On September 27, Einstein declared that E=mc²

On September 27, 1905, Albert Einstein published an article in the journal Annalen der Physik entitled Does the body consume a lot of energy?Or “Does the inertial mass of an object depend on its energy?” The aim of this article was to radically change the concept of space-time among scientists of the time: in it, in fact, Einstein introduced the famous equation E=mc² for the first timeIt is one of the most famous and important formulas in the history of science.

In the article, Einstein examined the implications of the theory of special relativity, which he developed that year. The formula E=mc² represents the equivalence between mass and energy. In other words, it indicates that the mass of an object is directly proportional to its energy. This revolutionary concept means just that Mass can be completely converted into energy, and vice versa.

Einstein demonstrated that Newton’s theory of mechanics needed to be revised and expanded to take these new concepts into account. A discovery that was not easily accepted by the scientific community, but after the first experimental correspondence changed the understanding of the physical world forever. It paved the way for important developments in theoretical physics, in the practical application of the equation in the production of nuclear and atomic energy, and in understanding the structure of the universe.

Where did enlightenment come from?

Einstein derived the equation E=mc² by reasoning based on a series of basic principles Special theory of relativitywhich he developed in 1905. This revolutionary theory was based on two main postulates:

1. Principle of relativity. Einstein assumed that the laws of physics are the same for all uniformly moving observers, regardless of their speed. This means that there is no distinct reference system The laws of physics must be consistent In all contexts.

2. The speed of light is constant. Einstein suggested this The speed of light in a vacuum (c) is constant It is independent of the observer’s speed. This was in contrast to the Newtonian concept of space and time, in which light was supposed to travel at infinite speed relative to a moving observer.

Based on these two axioms, Einstein began to examine… Lorentz transformationsWhich describes how physical quantities, such as time and length, change when moving from one inertial reference system to another. During this process, the world realized that energy (And(of the physical system and its mass)M) must be interconnected in some way to achieve constant speed of light.

Einstein proved that the energy of a moving body must include a contribution related to its mass. This is perfectly summed up by the formula E=m²where C It represents the speed of light.

Why is this equation so important?

The equation E=mc² is of fundamental importance for understanding the universe, its structure, and the laws that govern it, because it emphasizes the deep relationship between matter and energy, which are, in fact, everything that makes up the universe.

First of all, the concept expressed by the formula is the basis for understanding how the universe formed after the Big Bang. In fact, during this event, Huge amounts of energy have been converted into matterHe created protons, neutrons and electrons, which eventually formed atoms, and later stars and galaxies.

However, in particle physics, the equation is essential for understanding the behavior of subatomic particles. E=mc² explains how a particle’s mass can be converted into energy (and vice versa), allowing the understanding of nuclear reactions and the creation of particles in particle accelerators. But also for nuclear fission used in power plants and nuclear weapons. Converting small amounts of mass into huge amounts of energy This is the basic principle of such operations.

However, in a cosmological context, the equation contributes to the theoryDark energyIt is a mysterious form of energy that appears to be driving the accelerating expansion of the universe. This equation highlights how energy and mass are intrinsically linked, affecting the structure and evolution of the universe itself.

But not everyone immediately accepted Einstein’s theory…

When Einstein published his article on that day in late September 1905, the concept he expressed was not immediately accepted by all scientists, especially because of its implications. This represents the theory A major challenge to traditional concepts of physicsMany scientists were skeptical or cautious about accepting these innovative ideas.

The most controversial concept at the time was the constancy of the speed of light in a vacuum, as postulated by the theory of relativity. This idea was in stark contrast to Newton’s classical physics, which considered space and time to be absolute entities and the speed of light to be affected by the motion of the observer.

Einstein’s theory replaced these concepts with a new framework Space and time were relative and the speed of light remained constant. It took years of experiments and observations before Einstein’s ideas were widely accepted by the scientific community.

One of the first supporters of the special theory of relativity was the physicist Max Planck, who noticed that Einstein’s predictions regarding the photoelectric effect were correct. However, only over the next few years, as other experimental confirmations emerged, did Einstein’s theory gradually gain acceptance. Now, although there is still much to understand, it is one of the most important foundations of modern physics and astrophysics.