(February 17, 1201 – June 25, 1274)
This Persian genius was a jack-of-all-trade. His works ramified arts and sciences. Tusi is regarded as the first person to demonstrate that Trigonometry is independent of Astronomy. His Treatise on the Quadrilateral unveiled Spherical Trigonometry in a manner neither seen nor contemplated before. He developed his famous Tusi-Couple, which is a geometrical contrivance that effectively replaced the cumbersome Ptolemy-Equant. His excellent works on planetary motions and accurate calculation of equinoxes were appreciated by Copernicus, who used it as basis to explore the then unknown realms of astrophysics. His bioresearches showcased some of the earliest forages into genetics and taxonomy. He classified living organisms into plants, animals and humans. As an avid reader of Avicenna’s works, Tusi was inspired to follow in his footsteps. From mathematics to medicine, and chemistry to physics, his tireless researches ushered-in some of the knowhow which buttressed Renaissance and the centuries of discoveries that followed it. For an example, this statement: “A body of matter cannot disappear completely. It only changes its form, appearance, condition, composition, color and other properties and turns into a different complex or elementary matter”, which is attributed to Tusi, precedes the very similar view of today’s Law of Conservation of Mass.