ארי זיבוטובסקי וארי גרינספן

A dentist who enjoys combining halakha with history, Dr. Ari Greenspan is also a mohel, shohet, and cofounder of Ptil Tekhelet, which produces blue tzitzit threads using dye made from Murex shells Associate professor of science, Jewish law, and education at Bar-Ilan University, Dr. Ari Zivotofsky completed his doctorate in biomedical engineering and researches the kosher status of unusual animals