Evangelista Torricelli was an Italian mathematical physicist born on October 15, 1608 in Faenza, Romagna, Italy. He pursued mathematical studies under Benedetto Castelli before receiving an invitation in 1641 to serve as assistant to the elderly Galileo Galilei in Florence during the final three months of the renowned astronomer's life. Following Galileo's death, Torricelli continued his investigations, taking up problems that had interested his mentor, including the question posed by Ferdinando II de' Medici about why water pumps could not raise water higher than 32 feet. His brief but brilliant scientific career positioned him as a crucial intellectual link between the era of Galileo and the emerging scientific revolution.
Torricelli's most groundbreaking contribution came in 1644 when he invented the mercury barometer, demonstrating for the first time that atmospheric pressure could support a column of mercury approximately 30 inches high. Through meticulous experimentation, he proved the existence of vacuum and established that air possesses measurable weight, fundamentally challenging the Aristotelian doctrine that nature abhors a vacuum. His work explaining that winds are produced by temperature and density differences between regions represented the first scientifically accurate explanation of meteorological phenomena. Additionally, Torricelli made significant mathematical contributions, most notably discovering Gabriel's Horn, a geometric figure with finite volume but infinite surface area.
The legacy of Torricelli's discoveries profoundly shaped the development of meteorology, fluid dynamics, and the scientific understanding of atmospheric pressure. His invention of the barometer provided the foundational tool for measuring atmospheric pressure, enabling systematic weather observation and prediction. Though his promising career was tragically cut short by typhoid fever at age 39 in October 1647, his contributions continued to influence subsequent generations of scientists including Blaise Pascal who confirmed Torricelli's atmospheric theories. Today, the pressure unit torr stands as enduring testament to his pivotal role in establishing the science of atmospheric physics.
