Black holes are part of the universe (is a space region) and the explanation issued by NASA is that black holes are not really holes themselves and are not empty. They are cold remnants of very old stars that contain large amounts of matter in a compact space. This is due to their powerful gravitational pull. The density of black holes is so great that no material particles, not even light, are able to free themselves from the enveloping gravitational force. Its gravity is so strong that if a bright star is close to the black hole, it cannot be seen, because the holes absorb starlight from nearby objects. Gravity often rips off the outer gases of a star and causes a disk to grow around it called an accretion or accretion disk.
The scientist Albert Einstein spoke about time and space in the universe. To get into this, it is indispensable that we imagine space and time as a flat and flexible surface or sheet. If space-time were empty, the surface would be totally flat, but this is not the case because of the large celestial bodies that occupy space in the cosmos; for example, our Earth and the Sun.
These two bodies will deform the sheet creating a curve, being that of the Sun deeper because it has a higher mass. This will generate gravity. The more mass a body has, the more curvature it will create in the space-time around it, therefore, the more gravity it will have.
The more a massive star cools down, the more it curves the space-time around it. It will reach a point where the size is so immense that it will create a black hole in space-time. Einstein did not call them in his time as black holes, but as «Schwarzschild singularities«.
Singularity of black holes (See also Technical singularity La singularidad técnica – miniowi.icu)
Science affirms that everything that falls into a black hole cannot get out of it.
The fundamental laws of physics state that at the bottom of a black hole there is a point called a singularity, i.e., a region where space and time are infinitely warped and cease to exist. Once matter enters the singularity region, it is totally destroyed.
The existence of black holes and the singularity have awakened the public imagination, to the point of saying that inside them there is something called a ‘wormhole‘; that is, tunnels where it is possible to travel in space and time that will someday be possible. Actually, there is no real proof of their existence or that this will ever be experienced.
In conclusion, although the singularity is not a reliable point, everything indicates that the rest of the story is: matter, once inside the black hole, spirals towards the center. Once there, we don’t quite know what happens, but gravity becomes more intense and the black hole grows. One way to imagine this process is to think that upon reaching the singularity matter «becomes gravity», as if its energy were used to bend space and, in return, matter ceases to exist. This is only one way of putting into words what the equations tell us, but at least it helps us to navigate the murky waters that remain when relativity is no longer helpful.
These ideas were fleshed out in a series of papers in the late 1960s and early 1970s, which showed that a black hole has only three properties: a mass, an electric charge, and angular momentum. (In short, the mass gives us the intensity of its gravitational field, since after falling into the singularity all of it has been «transformed into gravity». If the black hole has an electric charge, it will have a static electric field around it, and we will be able to observe it from the outside. And as for the angular momentum..it gives us the rotation of the black hole; in both cases the same thing happens: the mass, or angular momentum, are properties of the matter that has fallen into the black hole. Once inside, that matter «transforms into gravity», and its properties are «translated» into gravitational properties. Mass is translated into gravitational field strength or, if we want, black hole size. Angular momentum, or rotation, translates into the black hole will force everything in its vicinity to rotate.Black holes are gravitational objects, and that means that they deform the space-time around them. The effect of mass is to create an event horizon, larger or smaller depending on how much mass has fallen into the black hole. The effect of rotation is to create around the event horizon a region in which it can only rotate. That region is called the ergosphere (as general relativity predicts.), and it has a shape similar to a donut with the event horizon in the hole.)
Stephen William Hawking
One of the most important physicists who spoke about the existence of black holes, but not as we know them, was Stephen William Hawking. His great legacy derived from the idea that «black holes dissolve slowly like aspirin in a glass of water» (black hole radiation theory).
