Who discovered the spherical Earth

Earth spherical discoverer

The ancient Greeks were the first to know that the earth was round, and it is estimated that Pythagoras may have been the first to suggest that the earth was round in about 500 BC, and his idea was based on the fact that the moon must be round, through his observation For the terminator, which is the line separating the part of the moon in the light, and the part of the moon in the dark, as it moves through its orbital cycle, Pythagoras explained that if the moon is round, then the earth must also be round, and at a later time between 500 BC , and 430 BC, a philosopher named Anaxagoras identified the real reason behind the solar and lunar eclipses, then used the shape of the Earth’s shadow on the moon during the lunar eclipse as evidence of the Earth’s sphericity, and in about 350 BC, Aristotle declared that the Earth was spherical, based on Observations he made about the planets that could be seen in the sky while moving away from the equator, and Aristarchus and Eratosthenes, during the next hundred years, measured the size of the Earth.

Evidence for a spherical Earth

One of the best documented methods of determining the sphericity of the Earth was carried out by the ancient Greeks. They did this by comparing the shadows of sticks at different locations. The stick had no shadow when the sun was perpendicular to it. At the same time, in an area about 804 km to the north, the stick had There is a shadow, so if the earth is flat, then both sticks must have the same shadow, or they must not have a shadow at all, because they will be placed at the same angle towards the sun, as the ancient Greeks found a difference in shadows, and this is due to the fact that the earth is spherical, and therefore The angles of the stick shadows were different, and then they used the difference in these angles to calculate the circumference of the Earth, and they were able to determine about 10% of the true value.

There is another evidence of the sphericity of the earth, which is the difference between the sky at night in the northern hemisphere from the southern hemisphere, where the view is completely different, because the earth under the person points in a different direction, so if the earth was flat, then the scene should be the same, as it is possible Observing the planets, which all rotate over the course of a few days, gives a clear picture of the sphericity of these planets, so the possibility that most of the planets are spherical and the Earth is flat seems very unlikely.

Earth form

The Earth appears from space in the form of a blue ball, surrounded by white swirls, and there are some parts that permeate it in different colors, such as brown, green, yellow, and white. The blue part of the Earth indicates water, which covers most of the surface area of ​​the Earth. They refer to clouds, and the brown, green, and yellow parts refer to land, while the white parts indicate ice and snow.