During the Middle Ages, there was frequently an exchange of works between Byzantine and Islamic science. The Byzantine Empire initially provided the medieval Islamic world with
Ancient and early
Medieval Greek texts on
astronomy,
mathematics and
philosophy for translation into Arabic as the Byzantine Empire was the leading center of scientific scholarship in the region at the beginning of the Middle Ages. Later as the
caliphate and other medieval Islamic cultures became the leading centers of scientific knowledge, Byzantine scientists such as
Gregory Chioniades, who had visited the famous
Maragheh observatory, translated books on
Islamic astronomy,
mathematics and science into
Medieval Greek, including for example the works of
Ja'far ibn Muhammad Abu Ma'shar al-Balkhi,
Ibn Yunus,
Al-Khazini (who was of Byzantine Greek descent),
Muhammad ibn Mūsā al-Khwārizmī and
Nasīr al-Dīn al-Tūsī (such as the
Zij-i Ilkhani and other
Zij treatises) among others. There were also some Byzantine scientists who used Arabic transliterations to describe certain scientific concepts instead of the equivalent Ancient Greek terms (such as the use of the Arabic
talei instead of the Ancient Greek
horoscopus). Byzantine science thus played an important role in transmitting ancient Greek knowledge to Western Europe and the Islamic world, and also transmitting Arabic knowledge to Western Europe. Some historians suspect that
Copernicus or another European author had access to an Arabic astronomical text, resulting in the transmission of the
Tusi couple, an astronomical model developed by Nasir al-Din al-Tusi that later appeared in the work of
Nicolaus Copernicus. Byzantine scientists also became acquainted with
Sassanid and
Indian astronomy through citations in some Arabic works.
J. R. Partington writes that Such mechanical devices reached a high level of sophistication and were made to impress visitors. Leo the Mathematician has also been credited with the
system of beacons, a sort of optical telegraph, stretching across Anatolia from
Cilicia to Constantinople, which gave warning of enemy raids and was used as diplomatic communication. ==Humanism and Renaissance==