THE Physicsquantum, also known as quantum mechanics, is a large area of study dedicated to analyzing and describing the behavior of physical systems of reduced dimensions, close to the sizes of molecules, atoms and particlessubatomic.
Through quantum physics, it was possible to understand the mechanisms of decays radioactive, from the emission and absorption of light by atoms, from the production of X ray, of photoelectric effect, electrical properties of semiconductors, etc.
Lookalso: Modern physics
Quantum Physics for Dummies
when we entered the scale of atoms and molecules, at laws of macroscopic physics, which are perfectly capable of describing the states of movement of the bodies that we see around us on a daily basis, become obsolete and incapable to determine any physical quantities related to such tiny particles.
What happens in the quantum world is that the laws of physics are no longer deterministic, that is, they are not able to predict exactly where some object is, or at what speed: nothing here is deterministic, measurements obtained from quantum systems are expressed in
odds.Currently, we have measurement systems capable of providing us with the position of an object with extremely accurate precision. However, even with the most advanced of technologies, we would not be able to determine the exact position of an atom, for example. That impossibility is not related to the resolution of a device or the skill of an instrument worker, but yes to the very nature of quantum physics.
Lookalso:Standard Model of Particle Physics
this one nature of quantum physics has been showing itself over time as a true unknown, for a long time misunderstood, which ended up leading many physicists to question it, give it different interpretations or even deny it completely. However, it also contributed to the creation of several myths and beliefs around the concept of quantum physics.
Despite seeming “strange”, quantum mechanics is one of the most successful theories of physics, the precision of the results achieved by this theory is frightening. Currently the most popular and accepted interpretation of quantum mechanics is called Copenhagen interpretation, developed by some of the biggest names in science, such as NielsBohr,MaxBorn,WolfgangPauli,WernerHeisenberg and others.
![The Copenhagen interpretation was consolidated during the Solvay conference. [1]](/f/da2205c24a4f5c7d0a59238e3ba57d86.jpg)
The Copenhagen interpretation was consolidated during the Solvay conference. [1]
According to this interpretation, all quantum systems have a wave function that describes them completely. This wave function is a complex and virtual mathematical expression (without its own reality), from which it is possible to extract all the information in this system.
The results obtained based on the wave functions, in turn, are the probabilities that something is observed or that we find an atom at some specific energy level. Still, it can be probabilities that an atom makes a radioactive emission, or that a neutron undergo a decay, turning into a neutron and a electron. The possibilities are huge.
The challenge for physicists is to find the wave function for the system, and that's not easy — one or more needs to be solved. equationsinSchrodinger, this equation relates the energies kinetics and potential of quantum systems.
Lookalso:Einstein and the atomic bomb
Quantum Physics Applications
Through quantum physics, it is possible to understand
light emissions by atoms;
the phenomena of radioactive decay;
the functioning of Laser, the photoelectric effect;
the attraction between neutrons and protons in atomic nucleus;
the standard model of particle physics;
the wave-particle duality;
all the laws of classical physics that we know (since, by being more general, the laws of quantum mechanics are able to derive from the laws that govern our classical world).
The functioning of the laser was only obtained by studying quantum mechanics.
Origin
The emergence of modern quantum physics took place in 1920, when the German physicist MaxPlanck managed to explain the mechanism of black body issue and his relationship with a bizarre miscalculation at the time, called ultraviolet catastrophe.
It turns out that the black bodies, objects capable of absorbing all the radiation that is directed at them, re-emitting it in the form of thermal radiation, did not emit it as expected by the current electromagnetic theory. To resolve the situation, Max Planck suggested that the energy of the electromagnetic field be quantized, that is, subdivided into small bundles of energy, which, a little later, would come to be called photons - you how much energy.
Planck's interpretation of blackbody radiation was not well accepted (or even by him), however, a few years later, Albert Einsteinhe made use of the same argument and succeeded in explaining the photoelectric effect.
In 1905, Einstein published a series of articles that marked the date as the “miraculous year of physics”, but the his acclaim came through his Nobel Prize in Physics, for explaining the mechanism behind the photoelectricity. Einstein had concluded that light behaves as both a particle and a wave. This behavior became known as the dual nature of light.
