Why is there so much gold in the known universe?

There is too much gold in the universe, or at least in the area where we live. Perhaps this is not a problem, because we value gold very much. The thing is, no one knows where it came from. And this intrigues scientists.

Because the earth was molten at the time it was formed, almost all the gold on our planet at that time probably plunged into the core of the planet. Therefore, it is assumed that most of the gold found in Earth's crust and the mantle was brought to Earth later by asteroid impacts during the Late Heavy Bombardment, about 4 billion years ago.

На example gold deposits in the Witwatersrand basin in South Africa, the richest resource known gold on earth, attribute. However, this scenario is currently being questioned. Gold-bearing rocks of the Witwatersrand (1) were stacked between 700 and 950 million years before the impact the Vredefort meteorite. In any case, it was probably another external influence. Even if we assume that the gold we find in the shells comes from within, it must also have come from somewhere within.

1. Gold-bearing rocks of the Witwatersrand basin in South Africa.

So where did all our gold and not ours originally come from? There are several other theories about supernova explosions so powerful that stars topple over. Unfortunately, even such strange phenomena do not explain the problem.

which means it's impossible to do, although the alchemists tried many years ago. Get shiny metalseventy-nine protons and 90 to 126 neutrons must be bound together to form a uniform atomic nucleus. This is . Such a merger does not occur often enough, or at least not in our immediate cosmic neighborhood, to explain it. gigantic wealth of goldwhich we find on Earth and in. New research has shown that the most common theories of the origin of gold, i.e. collisions of neutron stars (2) also do not provide an exhaustive answer to the question of its content.

Gold will fall into the black hole

Now it is known that the heaviest elements formed when the nuclei of atoms in stars trap molecules called neutrons. For most old stars, including those found in dwarf galaxies from this study, the process is fast and is therefore called the "r-process", where "r" stands for "fast". There are two designated places where the process theoretically takes place. The first potential focus is a supernova explosion that creates large magnetic fields - a magnetorotational supernova. The second is joining or colliding two neutron stars.

View production heavy elements in galaxies In general, scientists at the California Institute of Technology in recent years have studied several nearest dwarf galaxies from Keck telescope located on Mauna Kea, Hawaii. They wanted to see when and how the heaviest elements in galaxies formed. The results of these studies provide new evidence for the thesis that the dominant sources of processes in dwarf galaxies arise on relatively long time scales. This means that heavy elements were created later in the history of the universe. Since magnetorotational supernovae are considered to be a phenomenon of the earlier universe, the lag in the production of heavy elements points to neutron star collisions as their main source.

Spectroscopic signs of heavy elements, including gold, were observed in August 2017 by electromagnetic observatories in the neutron star merger event GW170817 after the event was confirmed as a neutron star merger. Current astrophysical models suggest that a single neutron star merger event generates between 3 and 13 masses of gold. more than all the gold on earth.

Neutron star collisions create gold, because they combine protons and neutrons into atomic nuclei, and then eject the resulting heavy nuclei into space. Similar processes, which in addition would provide the required amount of gold, could occur during supernova explosions. “But stars massive enough to produce gold in such an eruption turn into black holes,” Chiaki Kobayashi (3), an astrophysicist at the University of Hertfordshire in the UK and lead author of the latest study on the subject, told LiveScience. So, in an ordinary supernova, gold, even if it is formed, is sucked into the black hole.

3. Chiaki Kobayashi of the University of Hertfordshire

What about those strange supernovas? This type of star explosion, the so-called supernova magnetorotational, a very rare supernova. dying star he spins so fast in it and is surrounded by it strong magnetic fieldthat it rolled over on its own when it exploded. When it dies, the star releases hot white jets of matter into space. Because the star is turned inside out, its jets are full of golden cores. Even now, the stars that make up gold are a rare phenomenon. Even rarer are stars creating gold and launching it into space.

However, according to the researchers, even the collision of neutron stars and magnetorotational supernovae does not explain where such an abundance of gold on our planet came from. “Neutron star mergers are not enough,” he says. Kobayashi. “And unfortunately, even with the addition of this second potential source of gold, this calculation is wrong.”

It is difficult to determine exactly how often tiny neutron stars, which are very dense remnants of ancient supernovae, collide with each other. But this is probably not very common. Scientists have observed this only once. Estimates show that they do not collide often enough to produce the gold found. These are the conclusions of the lady Kobayashi and his colleagues, which they published in September 2020 in The Astrophysical Journal. These are not the first such findings by scientists, but his team has collected a record amount of research data.

Interestingly, the authors explain in some detail the amount of lighter elements found in the universe, such as carbon ¹²C, and also heavier than gold, such as uranium ²³⁸U. In their models, the quantities of such an element as strontium can be explained by the collision of neutron stars, and europium by the activity of magnetorotational supernovae. These were the elements that scientists used to have difficulty explaining the proportions of their occurrence in space, but gold, or rather, its quantity, is still a mystery.