Evangelista Torricelli was an Italian physicist and mathematician born on October 15, 1608. He is best known for inventing the barometer, an instrument used to measure atmospheric pressure. Torricelli's work laid the foundation for the study of fluid dynamics and contributed significantly to the field of physics. In addition to his invention of the barometer, Torricelli was a student of Galileo Galilei and made important contributions to mathematics, particularly in the area of calculus. He passed away on October 25, 1647, but his legacy continues to influence science and engineering today.