Everyday objects may hide evidence of black holes

Dec. 2 () –

A theoretical study suggests that small black holes in the early universe may have left behind hollow planetoids and microscopic tunnels, and that can be found in rocks and ancient buildings.

The formation of a black hole is associated with a massive star that runs out of fuel and collapses in on itself. However, the chaotic conditions of the early universe may also have allowed Many small black holes formed long before the first stars.

These primordial black holes have been theorized for decades and could even be dark matter, the invisible matter that makes up 85% of the universe’s total mass. However, no primordial black hole has ever been observed..

New research co-led by the University at Buffalo proposes thinking both big and small to confirm their existence, suggesting that their signatures could range from very large (hollow planetoids in space) to tiny (microscopic tunnels). in everyday materials found on Earth, such as rocks, metal and glass).

The theoretical study, which will be published in the December issue of Physics of the Dark Universe and is now available online, suggests that a primordial black hole trapped inside a large rocky object in the cosmos would consume its liquid core and leave it gap. On the other hand, a faster primordial black hole could leave behind straight tunnels that large enough to be visible with a microscope if it passed through solid material, including material from right here on Earth.

“The chances of finding these signals are small, but searching for them would not require many resources and the possible result, the first evidence of a primordial black hole, would be immense,” he says. in a statement study co-author Dejan Stojkovic, a physics professor at the University at Buffalo. “We have to think creatively, because what has been done so far to find primordial black holes has not worked.”

As the universe expanded rapidly after the Big Bang, it is possible that some areas of space were denser than their surroundings, causing them to collapse and form primordial black holes (PBHs).

PBHs would have much less mass than stellar black holes formed later by dying stars, but they would still be extremely dense, like the mass of a mountain compacted into an area the size of an atom.

Stojkovic, who previously proposed where to find theoretical wormholes, wondered if a PBH was ever trapped inside a planet, moon or asteroid, either during or after your training.

“If the object has a liquid central core, then a captured PBH can absorb the liquid core, the density of which is greater than the density of the outer solid shell,” says Stojkovic.

The PBH could then escape from the object if it were hit by an asteroid, leaving nothing more than a hollow shell.

But would such a shell be strong enough to support itself, or would it simply collapse under its own stress? By comparing the strength of natural materials such as granite and iron with surface tension and density, the researchers calculated that such a hollow object could be no more than a tenth the radius of the Earth, making it smaller. It is probably a smaller planet than a planet proper. “If it’s bigger than that, it will collapse,” says Stojkovic.

These hollow objects could be detected with telescopes. Mass, and therefore density, can be determined by studying the orbit of an object. “If the density of the object is too low for its size, that is a good indication that it is hollow,” says Stojkovic.

ROCKS AND OLD BUILDINGS AS DETECTORS

For objects without a liquid core, PBHs could simply pass through it and leave behind a straight tunnel, the study proposes. For example, a PBH with a mass of 10 to the power of 22 grams (i.e. a 10 with 22 zeros) would leave behind a tunnel 0.1 microns thick.

A large plate of metal or other material could serve as an effective black hole detector if it were monitored for the sudden appearance of these tunnels, but Stojovic says there would be a better chance of looking for existing tunnels in very old materials, from buildings hundreds of years old to rocks billions of years old.

Still, even assuming that dark matter is actually made up of PBH, they calculated that the probability of a PBH passing through a billion-year-old rock is 0.000001.

“You have to consider the cost versus the benefit. Does it cost a lot to do this? No, it doesn’t cost much,” says Stojkovic.

Therefore, the probability of a hydrogen projectile passing through a person during their lifetime is small, to say the least. Even if he did, he probably wouldn’t notice.

Unlike a rock, human tissue has a small amount of tension, so a hydrogen projectile would not tear it apart. And although the kinetic energy of a hydrogen projectile can be enormous, It can’t release much of it during a collision because it moves so fast.

“If a projectile moves through a medium faster than the speed of sound, the molecular structure of the medium does not have time to respond,” Stojkovic says. “If you throw a rock through a window, it’s likely to break into pieces. If you shoot a window with a gun, it’s likely to just leave a hole.”