Lead
Through the study of the formation of the earth's crust, scientists have found that the formation of the earth's crust is very related to the periodicity of the earth through the spiral arm of the Milky Way, and this periodicity occurs exactly once every 2.2 billion years, and the formation time of the earth's crust occurred 2.27 billion years ago.
The Earth's crust was formed 2.27 billion years ago, probably because 70 million years before this crossing, the accompanying huge meteorites in the solar system were torn apart by a huge gravitational force to form ice fragments that hit the Earth.
In addition, there is another theory that there may be comet impacts, because there are more comets than meteorites, and from the results of several meteorites on Earth, the composition of the earth's crust and meteorites is different, so the formation of the earth's crust may be caused by the impact of comets.
1. The relationship between the formation of the Earth's continents and the spiral arms of the Milky Way.
Scientists have found that the time difference between the formation of the earth and the time when the earth crosses the cantilever of the Milky Way is 70 million years, and the formation of the earth's crust must be related to the high-speed movement of the earth inside the spiral arm of the Milky Way.
The formation of the earth's continents is also from the relatively simple Loli Sea on the earth's surface, which is also a region in the southwest of Australia, to the seven continents that we are familiar with in modern times.
The formation of the earth's crust and the laws of physics associated with it have taken scientists hundreds of years to make a breakthrough.
Under the gravitational pull of the sun, the earth is formed into a large and small planet, the structure of the earth's crust and the iron core of the earth's core and the mantle have a very large relationship, the earth's crust and mantle are just formed in the planet, and the small volume of material escapes under the action of the sun's gravity, and finally converges to form the crust and mantle.
The crustal structure can be divided into two types, one is the stony crust, the other is the silicate crust, and the composition of the stony and silicate stone in the crust is also very similar, the formation of the crust was formed about 350,000 years after the birth of the earth, the crust can only be formed under the action of water, scientists analyze the structure of the earth's crust and the structure of the mantle are formed under the action of water, and in a survey in 57 years, it was found that there is a mineral on the bottom of the Lori Sea that can form a stony structure of the crust, This mineral is the Pilbara craton.
In an experiment in 51 years, scientists found that a newly unearthed mineral in Australia can form the structure of silicate stone in the mantle, the name of this mineral is zircon, zircon is a mineral found in the Pilbara craton, and the mineral of zircon also contains a part of uranium, which is also an important reason for scientists to determine the time of the formation of the earth's continents.
Scientists have targeted the area of the Pilbara Craton, because the zircon unearthed in the Pilbara Craton contains uranium, and each samarium crystal will naturally contain radioactive elements, which will decay little by little over time, which is why scientists estimate the time of formation of the earth's crust.
2. Zircon body analysis.
Scientists have collected hundreds of samarium stone crystals from the Pilbara Craton, using the most advanced technology to analyze them, the radioactive elements in the samarium stone crystals have different degrees of decay, theoretically speaking, in the same area, the degree of decay of the radioactive elements contained in the samarium stone crystals is similar, but after the analysis of scientists did not find this phenomenon, from this point of view, the hundreds of samarium stone crystals analyzed by scientists ultimately came from different locations.
Judging from the decay rate of uranium and samarium, scientists finally concluded that the Pilbara craton was formed 2.27 billion years ago, and this time happened to be 70 million years away from the formation time of the Earth 2.85 billion years ago.
There is some truth in this statement, so it has also been recognized by many scientists, and there is also a theory that comets are formed under the action of ice fragments, and in summary, the formation of the earth's crust may be caused by the impact of fragmented ice fragments on the earth, or by the impact of comets.
In addition, there is another theory that the earth itself has relatively small meteorites, but this theory is still relatively weak.
In the process of the formation of the earth, most of the super-heavy elements are in the interior of the earth's core, and over time, the earth gradually exudes extremely high temperatures, and then these super-heavy elements will gradually float up, and then some of the light elements in the iron and nickel will be washed into the center of the earth, these elements are very heavy, and the density is also very large, so in the core of the earth iron and nickel, the proportion of these two elements will gradually increase.
Metal structures are formed in the center of the earth, and then over time, the metal structures will gradually spread around the center of the earth, and then these metal structures will form the structure of magma on the earth, and in the high temperature environment generated by these magma surges, the iron on the earth will gradually sink into the ground, and the mantle on the earth is mainly composed of material floating in the center of the earth.
3. Meteorite impacts form the Earth's continents.
In order to exclude the huge impact of the earth in the formation process, for example, the time node of the earth's crossing of the galactic cantilever is 2.27 billion years ago, and the time node in the formation of the earth's continents has not been described before, nor has it been described in the formation of the earth's continents in these 2.27 billion years.
After years of discovery and observation, scientists have also found the same metal elements on some meteorites on the earth as on other continents, and flammable iron oxide elements will be formed through chemical reactions.
After such discoveries, scientists speculate that after the formation of the earth, there may be some asteroids in the solar system, and these asteroids will hit the earth from time to time, and the formation of the earth also has a certain relationship with these asteroids.
In the early stage of the formation of the earth, the ground is full of magma, under the action of these magma, the main component of the metal iron will gradually float to the surface of the magma, and then as the temperature drops, these materials will gradually solidify to form the earth's mantle, and some materials in the mantle will float to the surface again, and these solidified materials will form the earth's crust.
After billions of years of evolution, under the action of oxygen in the water, the earth's crust will gradually form, and the formation of the earth's crust is also 350,000 years away from the newly unearthed 2.27 billion years ago.
epilogue
In the process of studying the formation of the Earth's continents, scientists have also observed that in the future, the solar system may pass through the galactic cantilever again, and there is also a possibility that with the high-speed movement of the solar system in the galactic spiral arm, more asteroids will be brought into the solar system, thus causing greater danger to the earth.
This is also expected to reveal more of the mysteries of the universe that we want to know in the future, and we humans will be able to understand the mysteries of the universe as well
There is also the possibility that the Earth's passage through the cantilevers of the Milky Way would make the solar system more exposed to cosmic dangers and more vulnerable to impact and damage.
Therefore, the Earth's crossing of the Milky Way cantilever may have a certain impact on the Earth's biological evolution and climate, which is also worthy of further exploration in the future.