Leonhard Euler - Amazing intellectual power

On September 18, 1783, mathematician, physicist Leonhard Euler - who had a miraculous intellectual and spiritual power, left science to go to the afterlife. But what he left is always cherished and cherished by the posterity not only because of its practical value but also because of its great spiritual value.

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From an early age Euler was a boy with exceptional talents in language and an extraordinary memory. But his life has undergone many changes and unhappiness: his eyes are broken, his house burns down all his assets, his beloved wife dies .

But all that does not affect his creativity, his ability to work. As he got older, Euler worked harder and harder. In the last 17 years of his life alone, Euler announced to 416 buildings. Calculated on average, he publishes up to 25 projects per year, three times more than the previous year he announced.

Leonhard Euler was born on April 15, 1707 in Basel, Switzerland.

After his death, his studies were compiled in the book 'Leonhard Euler Opera Omnia' , consisting of 85 large volumes of nearly 40,000 pages, which cover most areas of mathematics. and many other science and technology.

Important contributions to Mathematics

For Euler, doing math is natural and necessary for life as if breathing in the air. He was obsessed with the miraculous transformation of calculations until his death. Leonhard Euler studied almost all areas of mathematics at that time: algebra, number theory, calculus, geometry . Mathematical works accounted for 58% of his total research works.

One of Euler's early successes was to find a solution to the Basel problem, asking for the exact value of the reciprocal sum of integers. Earlier, mathematicians spent a lot of effort and failed to find the problem. By 1735, when Euler used the approximation technique to find out the exact result of the problem is pi ^ 2/16.

The Euler Königsberg map, describing the actual location of the 7 bridges and the River Pregel.

In 1736, Euler continued to solve the famous problem of the 7 Königsberg bridges. At that time, the city of Königsberg consisted of two islands connected to each other and to the mainland by seven bridges. The problem is to find a route through each bridge only once. By graph theory, Euler proved that it could not be done. His solution to this problem is considered the first theorem of graph theory and marks the development of topology .

Not only at that success, Euler continued to study and publish many other important mathematical works such as: mechanical motion explained by the calculus, the Euler line, the Euler circle in the triangle, the Euler's theorem on the relationship between the number of vertices, edges and the inner surface of a convex polyhedron, introductions of micro-calculus, the principle of microbiology, the principle of integrative learning, extremely small analysis, . Euler also invented a series of approximation methods, which are used in many calculations.

He also gave many mathematical symbols that we still use today: "pi" to represent the ratio between the circumference of the circle and its diameter, sin, cos, tg, cotg, Δx (increment), Σ (sum), f (x) (function f of x), etc.

Contribute to physics and engineering sciences

Euler has many contributions to mechanics and physics. He specifically studied the laws of motion of Issac Newton. This research helped him explain Newton's laws of physics in the form of calculus, while helping him discover many other physical theories. For example, when Euler proved the laws of motion of liquids that Newton had given, Leonhard Euler developed the theory of hydraulic equilibrium.

Similarly, through the analysis of solid movement and the application of Newton's laws, Euler explained in detail the deformation of solid objects in the presence of external forces, thereby contributing to the formation of elastic theory. In 1936, his studies were gathered in the essay 'Study Force'.

Portrait of Leonhard Euler on a Swiss stamp.

In addition to physics, Euler also studied astronomy, ballistic theory, maps, construction, music theory, theology and philosophy, . During the blind years, he wrote a long dissertation. 775 pages about the motion of the moon. He also studied the orbit of Uranus, so that astronomers find Neptune later.

With his contributions to science, Euler was promoted to be a academic of 8 academic institutes around the world, including England, France, Russia, and Germany, etc. He is also considered the most important mathematician of the XVIII century. .

Evaluating the scientific work of Euler, the famous French materialist Diderot wrote: 'He is willing to trade everything he has built to take a page of Mr. Euler's writings. ".