Daniel Bernoulli
1700-1782
Bernoulli's Principle Demo by a Student Where the velocity of a fluid is high, the pressure is low, and where the velocity is low, the pressure is high.
Bernoulli's Equation P1 + (1/2)pv12 + rgy1 = P2 + (1/2)rv22 + rgy2 |
After studying philosophy,
logic, and medicine at the universities of Heidelberg, Strasbourg, and
Basel, he received an M.D. degree (1721). In 1723–24 he wrote Exercitationes
quaedam Mathematicae on
differential equations
and the physics of flowing water, which won him a position at the
influential Academy of Sciences in St. Petersburg, Russia. Bernoulli
lectured there until 1732 in medicine, mechanics, and physics, and he
researched the properties of vibrating and rotating bodies and contributed
to
probability theory. In
that same year he returned to the University of Basel to accept the post in
anatomy and botany. By then he was widely esteemed by scholars and also
admired by the public throughout Europe. Daniel’s reputation was established in 1738 with
Hydrodynamica, in which he considered the properties of basic importance in
fluid flow,
particularly pressure, density, and velocity,
and set forth their fundamental relationship. He put forward what is called
Bernoulli’s principle,
which states that the pressure in a fluid decreases as
its velocity increases. He also established the basis for the
kinetic theory of gases
and heat by demonstrating that the impact of molecules on a surface would
explain pressure and that, assuming the constant, random motion of
molecules, pressure and motion increase with
temperature. About 1738 his father published Hydraulica; this attempt by
Johann to obtain priority for himself was another instance of his antagonism
toward his son. Between 1725 and 1749 Daniel won 10 prizes from the Paris Academy of Sciences for work on astronomy, gravity, tides, magnetism, ocean currents, and the behavior of ships at sea. He also made substantial contributions in probability. He shared the 1735 prize for work on planetary orbits with his father, who, it is said, threw him out of the house for thus obtaining a prize he felt should be his alone. |