Eratosthenes Today and the Belief in the Flat Earth

We analyze the implementation of Eratosthenes' experiment between two Brazilian cities. Considering questions brought by the students, we incorporated the idea of using technological communication tools to measure simultaneously the size of the shadows of vertical rods of one meter high, generated by the sun's rays, in the cities of Pedreiras - MA and Sao Paulo - SP, similarly to the idea of the experiment proposed by Eratosthenes, in antiquity, to determine the size of our planet. In addition, this work seeks to reflect on the relations of the flat Earth belief, as a movement of denial of science, with the concept of post-truth and on the nature and methods used in experimental observations with scientific characteristics.