The yellow metal, a simple chemical element with atomic number 79. The object of desire of people at all times, the measure of value, a symbol of wealth and power. How many lives have been ruined for the sake of owning this metal !? And how many more will be ruined? In contrast to the iron or, for example, by aluminum, gold in the world is very small. Throughout its history, mankind has extracted the gold as much as it produces iron per day. But where this metal appeared on Earth? ...
It is believed that the solar system was formed from the remnants of exploded sometime in antiquity supernova. In the depths of the ancient stars is a synthesis of chemical elements heavier than hydrogen and helium. But in the depths of the stars can not be synthesized elements heavier than iron, and therefore, the gold could not be formed as a result of thermonuclear reactions in stars. So, where does all this metal appeared in the universe?
It appears, astronomers can now answer this question. Gold can not be produced in stars. But it can be formed as a result of the grand cosmic catastrophes that scientists casually called gamma-ray bursts (GW).
Astronomers closely watched one of these gamma-ray bursts. These observations give a fairly good reason to believe that the powerful flash of gamma radiation produced by the collision of two neutron stars - dead cores of stars who died in a supernova explosion. In addition, a unique glow, keeps in place the GW for a few days, indicating that during this catastrophe formed a significant amount of heavy elements, including - gold.
"According to our estimates, the amount of gold, formed and ejected into space during the merger of two neutron stars, can sotavit more than 10 lunar masses," - said the study's lead author Edo Berger of the Harvard-Smithsonian Center for Astrophysics (CfA) at a press conference CfA in Cambridge, Massachusetts.
Merging neutron stars
Gamma-ray burst (HS) - a flash of gamma radiation from extremely energetic explosion. Most hepatitis B detected in very remote areas of the universe. Berger and his colleagues studied the object GRB 130603B, located at a distance of 3, 9 billion light-years. This is one of the closest of the HS seen to date.
GW are of two types - long and short, depending on how much lasting flash of gamma rays. Flash duration GRB 130603B, fixed satellite NASA "Swift" was less than two tenths of a second.
Though the gamma rays disappeared quickly, GRB 130603B continued to shine in infrared. The brightness of the light and the behavior did not fit the typical afterglow, which occurs when bombarded by accelerated particles surrounding matter. The glow of GRB 130603B behaved as if it comes from decaying radioactive elements. The substance is rich in neutrons ejected in the collision of neutron stars can turn into heavy radioactive elements. Radioactive decay of these elements produces infrared radiation characteristic of GRB 130603B. That's what astronomers have observed.
According to the calculations group, while the explosion had thrown a substance with a mass of about one hundredth of the sun. And part of this material was gold. Estimate the amount of gold formed during this GW, and the number of explosions that have occurred in the history of the universe, astronomers have come to the assumption that all the gold in the universe, including the world may have been formed during these gamma-ray bursts .
Here is another interesting but terribly controversial version:
During the formation of the Earth's molten iron descended down to its center, to make it the core, carrying with them the majority of the planet's precious metals such as gold and platinum. In general, the precious metals in the core will be enough to cover their four-meter thick layer of the entire surface of the Earth.
Move gold in the core was to deprive the outer part of the Earth's treasures. However, the prevalence of precious metals in Earth's silicate mantle exceeds the calculated value in the tens of thousands of times. Already I discussed the idea that this had fallen on his head superabundance has as its cause a catastrophic meteor shower, which overtook the Earth after the formation of its core. The entire mass of the meteorite gold thus went into the mantle apart and not gone deep inside.
To test this theory, Dr. Matthias Villbold and Professor Tim Elliott of Bristol Isotope Group School of Earth Sciences were analyzed collected in Greenland, a professor at Oxford University Stephen Murbatom rocks dating back about 4 billion years. These ancient rocks provide a unique picture of the composition of our planet shortly after the formation of the core but before the proposed meteorite bombardment.
Then scientists began to examine the contents of tungsten-182 and in meteorites, called chondrites, - it is one of the main building materials firm part of the solar system. On Earth, unstable hafnium-182 decays cobrazovaniem tungsten-182. But in the space of cosmic rays, this process does not occur. As a result, it became clear that the samples of ancient rocks contain more than 13% of tungsten-182 as compared with younger rocks. This allows geologists to assert that the Earth already had a solid crust, it struck about 1 million trillion (10 to the 18th power) tons of asteroid and meteorite material, which had a lower soderzhanievolframa-182, but it is much more than in the earth's crust, the content of heavy elements such as gold.
