While the greatest great voids have actually been currently found and even photographed, there is now also practical proof– as I display in my current research study– for tiny black holes the size of potassium atoms (with a radius of about 0.23 nanometers, equivalent to 0.23 billionth of a meter). These atomic-sized great voids were formed in the very first moments of the Big Bang and may even make up the totality of the dark matter of the universe.
Taking photos.
In 2019, a cooperation of eight radio telescopes located in different parts of the world was able to take the very first photo of a massive black hole (6.5 billion times more enormous than our Sun). It is located about 55 million light years from us (a light-year representing a distance of about 9.5 trillion kilometers) at the center of the Messier 87 galaxy.
The italics of the word photograph is no coincidence: how can a picture be taken of an item that catches light and, for that reason, would not have the ability to be seen by video cameras, which utilize light to create a photo? The answer is easy: we are not observing the item itself, but the remains of star that are being swallowed up by these black holes.
When it reaches temperatures of the order of a million degrees celsius, this stellar matter turns at enormous speeds around the black hole and its brightness can be found. The disk of matter that surrounds the black hole is called the “accretion disk” and is thought about the edge of the great void– once it is passed, nothing can leave, something we call an occasion horizon.
Picture of a supermassive great void situated in the center of the galaxy M87. Credit: EHT Collaboration.
In the image above you can see the accretion disk and the occasion horizon of the great void located in M87.
Primitive great voids.
Substantial parts of the black holes in the universe were formed by the gravitational collapse of stars consuming all their fuel in their lasts: these are called “stellar great voids.” Not all stars will turn into great voids at the end of their life time; when the core of a star is less than two or three solar masses, an excellent black hole can not be produced.
That is, there exists a minimum excellent mass listed below which a star can not collapse into a black hole. As an example, our Sun will never ever turn into a black hole at the end of its life, however other massive stars like the red supergiant Betelgeuse will undoubtedly become great voids.
There are also other black holes called “primitive” or “prehistoric” great voids, which– as their name indicates– were created in the first moments of the Big Bang, when the universe first started, and can theoretically possess any mass. They might range in size from a subatomic particle to a number of hundred kilometers.
And when it comes to black holes, supermassive ones emit almost no radiation, while the smallest ones release the most radiation. How is this phenomenon possible: supermassive black holes that release almost no radiation and trap everything, even light?
The response was supplied by physicist Stephen Hawking in the mid-1970s. He postulated that the quantum results near the event horizon of a black hole may produce the emission of particles that might escape from it. That is, great voids that do not get mass by any other methods will gradually lose their mass and finally vaporize.
This Hawking radiation is more obvious in low-mass great voids: the evaporation time of a million-solar-mass supermassive great void is 36 × 10 to the power of 91 seconds (a lot longer than the present age of the universe).
On the other hand, a great void with a mass equivalent to a 1,000-ton ship would evaporate in about 46 seconds.
In the last stages of a great voids evaporation, they would blow up and produce a substantial amount of gamma rays (a radiation much more intense than X-rays).
Recording an atomic-sized prehistoric black hole.
So how can atomic-sized holes be evidenced prior to they evaporate totally?
In the recent study of atomic-sized black holes, an astrophysical situation is proposed where among these small black holes is captured by a supermassive one. As the atomic-sized great void approaches the occasion horizon of the supermassive one, the portion of Hawking radiation that may be detected from the Earth gradually decreases, until it reaches the size of a ray of light.
The following animation shows the above process in more information.
The capture of an atomic-sized primitive black hole by a supermassive great void.
This beam is compatible with thermal gamma ray bursts (GRBs) currently measured at huge observatories. It is these GRBs that make up an experimental evidence for such small black holes, which are major prospects for the dark matter of a fascinating and yet undiscovered universe.
Written by Oscar del Barco Novillo, Profesor asociado en el área de Óptica, Universidad de Murcia.
This article was first published in The Conversation.
Creative analysis of a primitive great void formed in the first minutes of the Big Bang. Credit: NASA/ G. Bacon (STScI).
Given that the earliest times, human beings have actually wanted to describe the most unpredictable and troubling phenomena in the universe. Although the study of astronomy has actually been a continuous in all civilizations, astronomical occasions of a more “unpredictable” nature, such as comets or eclipses, were considered an “omen of misfortune” and/or “actions of the gods.”.
The fall of the Saxon king Harold II in 1066, throughout the Norman invasion of William the Conqueror, was associated to the bad prophecy from the passage of a comet (later baptized as “Halley”). And during the battle of Simancas (Valladolid, Spain) in between the soldiers of León Ramiro II and the Caliph Ad al-Rahman in 939, a total solar eclipse triggered panic amongst the soldiers on both sides, delaying the battle for several days.
How would our forefathers have responded, then, to the presence in deep space of objects– so-called black holes– capable of swallowing whatever that fell under them, including light?