Wednesday, January 11, 2012

Rabbi Yosef Shelomo Delmedigo (1591-1655)

Yosef Delmedigo was born in Candia (Crete, Republic of Venice). He was a rabbi, philosopher, mathematician, physician and astronomer.  The author of works whose number is estimated by some authorities at 30, by others at over 60.  At the age of 15, he was admitted to the University of Padua, where he studied astronomy and mathematics under Galileo Galilei. He also studied medicine and at the same time continued with his Jewish studies. While at Padua, he frequently visited Rabbi Aryeh di Modena of the neighboring city of Venice, who, it appears, exercised a lasting influence on him. In 1613, he completed his studies at the University of Padua, and traveled to Crete, where he began to practice medicine. 
Rabbi Delmedigo visited to Cairo, where he became acquainted with Ali b. Rahmadan, a renowned Arab mathematician, whom he refuted in a public disputation concerning spherical trigonometry. Then he traveled to Constantinople and Poland.  
In 1620, he was practicing medicine in Vilna, as the private physician of Prince Radziwill, and had many nobles for his patients. During the week, he used to make the circuit of the environs of Vilna to cure the sick, and on Shabbath he would lecture in the synagogue.  He was a pioneer in a number of aspects of scientific research. In astronomy, he espoused the Copernican system against the Ptolemaic system. He was the first Jewish scholar to use logarithmic tables, which had just been invented.  He was a pioneer in empiric medicine. He spoke against the unsanitary conditions prevailing in the ghettos.  Toward the end of his life, Delmedigo settled at Frankfurt on the Main, where he acted as the community physician.  On his tombstone  are written the words: "He practiced what he preached - he was just to everyone - the glorified rabbi, scholar, divine philosopher, and mighty one among physicians."

Portray of Rabbi Yosef Delmedigo 

One of his books, Elim, was first published by Menashe Ben Israel in Amsterdam 1629. The book is a response to religious and scientific questions (Tora umada') sent to Delmedigo by a Karaite Jew, Zerach ben Natan. The format of the book is taken from the number of 12 fountains and 70 palm trees at Elim in the Sinai Desert. Delmedigo divided his book into twelve major problems and seventy minor problems. The subjects discussed include astronomy, physics, mathematics, medicine, and music theory. In the area of music, for example, Delmedigo discusses the physics of music including string resonance, intervals, and their proportions, consonances and dissonances . 

In Elim and his other books, Rabbi Delmedigo also dealt with the first two books of Ptolemy's Almagest on astronomy, on astronomical instruments, on Kabbala and the supernatural,  on algebra, on chemistry, on the aphorisms of Hippocrates on the opinion of the ancients concerning the substance of the heavens, on the astronomy of the ancients, who considered the motion of the higher spheres due to spirits (Delmedigo shows that their motion is similar to that of the earth), on the principles of religion, and mathematical paradoxes, etc.