Contrary to popular belief, that not only did Columbus realize the world was round, but his contemporaries, too, realized the same. It was the year 1492 when Columbus decided to sail the ocean blue with a whole lot of information and maps about the very round Earth. It was also well accepted that daring seafarers had been exploring the Atlantic Ocean much before Columbus’ time. It is also said that the men of the early renaissance knew the world was round. The Nina, the Santa Maria, and the Pinta were in no danger of sailing over the edge.
It can also be noted that ancients assumed that the world is a sphere. We know this as Pythagoras (6th century B.C.) is generally credited with having first suggested that the Earth is round. Aristotle (4th century B.C.) too agreed and supported the theory with observations such as when a person travels south, the southern constellations rise higher in the sky. He also noted that the Earth’s shadow is round during a lunar eclipse. Eratosthenes (3rd century B.C.) built on their ideas and calculated the circumference of the Earth with remarkable accuracy.
Flat earth theory
It happened much later that the Roman Ptolemy added to the collected wisdom. Columbus observed that as a man approached a far off mountain, but it appeared to grow out of the ground, which makes it a clear indication of a curved surface. He later devised the forerunner of modern-day latitude and longitude, including measuring what we now call latitude from the equator.
Another Catholic monk, and a scholar of Christian Medieval Europe named Bede (7th century C.E.), produced an influential treatise, which included a discussion of the spherical nature of the world. The Catholics weren’t the only religious group that thought the world was round. The Islamics are known to have consistently maintained the scientific knowledge of the Romans and Greeks, preserving the works of Ptolemy and Aristotle, among others. With calculation, and relatively good precision, its circumference in the early 9th century, they were very well aware that the Earth was round.
Seeing the ships getting disappeared over the horizon with the bottom first and then the mast, even the most empty-headed sailor knew the Earth was round as it was very simple to figure out. A similar effect can indeed be observed while spotting land from a ship. But the real mystery lies in the question, “What was the actual circumference of the Earth?”
The conceived myth that people during Medieval times assumed that the Earth was flat is believed to have been first popped up during the 17th century. It was put forth by secular scientists railing against the misguided notions and ignorance of religious groups (specifically Catholics), who they claimed (in Medieval times) believed the world was flat. But ironically, despite the lack of much evidence supporting that claim, there have been numerous documented instances of religious scholars from that era stating the Earth is round. This myth certainly gained significant traction in the 19th century with various works, such as History of the Warfare of Science with Theology by Andrew Dickson White.