Giovanni Alfonso Borelli, Italian physiologist and physicist (died 1679)

Giovanni Alfonso Borelli was a Renaissance 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.

January 28 is the 28th day of the year in the Gregorian calendar; 337 days remain until the end of the year.