mathematics were or are Jewish. The early Jewish activity in science can be found in the Hebrew Bible where some of the books contain descriptions of the physical world. Biblical cosmology provides sporadic glimpses that may be stitched together to form a Biblical impression of the physical universe. There have been comparisons between the Bible, with passages such as from the Genesis creation narrative, and the astronomy of classical antiquity more generally. The Old Testament also contains various cleansing rituals. One suggested ritual, for example, deals with the proper procedure for cleansing a leper (). It is a fairly elaborate process, which is to be performed after a leper was already healed of leprosy (), involving extensive cleansing and personal hygiene, but also includes sacrificing a bird and lambs with the addition of using their blood to symbolize that the afflicted has been cleansed. The Torah proscribes Intercropping (Lev. 19:19, Deut 22:9), a practice often associated with sustainable agriculture and organic farming in modern agricultural science. The Mosaic code has provisions concerning the conservation of natural resources, such as trees () and birds (). During Medieval era astronomy was a primary field among Jewish scholars and was widely studied and practiced. Prominent astronomers included Abraham Zacuto who published in 1478 his Hebrew book Ha-hibbur ha-gadol where he wrote about the Solar System, charting the positions of the Sun, Moon and five planets. His work served Portugal's exploration journeys and was used by Vasco da Gama and also by Christopher Columbus. The lunar crater Zagut is named after Zacuto's name. The mathematician and astronomer Abraham bar Hiyya Ha-Nasi authored the first European book to include the full solution to the quadratic equation x2 – ax + b = 0, and influenced the work of Leonardo Fibonacci. Bar Hiyya proved by the method of indivisibles the following equation for any circle: S = LxR/2, where S is the surface area, L is the circumference length and R is radius. Garcia de Orta, Portuguese Renaissance Jewish physician, was a pioneer of Tropical medicine. He published his work Colóquios dos simples e drogas da India in 1563, which deals with a series of substances, many of them unknown or the subject of confusion and misinformation in Europe at this period. He was the first European to describe Asiatic tropical diseases, notably cholera; he performed an autopsy on a cholera victim, the first recorded autopsy