Man's ideas about the world began to develop around the middle of the 14th century. Later, Rene Descartes, the great mathematician, suggested that our planet formed from a lump of mass, which was like the first bright sun, but then cooled down. In this regard, the "core of the Earth" is hidden in the bowels. However, it was not possible to verify this assumption at that time.
Subsequently, Newton established, and the French expedition of scientists confirmed that the planet is somewhat flattened at the poles. From this it follows that the Earth is not a sphere of regular shape. Buffon (French naturalist), supporting this statement, suggested that this is possible if the bowels of the planet have a molten structure. Buffon in 1776 suggested that in ancient times there was a collision of the Sun and a certain comet. This comet “knocked out a certain mass of substance from the star. This mass, gradually cooling, became the Earth.
The Buffon hypothesis began to be checked by physicists. According to thermodynamic laws, no process can go on indefinitely: from the moment its energy is exhausted, it will stop. In the 19th century, certain calculations were made. A mathematician and physicist from England, Lord Kelvin, established that in order to cool down, lose a large amount of energy and cease to be a molten mass, becoming what it is now, it takes about one hundred million years. Geologists, in turn, indicated that the age of the rocks is much greater. In addition, the phenomenon of radioactivity was already discovered in the 19th century. Thus, it became clear that many hundreds of millions of years are needed for the decay of elements.
Until recently, it was believed that the Earth’s core is an absolutely smooth ball of regular shape (like a
cannonball). In the eighties, the so-called seismic tomography was invented. With its help, scientists found that the Earth’s core has its own relief. The thickness of the surface, as it turned out, is different. In some sections, it is one hundred and fifty kilometers, and in others it reaches three hundred and fifty.
According to information obtained using seismic waves, the outer core of the
Earth (a layer with an uneven relief) is liquid (molten). The inner part is “solid”, because it is under pressure from the entire planet. Theoretically calculated pressure of the outer part is about 1.3 million atmospheres. In the center, pressure rises to three million atmospheres. The temperature of the Earth’s core is about 10,000 degrees. The weight of a cubic meter of substance from the bowels of the planet is about twelve to thirteen tons.
There is a certain correlation between the sizes of the parts that the Earth’s core includes. The inner part is about 1.7% of the mass of the planet. The outer part is about thirty percent. The material that makes up the majority is obviously diluted with something relatively light, most likely gray. Some experts suggest that this element is about fourteen percent.