length of the year is said to differ from the modern measure by about a minute. After Ulugh Beg the observatory fell into ruin, and its remains were found only in the early 20th century.
“Sky map”: children draw a constellation and write its position like a table row (observe at home at night with an adult).