Daniel bernoulli Bernoulli (1700 ~ 1782) is a Swiss physicist, mathematician and physician. 1700 was born in Groningen, the Netherlands on February 8th. The most outstanding member of the famous Bernoulli family. He is the second son of mathematician j Bernoulli. Like his parents, he went into business against their wishes and insisted on studying medicine. He was once a famous surgeon. Influenced by my father and uncle's academic thoughts since childhood, I finally turned to study mathematics and mechanics. He and L. Euler work in the Academy of Sciences in St. Petersburg. They are close friends and competitors. They are all famous for winning 10 French Academy Awards within 25 years. At the age of 25 (1725), Bernoulli was recruited as an academician of mathematics in St. Petersburg Academy of Sciences. Eight years later, he returned to Basel, Switzerland, where he was first a professor of anatomy, then a professor of dynamics and finally a professor of physics. After he left St. Petersburg (now Leningrad), he began the most famous scientific exchange with Euler. He provided Euler with the most important scientific information, and Euler gave him the fastest help with his excellent analytical ability and rich work experience. They have corresponded for 40 years, and the most important correspondence was at 1734 ~ 1750. Their address book is important information for understanding Bernoulli.

Bernoulli's contribution involves medicine, mechanics and mathematics, especially fluid mechanics. The subject of fluid dynamics was named by him. He is the author of fluid dynamics with 13 chapter. He used the pressure, density and velocity of fluid as the basic physical quantities to describe the motion of fluid, and wrote the basic equation of fluid dynamics, which was later called Bernoulli equation. Bernoulli's principle of "increasing flow and decreasing pressure" is put forward. He also put forward that pressure is regarded as the effect of gas molecules hitting the surface of container wall, established the basic concepts of molecular motion theory and heat, and pointed out that pressure and molecular motion increase with the increase of temperature. Starting from 1728, he and Euler also studied the mechanical problems of flexible and elastic chains and beams, including the equilibrium curves of these objects, and also studied the vibration of strings and air columns. His achievements in astronomical measurement, gravity, tides, magnetism, ocean currents, stability of ship navigation, irregular motion and vibration theory of Saturn and Jupiter have won awards. He also did a lot of important work in probability theory. He made an important contribution to almost all the frontier problems of science at that time, especially the navigation problems. His father once cooperated with him and shared the prize about planetary orbit research. 1782 March 17 died in Basel.