Being a very rare element (per kg breed accounts for only about 0, 1 milligram of tungsten), like gold and other precious metals he had to enter into the kernel at the time of its formation. Like most other elements, tungsten is subdivided into several isotopes - atoms with similar chemical properties, but slightly different masses. Isotopes can confidently judge the origin of matter, and mix of meteorites to Earth was to leave characteristic traces in the composition of its tungsten isotopes.
Dr. Villbold noticed in modern rock reducing the amount of the isotope tungsten-182 on 15 million shares as compared to Greenland.
It is a small but meaningful changes in excellent agreement with the fact that we wanted to prove - that the excess of available gold in the world is a positive side effect of meteorite bombardment.
Dr. Villbold says: "Removing the tungsten from the rock samples and analyzes with the required accuracy of its isotopic composition was extremely challenging, taking into account the low level of tungsten in rocks. In fact, we became the first laboratory in the world that has successfully completed a level measurement ».
The fallen meteorites are mixed with the Earth's mantle at the giant convection processes. The maximum objective for the future is to find out the duration of this mixing. Subsequently, geological processes formed the continents and led to a concentration of precious metals (and tungsten) in deposits of ore, which is mined today.
Dr. Villbold continues: "Our results show that most of the precious metals on which to base our economy and many of the key business processes, has been brought to our planet by lucky coincidence when the Earth covered around 20 quintillion tons of asteroid material." < br />
Thus, we are obliged to present their gold reserves flow of items that were on the surface of the planet thanks to the massive asteroid "bombardment." Then in the course of development of the Earth over the last billion years, gold has entered a cycle of rocks, appearing on the surface and again hiding in the depths of the upper mantle.
But now his path to the kernel is closed, and a large amount of gold just doomed to be in our hands.
And the opinion of another scholar:
- The origin of the gold remained unclear until the end because, unlike the lighter elements such as carbon and iron, it can not be formed directly inside the star, - he admitted one of the researchers of the center of Edo Berger.
The scientist came to this conclusion by observing gamma-ray bursts - large-scale release of radioactive cosmic energy caused by the collision of two neutron stars. Gamma-ray burst was observed by NASA Swift spacecraft and lasted just two-tenths of a second. And after the explosion remains glow that gradually disappears. Glow is the collision of these celestial bodies indicates release of large quantities of heavy elements, experts say. And the evidence that formed after the explosion the heavy elements can be considered in their infrared light spectrum.
- The fact that the neutron-rich substances emitted during the collapse of neutron stars can produce elements that undergo radioactive decay, while emitting a glow mainly in the infrared range, - explained Berger. - We believe that the gamma-ray burst is emitted about one hundredth of a solar mass of material, including gold. Moreover, the amount of gold produced and released in the merger of two neutron stars, it can be compared with the mass of 10 Moons. And the cost of such quantity of precious metal equal to 10 oktilonam dollars - it is 100 trillion square.
For reference, oktilon - a million or a million septillionov the seventh degree; a number equal to 1042 and recorded in the decimal system as a unit with 42 zeros.
Also today, the scientists found that almost all the gold (and other heavy elements) in the world - cosmic origin. Gold turns out to be horrible to Earth as a result of asteroid bombardment, which occurred in the early days after the solidification of the planet's crust.
Virtually all heavy metal "drowned" in the Earth's mantle at a very early stage of formation of our planet, they formed a solid metal core in the center of the Earth.
The alchemists of the XX century
In 1940, American physicists A. Scherr and KT Bainbridge Harvard began irradiated with neutrons neighboring gold elements - mercury and platinum. It is quite expected, irradiating mercury, gold received isotopes with mass numbers 198, 199 and 200. They differ from normal natural Au-197 is unstable and that the isotopes emitting beta rays, the most for a few days again converted into mercury with mass numbers 198, 199 i200.
But still it was great the first time people could independently create the necessary elements. It soon became clear, as all you can get a real, stable gold-197. This can be done using only the isotopes of mercury-196. This isotope is quite rare - its content of mercury in the conventional mass number 200 is about 0, 15%. It must be bombarded with neutrons to obtain a low stability of mercury-197, which is electron capture, and become a stable gold.
