How did mankind discover that the earth was spherical, and why did they initially believe it to be flat?

The discovery that the Earth is spher ical in shape has a long history , with evidence d ating back to ancient civil izations such as the Gree ks and the Chinese . However , the idea that the Earth is flat was a widely held belief for many centuries , and it was not until the 1 5 th and 1 6 th centuries that the spher ical shape of the Earth was widely accepted . \n \n One of the earliest recorded observations of the Earth ' s spher ical shape was made by the ancient Greek phil os opher P yth ag or as , who lived in the 6 th century B CE . P yth ag or as is cred ited with the discovery that the Earth is a sphere , and he based his conclusion on the observation that the sh adows cast by the Earth during a lun ar eclipse are cur ved . \n \n However , the idea that the Earth is flat was a more popular belief among the general population , and it was not until the 1 5 th and 1 6 th centuries that the spher ical shape of the Earth was widely accepted . This was due in part to the work of European expl or ers such as Christopher Columb us , who used astronom ical observations to prove that the Earth is a sphere . \n \n Col umb us ' s voyage to the New World in 1 4 9 2 was a major event in the history of the discovery of the Earth ' s spher ical shape . Columb us used astronom ical observations to determine that the Earth is a sphere , and his voyage helped to spread the idea that the Earth is a sphere among the general population . \n \n In the centuries that followed , a number of other expl or ers and scient ists made important contributions to the understanding of the Earth ' s spher , including Ferdinand Mag ellan , who led the first voyage to circ umn avig ate the Earth , and Sir Francis Dra ke , who made a similar voyage in the 1 6 th century . \n \n T od ay , the spher ical shape of the Earth is widely accepted , and it is understood to the Earth is an ob late s ph ero id , meaning that it is slightly fl atten ed at the pol es and bul ging at the equ ator . </s>