I am copy-pasting a post that I published on Facebook...
Between Sanremo and the various BULLSHIT fed to us by these idiots who muddle minds, proper value was not given to a discovery that is, without any doubt, the most important one in the last 100 years. Not only, in fact, has the scientific community verified an as-yet unproven part of one of the most famous and, at the same time, most debated theories in history, but it also paves the way for new theories that finally boast a new stable point to anchor themselves on in the climb towards the theory of everything.
To understand the importance of this discovery, one must start from the bottom, and I would like to try to tell it in the simplest and humblest way possible, providing a non-strictly technical-scientific overview, accessible to all interested parties, to provide food for thought on what genius is and on which points we must invest to guarantee a future for our planet, our children, and the generations to come...
Galileo was the first to ask the question regarding the validity of the laws of mechanics, focusing in particular on the role of different observers in different reference frames. In essence, according to Galileo, by performing the same experiments simultaneously from two different observers, in different inertial reference frames, these were supposed to produce an identical result (according to Galileo, the laws of mechanics are always the same for reference frames that satisfy the principle of inertia).
To synchronize two experiments, observers will need to exchange information...
Galileo tried to measure the speed of light to see if it could affect the methods of exchanging information between observers, but without success, deducing that it was so high as to be irrelevant. Galileo concluded that time remained the same when passing from one to the other of the two inertial systems. Assuming that the two reference frames moved at different speeds, applying Euclidean geometry, he derived the equations for the transition of space-time coordinates from one system to another.
In Newton's view, derived from astronomical observations, he stated that gravitational force is responsible both for the acceleration of gravity on our planet and for the mutual attraction between planets. To assert this, he had to make two assumptions: the mass that appears in the second law of dynamics is called inertial mass, while that which appears in the law of universal gravitation is called gravitational mass. The second assumption is that gravitational force is a force that has an immediate effect between masses even if separated by an astronomical distance. This extended the concept of Galilean relativity, positing space and time as absolutes. All this (what took the name of classical physics) worked for a couple of centuries, until some experimental verifications, especially in the astronomical field, found no support in the laws of "classical" mechanics.
The second problem of classical physics was related to electromagnetism, where attempts were made, without success, to apply the concepts of Galilean relativity, which however went along with Newtonian mechanics. However, Maxwell's equations were not invariant with respect to the transformations enunciated by Galilean relativity in different reference frames and thus the theory presented a flaw.
Lorenz, later, discovered that Maxwell's equations were invariant with respect to another kind of transformation that today takes the name of Lorentz transformations, which also considered the speed of light. It is important to say that at speeds not comparable to those of light, Lorentz transformations reduce to Galilean ones. In essence, it is therefore a subsequent extension of Newton's theory, which would see classical mechanics as one of the possible cases.
At this point, however, it was a matter of providing an explanation for two possible cases:
- To declare the equations of Newton's classical mechanics, which until then had worked excellently in non-relativistic reference frames, to be unfounded?
Or
- To declare Maxwell's equations to be unfounded?
A theory was sought that could unify the two, but not much was achieved, enunciating a concept more philosophical than scientific regarding the existence of an "ether."
In 1905, Einstein's solution arrived with his famous "Special Theory of Relativity," which was based on three points. The first was that the correct transformations to pass from one inertial reference frame to another are the Lorentz transformations; the second is that the laws of mechanics are independent of the reference frames; and, lastly, the speed of light is a constant that does not depend on the velocity of the reference frame. According to Einstein
there is an equivalence between mass and energy and the famous formula e=mc^2 is not much different from Newton's kinetic energy formula (E = 1/2mv^2).
Einstein's revolution in thought occurs precisely upon reading this formula, which would be more correctly read as c^2=E/m where we find the speed of light: an independent variable (precisely because, as postulated from the beginning, it is an absolute constant that does not depend on the velocity of the reference frame); energy: the dependent variable, and mass: a parameter.
This formula, read in this way, also gives us the opportunity to say that if the speed of light is a constant given by the ratio between energy and mass, it also tells us that mass and energy are mutable between each other under appropriate conditions. Mass can change into energy (see the atomic bomb) and energy can change into mass (the exact opposite of the former, which is observed in electrosynchrotrons).
Einstein also criticized the concept according to which Newton asserted that space and time are absolute, asserting instead that velocity was absolute and space and time were relative.
In light of Einstein's publication on special relativity, inconsistencies also arose with what Newton had said regarding the laws of gravitation, according to which the force of gravity manifested instantaneously regardless of the distance between the two reference frames.
