On March 14, 1879, Albert Einstein (1879-1955) was born in the German town of Ulm. After studying in Munich, his parents emigrated to Milan in 1895, but he decided to study in Aarau (Switzerland) to prepare for his admission as a Physics and Mathematics student at the Polytechnic (ETH) in Zürich. In that year, Einstein renounced German citizenship, adopting Swiss citizenship in 1899.
After graduating from the ETH in Zürich (1900), he did not get a job at a Swiss university, so he started working at a college in Winterthur (Switzerland) in 1901. In 1902 he started working at the Swiss Patent Office in Bern, where it remains until 1909.
While working in Bern, Einstein did important research in Theoretical Physics. In 1905 he presents his doctoral thesis at the University of Zürich on a new method for determining molecular size. This was the subject of the first article he published in the Annalen der Physik in 1905, which has been called the Miraculous Year of Physics. After this first article, Einstein broadened this topic of work, explaining Brownian motion and developing theoretical methods to determine Avogadro's number, which Jean Perrin later carried out experimentally. Einstein's theoretical work, confirmed by Perrin, was a boost to the existence of molecules, which at that time was not accepted by the entire scientific community.
In the third publication, Einstein develops a new kinematics, modifying the concepts of absolute time and reference frame; which he applies to charged bodies, extending Maxwell's electromagnetic theory. Here he lays the foundation for what Einstein defined as the Principle of Relativity. The fourth publication develops the previous one, reaching the conclusion of the equivalence of mass and energy.
Einstein's fifth publication in this miraculous year is essential for Chemistry. Einstein develops a theory of the interaction of energy and matter, whose conclusions serve to explain phenomena such as the Stokes effect, the photoelectric effect, and the ionization of gases by ultraviolet light. Einstein starts from different premises than those that Planck had started when explaining the radiation of the black body, but reaches the same conclusions. This publication, for which he was awarded the Nobel Prize in 1921, is a true marvel of reasoning and a scientific revolution; and unequivocally establishes the nature of electromagnetic radiation, matter and the interaction between the two.
In the following years he continued to work on aspects related to quantum theory, which allowed him to explain the specific heat of solids. However, from 1907, Einstein was mainly interested in the application of the Principle of Relativity to accelerating masses; which led him to the conclusion that inertial mass and gravitational mass are indistinguishable; which was the origin of his great scientific contribution: The Theory of General Relativity (also called the General Theory of Relativity, 1905), in which he refines Newton's theory of gravitation and reaches the conclusion that the origin of Gravity is a warp in four-dimensional space-time.
Although it has been mentioned that Einstein was awarded for the explanation of the photoelectric effect and other phenomena related to matter-energy interaction, he possibly deserved a second Nobel Prize for the Theory of General Relativity.
Of course, by the time Einstein was already a famous physicist (circa 1907), he no longer had a problem finding work in academia. He was Privatdozent in Bern (1908, combining it with his work in the patent office) and professor at the universities of Zürich (1909), Prague (1911), ETH (1912), Prussian Academy of Sciences and University of Berlin (1914) and Princeton (1932), obtaining American nationality in 1940, but retaining Swiss citizenship.
Apart from his many scientific achievements, Einstein has been a benchmark in many aspects (ethical, social, active pacifist, etc.), being chosen as the character of the 20th century by Times magazine.
He died in Princeton on February 18, 1955.
Although the images that usually appear of Albert Einstein is that of an older scientist (messy white hair), we must remember that in his miraculous year he turned 26 and that his greatest scientific contributions were made when he was less than 40 years old. He is a clear example of the relationship between youth and scientific creativity.