The Flat Earth International Conference will in 2020 charter a cruise ship to sail to the edge of the earth. That presents an ironic problem as the ship will navigate with the help of GPS and that system proves in fact that the earth is round! In total 24 satellites are necessary to cover the round Earth. If the Earth would be flat only 3 satellites are needed.
More than 2000 years ago Aristoteles observed the curved shadow that the planet Earth casts on the moon and concluded that the Earth was round. With a flat Earth it would have been a thin line that is projected on the Moon’s surface.
But all these things donot impress the true believers, probably totally bored nitwits.