A Swiss mathematician (one of eleven eminent mathematicians his family produced over four generations), whose most important work was in the field of hydrodynamics. In his book Hydrodynamica (1738), he showed that the pressure within a flowing fluid depends inversely on its velocity (the greater the velocity, the lower the pressure). This is now known as Bernoulli's principle (see bernoulli equation). Bernoulli was born at Groningen, the Netherlands, and educated at Basel, Switzerland, where his father had been appointed professor of mathematics on the death of his brother (Daniel's uncle) who held the post previously. Daniel obtained his master's degree at the age of 16 and his doctorate, on the action of the lungs, at 21. In 1725 he was appointed professor of mathematics at St Petersburg Academy, Russia, but left Russia in 1732. In 1733 he became professor of anatomy and botany at the University of Basel; in 1750 he became professor of natural philosophy, a post he held until his retirement in 1777. He died in Basel.
Subjects: Earth Sciences and Geography — Mathematics.