Such measurements show no shifts in the stars' positions. How do we know this? Observations of Foucault pendulums, popular in science museums around the world, demonstrate both that the world is spherical and that it rotates (not that the stars are rotating around it). But because the Earth is spherical, in reality it will have travelled along three sides of a triangle, and arrive back very close to its starting point. The early Earth was thus mostly liquid. [55], 1,700 years after Eratosthenes, Christopher Columbus studied Eratosthenes's findings before sailing west for the Indies. [70][71], Greek ethnographer Megasthenes, c. 300 BC, has been interpreted as stating that the contemporary Brahmans believed in a spherical Earth as the center of the universe. People in high-flying aircraft or skydiving from high-altitude balloons can plainly see the curvature of the Earth. On a flat Earth, the Sun's shadow would reach the upper atmosphere very quickly, except near the closest edge of the Earth, and would always set at the same angle to the ground (which is not what is observed). [47] After the 5th century BC, no Greek writer of repute thought the world was anything but round.[44]. Image Credit: Shutterstock. This is an analysis of the poem Holy Sonnet Vii: At The Round Earth's Imagined Corners Blow that begins with: At the round earth's imagined corners blow Your trumpets, angels, and arise, arise... full text. Assuming light travels in straight lines, actual measurements of the Sun's angle in the sky from locations very distant from each other are only consistent with a geometry where the Sun is very far away and is being seen from the daylight half of a spherical Earth. James S. Aber (2003). A terrestrial globe (Kura-i-ard) was among the presents sent by the Persian Muslim astronomer Jamal-al-Din to Kublai Khan's Chinese court in 1267. San Francisco[23] is at 122.41°W longitude and Richmond, Virginia[24] is at 77.46°W longitude. [52] Subsequently, in propositions 8 and 9 of the same work, he assumes the result of proposition 2 that the Earth is a sphere and that the surface of a fluid on it is a sphere centered on the center of the Earth. With the presumption of a spherical earth, an expedition commissioned by caliph al-Ma'mun used this fact to calculate Earth's circumference to within 7,920 kilometres (4,920 mi) of the correct value of around 40,000 kilometres (25,000 mi), and possibly as accurately as 180 kilometres (110 mi). The amount of surface blocked would be different for a mountain close to the edge of a flat Earth compared to a mountain in the middle of a flat Earth, but this is not observed. When a given location on the spherical Earth is in sunlight, its antipode - the location exactly on the opposite side of the Earth - is in darkness. Over 2,000 years ago, the … These two phenomena are related: A low-altitude spotlight Sun would spend most of the day near the horizon for most locations on Earth, which is not observed, but rise and set fairly close to the horizon. [82], The monk Bede (c. 672–735) wrote in his influential treatise on computus, The Reckoning of Time, that the Earth was round. [114] In the 17th century, the idea of a spherical Earth, now considerably advanced by Western astronomy, ultimately spread to Ming China, when Jesuit missionaries, who held high positions as astronomers at the imperial court, successfully challenged the Chinese belief that the Earth was flat and square. These lines define "north" and "south". 307–345), who suggested that the Earth could be either square or round, in accordance with the shape of the heavens. And validated by Aristotle a couple centuries later fast elevator Qibla, or Muslim direction of prayer ’... 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