Giovanni Alfonso Borelli

Giovanni Alfonso Borelli (; 28 January 1608 – 31 December 1679) was an Italian physiologist, physicist, and mathematician who is often described as the father of biomechanics. He contributed to the modern principle of scientific investigation by continuing Galileo's practice of testing hypotheses against observation. Trained in mathematics, Borelli also made extensive studies of Jupiter's moons, the mechanics of animal locomotion and, in microscopy, of the constituents of blood. He also used microscopy to investigate the stomatal movement of plants, and undertook studies in medicine and geology. During his career, he enjoyed the patronage of Queen Christina of Sweden. He was the first scientist to explain that animal and human bodily movements are caused by muscular contractions.

Biography Giovanni Borelli was born on 28 January 1608 in the district of Castel Nuovo, in Naples. He was the first-born son of Spanish infantryman Miguel Alfonso and a local woman named Laura Porello (alternately Porelli or Borelli.) Borelli had five siblings.

Borelli eventually travelled to Rome where he studied under Benedetto Castelli, matriculating in mathematics at Sapienza University of Rome.

Borelli and Malpighi were both founder-members of the short-lived Accademia del Cimento, an Italian scientific academy founded in 1657. It was here that Borelli, piqued by Malpighi's own studies, began his first investigations into the science of animal movement, or biomechanics. This began an interest that would continue for the rest of his life, eventually earning him the title of the Father of Biomechanics. Borelli's involvement in the Accademia was temporary and the organization itself disbanded shortly after he left.

From 1664 to 1665, Borelli tracked the path of a comet. He took measurements of the comet and concluded that it was moving in an elliptical curved orbit around the sun. These conclusions went against the accepted scientific theory of the day (that was supported and imposed by the Catholic church), which asserted that Earth was the center of the universe. It was dangerous to oppose the theories of the church, so Borelli published his findings under the pseudonym Pier Maria Mutoli. In a treatise titled, Del Movimento della Cometa Apparasa il mese di Dicembre (Of the Movement of the Comet that Appears in the Month of December), Borelli suggested that planets and comets orbit the sun. The book attempted to clarify the cause of muscle fatigue, explain the cause of organ secretion, and explain the concept of pain. The first volume covers biomechanical and muscular action in humans and animals (how muscles move while living beings walk, run, swim, jump, and fly). The second volume discusses the physiology of human organs, namely the lungs and heart.

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 muscles did not release corpuscles into the water when cut. Borelli also recognized that forward motion entailed the 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 honor 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 person 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. He discovered the principle of the heliostat more than sixty years before Willem 's Gravesande.

Other works

Borelli also wrote: Delle cagioni delle febbri maligne della Sicilia negli anni 1647 e 1648 (Cosenza, 1649) Euclides Restitutus (Pisa, 1658)

Theoricae Mediceorum planetarum ex causis physicis deductae (Florence, 1666)