Evangelista Torricelli

17/07/2026

🗓️

🌱October 15, 1608 – Faenza, Italy.

🍂October 25, 1647 – Florence, Italy.

🌟 Main Contribution

Evangelista Torricelli invented the mercury barometer, demonstrating the existence of atmospheric pressure, and made advances in hydrodynamics, geometry, and applied optics

“We have only today; let us make good use of this day”

🧐 Did you know?

Evangelista Torricelli conducted his experiments utilizing mercury instead of water out of pure mathematical logic and space efficiency: since mercury is about fourteen times denser than water, it required a glass tube just one meter long, whereas an equivalent water experiment would have demanded an awkward vertical tube over ten meters high in the middle of a public street.

🏅 Awards and Honors

Torricelli received no formal awards during the 17th century. However, his extraordinary mathematical and physical contributions in Italy earned him the appointment as court mathematician to Ferdinand II de’ Medici, Grand Duke of Tuscany, succeeding Galileo.

📚 Their name in science

🔆 Torr (torr)

Historical unit of pressure, equivalent to 1 millimeter of mercury, named in honor of his fundamental experiments with the barometer.

➤ Torricelli’s Theorem

Principle of fluid mechanics stating that the velocity of a liquid flowing through an orifice in a container is equal to the velocity a body would acquire in free fall from the liquid’s free surface.

➤ Torricelli’s Law

Mathematical statement derived from Bernoulli’s principle that quantifies the discharge rate of a liquid through an orifice under the sole influence of gravity.

❓ Who was Evangelista Torricelli?

Evangelista Torricelli was an Italian physicist and mathematician ranked among the most brilliant minds of the generation that consolidated the Scientific Revolution. Orphaned at a very young age, his astonishing talent for exact sciences was nurtured by his monk uncle and later cultivated in Rome. His brilliant analysis of projectile motion caught the attention of the aging Galileo Galilei, leading Torricelli to become his student and secretary during the master’s final months of life. Gifted with exceptional dexterity for mechanical experiment design and optical lens grinding, he assumed the post of court mathematician to Tuscany, dedicating his brief existence to unraveling the mysteries of air and fluids.

🌍 The world in their time

In the early 17th century, fluid physics was paralyzed by the Aristotelian dogma asserting that “nature abhors a vacuum” (*horror vacui*). Engineers of the era faced a frustrating practical limit: mechanical suction pumps were completely unable to lift water in wells higher than ten meters, and no one could comprehend the physical cause behind this boundary.

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🔬 Scientific legacy

Evangelista Torricelli revolutionized science in 1643 by designing the celebrated Torricelli Experiment. Utilizing a glass tube filled with mercury inverted over a basin, he proved mathematically that the mercury dropped until stopping at exactly 760 millimeters in height, demonstrating for the first time the existence of a vacuum and atmospheric pressure. This scientific milestone meant the invention of the barometer. Furthermore, he formulated Torricelli’s Law for the speed of a fluid exiting an orifice.

👣 Footprint in today's world

The discovery of Evangelista Torricelli remains fundamental to contemporary meteorology and aviation. The barometer he invented forms the mechanical basis of instruments measuring air pressure to predict weather patterns and altimeters used by modern aircraft to calculate flight altitude. The pressure unit torr (Torr), equivalent to one millimeter of mercury (mmHg), immortalized his name in science.

🏃‍♂️ The relay race

📥 Taking the baton

The monumental experimental breakthroughs of Evangelista Torricelli built directly upon the scientific method and projectile motion mechanical investigations developed by his master Galileo Galilei, combined with classical mathematical geometry studies by Archimedes.

📤 Passing the baton

The bold scientific conclusions of Evangelista Torricelli regarding the vacuum and the weight of air crossed Europe and directly inspired the famous barometric experiments of Blaise Pascal in France, as well as the developments of mechanical vacuum pumps conducted by Otto von Guericke in Germany.