Is the Earth really round?
The flatness of the earth is theorized by a large community of "truthers". The Flat Earth Society, an American organization founded in 1956, structures this idea using arguments that go against those of the National Aeronautics and Space Administration (NASA) and other government or private agencies developing space programs. This idea brings together millions of people around the world nicknamed the "flat earthers" (followers of the theory of the flat earth). In the United States, approximately 12 million people subscribe to the idea that our planet is not round but rather flat, like an infinite horizon that the rays of the Sun only caress. In USA, 1 in 10 people would also be convinced.
THE EARTH, A HORIZON LIKE ANOTHER?
There are several supposedly scientific arguments against the "official" versions. The flatness of the horizon, for example, raises several questions: the human eye sees this horizon flat and straight, without curvature, even on a sea as far as the eye can see. This would be a first clue inconsistent with the theory of a spherical planet. Also highlighted are the shots taken by meteorological balloons at an altitude of more than 30 km, which bear witness to an equally flat horizon.
The "platists" also rely on global aviation to base their theory: when developing flight plans, the curvature of the Earth is never taken into account. But if the Earth is round, how do planes go from one hemisphere to another in a straight line? The curvature of the Earth is also not recognized as a constraint by architects and engineers, who should take it into account in their construction plans. In order to corroborate these theories, results of laser measurements on bodies of water which would show no curvature have been put forward.
The very shape of the Earth is not the only one to be questioned. Platists also question the principle of the Earth's rotation, both on itself and around the Sun. According to pictures taken by "flat earthers", the Moon would always present the same face to us and during solar eclipses the movement of the Sun, from east to west, would be reversed, which would call into question the rotation of the Earth.
A MOST TROUBLE PARALLAX
But one of the flat earthers' most advanced arguments is the parallax phenomenon. Parallax is the displacement of the apparent position of a celestial body due to the change of position of the observer. In astronomy, parallax is the angle of observation of a star from a reference length. Since the stars are at different distances, we should therefore observe a difference in the speed of their movements. However, according to the flat earthers, we only observe a uniform movement, which means that they are all on the same plane. This is in addition to many questioning of the nature of stars following observations of these organizations whose images differ from the pictures presented by NASA.
The questioning sometimes goes even further. Some question the principle of gravity, which is one of the movement's flagship arguments. According to some proponents of the Flat Earth if gravity is powerful enough to hold buildings and waters as dense as oceans on the ground, how then can bodies as light as small birds or even airplanes stand? so easily rise in the air?
According to the Flat Earth Society, the origins of this plot that would lead us to believe that the Earth is round accelerated during the Cold War. The theorists explain that this is a strategy of political manipulation between the United States and the USSR, the conquest of space having for sole purpose to prove the superiority of one of the antagonistic models: Americans and Soviets would have multiplied the false missions to gain the upper hand over the other.
SPHERE ONE DAY, SPHERE ALWAYS
The Earth is indeed not perfectly curved. The distribution of masses, both at the surface and at depth, is not homogeneous. The shape of the Earth changes in response to gravity. The great glacier episodes in our planet's history have contributed to its irregularity by forming bumps and valleys over the millennia. However, this phenomenon cannot be observed with the naked eye and does not change the generally round shape of our planet.
Many facts, which everyone can see, confirm the roundness of the Earth. First of all, anyone who has observed a lunar eclipse will have noticed that when the Earth comes to position itself between the Moon and the Sun, the shadow formed by the latter on the Moon is completely spherical. Astronomical observation also points in this direction since, depending on where we are on Earth, we can observe some constellations and not others. If the Earth were flat, we could all observe the same stars. At different distances, yes, but none would be obstructed.
The Sun is also a revealing element of the spherical character of our planet. If the Earth were flat, the Sun would remain visible even when its rays do not reach the region we are in; black and complete nights could not exist in this case. The course of the Sun as well as the rotation of the Earth are very simply observable with the movement of the shadow on our sundials in the space of 24 hours.
Another element specific to our globe: the distribution of gravity. According to Isaac Newton's definition, the law of universal attraction is the attraction between bodies with gravitational mass. The center of the Earth represents a gravitational mass strong enough to keep our feet on the Earth. All over the world, all humans can evolve on the ground in the same way because gravity is the same for all, each part of the surface of the Earth being at an equal distance from its center. This phenomenon is only made possible by a spherical shape; a flat Earth would not correspond to an attraction towards the ground but on the sides in order to make converge all the masses towards the same gravitational center.
One of the most trivial phenomena that can confirm the spherical nature of the Earth are time zones. If our planet was not a globe and did not turn on itself, it would be impossible to explain the differences in sun exposure according to the hours of the day as well as the simple phenomenon of night in the absence of eclipse.
To corroborate the roundness of the Earth, NASA astronauts like Terry Virts (more than 200 days in space), Scott Kelly (520 days in space) and even Buzz Aldrin do not hesitate to refer to the skeptics. photos they themselves took of the Earth, round is sublime, seen in all its glory from the International Space Station.