This was not in agreement with special relativity, according to which the speed of electromagnetic waves was the maximum possible. Two problems opened up: the first concerned the difference claimed by Newton but not demonstrated between gravitational mass and inertial mass, and the second concerned special relativity and its applicability to non-inertial (accelerated) reference frames.
In 1908, Einstein postulated the coincidence of these two masses and the consequences within non-inertial reference frames, concluding that there was no difference between gravity and acceleration. This was the basis for the theory of general relativity, which was an extension of the theory of special relativity and required more than 10 years of study, needing a new mathematical system to be proven, known as tensor mathematics, through which Einstein demonstrates that a particle free to move in space-time moves along curved trajectories (for non-inertial systems) and that the case where space-time is flat refers solely to the particular case in which we are in a non-accelerated reference frame. In general, however, space-time is curved; therefore, Euclidean geometry does not apply. In a curved space-time, a trajectory of minimum distance (geodesic) is thus always represented by a curve (in Euclidean space, the minimum distance between two points would be a straight line – but this is a particular case relative to inertial systems) and this explains the elliptical motion of planets around the sun. The curvature of space-time is due to mass. From this derive the gravitational field equations. Einstein, believing in the existence of a static universe, concluded that the geometry of the universe is globally Euclidean (static universe = no acceleration = globally inertial reference frame -> Euclidean geometry).
Subsequently, some experiments confirmed Einstein's theories and others refuted them.
Among the refutations, we find those related to the idea of a static universe and the cosmological constant, which clashed with an experimental fact discovered by Hubble.
Among the confirmations, we find the effect of gravitation seen as the curvature of space-time, which allowed planets to follow the shortest path (the concept of geodesic mentioned above) and not seen as a force that attracts planets at a distance. Another confirmation was that related to the optical illusion regarding the position of stars, in which a mass positioned between a light source (a star) and the observation point showed the star in a position where it should not be found. This is caused by the gravitational lensing effect, which bends light rays near the mass that deviates their path.
Lastly, the theory of general relativity predicts the existence of gravitational waves, which are wave-like variations of the geometry of space-time caused by the movement of masses under particular conditions (sudden change in mass: supernova explosion, black hole merger, movement of strongly massive objects in binary formation).
According to Einstein, such gravitational waves propagate at the speed of light perpendicularly to the direction of propagation of the gravitational field, and the equation for these waves is of a tensorial type.
The problem in detecting gravitational waves lies in the fact that they are
extremely weak since the coupling constant of the gravitational field is infinitely lower than other fundamental forces, such as nuclear interactions, and therefore in order to detect the presence of these waves we need a very important cosmic event to occur which, as we said before, could be for example the explosion of a supernova or the merger of two black holes: phenomena of sudden mass variation that results in a sudden variation of spacetime geometry. Imagine a pond with a completely still body of water. If we gently inserted a pen, with great caution we would not generate large arabesques or at least we would generate some that are "undetectable"; things would be different if we threw a stone. Unfortunately, as stated, the effects are not comparable to those of a stone inside a lake mirror; the waves formed are infinitely weaker and to detect them instruments at the limit of our technology are needed, capable of measuring distance variations on the order of a thousandth of the size of a proton.
Today we have managed to verify the existence of gravitational waves and not only that, but also the existence of black holes in binary systems and black holes. For us, it was a great stroke of luck! It was luck because it is easy to understand that cosmic catastrophes do not happen every day. In particular, on September 24, 2015, gravitational waves were captured caused by the merger of two black holes 1.3 billion light-years away from us and therefore we are talking about an event that happened 1.3 billion years ago, an era in which man did not yet exist. This discovery gives us a cornerstone to move forward with theories and answer, in a future based on research, questions to which even Einstein's equations have not given an answer. To clarify those that are called "essential singularities," i.e., unsolvable ones, within which the laws of physics as we know them cease to exist and which exist up to that impassable limit for our current knowledge called the "event horizon"... We are talking about black holes. These objects could tell us where we come from, where we are going, and what the fate of the universe is.
Is it only me who remains fascinated by the poetry of nature and by science's attempts to give it a formal interpretation?
How is it possible that governments do not understand, in light of these discussions, what emerges so trivially? We must invest in research; this is our future, this is what one day could determine our survival as a species in a universe full of gigantic pitfalls. Enough with all this bullshit! Enough with the cuts to universities and research, get this fucking ball out of the way and if you have to take to the streets, do it for a reason of common good, not for 11 idiots running after a ball enjoying to your faces the millions of euros that you give them every year... Wake up!