Lookalso: fundamental forces of nature
In 1924 it was the turn of LouisinBrogliecontribute to quantum mechanics. De Broglie published, in his doctoral thesis, that quantum particles also have a wave-length, as well as light and, therefore, should present wave behavior under certain conditions.
The French physicist predicted that electrons should show an interference pattern when subjected to the double-slit experiment, just as waves do. In 1927, his hypothesis was confirmed by the Davisson-Germer experiment: was established the duality in between wave and matter.
The reason behind the dual behavior of matter remained unknown until, in 1927, WernerHeisenberg enunciated a physical principle derived from the mathematical properties of quantum theory. According to this principle, known as the uncertainty principle, there are pairs of variables that could not be measured simultaneously with full precision. These variables are called conjugate variables.
position and speed, for example, are physical quantities that cannot be determined with complete precision in the quantum world: if we know with great precision the speed at which an atom is, we completely lost precision in its position, similarly, if we could measure the velocity of an atom, we could not tell what its position is in that same instant.
To understand the uncertainty principle, just think about how we see things: the light emanating from objects must reach our eyes, so that this information is translated by our brain. In other words, for us to see, we need exchange photons with the surroundings. In the case of atoms and particles, this is more serious than it sounds: imagine you want to know where an atom is, to do that you would need emit a photon towards you, but in doing so, the atom would pick up speed because of the collision, so you wouldn't be able to tell anymore where it was. it is.
Therefore, the uncertainty principle allows us to understand a little better the duality wave matter: in the quantum world, the physical quantities behave in a non-deterministic way, as if they were waves, whose amplitudes are, in fact, odds.
Lookalso:Nuclear physics
Quantum Physics, Spirituality and Pseudoscience
Nowadays, it has become common to read advertisements for courses, miracle cures, revolutionary products, therapies infallibles, prayers to attract money, and even methods of healing using terms relating to physics quantum.
However, it is necessary to emphasize that in none of these cases is there a direct relationship with the knowledge that resulted from research in quantum physics. They are, in fact, a misappropriation, which was only made possible thanks to ignorance of a large part of the population, when it comes to modern and contemporary Physics.
Understanding quantum physics involves mastering a large mathematical formalism and a lot of knowledge of Physics, Algebra, Geometry, Electrodynamics and so on. Therefore, it takes many years of study to understand it in a way that is minimally acceptable by academic standards.
It is also true that many people believe that their practices are based on quantum phenomena, and it is not uncommon to find testimonials from people who felt better when resorting to these actions. However, we can cite reasons that belie the effectiveness of the so-called quantum practices:
Quantum phenomena only become relevant and observable on atomic scales. After a certain size, everything starts to behave in accordance with classical physics, the physics of the macroscopic scale.
The benefits experienced by people who purchase products or start performing some type of related activity to "quantum" can be seen in some experiments, in which improvements are observed in patients treated with placebo. These effects happen because patients believe they are better, and they condition themselves on it.
Due to the great lack of knowledge about the real meaning attached to the word quantum, it is natural for this to involve mysticism, causing us to see it frequently used in the most unlikely contexts: motivational lectures, courses of coaching quantum, quantum prayers, quantum cosmetics, quantum cures, etc.
Despite being very different, all these ads have something in common: they are pseudoscientific and, for the most part, they aim for profit. Therefore, in some cases, they can be called quackery, whose aim is to add value and reliability to products, services or ordinary customs in their essence.
When you notice the use of very abstract concepts in unlikely contexts, distrust and look for information from reliable sources, such as established educational websites, pages linked to educational institutions or scientific articles. THE information it is the only way to prevent scams, charlatanism and other types of beliefs that use, improperly, the name of areas of knowledge that are consecrated but known by few.
Lookalso:String theory
Books
If you are interested in better understanding how quantum physics works, but you are a layman, or would like to consult sources trusted in this area of Physics, check out some books that can help you better understand the strange world quantum:
the quantum mystery - Andrés Cassinello and José Luiz Sánchez Gomez
Understanding Quantum Theory: An Picture Book - JP McEvoy and Oscar Zarate
the elegant universe -Brian Greene
The Quantum Enigma: Finding Physics with Consciousness - Charles Townes
[1] Image credits: Benjamin Couprie, Institut International de Physique de Solvay / Wikimedia Commons.
By Me. Rafael Helerbrock
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/fisica/o-que-e-fisica-quantica.htm