News from Beijing time September 6, according to foreign media reports, in the eyes of many people, black holes are a very scary existence in the universe. They are very dark, have a strong gravitational pull, and seem to have some ominous meanings. Now, astronomers have suggested an imaginary black hole type: the real black hole. This kind of black hole is not formed by the collapse of stars, but by the very beginning of the universe and the flooding of our present universe.

So, what is the possibility of such an ancient monster escaping to Earth? An astronomer calculated this.

Born in the Big Bang

The early universe was wild and complex, very different from the gentle universe we live in today. At the beginning of the Big Bang, the universe underwent a gradual change. Although scientists have a preliminary understanding of physical phenomena in the first minutes of the Big Bang, what happened before is obscured by mathematical calculations related to Nigu-ta.

For a black hole to form, some extreme conditions are required, such as the collapse of some star at the last moment of its life. Stars do not exist in the first moments of the universe’s birth, but there may be conditions conducive to the formation of black holes; The formation of a true black hole requires the packing of a large amount of matter. Or enough energy for a small enough space.

In the distant past of the universe, in the unknown realm of the universe we have not yet discovered, the real black hole may have caused some conditions to flood the entire universe. These black holes may have different masses depending on the conditions under which they formed. However, scientists have been searching for primitive black holes for decades, but to no avail, and public interest has gradually waned. Until recently, we finally had an efficient detection device — the Laser Interferometer Gravitational Wave Observatory (LIGO).

When LIGO first discovered the gravitational waves caused by the collision of black holes, astronomers found that the mass of these black holes was a dozen times the mass of the Sun. This mass range is difficult to achieve with traditional stellar black hole mergers, as such merger events must occur from time to time to form a black hole of this size. As a result, the original black hole returned to the view of astronomers.

Searching for primitive black hole

As for the various processes that took place in the primitive universe, if there was a strange mechanism that could produce black holes, it would not only create a few black holes, but would fill the entire universe. In fact, there may be enough primitive black holes in the universe to explain at least part of the dark matter; Astronomers estimate that more than 80% of all matter in the universe is caused by mysterious dark matter.

In a recent paper on the preprint database arXiv, scientists speculated that there could be amazing little black holes in the universe. What changes will they experience?

In fact, black holes are not 100% black. They lose mass through Hawking radiation. Hawking radiation is a complex quantum mechanical process that occurs on the event horizon of a black hole, allowing some particles and radiation to escape from the black hole. Its rapid loss as the black hole becomes smaller. A black hole slightly lighter than a normal asteroid is less than 100 million tons — about half of its mass will be lost during the current period of the universe. For large black holes, at the current age of the universe, only a small amount of mass is lost due to Hawking radiation.

The total number of black holes in each galaxy depends on how much dark matter there is in the galaxy and how large each black hole is. However, no matter how you divide it, there must be a lot of small black holes in different galaxies.

Moreover, these black holes move very fast. According to computer simulations and observations of galactic dynamics, the speed of dark matter exceeds 160 kilometers per second. At this speed, an asteroid-mass black hole could cover the distance between Jupiter and Earth in a matter of weeks. So, should we be afraid of these black holes falling to the ground?

The collision of the original black hole with the Earth

What happens if an asteroid mass hits Earth? Simply put: the tragedy of extinction. The black hole will pierce the surface of our planet like a hot knife piercing butter; On the other hand, a black hole will suddenly start to slow down because it will interact with the Earth’s gravity. Once any atom or molecule (or each of us) passes through the event horizon, it slips out of the known universe and can never be seen again. The event horizon is the boundary of the black hole. Within this boundary, not even light can escape.

In the most ideal case, the black hole would leave the other side of the earth, allowing the survivors to clear the mess. At worst, the black hole will fall to the core of the earth, where the earth’s gravity will be enough and the black hole will begin to “eat”. Gradually, black holes will destroy our entire planet.

Fortunately, according to the calculations in this paper, the chances of black holes falling into the Earth’s core are very small – they move very fast.

On the other hand, the collision between the Earth and the black hole can lead to another unpleasant result: overheating. In the process of passing through the Earth, the black hole collects matter and creates accretion heat (this kind of heat activates the galaxy’s nucleus). After an asteroid mass hits the black hole on Earth, the final energy emitted is equal to the energy emitted by a 1 km wide asteroid impact. 65 million years ago, an asteroid of this size fell to Earth and led to the extinction of the dinosaurs.

Fortunately, black hole collisions can be very rare. According to the calculations in this paper, in the most “optimistic” situation (by the standards of scientists, that is, when the number of black holes in a galaxy reaches its maximum), only one collision will occur more than every billion years. Therefore, we do not have to worry too much about falling into what is called a black hole.