It is often said that quantum physics is a field that challenges the perception of reality. Well, although it is a rather poetic and romantic statement, it can be considered partly true. Quantum physics governs behavior Subatomic particlesThey are too small to be seen with our eyes, and their study often immerses scientists in research in which the usual laws do not exist. In this context, there is a protagonist, whom you may have heard of, who acts as a major key to understanding this microcosm: Planck's constant.
Named after the physicist who introduced it, Max Planck, the constant was first named in the early twentieth century. In an absolutely revolutionary work, Planck was not only able to explain a large number of concerns of the time, but also laid the foundations for ushering in a new era in physics: quantum physics.
Max Planck's great legacy: quantum mechanics
The birth of the era
Since the beginning of the twentieth century, progress in physics has seemed to stall. Scientists began to face puzzling dilemmas that they could not explain, and for which there were no coherent and effective laws. It was one of those problems Black body radiationAny body absorbs all the radiation that falls on it, but radiates an amount of energy characteristic of it.
In order to solve this phenomenon, Max Planck presented an innovative idea about the quantization of energy in 1900: he proposed that The power has been disconnected In separates or small bags, which he called “how manyIn other words, he introduced the idea that emitted energy does not have a fixed value, but is emitted in small quantities that are always proportional to a value: Planck's constant.
Portrait of Max Planck, winner of the Nobel Prize in Physics in 1918.
However, acceptance of this idea was by no means immediate. Planck's proposal She was bold Although it seemed to explain some phenomena, it contradicted many prevailing theories of the time. Fortunately, there were other important physicists at that time, e.g Albert EinsteinNiels Bohr or Werner Heisenberg contributed other essential advances that ended Strengthening Planck's theory. In general, wave-particle duality, the uncertainty principle, and quantum mechanics were the pillars that made this new concept of the microscopic world grow.
What is Planck's constant?
In this way, Planck's constant, represented by the letter h, has established itself as one of the cornerstones of quantum physics, playing a fundamental role in… Quantization of phenomena that occur in nature. Until then, it was thought that the emission of energy could have any value, but with Planck's hypothesis, it was decided that it should always be measured in quantities Integer multiples of the constant, h. To be precise, its value is 6.626×10-3.4 Joules per second according to the International System of Units.
The five points of understanding quantum physics
Likewise, Planck's constant was also instrumental in formulating another of the great approaches to quantum physics: Uncertainty principle By Heisenberg. The idea of this approach is that it is impossible to know the location and momentum of a particle with absolute accuracy. In this case, Planck's constant appears as an obstacle, just as if it were an obstacle Constraint The ability to measure certain quantities accurately.
A formula that relates the energy emitted by a particle to the frequency of its motion through Planck's constant.
Master piece
Its existence, deduced theoretically, is able to explain and manifest itself through quantum phenomena observed in various experiments, which has definitively enhanced its importance. For example, based on Planck's testimony, Albert Einstein in 1905 proposed a Quantitative interpretation of the photoelectric effectbetting that light falling on a metal repels electrons.
To prove this idea, Einstein postulated that light consists of particles called photons, each of which has an energy proportional to Planck's constant. It was precisely this phenomenon that was able to explain that light presents both wave and particle behaviour, laying the foundations for Wave-particle duality.
Likewise, in 1927, Clinton Davison and Lester Germer performed various electron diffraction experiments, showing that they exhibited wave behaviors very similar to light waves. This phenomenon has become known as Electron diffractionHe confirmed this wave-particle duality and highlighted the need to consider Planck's constant as an indispensable element in the study of the microscopic world.
Electron: The particle responsible for nothing touching anything
Also in 1981 he played a very important role during Invention Tunneling microscope. It is a phenomenon in which particles are able to cross classically forbidden energy barriers, which is directly related to the energy they possess, which is quantified in multiples of Planck's constant.
