[1] 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.

[3] He was the first-born son of Spanish infantryman Miguel Alfonso and a local woman named Laura Porello (alternately Porelli or Borelli.)

Borelli was designated to investigate "the causes of the malignant fever that lashed a large part of Italy in 1647.

He attributed the cause to an airborne infection and contested the prevailing opinion that the illness was due to excessive heat, humidity, or astrological influences.

Borelli also revised Apollonius of Perga: Conics, a treatise on mathematics that examined parabolas and ellipses.

[2] Around 1655, Borelli was invited to the University of Pisa by Ferdinando De' Medici Grand Duke of Tuscany.

[4] While it is likely that they remained acquaintances, Galileo rejected considerations to nominate Borelli as head of Mathematics at the University of Pisa when he left the post himself.

[5] Borelli and Malpighi were both founder-members of the short-lived Accademia del Cimento, an Italian scientific academy founded in 1657.

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.

[2] In 1674 Borelli was exiled from Messina to Rome[2] for suspected involvement in the political conspiracy to free Sicily from Spanish rule.

[4] Here he first became acquainted with ex-Queen Christina of Sweden who had been forced to give up her crown and exiled to Rome two decades prior as a punishment for converting to Catholicism.

[2] He was buried in the Church of San Pantaleo, adjacent to the convent of the Piarists Fathers, in the Parione neighborhood, where he had lived during the last two years of his life.

[9] The first volume covers biomechanical and muscular action in humans and animals (how muscles move while living beings walk, run, swim, jump, and fly).