However, calculations have shown that if you take 50 kg of natural mercury, then it will be only 74 grams of mercury-196. For the transmutation into gold reactor neutron flux can give 10 to 15-degree neutrons per square meter. cm per second. Given the fact that 74 g of mercury-196 contains about 2 7 10 23 nd degree atoms, for full transmutation mercury gold would have four and a half years. This synthetic gold is worth infinitely more than gold out of the ground. But it meant that for the formation of gold in space also needs a giant neutron fluxes. And the explosion of two neutron stars just all explained.
And more details about gold:
German scientists have calculated that to Earth was recorded present today the volume of precious metals, needed only 160 metallic asteroids with a diameter of about 20 km each. Experts note that the geological analysis of various precious metals shows that all of them appeared on our planet at about the same time, but on the earth itself was not and there are no conditions for their natural origin. That is what prompted experts to the space theory of the emergence of precious metals on the planet.
The word «gold», according to linguists, is derived from the Indo-European term "yellow" as a reflection of the most notable characteristics of this metal. This fact is confirmed by the fact that the pronunciation of the word «gold» in different languages seems like Gold (in English), Gold (German), Guld (in Danish), Gulden (in Dutch), Gull ( in Norwegian), Kulta (in Finnish).
Gold in the bowels of the earth
At the core of our planet contains 5 times more gold than all other breeds available for development together. If all the gold in the earth's core spilled on the surface, it would cover the entire planet to a depth of half a meter. Interestingly, in every liter of water of all the rivers, seas and oceans dissolved about 0, 02 milligrams of gold.
It was determined that for the time of extraction of the precious metal from the bowels were recovered about 145 tons (according to other sources - 200 thousand tons). Gold production increased year by year, but the main growth came at the end of the 1970s.
The purity of gold is determined by a variety of ways. Carat (in the United States and Germany is written «Karat») was originally a unit of mass based on the carob seed «carob tree» (consonant with the word "carat"), used by ancient traders of the Middle East. Karat today is mainly used in the measurement of the weight of precious stones (1 carat = 0, 2 grams).
The purity of gold can also be measured in carats. This tradition dates back to ancient times, when the carat in the Middle East has become a measure of the purity of gold alloys. British carat gold - non-metric assessment of gold content in alloys is equal to 1/24 of the mass of the alloy. Pure gold corresponds to 24 carats. Purity gold is also measured and the concept of chemical purity, i.e. thousandths of pure bulk metal alloy. So, 18K - 18/24 and is based on 750 thousand shares corresponds to the second sample.
As a result, the natural concentration of only about 0, 1% of the gold contained in the earth's crust, is available, at least in theory, for the production, but due to the fact that gold is found in native form, shines brightly and easily noticeable, it was the first metal to whom he met people. But natural nuggets are rare, so the oldest method of producing rare metals, based on the high density of gold - washing gold-bearing sand. "Extraction of gold washing requires only mechanical means, and therefore it is no wonder that the gold was known even in the most savage and ancient historical times" (Mendeleev).
But the rich placer gold is almost gone, and at the beginning of the XX century 90% of all the gold mined from the ore. Now, many gold mines are almost exhausted, so mined, mainly gold ore mined largely mechanized, but the production is difficult, as is often found deep underground. In recent decades, constantly growing proportion of more profitable opencast. The deposit is economically advantageous to develop if tonne ore contains only gold 2-3g and when exceeding 10 g / m, it is considered rich. It is important that the costs of prospecting and exploration of new gold deposits ranged from 50 to 80% of the cost of exploration.
Who is the largest supplier of gold on the world market is South Africa, where the mine has reached a depth of 4 kilometers. South Africa is the world's largest mine in the Vaal-Rifs Kleksdorpe. South Africa - the only country where the gold - the main product production. There he is produced by 36 large mines, which employ hundreds of thousands of people.
The Russian gold mining is conducted from the ore and placer deposits. About the beginning of its production the views of researchers disagree. Apparently, the first domestic gold were produced in 1704 Nerchinsk of ore with the silver. In the decades at the Moscow Mint gold recovered from silver, which contained some gold as an impurity (about 0, 4%). Thus, in 1743-1744gg. "Gold, silver gains melted at Nerchinsk factories", was produced in 2820 ducats with the image of Elizabeth.
Russia's first gold deposit discovered in the spring of 1724 peasant Erofey Markov near Yekaterinburg. Its operation began only in 1748. Ural Mining gold is slowly but steadily expanded. At the beginning of the XIX century the discovery of new gold deposits in Siberia.
Where are they?