Werner Heisenberg (English version)

Werner Karl Heisenberg was one of the greatest scientists of all time, playing a key role in the development and eventual success of quantum theory. Heisenberg excelled in the fields of theoretical physics and mathematics from an early age, but had a certain difficulty in the field of applied physics, and narrowly did not obtain his doctorate because he could not explain the functioning of a battery .

Heisenberg was born on December 5, 1901, in Wurzburg, Germany, and thus experienced the horrors of the two world wars, especially the second, and his country (Germany), under the Nazi regime, aimed at the scientist since his main field of study, quantum mechanics, was regarded as "Jewish science." Speaking to the government, Heisenberg said it was essentially impossible to develop an atomic bomb, which is now widely regarded as a maneuver used by the scientist to discourage the German dictatorship from obtaining nuclear-war material. After World War II, Heisenberg worked for the peaceful use of atomic energy and was also one of the founders of CERN (European Organization for Nuclear Research), which is the largest particle physics laboratory in the contemporary world.

With the verification of the phenomena involving wave-particle duality, as well as other quantum properties, the need for a new theory capable of describing the behavior of atomic scale particles was evidenced. One of the pioneers in formulating the new field of science was Werner Heisenberg.

In the year 1920, Niels Bohr (famous for his atomic model “Bohr's atom”) opened an institute at the University of Copenhagen, which attracted scientists from around the world, including Heisenberg. At the time, Bohr's atomic model was dominant, but flawed, especially in describing more complex systems, with efficiency centered on the (simplistic) hydrogen atom. The main question that echoed in the brightest minds of the twentieth century was: how to develop a new theory without a well-defined starting point? Heisenberg has an interesting phrase that illustrates well the difficulty faced by scientists of the day: “All the qualities of the atom in modern physics are derived. He has no direct or immediate physical property. ” However, the solution, as always, was found in the scientific method, with the first step being observations obtained from experiments performed.

The German physicist then began his research for a way to describe quantum systems, trying to devise a scheme that involved all known quantum variables. Due to the fact that he had rhinitis, Heisenberg decided to move to the coast due to the lower concentration of pollen and, one night, at dawn, came to a conclusion with his calculations, making him so excited that he lost sleep. The physicist then left his house and calmly waited for the sun to come upon a rock.

In short, Heisenberg's research has adapted ideas from Bohr's model to make his set of calculations agree with the results obtained experimentally. However, the scientist's model was “messy” and somewhat “chaotic”, which led him to resort to his friend Max Born, whose experience in mathematics was exceptional. Born was able to visualize the beauty behind his friend's work and was able to “mop up” the mathematical formulation into a matrix representation, which came to be called “matrix mechanics”.

Shortly afterward, Austrian Erwin Schrödinger proposed a description of quantum systems through a kind of wave equation (ie Schrödinger equation), achieving immediate success among the scientific community. The formulations of Heisenberg and Schrödinger were equivalent, but matrix mechanics were described by very abstract mathematics, unfamiliar to scientists of the time, while Schrödinger's description was elegant and familiar to those with knowledge of wave mechanics. A certain "rivalry" arose among physicists, and the Austrian physicist argued that his formulation was better, irritating the young Heisenberg.

In later studies, Werner realized a curious limitation: it was impossible to measure certain properties precisely because the apparatus used (to determine observables such as position) would interfere with the particles being measured. Upon further investigation, Heisenberg realized that it was impossible to measure two quantities (such as the velocity and position of a particle) simultaneously and that this condition was not due to the experimentalist's lack of "skill" or lack of more advanced technologies, but rather it was a fundamental and intrinsic property of nature; it was the universe imposing limits on the reach of human knowledge. The uncertainty principle has overlapped determinism, a view that everything in the universe is well defined and can be determined (position advocated hard by Einstein, as evidenced in his maxim “God does not play dice”).

In 1927, the search began to understand the descriptions of quantum mechanics, aiming at more “physical” meanings, in order to try to soften the high abstract content of such theory. Mainly involved was Niels Bohr, who condensed the main ideas of quantum theory, such as Heisenberg's uncertainty principle, wave-particle duality, Schrödinger equation, and other key concepts. Bohr came to an interpretation of quantum phenomena which became known as the “Copenhagen interpretation” (which will be discussed in detail in future articles). Many scientists adopted Bohr's view, which proposed that the dual (wave-particle) behaviors exhibited by "quantum entities" were two sides of the same coin, and the observer had deep implications for the development of a system. However, Niels Bohr's interpretation was not the only one to explain quantum mechanics, the many worlds and the pilot wave interpretations (among others) also offer interesting explanations and agree with predictions/experimental results within what it proposes to be. To this day it is impossible to say which, if any, of the interpretations is the correct one and most scientists believe that this condition will last forever, thus restating the whole mystery surrounding the quantum world.

Reference material: a brief history of time (Stephen Hawking), universe in a nutshell (Stephen Hawking), the quantum universe (Brian Cox and Jeff Forshaw), 50 ideas of quantum physics (Joanne Baker) and

https://pt.wikipedia.org/wiki/Werner_Heisenberg

Photo 1: Werner Heisenberg

Photo 2: The Uncertainty Principle in its Most Famous Formulation