Evangelista Torricelli Biography

Evangelista Torricelli (1608-1647) was an Italian physicist and mathematician who made great contributions in the fields of pure mathematics, integral calculus and the movement of projectiles and fluids. Evangelista Torricelli thought that mathematics was the language that allowed humans to understand nature.

Torricelli was the first man to recognize that air has weight and that atmospheric pressure is variable. From this idea, he created an artifact that was known as Torricelli’s tube and that gave rise to the invention of the barometer. On the other hand, in the field of mathematics, Evangelista developed hat is called Torricelli’s theorem which helps to calculate the flow of a liquid through an open hole at a certain depth.

Evangelista Torricelli was born on October 15, 1608, in Faenza, province of Ravenna, Italy, and grew up in a humble family. His parents were Gaspare Torricelli, a textile worker, and Caterina Angetti. When their parents realized his potential, they decided to send him to study humanities with his father’s brother, Jacobo, who was a Camaldulense friar.

In 1624, he entered a Jesuit college where he was taught in mathematics and philosophy for two years. After his father died, between 1626 and 1627 he traveled to Rome with his whole family (his mother and two brothers) to study with the Benedictine friar, Benedetto Castelli.

Torricelli would be assigned the position of private secretary of Castelli. He used the money obtained with work to pay for his studies so he could stay in the position and studying at the University College of Sapienza until 1632. Later, Castelli appointed Torricelli to replace him as the teacher in mathematics, mechanics, hydraulics, and astronomy in the University College of Sapienza.

On September 11, 1632, Torricelli received a letter from Galileo addressed to Castelli. In his response, Torricelli besides explaining the reason for the absence of his teacher, he took the opportunity to express his admiration for the text Dialogue Concerning the Two Chief World Systems, Ptolemaic and Copernican that was written by Galileo six months earlier, and presented his support for the Copernicus theory that the earth revolves around the sun.

After Galileo was ordered to appear in Rome for his astronomy approaches, Torricelli decided to move his attention to less dangerous terrain, so he concentrated on mathematics.

In De Motu Gravium et Levium, Torricelli consigned some developments to the mechanical principles set forth by Galileo in his book Two New Sciences (1638). Shortly afterward, on April 10th, 1641, Castelli handed Galileo

a copy of this work, and later, Torricelli became Secretary of Galileo. Unfortunately, after three months of coexistence with Galileo in Florence, Galileo passed away.

In spite of the death of Galileo, he remained in Florence as a philosopher and mathematician of the Grand Duke Ferdinand II and professor of mathematics at the Academy. Shortly after, he managed to answer the question that had haunted Galileo: the question of the veracity of Aristotle’s theory, which said that Nature abhors a vacuum.

Torricelli achieved the answer by means of an experiment that consisted of filling a tube with mercury (liquid that is 13.5 times denser than water) covering one end of the container and inserting it into another container with more mercury. In this way, it was observed that a part of the mercury that filled the tube is transferred to the second container creating a space for the vacuum. In addition, his demonstration of the existence of emptiness included the clarity that it is not possible to find it in nature but it is necessary to generate it artificially.

In 1643, he demonstrated the existence of atmospheric pressure and developed the basis for the barometer.

The barometer was not Torricelli’s only important discovery. For example, thanks to him we know that geometric curves are not limited to their theoretical form but are representations of real physical movements. From this idea, it was proposed to study the parabolic trajectories followed by the projectiles when being fired and reached two conclusions: the first was that “the envelope of all these parables is another parable” and the second was that “the locus of the vertices of all the parabolas is also another parabola.” Apart from this, he showed that “the rotation of curves of infinite length can produce solids of finite volume.” (Suma, 2009).

Undoubtedly Torricelli was one of the most productive and promising mathematicians of the seventeenth century. It is believed that if he had not died so young (he was only 39 years old at the time of his death) he would have formulated his methods mathematically and would have approached the concept of the limit. It is even believed that he could have invented the infinitesimal calculus. Unfortunately, he lost the battle against pleurisy in 1647, and died in Florence, Italy.