# Daniel Bernoulli

Not many people must have heard of Daniel Bernoulli perhaps because he did not bring about the significant changes men like Einstein and Newton brought to the scientific world. Nevertheless his contributions earned him a great name during his time. Daniel Bernoulli was a Swiss physician, doctor and mathematician. He is most prominent for his applications of mathematics to mechanics, particularly fluid mechanics, and for his exceptional work in probability and statistics. Bernoulli’s theorem is the foundation of many engineering applications, such as aircraft wing design.

### Academic Life and Career

Daniel was born in a family of leading mathematicians on 8th of February, 1700 in Groningen. His father Johann Bernoulli was also a mathematician and so was his older brother Nicolaus(II) Bernoulli and his uncle Jacob Bernoulli. His father encouraged him to pursue a business career but little Daniel was always fascinated with mathematics; however, when Daniel turned thirteen his father sent him to Basel University to study philosophy and logic. He graduated in 1715 and a year later received his Master’s degree. Later upon his father’s wishes he studied medicine on the condition that his father would teach him mathematics privately, which they continued for some time. During 1718, he spent time studying medicine at Heidelberg and Strasbourg in 1719. In 1720 he returned to Basel to complete his doctorate in medicine. He also went to Venice to study medicine. Here he worked on mathematics and his first mathematical work was published in 1724 with the support of Goldbach. This mathematical work was named as Mathematical exercises. In the same year he went to St. Petersburg as professor of mathematics, but was unhappy there, and a temporary illness in 1733 gave him an excuse for leaving. He returned to the University of Basel, where he consecutively held the chairs of medicine, metaphysics and natural philosophy until his death.

### Contribution to Mathematics, Statistics and Physics

His most prominent work titled as ‘Hydrodynamica’, which was published in 1738, was a milestone in the theory of the flowing behavior of liquids. His work was based on the principle of conservation of energy, which he had studied with his father in 1720. In this Bernoulli developed the theory of watermills, windmills, water pumps and water propellers. He was the first to distinguish between hydrostatic and hydrodynamic pressure. His Bernoulli Principle on stationary flow has remained the general principle of hydrodynamics and aerodynamics even today and is the basis of modern aviation.

He is also the author of Specimen theoriae novae de mensura sortis (Exposition of a New Theory on the Measurement of Risk) which is the basis of economic theory of risk aversion, risk premium and utility.

He is one of the earliest writers who made an attempt to devise the kinetic theory of gases and used the idea to explain Boyle’s law. He has also worked on elasticity with his close friend Leonhard Euler and helped his friend with development of the Euler-Bernoulli beam equation. Bernoulli’s principle is of significant use in aerodynamics.

### Death

Daniel Bernoulli died on March 17, 1782 in Basel, Switzerland. Bernoulli won or shared 10 prizes of the Paris Academy of Sciences, with Euler.