Primordial black holes are believed to have formed in the early universe, shortly after the Big Bang, while stellar black holes formed when the center of a very massive star consumes all its fuel, collapses and explodes, known as a supernova. Subsequently, the debris collapses and transforms into a very compact object, called a black hole (in 1999, NASA and the European Space Agency launched XMM-Newton, an X-ray space observatory named after Isaac Newton. This technological creation makes it possible to observe the universe in high-energy X-rays, something impossible for the human eye. With this work, X-rays released from gases and dust particles circulating near black holes can be detected before the black hole swallows them. The Chandra X-ray Observatory, the Swift satellite and the Fermi Gamma-ray Space Telescope are also part of the team launched to locate supermassive black holes, as well as other astronomical phenomena. This is intended to learn more details about black holes, as well as to continue the advance on the origin, evolution and destiny of the universe).
In 2018, astronomers released an image of the formation and expansion of abundant fast-moving material when the gravity of a supermassive black hole absorbed the energy of a nearby star.
A recent study on June 2, 2023 (has been published in Physical Review Letters, and carried out by Michael Wondrak, Walter van Suijlekom and Heino Falcke of Radboud University in the Netherlands); has confirmed the validity of Stephen Hawking’s black hole radiation theory, which holds that black holes will eventually evaporate. However, this new research adds a disturbing twist, suggesting that not only black holes, but everything in the universe, is doomed to gradually evaporate.
In 1974, Hawking proposed that black holes evaporate by losing what we now know as Hawking radiation, a gradual drain of energy in the form of light particles that arise around the immensely powerful gravitational fields of black holes.
To reach this conclusion, Hawking used a combination of quantum physics and Einstein’s theory of gravity in which he argued that the spontaneous creation and annihilation of particle pairs must occur near the event horizon (the point beyond which there is no escape from the gravitational force of a black hole). A particle and its corresponding antiparticle would be created very briefly from the quantum field, but would annihilate almost as quickly. However, an exception to this disappearance would occur when one particle falls into the black hole allowing the other particle to escape. It is this phenomenon that would eventually lead to the evaporation of black holes.
In this new study, researchers at Radboud University combined techniques from physics, astronomy and mathematics to examine what happens if these pairs of particles are created in the vicinity of black holes. The study showed that new particles can also be created far beyond this horizon; they have demonstrated that, in addition to the well-known Hawking radiation, a new form of radiation also exists; they have also shown that far beyond a black hole the curvature of space-time plays an important role in the creation of radiation. There the particles are already separated by the tidal forces of the gravitational field (it was previously thought that radiation was not possible without the event horizon, this study shows that this horizon is not necessary). All this means that objects without an event horizon the gravitational point of no return beyond which nothing, not even light, can escape from a black hole, such as the remains of dead stars and other large objects in the universe, also have this type of radiation. And, after a very long period, that would lead to everything in the universe eventually evaporating, just like black holes. This changes not only our understanding of Hawking radiation, but also our view of the universe and its future.
Although the results demonstrated in the new study, this theory has not yet been confirmed, so it remains speculative. To determine whether this prediction is really the ultimate fate of our universe, physicists will have to detect Hawking radiation around gravitationally dense objects, such as black holes, planets, stars and neutron stars.
And to finish I launched an idea, if the Higgs Boson, has to do with the amount of Mass (the denser the better), with the concept of Waves (Gravitational Waves), with the Space-time Curvature, with the Singularity (Event Horizon), with the concept of Gravity, with the Higgs Field that would be found everywhere, even in the «vacuum» (not even that vacuum would be completely empty, because it would be occupied, at least, by the Higgs field).
In general, we define a black hole (at least to date), as a region of «empty» space; because do not suppose that a black hole is not completely empty and at least, it would be composed of that Higgs field and therefore have inside it the Higgs Boson.
At the moment the existence of Higgs radiation has not been proven (Higgs radiation is a hypothetical elementary particle that is predicted in the standard model of particle physics. The existence of the Higgs Boson and the associated Higgs field would be the simplest of several methods of the Standard Model of particle physics that attempt to explain the reason for the existence of mass in elementary particles.)