Torricelli (1608 ~ 1647) is an Italian physicist and mathematician. He worshipped Galileo and read many of his works intensively. Torricelli has done a lot of research in mechanics. He published some papers on dynamics independently, which aroused Galileo's interest in him. Later, at the invitation of Galileo, he worked closely together and became a student of Galileo. It's a pity that they only cooperated for three months, and Galileo died. The Archduke of Tuscany hired Torricelli as a court mathematician and philosopher to replace Galileo.

Torricelli's greatest contribution is to prove the existence of atmospheric pressure through experiments. He inherited Galileo's idea that air is acted by gravity, got rid of Galileo's "natural aversion to vacuum" and began to study the principle of lifting liquid by hydraulic press. He believes that the height of lifting liquid is related to the specific gravity of liquid, which is lower than the height of heavy liquid. He put forward the idea of using mercury instead of water for experiments, and predicted that the height of mercury column should be114 of the height of water column. This experiment was completed by his student Vivienne at 1643, which proved the existence of atmospheric pressure. At present, the method of measuring atmospheric pressure with mercury has been improved. In memory of this great experimenter, later generations called this experiment Torricelli Experiment.

Torricelli is also very good at optical instruments. He made a big lens to be used as the objective of the telescope. He is also a mathematician, who has been deeply engaged in the research of cycloidal mathematics, and the determination of the area of parabolic bow and the volume in parabola.