The Earth is a spheroid. This fact has been known to man for hundreds of years and was definitively confirmed with the launch of the first artificial earth satellite Sputnik 1 in 1957 by the Soviet Union. Since then, data, observations and images on this subject have accumulated by the hundreds of thousands. However, a group of people, called Flat-Earthers , who believe the Earth is flat, have emerged in recent years, concocting theories as to why the Earth behaves as if it's round when in fact it's disc-shaped. Even if the sphericity of the Earth corresponds to all the observations made by Man during the last millennium. However, if the Earth were really flat, what would happen?
To shape a cosmic body into a disk (rather than a sphere), you have to spin it very quickly, says Caltech planetary scientist David Stevenson. This would unfortunately destroy the planet by tearing it into tiny particles. In the 1850s, astronomer James Clerk Maxwell showed mathematically that a solid disc-like shape is not a stable configuration in the cosmos, as part of his work on Saturn's rings.
Maxwell's research predicted that Saturn's rings would be made of many small, unbound particles; it turned out he was right. His calculations also explain why no planet-sized discs float around the galaxy. To flatten the Earth without spinning it very quickly would require not physics, but magic. In any case, a flattened Earth would not last long. Within hours, the force of gravity would return the planet to a spheroid shape.
Gravity also pulls on all sides, which is why planets are quasi-spheres (depending on how fast a planet spins, these forces can work against gravity to create a bulge at the equator). A stable, solid disc-shaped Earth is simply not possible under real gravity conditions, as Maxwell's calculations have shown.
And if you want to remove the earth's gravity to get rid of these obstacles, well, everything disappears. The atmosphere? She is held back by gravity. Tides ? They are a consequence of the gravitational impact on the oceans. The moon ? Gone too, because all moon formation scenarios involve gravity. In the most widely accepted scenario, the Moon was created when a giant planet-sized body crashed into early Earth; debris from the crash was captured by Earth's gravity. Another scenario suggests that the Moon formed at the same time as the Earth (again, thanks to gravity).
Gravity is also responsible for the layered structure of the Earth, with the denser materials sinking into the core, the lighter materials making up the mantle, and the lighter materials forming the crust. Without this layered structure, the planet would behave very differently. The Earth's liquid outer core, for example, acts like a giant, dynamic magnet, which creates the planet's magnetic field by dynamo-convective effect.
The magnetic field helps protect the planet's atmosphere from the effect of the solar wind, which destroyed Mars' atmosphere after that planet's magnetic field weakened 4 billion years ago. If the Earth were flat, plate tectonics — the movement of the rigid plates that make up the planet's crust — wouldn't work either, says James Davis, a geophysicist at Columbia University's Lamont-Doherty Earth Observatory. . “When you do the calculations, very simple plate motion calculations, you have to do it on a sphere. You don't get the right answer, the answer that matches real-world observations, if you perform these calculations on a flat model .
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The Flat-Earthers explain how all of these observations might be possible on a flat planet. The problem, says Davis, is that these explanations have no basis in mathematics or physical reality. When Maxwell predicted in the 1850s that Saturn's rings were made of lots of small particles, he did so by applying his general knowledge of how gravity and rotational forces work. His essay on the subject, in fact, was mostly mathematical equations.
Flat Earth theories don't work that way. The flat Earth worldview also involves choosing different explanations for different phenomena. In real life, the Earth and the Moon are both round for the same quantifiable reason — gravity. The Flat-Earthers have to invent independent explanations for both, and these independent explanations often contradict each other. This is not how scientific methodology works, Davis reminds. "If we can explain a thousand observations with a theory, a simple theory, it's better than explaining a thousand observations with a thousand theories .