For over two thousand years, the greek philosopher aristotle, through observations of the positioning of the stars, stated that the Earth should have a circular shape. In 500 BC C., the Greeks observed that, in different positions on Earth, the constellations in the sky they change, and that ships approaching the coast show the mast first. This evidence proves that we are on a sphere, not a flat system.
However, currently, even after all contributions from Newton, Kepler, Einstein and other great scholars, discussions about the “real” shape of the Earth have gained momentum. Spreading their ideas mainly on social networks, earth planners claim that the Earth is flat.
According to this current of thought, the planet has a flat shape and is covered by the dome-shaped firmament (dome). O Sun and the Moon they would have sizes much smaller than the real one and would make movements within the space of the firmament. THE Antarctica would be on the edges of this disc, as shown in the following figure.
For people who believe in this theory, the Nasa, US Space Agency, would be the main responsible for keeping the Earth farce round, and the justification for this would be the financial and hegemonic power.
According to the earth planners, one of the ways to show that the planet has a flat shape is to use cameras with very high approximation capacity and show that the horizon will always be approached in line straight. Other “evidence” that would prove this flat Earth shape would be in the fact that very long rivers, like the Nile, flow for long extensions without suffering reductions in their levels.
Some evidence of the Earth's circular shape
There is ample evidence of the Earth's circular shape. Below we describe some of the simplest facts that can prove the rounded shape of our planet.
1) The measurement of the Earth's radius made by Eratosthenes:
Do not stop now... There's more after the advertising ;)
Greek Eratosthenes was born in 275 BC. Ç. and managed to determine the first value for the radius of the Earth. The scholar's certainty regarding the Earth's circular shape comes from observing the incidence of sunlight on wells made in different cities. Eratosthenes found that on the day of Summer Solstice a well in Siena had the bottom lit by the sun, without the shadow formation on the edges. On the same day in Alexandria, the sun illuminated a well, but there was shadow formation. The only explanation for this is the Earth's rounded shape.
2) Circumnavigations
Ferdinand Magellan, in the 16th century, carried out the first circumnavigation successful. By always following in the same direction, the ship, after a certain time, returned to the starting point, confirming the circular shape of the Earth.
3) Time zones
For a planet with a flat shape, the sun should rise at the same time for all its inhabitants, but this is not what is observed. When sunlight shines in a certain place, it's always night at an opposite point., and this is only because the Earth has a rounded shape.
4) Launch of helium balloons
When launching a camera attached to a balloon helium to the highest possible position, the images showed a rounded earth!
5) Explorations and spatial evidence
the orbits of satellites, a International Space Station, the launch of astronauts since Yuri Gagarin, the first person to leave the planet, and the images captured by satellite are excellent evidence of the planet's circular shape.
These and many other findings prove that the planet has a spherical shape, with flat poles. The Earth maintains a rotational movement with a speed of 1645 km/h and rotates around the Sun, a star that provides us with light and heat.
By Joab Silas
Graduated in Physics
Would you like to reference this text in a school or academic work? Look:
JUNIOR, Joab Silas da Silva. "What is the shape of the Earth?"; Brazil School. Available in: https://brasilescola.uol.com.br/curiosidades/qual-formato-terra.htm. Accessed on June 27, 2021.