They are centers of extreme gravity deep in the cosmos. Black holes are also a major source of uncertainty among scientists. The Academy recently awarded the Nobel Prize to those who unravel its secrets. Roger Penrose is one of them. The uniqueness of the black holes makes them unique. But what does that mean?
The death of the stars
Eduard Larrañaga is a theoretical physicist and professor at the National Observatory of Colombia. He explains that black holes were an Einstein theory before their existence was proven.
‘The general theory of relativity goes back to 1916. But it wasn’t until 1950 that the subject was dealt with much. Einstein himself believed that because of their strange properties, black holes would not be possible in nature, “he recalls. Some Einstein students began doing some calculations to explain how a star, when it died, creates a black hole could.
“The calculations at the time assumed that the star was completely spherical. But it is an idealization of the problem. In reality, stars are not like that, ”says Larrañaga.
And Penrose proves it. Stars without completely spherical behavior could go through a collapse. Something that led to the formation of a black hole, “he adds.
Penrose’s theory proved the possibility of the existence of these elusive objects in nature. But his study of the black holes did not finish determining their origins. The now British Nobel Prize laureate was of the opinion that certain “singularities” existed in certain points in the universe and in particular in the center of the black holes. Somehow they challenged all the laws of physics.
Years later his theorem on singularities would be applied by his student Stephen Hawking. It would also help to understand the primordial moment of the Big Bang. Penrose started from the understanding that there are certain points where physics no longer works. Where the laws that we believe to be universal do not apply.
«For example a black hole. They know that a black hole is an object with enormous gravity. Why does it have enormous gravity? Because it has a lot of mass. And it turns out that this mass is concentrated in a very small region. All this mass came to one point. So at this point gravity is infinite. The density is infinite and many other physical quantities go into infinity, “he explains.
The denial of everything
In this case, these “infinities” cannot be treated with normal mathematics. “Any equation with infinity no longer makes sense,” he says. This, he says, leads to these “singularities” in space-time. “It’s the point in the universe where the equations of physics no longer work for some reason. That happens in the middle of the black holes. “
There «the whole mass gathers, then the density is infinite. At this point the physical equations of general relativity no longer work, ”he says. The singularity is then the central point of the black holes where the entire mass is concentrated. ‘In the core of the black hole, the density is infinite. Because of this, the equations of physics don’t work, because where there is density, everything grows. Then the equations no longer work, ”he argues.
This theory is so complex that many scientists are questioning its existence. “There are many physicists today who do not believe in the singularity of black holes. They doubt they exist. And if we accept that, the laws of physics break down there, “he says.” If we physicists accept singularities, we accept that physics has a limit. “
And for physicists that is almost the equivalent of believers who doubt God. The origin of the existential crisis. Welcome the doubt!