In the daily life of a human being, his past determines his future in a decisive way; both the immediate and long-term. And the same is true in the rest of the universe. In fact, if a physicist knew exactly how the universe begins, he could calculate the future of that space-time. Scientists assume that the laws of our universe are “deterministic,” that is, they assume that there is only one possible future.
This principle was postulated decades ago by physicist Roger Penrose.
However, a mathematician at UC Berkeley University has found some types of black holes in which this law is broken. In fact, if someone ventured into one of these black holes, they would not die: they could survive, but their past would be erased; instead, it would have an infinite number of possible futures.
According to Dr. Peter Hintz, lead author of the study, mathematical calculations show that, for some specific types of black holes, in a universe like ours – which is expanding at an accelerated rate, it is possible to go from a “deterministic world “(Which presupposes that there is only one possible future) to a” non-deterministic “world, whose physical laws would allow several possible futures.
What would life be like in a universe where the future is unpredictable?
It is not clear. But the finding does not mean that Einstein’s equations of general relativity, which so far perfectly describe the evolution of the cosmos, are wrong.
“It is not possible to travel to a black hole and measure it, this is just a mathematical question,” says Hintz. But from that point of view, this makes Einstein’s equations more mathematically interesting. “This is a question than one alone. it can study mathematically, but it has physical, almost philosophical implications, which makes it great, “in the words of the physicist.
Would it be possible to survive the event horizon?
Black holes are strange objects that take their name from the fact that nothing can escape their gravity, not even light. If someone ventures too close and crosses the so-called event horizon, they will never get out of it: they would stretch anything into a chain of atoms.
But for large black holes, such as supermassive objects in the cores of galaxies like the Milky Way, weighing tens of millions or billions of times the mass of a star, crossing the event horizon would be possible, and could occur without incidents, according to investigators.
Therefore, it should be possible to survive the transition from our universe to that of the black hole. For this reason, physicists and mathematicians have wondered what that world would be like, and have resorted to Einstein’s equations of general relativity to predict the world inside a black hole.
These equations work well until an observer reaches the center or singularity, where in theoretical calculations the curvature of space-time becomes infinite.
Cauchy’s horzonte
However, even before reaching the center, a black hole explorer – who, on the other hand, could never communicate what he was experiencing to the outside world – might encounter some rare, and deadly, landmarks.
Hintz studies a specific type of black hole: a standard, non-rotating, electrically charged black hole, and such an object has a so-called Cauchy horizon within the event horizon.
The Cauchy horizon is the point where determinism breaks down, where the past no longer determines the future. But some physicists, including Penrose, have argued that no observer could pass through the Cauchy horizon point because they would be annihilated.
An observer traveling through the event horizon will eventually find the Cauchy horizon, the boundary of the region of spacetime that can be predicted from the initial data. Hintz and his colleagues found that a region of spacetime, indicated in the diagram by a question mark, cannot be predicted from the initial data in an acceleratingly expanding universe like ours. (Image courtesy of APS / Alan Stonebraker)
When an observer approaches the horizon, time slows down, as clocks mark the slowest time in the face of a strong gravitational field. As light, gravitational waves, and whatever else encounters the black hole inevitably fall toward the Cauchy horizon, an observer falling inward will also see all of this energy coming in at the same time.
Therefore, all the energy that the black hole sees over the life of the universe hits the Cauchy horizon at the same time, destroying the observer who reaches that far.
