Physicist and mathematician — Evangelista Torricelli (Faenza, 1608 – Florence, 1647) was an Italian physicist and mathematician, a pupil and collaborator of Galileo Galilei during the final months of the latter’s life, whom he succeeded as mathematician to the Grand Duke of Tuscany. In 1643 he carried out the famous experiment with a tube filled with mercury, demonstrating the existence of atmospheric pressure and building the first barometer. In doing so he also produced the first stable vacuum in history (the “Torricellian vacuum”), refuting the Aristotelian idea that a vacuum was impossible. He also made important contributions to hydrodynamics, formulating the law for the outflow velocity of a liquid from a hole, and to the mathematics of indivisibles.
Curiosity
The unit of measurement torr, used for low pressures, is named after him; he is also credited with the phrase that “we live submerged at the bottom of a sea of air”.
Theories and contributions
- Atmospheric pressure and the barometer — Air exerts a pressure that supports a column of mercury about 760 mm high: .
- Torricelli’s law — The outflow velocity of a liquid from a hole depends on the height: .
- Torricellian vacuum — Above the column of mercury in the barometer an empty space forms, proof of the existence of a vacuum.
Present in chapters
Linked atoms
1 linked atom.