(Ulm, 1879 - Princeton, 1955) Scientific American of German origin. In 1880 his family moved to Munich and then (1894-96) in Milan. Attended a Munich-based institute, he continued his studies in Italy and eventually enrolled at the Polytechnic School of Zurich (1896-1901). Obtained Swiss citizenship (1901), found a job in the patent department, that same year he married.Albert Einstein
In 1905 he published in Annalen der Physik his early work on quantum theory, the relativity and Brownian motion, and free teacher came to the University of Bern. In 1909 he was appointed assistant professor of Zurich and in 1910 went on to teach theoretical physics at the German University of Prague. Then she taught the same subject at Zurich-Technical School (1912). In 1913,elected to the Prussian Academy, he moved to Berlin. In 1916 he remarried. Then published Die Grundlagen der allgemeinen Relativitätstheorie and initiated a series of trips to the United States, Britain, France, China, Japan, Palestine and Spain (1919-1932).
In 1924 the press gave Über die Spezielle und die allgemeine Relativitätstheorie and the following year received the Nobel Prize for his theoryon the photoelectric effect. In 1933 he left the Prussian Academy and fought bravely against Hitler. Started the Nazi persecution of Jews went to America and taught at the Institute for Advanced Studies in Princeton (New Jersey). In 1945 he retired to private life, which continued despite intense scientific activity.
Einstein is one of the great geniuses of mankind and the physical sciences hasled to a revolution still in progress and whose effects can not be measured even in all its breadth. In its initial formulation (theory of relativity) extended to optical and electromagnetic phenomena, the principle of Galilean-Newtonian relativity, previously limited only to the field of mechanics, and affirmed the validity of the laws of the latter both in terms of a system Galilean reference K,and in relation to other reference K 'in uniform rectilinear motion with respect to K.
According to Einstein's theories, the law of propagation of light in a vacuum must have at any other general in nature, the same expression already mentioned, for example, a checkpoint or a railway train car in rectilinear motion uniform with respect to that, in other words, the speed of light is notconsistent with the reference systems that move in a straight line and uniformly with respect to the movement of the same light. In fact, the Michelson-Morley experiment, repeated a thousand times and tested from 1881, proved the difference between the speed of light and the Earth.
Relativity provides the reason for this fact, before inexplicable. In turn, the stability of the speed of light leads tothe introduction in Physics, Lorentz transformations, whereby the time distance between two events and that between two points on a rigid body are based on moving reference system, and are therefore different for K and K '. This frees us in the development of optical and electromagnetic laws, the relationship with the hypothetical fixed system "absolute" metaphysical puzzle of classical physics,since such laws, as formulated in relativity, valid for K and also for K ', the same as those of mechanics.
The transition from classical physics to relativity is not only a methodological progress. The latter, in fact, presented as observed by Einstein (on the special and general theory of relativity) - a heuristic value much greater than that of classical physics, since it allows to include inthe theory, as a result of her remarkable number of phenomena, which include, for example, the apparent exception in the ratio of the speed of light with a stream of water in the Fizeau experiment, increasing the mass of the electrons with increasing speeds those observed in the cathode rays and the emanations of radio, the mass of cosmic rays, forty thousand times higher than the same at rest,...