1678 and 168 1 year, Jacob Bernoulli went to France, Holland, England and Germany, contacted and interacted with Xu De, Boyle, Hook and Huygens, and wrote about comet theory (1682) and gravity. 1687, Jacob published a mathematical paper "Method of Dividing Triangle Area with Two Vertical Lines" in Teacher's Magazine, and became a professor of mathematics in university of basel in the same year until 1705 died.
1699, Jacob was elected as a foreign academician of the Paris Academy of Sciences; 170 1 was accepted as a member by Berlin Science Association (later Berlin Academy of Sciences). Many mathematical achievements are related to Jacob's name. For example, catenary problem (1690), curvature radius formula (1694), Bernoulli lemniscate problem (1694), Bernoulli differential equation (1695) and isoperimetric problem (65438+).
Jacob's greatest contribution to mathematics is in the study of probability theory. He began to publish papers on the number of winners and losers in gambling games from 1685, and later wrote a masterpiece "Guessing", which was published eight years after his death, that is, 17 13.
1726, Bernoulli discovered the "boundary layer surface effect" through numerous experiments: when the fluid velocity is accelerated. The pressure on the interface between the object and the fluid will decrease, and vice versa. To commemorate this scientist's contribution, this discovery is called "Bernoulli effect". Bernoulli effect applies to all fluids, including gases. Bernoulli introduced Newtonian mechanics into the study of fluid mechanics, and became famous for his book Fluid Dynamics (1738), in which he put forward a theorem of fluid mechanics, which reflected the law of conservation of energy in an ideal fluid (incompressible fluid without considering viscosity). This theorem and the corresponding formula are called Bernoulli theorem and Bernoulli formula. 1782 March, daniel bernoulli died in Basel, Switzerland.
One of the most interesting anecdotes is that Jacob is obsessed with the study of logarithmic spiral, which started at 169 1. He found that the logarithmic spiral was still a logarithmic spiral after various transformations. For example, its inflection point line and extension line are logarithmic spirals, and the trajectory from the pole to the tangent is vertical. The reflection line obtained by reflecting the logarithmic spiral with the pole as the luminous point, and the curves tangent to all these reflection lines (back rays) are logarithmic spirals. He was amazed at the magic of this curve, and even asked future generations to carve the logarithmic spiral on their tombstones in his will, accompanied by a eulogy "Even if it changes, it will still be me" to symbolize immortality after death.
The 22nd International Congress of Mathematicians was held in Zurich, Switzerland. The commemorative stamps issued by Switzerland Post have the head of Jacob Bernoulli, the law of large numbers named after him and its geometric schematic diagram (that is, when the number of experiments increases indefinitely, the Bernoulli family is the family of 1 1 scientists in Switzerland, and Jacoby Bernoulli is one of them, who has made many great achievements in mathematics. For example, he made an important contribution to the development of calculus; It lays a theoretical foundation for the integral method of ordinary differential equations. When studying the curve problem, he put forward a series of new concepts; He founded the variational method; He was also an early researcher and founder of probability theory.