Daniel Bernoulli

Biography

Daniel Bernoulli was born in Groningen, the son of the eminent mathematician Johann Bernoulli. He studied at the University of Basel, where he studied medicine, but under his father's influence became interested in mathematics. In 1725 he accepted an invitation to the St. Petersburg Academy of Sciences, where he worked with Leonhard Euler. In 1733 he returned to Basel, where he became a professor of anatomy, botany, and later physics and philosophy. His main work, “Hydrodynamics” (1738), laid the foundations of the kinetic theory of gases and hydrodynamics.

Key discoveries

• Bernoulli's principle: in a steady flow of a liquid or gas, the sum of static and dynamic pressure remains constant; an increase in flow speed leads to a decrease in pressure.
• Kinetic theory of gases: a model of a gas as a collection of randomly moving particles, explaining pressure through molecular impacts on the walls.
• Work on the theory of vibrating strings, probability theory, and mathematical analysis (Bernoulli's equation).