Evangelista Torricelli (15 October 1608 – 25 October 1647) was an Italian physicist and mathematician renowned for his groundbreaking contributions to science. A student of Galileo, he is most celebrated for inventing the barometer. In addition to this, Torricelli made significant advancements in optics and contributed to the method of indivisibles. His legacy is honored in the field of measurement with the unit “torr” named in his memory.
Who Was Evangelista Torricelli?
Evangelista Torricelli was an Italian physicist and mathematician born on October 15, 1608, in Faenza, Italy. Growing up during a time when science was beginning to break free from the shackles of superstition and religious doctrine, Torricelli became a leading figure in the scientific revolution. After completing his studies at the University of Bologna, he caught the attention of Galileo Galilei, one of history’s most significant scientists. Under Galileo’s mentorship, Torricelli honed his skills and knowledge, delving deep into the mysteries of physics and mathematics.
Torricelli’s passion for experimentation and inquiry would lead him to make groundbreaking discoveries that laid the foundation for modern science. His most notable achievement? The invention of the barometer.
Early Life
Evangelista Torricelli was born on 15 October 1608 in Rome as the first child of Gaspare Torricelli and Caterina Angetti. His family hailed from Faenza in the Province of Ravenna, then part of the Papal States, and lived in poverty, as his father worked in textiles. Recognizing his potential, Torricelli’s parents sent him to Faenza to receive an education under the care of his uncle, Giacomo, a Camaldolese monk. His uncle ensured that Torricelli received a solid foundation in education and later enrolled him in a Jesuit college around 1624, where he studied mathematics and philosophy until 1626, the year of his father’s death.
Afterward, his uncle sent him to Rome to study science under Benedetto Castelli, a Benedictine monk and professor of mathematics at the Collegio della Sapienza (now known as Sapienza University of Rome), who was a student of Galileo Galilei. Castelli conducted experiments on running water and was entrusted by Pope Urban VIII with various hydraulic projects. Although there is no definitive evidence that Torricelli was officially enrolled at the university, it is highly likely that he learned from Castelli while serving as his secretary from 1626 to 1632, which allowed him to participate in experiments funded by the Pope. During his time in Rome, he also became friends with mathematician Bonaventura Cavalieri and two other students of Castelli, Raffaello Magiotti and Antonio Nardi. Galileo referred to them affectionately as his “triumvirate” in Rome.
Career
In 1632, shortly after the publication of Galileo’s Dialogue Concerning the Two Chief World Systems, Torricelli wrote to Galileo, expressing his admiration for the work. He stated that he had diligently practiced geometry and studied the works of Ptolemy, Tycho Brahe, Kepler, and Longomontanus, ultimately embracing the Copernican view. This letter represents one of the few instances where Torricelli publicly declared his support for Galileo’s ideas.
Details about Torricelli’s activities between 1632 and 1641 are sparse, but in 1641, Castelli sent Torricelli’s monograph on projectile motion to Galileo, who was then confined to his villa at Arcetri. Although Galileo invited Torricelli to visit him, he delayed the trip until three months before Galileo’s death, primarily due to the passing of his mother, Caterina Angetti. This brief interaction with Galileo allowed Torricelli to complete the fifth dialogue under Galileo’s guidance, which was later published by Viviani, another of Galileo’s pupils, in 1674.
After Galileo’s death in January 1642, Grand Duke Ferdinando II de’ Medici appointed Torricelli as the grand-ducal mathematician and chair of mathematics at the University of Pisa. Just before accepting this position, Torricelli considered returning to Rome, feeling there was little left for him in Florence, where he had invented the barometer. In his new role, he tackled significant mathematical challenges, such as determining the area and center of gravity of a cycloid, leading to the publication of Opera Geometrica in 1644.
Although Torricelli was not widely known for his contributions to geometry before his appointment, the publication of Opera Geometrica enhanced his reputation in the field. He was also interested in optics and developed a method for creating microscopic glass lenses that could be melted easily. He designed and constructed several telescopes and simple microscopes, with several large lenses bearing his name still preserved in Florence. In a letter to Michelangelo Ricci dated 11 June 1644, he famously remarked, “Noi viviamo sommersi nel fondo d’un pelago d’aria” (“We live submerged at the bottom of an ocean of air”).
However, Torricelli’s work on the cycloid led to a dispute with Gilles de Roberval, who accused him of plagiarizing his earlier solution to the problem of its quadrature. Despite Torricelli’s independent discovery of the solution, the controversy persisted until his death.
