Giovanni Alfonso Borelli - Scientific Achievements

Scientific Achievements

Borelli’s major scientific achievements are focused around his investigation into biomechanics. This work originated with his studies of animals. His publications, De Motu Animalium I and De Motu Animalium II, borrowing their title from the Aristotelian treatise, relate animals to machines and utilize mathematics to prove his theories. The anatomists of the 17th century were the first to suggest the contractile movement of muscles. Borelli, however, first suggested that ‘muscles do not exercise vital movement otherwise than by contracting.’ He was also the first to deny corpuscular influence on the movements of muscles. This was proven through his scientific experiments demonstrating that living muscle did not release corpuscles into water when cut. Borelli also recognized that forward motion entailed movement of a body’s center of gravity forward, which was then followed by the swinging of its limbs in order to maintain balance. His studies also extended beyond muscle and locomotion. In particular he likened the action of the heart to that of a piston. For this to work properly he derived the idea that the arteries have to be elastic. For these discoveries, Borelli is labeled as the father of modern biomechanics and the American Society of Biomechanics uses the Borelli Award as its highest honour for research in the area.

Along with his work on biomechanics, Borelli also had interests in physics, specifically the orbits of the planets. Borelli believed that the planets were revolving as a result of three forces. The first force involved the planets' desire to approach the sun. The second force dictated that the planets were propelled to the side by impulses from sunlight, which is corporeal. Finally, the third force impelled the planets outward due to the sun’s revolution. The result of these forces is similar to a stone’s orbit when tied on a string. Borelli's measurements of the orbits of satellites of Jupiter are mentioned in Volume 3 of Newton's Principia.

Borelli is also considered to be the first man to consider a self-contained underwater breathing apparatus along with his early submarine design. The exhaled gas was cooled by sea water after passing through copper tubing. The helmet was brass with a glass window and 0.6 m (2 ft) in diameter. The apparatus was never likely to be used or tested.

Borelli also wrote:

• Della cagioni delle febbri maligne (Pisa, 1658)
• Euclides Restitutus (Pisa, 1658)
• Apollonii Pergaei Conicorum libri v., vi. et vii (Florence, 1661)
• Theoricae Mediceorum planetarum ex causis physicis deductae (Florence, 1666)
• De vi percussionis (Bologna, 1667)
• Meteorologia Aetnea (Reggio, 1669)
• De motionibus naturalibus a gravitate pendentibus (Bologna, 1670)