Studying what a laser is means reviewing humanity’s advances in understanding natural phenomena over the last 200 years.
The laser is an achievement in human manipulation of electromagnetic force.
Electromagnetic forces prevent gravity from pulling us to the center of the Earth. They manifest as electric charges that define each object.
Like charges repel, different charges attract, and thus, the things we can touch are balanced.When a body’s charge balance is lost, electrons move towards where there are fewer, and we have electrical manifestations like lightning and sparks.
By convention, we call it a positive charge when there’s an electron deficit and negative when there’s an excess of electrons.
Charges generate electromagnetic activity spaces around them called fields, which, when in contact with each other, collide and generate waves in space.
The spectrum of waves we manipulate ranges from radio waves of several meters to gamma rays.
Electromagnetic forces don’t act within the atom’s nucleus; other forces govern there, some that overcome the electrical repulsion between protons and other forces that have mass and their own field (Higgs).
Maxwell conceptualized electromagnetism as the result of field movement by charges and predicted that waves traveled at the speed of light.
Man then had the need to find out how far and where a light wave would travel, and it was necessary to arrive at an abstract concept, energy, the vital force that made a wave move against a medium occupied by many fields.
Einstein formulated the theory of relativity to explain the movement of matter and its relationships with electromagnetic force.
He applied mechanical laws to electromagnetic waves, considering the speed of light as the maximum possible in an ideal medium, without interference and according to the time for the measurement observer.
The inclusion of events in the formulas placed the variable of the speed of light with a stable value, thus enabling experiments at comparable values.
That energy was conserved was understood from mechanics, observing that something capable of producing movement would spend a force equivalent to what it generated.
Galileo had already found a constant unrelated to mass in his studies on the fall of objects, and Leibniz takes this up with his approach to vis viva, “living force” with an equation that related energy equal to its mass times its velocity squared.
Descartes didn’t square it.
Time was already being discussed when considering velocity, but there was no reference value that included it.
Einstein changes the concept to time relative to the observer.
Planck had established that the way energy and matter interrelated was related to a constant that appeared as the only way to explain that energy jumped in levels according to the frequency of waves, to explain the change in color of light emitted by a metal at different temperatures.
Einstein postulated photons, massless light-carrying corpuscles.
Einstein explained Hertz’s findings regarding the photoelectric effect. Hertz had observed that the addition of ultraviolet light to an electrical stimulus produced light from a metal immediately.
Einstein, based on the constant postulated by Planck, proposed that for energy to be conserved, it would have to happen that the energy with which electrons are expelled from the metal should be equal to the energy provided by the incoming photons, minus the energy needed to extract a single electron from the material.
That is, what is obtained in light depends on the energy according to the frequency of the incident wave.
Both values were thus measurable, and in 1916 Millikan verifies the value of Planck’s constant, thus defining that energy values change according to the wave frequency in energy jumps.
The model conceived of the atom when Einstein formulated the theory of relativity (1905) was still that of a plum pudding (Thomson, 1987).
Electrons were the raisins with negative charge; the nucleus had not been discovered, it was part of the pudding with positive charge.
The atom remained in equilibrium of its charge numbers.
Once the existence of a “nucleus” was insinuated by Rutherford (1911), Bohr, in a planetary model, extends Planck’s concept of energy levels in 1914.
The existence of precise energy thresholds explains that, to gain an energy level as well as to return to its level, a precise level of energy is necessary. To return from a gained level, it would emit it in an equivalent type of light.
Bohr’s model only explained the spectroscopy of the hydrogen atom, recently discovered, and it was from there that the need to explain subatomic phenomena was seen.
Thus, quantum mechanics was born.
Bohr’s simple planetary model of the atom was converted by Schrödinger in 1926 into a cloud to try to “find” the position of the electron at a given moment. Previously, Louis de Broglie had made his main contributions, which were:
Wave-particle duality of matter: De Broglie proposed that all particles, not just light, can exhibit both wave and particle properties. This idea extended the concept of wave-particle duality, previously applied only to light, to all matter.
Wavelength associated with particles: He developed an equation that relates the wavelength of a particle to its momentum, establishing that λ = h/p, where λ is the wavelength, h is Planck’s constant, and p is the particle’s momentum.
Unification of concepts: He ingeniously combined Planck’s quantization (E = hν) with Einstein’s famous equation (E = mc²), associating wavelength with particle velocity.
Explanation of Bohr’s atomic model: He applied his theory to Bohr’s atomic model, explaining why electrons can only exist in certain allowed orbits.
This provided a theoretical justification for the quantization of the electron’s angular momentum in the hydrogen atom.
Schrödinger took Broglie’s formulation to terms of probabilities, to locate the electron wave and forcing us to change the interpretation we would have to make of these probabilistic waves, equal to the others but reconstructed in bits.
And although when we don’t know something we resort to probability, it’s true that when we have almost all the information in the same system, this rises to 100% certainty.
The wavelength was then related, in probabilities, with a constant divided by mass and velocity so that we could see subatomic structures.
Thus, electrons could be manipulated by increasing their velocity with magnetic forces, to achieve increasingly smaller waves, and so we arrived at the electron microscope and all other proton and neutron generation systems.
Einstein invents the laser 50 years before its manufacture
Einstein was able to explain the sustained equilibrium of a light emission from the presence of a repetition of stimuli that would multiply photons, in what he described as stimulated emission.
An electron would rise to a higher energy level when it gained sufficient energy value and release it to return to its basic level, but if excited before decaying, a multiplication phenomenon would occur because the electron decays anyway but releases two photons.
It doesn’t gain another level.
His laser equation, the possibility of obtaining a purer and more powerful light, became a reality with Theodore Maiman in 1960, five years after Einstein’s death.
ALBERT EINSTEIN https://2.bp.blogspot.com/-Tf8nq8eYpDg/URjc8BkoZHI/AAAAAA