Death
Evangelista Torricelli passed away from fever, likely typhoid, in Florence on 25 October 1647, just ten days after his 39th birthday. He was buried at the Basilica of San Lorenzo. Torricelli left his belongings to his adopted son, Alessandro. His early works included pamphlets on Solidi spherali and Contatti, along with the majority of propositions and problems compiled by Viviani after his death. Even sixty-eight years after his passing, Torricelli’s brilliance continued to captivate his contemporaries, as reflected in the anagram on the title page of Lezioni accademiche d’Evangelista Torricelli, published in 1715: “En virescit Galileus alter,” meaning “Here blossoms another Galileo.”
Honours
In recognition of his significant contributions to science, a statue of Evangelista Torricelli was erected in Faenza in 1868.
Several celestial features have been named in his honour, including the asteroid 7437 Torricelli and a crater on the Moon. Additionally, the Torricelli Mountains, located in New Guinea, bear his name.
In the botanical realm, the genus Torricellia, named by botanist Augustin Pyramus de Candolle in 1830, represents flowering plants from Asia and belongs to the family Torricelliaceae, further commemorating Torricelli’s legacy.
Torricelli’s Work in Physics
Torricelli was deeply influenced by Galileo’s Two New Sciences (1638), which inspired him to develop various mechanical principles that he later detailed in his treatise De motu, included in his Opera Geometrica published in 1644. Castelli’s communication of this work to Galileo in 1641, along with a suggestion that Torricelli reside with him, ultimately led to Torricelli’s journey to Florence, where he assisted Galileo as his amanuensis during the last three months of the great scientist’s life.
The Invention of the Barometer
What is a Barometer?
A barometer is an instrument that measures atmospheric pressure. Its readings are crucial for weather forecasting, helping us predict changes in weather patterns. By understanding how air pressure affects weather, we can better prepare for the elements.
How Torricelli Invented the Barometer
In 1643, Torricelli conducted a simple yet revolutionary experiment that would change our understanding of atmospheric pressure forever. He filled a long glass tube with mercury and inverted it into a dish filled with the same liquid. To his surprise, he noticed that the mercury column in the tube didn’t fall to the bottom of the tube but instead remained suspended, with the height of the mercury fluctuating based on the surrounding atmospheric pressure.
This experiment was groundbreaking. Torricelli realized that the weight of the mercury was balanced by the weight of the air above it. He proposed that air has weight and that changes in atmospheric pressure could be measured by the height of the mercury column. This discovery not only resulted in the invention of the barometer but also marked a pivotal moment in the study of fluid mechanics.
The Science Behind Torricelli’s Work
Understanding Atmospheric Pressure
Atmospheric pressure is the force exerted by the weight of air in the atmosphere. Torricelli’s barometer provided a direct way to measure this pressure. He demonstrated that as the atmospheric pressure increases, the mercury rises in the tube, and when the pressure decreases, the mercury falls. This relationship allows us to understand weather changes better, as high-pressure systems typically indicate fair weather, while low-pressure systems can signal storms.
How Torricelli’s Findings Contributed to Fluid Dynamics
Torricelli’s work laid the groundwork for fluid dynamics, a field that examines how fluids (liquids and gases) behave under various conditions. His insights into the principles of pressure and buoyancy helped future scientists, including Blaise Pascal and Isaac Newton, build upon his theories, advancing our understanding of physics and engineering.
Torricelli’s Other Contributions
While Torricelli is best known for the barometer, his contributions to science didn’t stop there. He also made significant advancements in optics and mathematics.
- Optics: Torricelli conducted experiments on the behavior of light and reflections, contributing to the field of optics and enhancing our understanding of lenses and vision.
- Mathematics: He worked on the concept of infinitesimals, which became a crucial aspect of calculus. His studies helped develop techniques for determining areas and volumes, influencing future mathematicians.
Legacy of Evangelista Torricelli
Torricelli’s legacy extends far beyond his own time. His invention of the barometer revolutionized meteorology, allowing for more accurate weather predictions. Today, barometers are used in various applications, from aviation to climate science, demonstrating the lasting relevance of his work.
Moreover, his influence can be seen in the fields of physics and engineering, where understanding fluid dynamics remains essential. Torricelli’s innovative spirit has inspired countless scientists and inventors, solidifying his place in the pantheon of great scientific minds.
FAQs
- What did Evangelista Torricelli invent?
- Torricelli invented the barometer, a device used to measure atmospheric pressure.
- How did Torricelli’s work influence modern science?
- His discoveries laid the groundwork for fluid dynamics and advanced our understanding of atmospheric phenomena.
- What is the relationship between Torricelli and Galileo?
- Torricelli was a student of Galileo Galilei and was influenced by his teachings and scientific principles.
Wrapping Up
In conclusion, Evangelista Torricelli’s innovative spirit and intellectual curiosity led to remarkable discoveries that continue to resonate in the fields of physics and engineering. His invention of the barometer not only revolutionized our understanding of atmospheric pressure but also opened the doors to future scientific explorations. As we look to the skies and measure the weather, we can appreciate the lasting legacy of this remarkable scientist.
