Antonio Aretxabala Díez, Geologist, School of Architecture of the University of Navarra, Spain
An ancient and at the same time modern image of the earth
Increasingly, we scientists practice more and more the ancient perspective to reach a vision of the world in accordance with the physical facts that so much technology offers us, this dwelling that converges with the observations, not to mention the intuitions, of the geniuses of the past bring us closer to the gaze of medieval man, even of the Greek.
The Earth's core rotates at different speeds, is the new vision that not even Jules Verne dared to capture in his work. And it does so by accelerating and decelerating with more frequency than such personalities as Edmund Halley commented at the time.
We now believe that this motion is not synchronized with that of the remaining mass of the planet, according to a study published in Australia. But as we say, in 1692, the astronomer and geophysicist Edmund Halley, who studied the orbit of Halley's comet, already speculated that the inner layers of the Earth rotated at different speeds and had different magnetic charge. Halley proposed that the Earth was made up of several spheres, each with a different magnetic charge. During the twentieth century there were even visions that pointed to rotations contrary to that of the outer layers, as a sort of dynamo, the Earth thus protects us from the lethal bombardment of cosmic rays.
Indeed, now a research from the Australian National University reveals that not only is the rotation rate of the core different from that of the mantle, which is the layer beneath the Earth's crust, but also its speed is variable. Scientists led by physicist Hrvoje Tkalcic found that compared to the mantle, the core rotated faster in the 1970s and 1990s, but slowed down in the 1980s.
This Earth, our home, is very much alive, and it sustains us because a constellation of current and past circumstances have been given quotation to make it so, and not only the rotating interior is our father-mother, we also have family a little further away. 4.5 billion years ago, when the Solar System was still in its infancy, a planet the size of Mars, named Theia after Selene's mother, collided with Earth.
A mass report of our core, crust and mantle was ejected to the outside, it could not go too far, it was trapped in the orbit of an Earth with a huge scar. Little by little that mass report , like a soap bubble that stretched and shrunk, was reconverted to the geometric perfection to which every stellar body wants to aspire: the sphere.
From that cataclysm the Moon emerged; later it would prove to be an essential companion for the appearance of life on our planet. The presence of the satellite not only protected the Earth from new meteorite impacts, it stabilized and slowed down our orbit, thus avoiding an extreme climate pernicious for the development of complex life and instilled in us rhythms and cycles orchestrated in such a perfect way that allowed the second law of thermodynamics, at least in the outermost layer, to be transgressed.
New layers have made their appearance over time, the hydrosphere, the atmosphere, the ionosphere, the magnetosphere... Still new conceptual envelopes appear in the modern and contemporary age, intelligent life can name them. Since the end of the 19th century and the beginning of the 20th century, a series of disciplines appear that no longer cut the sciences into small pieces of increasingly specific specializations, but integrate them, instead of disintegrating them; such is the case, for example, of ecology, which agglutinates words such as Biosphere; concept that we owe to Vladimir Vernadsky, also immediately adopted by Teihard de Chardin; they speak of it as a geometrical physical sphere while not losing the particle "bio" referring to life, moreover, Teilhard already speaks of "noosphere", a term even more heartbreaking for the physical and spiritual force that encloses a sphere of knowledge and ethics on Earth.
This new holistic step is already uncontainable, it will not be something apart, but it will discover new layers, then we will understand the Greeks better, this impulse grows and grows in the minds of scientists; it will not be a new discipline, but a compendium of common sense rules that no one, like breathing or eating, will see as an ornament or obligation, but as a new part of the world or the human being, two entities to which it is increasingly difficult to separate and put limit or boundary. This new ethical impulse will permeate life as does the atmosphere, a word used for the first time in 1677 by Scheele based on Torricelli's experiments that he had been carrying out since 1644, they are "his discoverers", which does not mean that human beings before Torricelli did not breathe.